Biochemistry Test Information v2.71 - baspath.co.uk · Department Of Clinical Biochemistry & Immunology: Test Information, Version 2.71 1 of 61 Reviewed: 07/06/10 Biochemistry Test

Department Of Clinical Biochemistry & Immunology: Test Information, Version 2.71 1 of 61

Reviewed: 07/06/10

Biochemistry Test Information Version 2.71

07/06/10

Department of Biochemistry & Immunology

Box 232

Addenbrooke’s Hospital

Cambridge

The information contained within this document is subject to regular review, therefore, please ensure that the

latest version of Biochemistry Test Information is referred to, when required. This can be found as a pdf,

downloadable at: http://connect/index.cfm?articleid=4207


Reviewed: 07/06/10

Version Number 2.71

Date of Issue 07/06/10

Review Interval Annual

Next Review Due 22/05/11

Document Location Addenbrooke’s Hospital Intranet Pages

(Connect)

Document Ownership Senior Executive, Dept. of Clinical

Biochemistry & Immunology

Document Amendment History

Version Number Issue Date Version Number Issue Date

1.0 03/09/07 2.1 13/03/09

1.1 17/09/07 2.2 19/03/09

1.2 17/10/07 2.3 23/04/09

1.3 03/12/07 2.4 07/07/09

1.4 04/01/08 2.5 03/12/09

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1.6 11/03/08 2.7 21/05/10

1.7 16/05/08 2.71 07/06/10

1.8 01/09/08

1.9 16/12/08

1.91 18/12/08

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Reviewed: 07/06/10

Department Of Clinical Biochemistry & Immunology: Test Information

Version 2.7

ACE (Angiotensin Converting Enzyme)

Specimen Type: 5ml clotted blood (brown or white top)

Reference Range: < 52 U/L

Notes: About 60% of patients with sarcoidosis have raised ACE but it can be raised in liver, renal and

thyroid disease.

Acetylcholinesterase (Red Cell)

Specimen Type: 5ml EDTA whole blood (red top)

Reference range: Interpretation will be given

Notes: Used in cases of poisoning by organophosphorus compounds. Please telephone the laboratory to

arrange analysis.

Acetylcholine Esterase Neural Isoenzyme (ACHE) (Amniotic Fluid)

Specimen Type: Amniotic fluid

Reference range: Not Applicable

Notes: Send to Cytogenetics who will harvest the cells for karyotyping and forward the fluid to

Biochemistry. Used in diagnosis of neural tube defects.

Acid Phosphatase (Prostatic)

Notes: Analysis of the prostatic isoenzyme of acid phosphatase is obsolete and no longer offered. Please

refer to Prostate Specific Antigen (PSA).

ACTH (adrenocorticotrophic hormone, corticotrophin)

Specimen Type: 5 ml EDTA whole blood (red top) on ice.

Reference Range: < 50 ng/L at 9.00 am

Notes: ACTH is very UNSTABLE and specimens MUST be brought quickly to the laboratory. Plasma

ACTH has a marked diurnal rhythm with a peak in the early hours of the morning and lower concentrations

later. ACTH is also pulsatile so concentrations vary.

Acylcarnitine (Carnitine)

Specimen Type: Guthrie card (Acylcarnitine profile)

Lithium Heparin Blood (orange tube) (plasma Total and

free Carnitine)

Reference Range: see Table below


Reviewed: 07/06/10

Acylcarnitine* (µmol/L) Acylcarnitine* (µmol/L)

Free 8 – 35 Hexanoyl < 0.2

Acetyl 5 – 27 Octanoyl < 0.2

Propionyl 0.13 – 4.00 Decanoyl < 0.2

Butyryl < 0.5 Myristoyl < 0.5

Isovaleryl < 0.3 Palmitoyl 0.6 – 4.5

*Please note: the above acylcarnitines are quantitated. Any other acylcarnitines present in abnormal amounts

will be reported qualitatively.

Notes: The Carnitine profile performed on a blood spot gives considerably more information than

quantitation of total and free Carnitine. Free Carnitine concentration is assayed as part of the Acylcarnitine

profile, therefore plasma total and free Carnitine is rarely required.

Acute Phase Proteins

Specimen Type: 5ml clotted blood (brown or white top).

Reference Range: Refer to specific acute phase proteins

Notes: There are many proteins whose concentrations change in response to infection, inflammation or cell

damage. The speed, size and direction of change vary markedly and the half-life of clearance vary also. The

most useful markers of the acute phase response are CRP and α1-antichymotrypsin. CRP is a fast reacting,

sensitive indicator of inflammation but is known to show poor responses in certain conditions such as viral

infections and SLE. ESR is similar to CRP but measures a combination of 3 factors: i) the acute phase

reaction, ii) the immune response and iii) changes in haematocrit, and red cell size and shape. α1-

antichymotrypsin reacts more slowly than CRP. Transferrin and albumin fall in the acute phase response.

Adiponectin

Specimen Type: 5 ml Clotted (brown or white top) or Lithium

Heparin (orange top) blood.

Reference Range: Reference range is likely to be dependant upon

age, sex and BMI. A reference range has yet to

be established.

Notes: Low concentrations of adiponectin are considered to be a risk factor for the development of insulin

resistance, type 2 diabetes, atherosclerosis and coronary artery disease.

Adrenaline (Plasma)

Specimen Type: EDTA blood (red tube), “on-ice”

Reference Range: 0 – 150 ng/L (Adrenaline)

Notes: Specimens for plasma catecholamine analysis MUST be sent quickly, “on-ice” to the laboratory.

Upon receipt by the laboratory, specimens must be centrifuged, the plasma separated and stored frozen prior

to analysis in order to maintain specimen integrity.


Reviewed: 07/06/10

Adrenaline (Urine)

For further information regarding urinary adrenaline, please see “Catecholamines (Urine)”

AFP (α-Foetoprotein) (Serum)

Specimen Type: 5ml clotted blood (brown or white top) or CSF

Reference Range: < 10 kU/L

Notes: Serum concentrations are raised in pregnancy. Concentrations in newborns are very high and decline

slowly but they do not reach adult concentrations until about age 6 months. Raised concentrations also occur

in hepatitis. Reference range varies with gestational age. [CSF: One ml required. Send paired serum

sample].

AFP (CSF)

Specimen Type: 1ml of CSF in a plain tube. It is essential to send

5ml clotted blood (brown or white top) also.

Reference Range: Please discuss with laboratory

Notes: Comparison of serum and CSF concentrations may help to identify a CNS lesion secreting AFP or

HCG.

Albumin (Serum)


Reference Range: 30 – 51 g/L

Notes: Albumin is part of the BFT and LFT profiles.

Albumin (Urine)

Please refer to Albumin/Creatinine Ratio or Albumin Excretion Rate below.

Albumin/Creatinine Ratio (ACR)

Specimen Type: Random Plain urine

Reference Range: < 2.5 mg/mmol Creatinine (Male)

< 3.5 mg/mmol Creatinine (Female)

Notes: Also referred to as 'microalbuminuria'.

Albumin Excretion Rate (AER)

Specimen Type: 24-hour urine (Plain)

Reference Range: < 20 µg/minute


Reviewed: 07/06/10

Alcohol (Ethanol)

Specimen Type: Fluoride blood tube (yellow top)

Reference Range: Not Applicable

Notes: When poisoning by other alcohols such as methanol or ethylene glycol is suspected, measure serum

osmolality and consult the laboratory about sending a sample to the Poisons Unit for specific assay. An

ethanol concentration of 14.5 mmol/L is equivalent to 80 mg/100ml, the UK legal drink drive limit for

alcohol. This analytical service is suitable for clinical purposes only, not for medico-legal or forensic use.

Aldosterone

Specimen Type: EDTA blood (red tube), Lithium Heparin (orange tube)

Reference Range: 100 – 450 pmol/L (Adults recumbent overnight)

100 – 800 pmol/L (Random sample or upright)

Notes: Aldosterone concentrations vary with posture and salt intake.

Alkaline Phosphatase (see also BFT and LFT)


Reference Range: 30 – 135 U/L (Adults)

< 450 U/L (Adolescents)

Notes: The measurement of serum alkaline phosphatase incorporates the contribution to enzymatic activity

of alkaline phosphatase of liver, bone, placental and gut origin. It is possible to separate the isoenzymes,

using electrophoresis, to assess the origin of a raised enzymatic activity: ask for 'alkaline phosphatase

isoenzymes'. Placental alkaline phosphatase (PLAP) is a specific immunoassay sometimes used as a tumour

marker. Raised liver alkaline phosphatase is suggestive of an obstructive cause of liver damage. Alkaline

Phosphatase is part of the BFT and LFT profiles.

Alkaline Phosphatase Isoenzymes


Reference Range: Not applicable

ALT (Alanine Aminotransferase) (see also LFT)



Notes: Raised ALT is suggestive of hepatocellular damage. ALT is part of the LFT profile.

Aluminium

Specimen Type: Special tube required - supplied by the laboratory

Reference Range: < 0.4 µmol/L


Reviewed: 07/06/10

Notes: Concentrations of up to 2.0 mol/L are normal for those taking aluminium.

Amino Acids (Urine)

Specimen Type: Random urine (Plain)

Reference Range: Please refer to Biochemical Genetics Unit, Users

Handbook 2009

Amiodarone

Specimen Type: 5ml clotted blood (brown or white top); pre-dose

Therapeutic Range: 0.5 - 2.0 mg/L (pre-dose or ≥ 6 hours from last dose)

Notes: The mean plasma half-life of amiodarone is 240 - 2400 hours; time to steady state 60 - 90 days.

Ammonia

Specimen Type: 2 ml blood in an EDTA whole blood (red top) on ice

Reference Range: Newborn: 50 – 90 µmol/L

Child: 20 – 47 µmol/L

Adult: 11 – 30 µmol/L

Amylase


Reference Range: Age related reference ranges apply – see table below

Age Range Males (U/L) Females (U/L)

1 – 30 days < 18 < 18

31 – 182 days < 43 < 43

183 – 365 days < 81 < 81

1 – 18 years < 106 < 106

> 18 years 25 – 115 25 – 115

Ghoshal A.K., Soldin S.J. (2003), Clin Chim Acta; 331:135-46.

Notes: Below 300 U/L, pancreatitis is unlikely; above 700 U/L pancreatitis is probable. Amylase is also

raised in salivary gland disorders such as mumps, and in hypothermia and peritonitis.

Androstenedione


Reference Range: 3 – 12 nmol/L (age dependant)

Notes: In pre-menopausal women, androstenedione is about 50% of adrenal origin and 50% of ovarian

origin. The adrenal component is under control of ACTH.

Antenatal Screening for Down's Syndrome & Neural Tube Defects (Triple Test)



Reviewed: 07/06/10


Notes: Please ensure samples are accompanied by a fully completed maternal serum screening request form.

Samples will be accepted by post provided they are clearly labelled, properly packaged and accompanied by

a completed request form.

Timing: 14 weeks to 20 weeks, 6 days gestation.

Preferably dated by an ultrasound scan.

Turnaround Time: Results are normally available within 3 working days

GP and patient letters sent by first class post

(allow 5 days)

Results: Reports sent to Obstetrician and General Practitioner

If low risk, option of a letter to the patient

Reports: Standard Report: Gives the interpretation and risk of Down's

Syndrome serum AFP and AFP MoM.

AFP Only: Gives the serum AFP and AFP MoM only.

Combined Risk Report: Provides a combined risk of Down's syndrome based

upon Nuchal translucency and serum biochemistry

Reports are treated as high risk if one or more of the following occur:

• The risk of Down's syndrome is greater than or equal to 1 in 250

• The risk of Edward syndrome is greater than or equal to 1 in 100

• The AFP MoM is greater than or equal to 2.5 MoM

Notes: It is essential that the patient receive adequate counselling before undertaking the test.

αααα1-Antitrypsin (Serum)


Reference Range: 0.9 – 1.8 g/L

Notes: Serum α1-Antitrypsin is an acute phase protein that rises slowly. Many genetic variants are known.

Deficiency of α1-Antitrypsin is associated with pulmonary emphysema in adults and with neonatal jaundice

and juvenile cirrhosis in children. The phenotype and the genotype can be determined. Please telephone ext.

3151 to discuss these specialised tests.

Antidepressive Drugs



Notes: Unlike some other drugs, serum concentrations of antidepressives do not correlate with clinical


Reviewed: 07/06/10

effectiveness or with side effects. It is, therefore, rarely useful or necessary to measure them. Please phone

3151 to discuss any request.

Apolipoprotein E Genotyping



Notes: Apolipoprotein E x 2 genotype can be determined for the investigation of familial

dysbetalipoproteinaemia. As with other genetic tests done in the department the test requester is responsible

for the appropriate genetic counselling.

Arylsulphatase A

Notes: Arylsulphatase A is deficient in metachromatic leucodystrophy and can be measured on a leucocyte

preparation. (See White Cell Enzymes). A genetic test for this condition is also available. Please contact the

laboratory (57130 or 3155) if you need these tests.

Ascorbic Acid (Vitamin C)

Specimen Type: 5 ml EDTA (red top) or Lithium Heparin

(orange top) blood on ice.

Send to the laboratory immediately.

Reference Range: 34 – 114 µmol/L

Notes: Plasma vitamin C levels are rarely useful in clinical situations. Plasma concentrations represent recent

dietary intake rather than overall vitamin C status. Low plasma concentrations precede onset of clinical

symptoms by many weeks. Please phone the laboratory in advance as a special preservative has to be

prepared. Specimens must be brought to the laboratory soon after collection. The vast majority of vitamin C

assays are performed as part of Research Studies.

Aspartate Aminotransferase (AST)


Reference Range: 5 – 40 U/L

Notes: Aspartate aminotransferase analysis is obsolete in modern clinical practice as it is too unspecific,

being present in roughly equal amounts in liver, heart and muscle. As a cardiac enzyme, it is of very low

specificity and sensitivity when compared to the alternatives. Its only use now is for research projects and

drug trials that follow protocols originating in the USA.

Beta Trace

Specimen Type: Small amount of fluid in a plain tube

Reference Range: > 2.0 mg/L suggests presence of CSF

> 6.0 mg/L strongly suggests presence of CSF

Notes: 'Beta trace protein' (also known as prostaglandin D synthetase) is protein found at high concentration

in CSF (20 mg/L) and low concentration in normal serum (0.5 mg/L). The concentration in serum may be


Reviewed: 07/06/10

elevated in renal failure. The measurement of beta trace is useful in identifying the presence of CSF in

otorrhea or rhinorrhea. It is untested in identifying the source of fluid originating from other sites.

Bicarbonate (Total CO2)



Age Range Males (mmol/L) Females (mmol/L)

0 – 1 week 13 – 21 13 – 21

1 week – 1 month 13 – 22 13 – 22

1 – 6 months 13 – 23 13 – 23

6 months – 1 year 14 – 23 14 – 23

> 1 year 16 – 25 16 – 25

> 18 years 21 – 32 21 – 32

Ghoshal A.K., Soldin S.J. (2003), Clin Chim Acta; 331: 135- 46.

Notes: Bicarbonate is not stable, particularly if there is air space above the blood in the collection tube. The

sample, therefore, needs to reach the laboratory quickly. In many cases, arterial blood gases are more useful.

Bile Acids (Serum)



Bilirubin, Total (see also LFT)



Age Range Males (µµµµmol/L) Females (µµµµmol/L)

0 – 1 day < 87 < 87

1 – 2 days < 123 < 123

3 – 5 days < 176 < 176

1 month – 18 years < 14 < 14

> 18 years < 17 < 17


Notes: Total bilirubin is part of the LFT profile. Total bilirubin and Conjugated (direct) bilirubin, often

referred to as “Split Bilirubin” is rarely required and must be requested separately.

Bone Function Test (BFT)


Reference Ranges (Adult): Albumin: 30 – 51 g/L

Calcium: Not applicable

Corrected Calcium: 2.10 – 2.50 mmol/L

Phosphate*: 0.8 – 1.4 mmol/L


Reviewed: 07/06/10

Alkaline Phosphatase*: 30 – 135 U/L

* Age-related reference ranges apply

Notes: The Bone Function Test is a profile that consists of Albumin, Calcium (Total and Corrected),

Phosphate and Alkaline Phosphatase analyses.

Blood Urea Nitrogen (BUN) – please refer to Urea

Ca125


Reference Range: < 30 U/mL

Notes: When used as a screening test, concentrations over 35 U/ml are usually taken as high enough to

justify recall for further investigation. Ca125 is a good marker for some ovarian carcinomas, but not all, and

it is not of good sensitive in early disease. Its main use is in following treatment of known ca ovary. Raised

concentrations also occur in pregnancy, in some individuals at the onset of menstruation, in pelvic

inflammatory disease and in endometriosis. Very high concentrations occur in ascites of any cause and

concentrations are raised in a few patients with gut carcinomas. The test is of no value in men.

Ca199


Reference Range: < 35 U/mL

Notes: Ca199 is a marker for a number of gut tumours, especially ca pancreas. However, it is rarely raised

except in advanced carcinoma. Concentrations can also be raised in non-malignant liver disease including

cirrhosis, hepatitis and cholecystitis.

Caeruloplasmin



Calcitonin

Specimen Type: 5ml clotted blood (brown or white top) “on-ice”

Reference Range: < 0.08 µmol/L

Notes: The only use of calcitonin is in detecting and monitoring medullary carcinoma of the thyroid.

Samples not received on ice cannot be analysed.

Calcium (Total) (see also BFT)


Reference Range: see Corrected Calcium

Notes: In blood, approximately 50% of plasma Calcium is “free”, 40% is protein-bound and 10% is


Reviewed: 07/06/10

complexed. About 80% of protein-bound Calcium is associated with Albumin, with the remaining 20%

associated with the globulins. Since the majority of protein-bound calcium is bound to serum albumin,

serum calcium concentrations are significantly affected by changes in serum albumin concentrations.

Calcium (Total) is part of the BFT profile.

Calcium (Corrected) (see BFT)


Reference Range: 2.10 – 2.50 mmol/L

Notes: Corrected calcium is part of the BFT profile. It is a derived parameter calculated using the measured

albumin and calcium concentrations. It corrects approximately for changes in serum albumin. The formula

is:

Corrected Calcium (mmol/L) = Total Calcium (mmol/L) ± (0.012 x (36 – Albumin (g/L))

Calcium (Urine)

Specimen Type: 24-hour urine (acid)

Reference Range: 3 – 7 mmol/24hr

Calculi

It is sometimes useful to analyse calculi of the urinary tract, particularly in patients with recurrent

calculi. There is no value in analysing calculi from the biliary tree or other sites. Dr Anthony Norden will be

pleased to advise. Please email [email protected] for advice.

Carbamazepine (Tegretol)


Therapeutic Range: 30 – 50 µmol/L

Notes: Average serum half-life 36 hrs; time to steady state 7 days - 4 weeks.

Carboxyhaemoglobin

Specimen Type: Heparinised venous or arterial blood

Reference Range: Up to 3% in non-smokers; Up to 5% in smokers

Notes: The elimination half-life breathing air is 250 min; breathing 100% oxygen at normal pressure, it is 50

min. Thus, there is no point in measuring carboxyhaemoglobin many hours after removal from the suspected

exposure to carbon monoxide.

Cardiac enzymes


Reference Range: see Creatine Kinase


Reviewed: 07/06/10

Notes: For diagnosis of acute coronary syndrome, please refer to Troponin I.

For investigating possible re-infarction within 10 days of a raised troponin, please use creatine kinase (CK).

Other older markers of cardiac damage, AST, LDH, CK-MB are no longer offered.

Carotenes and Carotenoids

Specimen Type: 5ml clotted blood (white top ONLY) or

5ml plasma (Lithium Heparin - Orange top) or

(EDTA – Red top)

Reference Range: please see Vitamin A, E & Carotenoids

Notes: Please telephone 3151 to arrange this test. Vitamin A, Vitamin E and Carotenoids form a profile that

are usually assayed together. Protect specimen from light, avoid haemolysis and do NOT collect blood in a

brown top gel tube.

Carnitine (Acylcarnitine)

Specimen Type: Guthrie card (Acylcarnitine profile); Lithium Heparin Blood (Total and Free)

Reference Range: see Table below

Acylcarnitine* (µmol/L) Acylcarnitine* (µmol/L)

Free 8 – 35 Hexanoyl < 0.2

Acetyl 5 – 27 Octanoyl < 0.2

Propionyl 0.13 – 4.00 Decanoyl < 0.2

Butyryl < 0.5 Myristoyl < 0.5

Isovaleryl < 0.3 Palmitoyl 0.6 – 4.5

* Please note: the above acylcarnitines are quantitated. Any other acylcarnitines present in abnormal

amounts will be reported qualitatively.

)

Notes: The Carnitine profile performed on a blood spot gives considerably more information than

quantitation of total and free Carnitine. Free Carnitine concentration is assayed as part of the Acylcarnitine

profile, therefore plasma total and free Carnitine is rarely required.

Catecholamines (Plasma)


Reference Range: 0 – 150 ng/L (Adrenaline)

100 – 900 ng/L (Noradrenaline)





Reviewed: 07/06/10

Catecholamines (Urine)

Specimen Type: 24-hour urine (Acid)

Reference Range: 0 – 144 nmol/24hr (Adrenaline)

100 – 560 nmol/24hr (Noradrenaline)

0 – 3194 nmol/24hr (Dopamine)

Notes: Investigation of neuroendocrine tumours and resistant hypertension.

Carcinoembryonic Antigen (CEA)


Reference Range: < 5 µg/L

Notes: CEA is rarely raised except in advanced carcinoma. A normal result does not exclude carcinoma.

Chitotriosidase


Reference Range: 0 – 140 µmol/L/hr

Notes: This test is used for the monitoring the treatment of patients with Gaucher's disease.

Chloride


Reference Range: 95 – 106 mmol/L

Cholesterol


Reference Range: Interpretation of cholesterol and other lipid results

should now follow the NSF guidelines. See, for

example, data at the back of the current BNF.

Notes: Cholesterol can be measured on a non-fasting sample for screening purposes. For full investigation,

measurement of HDL and LDL cholesterol and triglycerides, the patient must fast overnight.

Cholinesterase & Pseudocholinesterase (Serum)

Specimen Type: EDTA blood (red tube)


Notes: Measurements of serum cholinesterase are used to screen for sensitivity to suxamethonium which

may cause ‘scoline apnoea’. It is often useful to follow these measurements by genotyping. To ensure that

this can be done, patients should be consented for molecular genetic studies at the time that the enzyme

measurement is requested. The fact of consent to genetic studies should be recorded in the notes and on the


Reviewed: 07/06/10

request. In cases of organophosphorus poisoning, the test used is serum/red cell acetylcholinesterase for

which EDTA whole blood is needed.

Ciclosporine

Specimen Type: Pre-dose EDTA whole blood (red top)

Reference Range: see Notes below

Notes: The target therapeutic range depends on the type of organ transplant that the patient has had and the

time after transplantation. As a guide heart and lung transplants are usually maintained at higher

concentrations than liver, kidney and bone marrow transplants. For queries on appropriate target levels,

please refer to the relevant clinical team. Average plasma half-life is 8-20 hours; time to steady state 2 - 4

days. Cut off time is 10.00 am for same day analysis (Monday to Saturday). NO SUNDAY SERVICE.

Complement


Reference Ranges: C3: 0.8 – 2.14 g/L

C4: 0.13 – 0.60 g/L

CH50: 392 – 1019 U/ml

Notes: Specimens for CH50 analysis MUST reach the laboratory within 2 hours of collection.

Copper (Serum)



Copper (Urine)

Specimen Type: 24 hr Acid Washed urine container

Reference Range: Up to 0.9 µmol/24hr

Notes: Only in Wilson's Disease.

Cortisol (Serum)


Reference Range: 280 - 650 nmol/L (8 – 9 am)

< 200 nmol/L (Midnight)

Notes: Cortisol has a diurnal rhythm and is pulsatile. Concentrations fall off rapidly after 9am but small

peaks may occur throughout the day. If adrenal insufficiency is suspected, collect sample, preferably as a

Synacthen test before giving steroid cover. Contact laboratory for urgent cortisol assay.

Cortisol, Urine Free Cortisol (Urine)

Specimen Type: 24-hour urine (plain)

Reference Range: < 180 nmol/24hr


Reviewed: 07/06/10

Notes: Because of the diurnal rhythm of serum cortisol, urine cortisol excretion varies through the day and

thus an accurate 24 hr collection is essential. In addition, urine cortisol, like serum cortisol, may show rises

due to stress. Urine cortisol concentration is not linearly related to cortisol production rate, and urine cortisol

concentration rises rapidly after serum CBG is saturated. This occurs at around 600 nmol/L. When used as a

screening test for Cushing's Syndrome, 270 nmol/24 hr is usually taken as the level at which further

investigation is indicated.

C-Peptide


Heparin (orange top) blood on ice.


Also, send a fluoride-oxalate tube (yellow) for

glucose measurement.

Reference Range: 174 - 960 pmol/L

(fasting adults with normal BMI)

Notes: Clearance of C-Peptide is delayed in patients with renal failure. Analysis of C-peptide may be useful

in the assessment of residual beta cell function in diabetics treated with insulin. The assay may also be useful

in the diagnosis of insulinoma and in the investigation of factitious hypoglycaemia by enabling

differentiation of exogenous and endogenous insulin secretion.

Creatine Kinase (Total CK)




0 – 90 days 40 – 314 54 – 485

3 – 12 months 36 – 183 38 – 253

13 – 24 months 39 – 173 36 – 128

2 – 10 years 42 – 163 36 – 128

11 – 14 years 42 – 163 42 – 183

15 – 18 years 45 – 158 39 – 153

> 18 years 24 – 195 24 – 170


Creatinine (Serum) (U&E) (E&C)




0 – 1 week 60 – 110 60 – 110

1 week – 1 month 30 – 70 30 – 70

1 month – 1 year 20 – 40 20 – 40

1 – 3 years 20 – 70 20 – 70


Reviewed: 07/06/10

10 – 12 years 40 – 100 40 – 100

> 12 years 35 – 125 35 – 125

Ghoshal A.K., Soldin S.J. (2003), Clin Chim Acta ; 331:135- 46.

Creatinine (Urine)

Specimen Type: Random or 24 hr urine (Plain or Acid container)

Reference Range 9 – 16 mmol/24hr (Adults)

Notes: Creatinine excretion depends on muscle mass and level of physical activity. Men generally have

greater urinary excretion of creatinine than women.

Creatinine Clearance

Specimen Type: 24-hour urine (Plain or Acid container)

5ml clotted blood (brown or white top)

Reference Range: 90 – 120 ml/min (Adults)

Notes: Creatinine clearance depends on body size and is sometimes normalised for body surface area.

Cryoglobulins

Specimen Type: Collect 5ml clotted blood (brown or white top) in a pre-

warmed tube and place in the vacuum flask to keep

warm and take it immediately to the laboratory.


Notes: Please contact the laboratory to discuss testing and to allow preparation of a vacuum flask.

CSF Glucose

Specimen Type: 1ml of CSF in a Fluoride (yellow) tube

Fluoride (Yellow) tube for plasma glucose

Reference Range: 2.5 – 5.3 mmol/L

Notes: If there is blood in the CSF, this will alter the glucose and protein concentration and may make it

impossible to interpret. If it is a bloody tap, try to obtain a non-bloodstained CSF specimen for glucose and

protein analysis.

CSF Lactate

Specimen Type: 1ml of CSF in a Fluoride (yellow) tube on ice

Fluoride (Yellow) tube on ice (for plasma lactate)

Reference Range: < 2.8 mmol/L (Adults)

< 2.2 mmol/L (Children)

CSF Oligoclonal Band



Reviewed: 07/06/10

5ml clotted blood (brown or white top) also


CSF Protein

Specimen Type: 1ml (approximately) CSF in a plain universal container


Ghoshal A.K., Soldin S.J. (2003), Clin Chim Acta; 331:135- 46.

Notes: If there is blood in the CSF, this will alter the glucose and protein concentration and may make it

impossible to interpret. If it is a bloody tap, try to obtain a non-bloodstained CSF specimen for glucose and

protein analysis.

CSF ττττ-protein

Notes: Please refer to Beta trace.

CSF HCG and AFP





HCG.

Cyclosporine




time after transplantation. As a guide heart and lung transplants are usually maintained at higher

concentrations than liver, kidney and bone marrow transplants. For queries on appropriate target levels,

please refer to the relevant clinical team. Average plasma half-life is 8-20 hours; time to steady state 2 - 4

days. Cut off time is 10.00 am for same day analysis (Monday to Saturday). NO SUNDAY SERVICE.

Age Range Males (g/L) Females (g/L)

0 – 14 days 0.15 – 1.00 0.15 – 1.53

15 – 30 days 0.15 – 0.96 0.15 – 1.00

31 – 90 days 0.15 – 0.48 0.15 – 0.93

3 – 6 months 0.15 – 0.48 0.15 – 0.44

7 – 24 months 0.15 – 0.50 0.15 – 0.48

2 – 7 years 0.15 – 0.45 0.15 – 0.45

8 – 12 years 0.15 – 0.40 0.15 – 0.45

13 – 18 years 0.15 – 0.40 0.15 – 0.45

>18 years 0.15 – 0.45 0.15 – 0.45


Reviewed: 07/06/10

Cystine (Urine)

Specimen Type Random urine (plain)

Reference Range: < 20 µmol/mmol creatinine

Notes: The sample must reach the laboratory promptly. Urine cystine reference range in those under a year of

age is less than 50 µmol/mmol creatinine and less than 20 µmol/mmol creatinine in older children and

adults. Occasionally 24hr collections may be helpful. Please discuss with laboratory.

Dehydroepiandrosterone Sulphate (DHEAS)


Reference Range: 2.2 – 13.5 umol/L (Adult Male)

1.5 – 11.6 umol/L (Adult Female)

Notes: Concentrations rise at adrenarche and decline slowly after age 35 yrs. DHEAS is of adrenal origin.

11-Deoxycortisol

Please contact laboratory for information about this test.

Digoxin


Therapeutic Range: 1.0 – 2.6 nmol/L

Notes: Sample should be taken at least 6 hours after the last dose, or just before the next dose. At

concentrations below 2.6 nmol/L toxicity is unlikely; above 2.6 toxicity is increasingly possible and above

3.8 toxic symptoms always occur. Low serum potassium increases sensitivity to digoxin and may produce

toxicity at lower concentrations. As digoxin is cleared by the kidneys, renal failure may lead to increased

half-life and toxicity. Average plasma half-life 36 hours; time to steady state 7 days.

5-αααα-Dihydrotestosterone (DHT)


Reference Range: 2.0 – 10.0 nmol/L (Adult Male)

0.34 – 1.4 nmol/L (Adult Female)

Notes: Used only when 5-α-reductase deficiency is suspected. A sample for testosterone at the same time is

essential, as the DHT/T ratio is a useful parameter. In prepubescent children, it is best to measure DHT/T

ratio after stimulation with HCG in a HCG stimulation test.

Drug Screen (Urine)

Specimen Type: 50ml Random Urine (plain) (two universal containers)



Reviewed: 07/06/10

Notes: Urine specimens should be collected as soon as possible after suspected drug ingestion. Drug screens

are done in two ways: there is a 'dipstick' test which is readily available for use in clinics and surgeries. This

is a screening test for certain common drugs of abuse but some other drugs are not detected. Where there are

special reasons for suspecting a drug not detected by the dipstick, urine samples can be sent to a specialist

laboratory. Results take at least a week to come back. Only Cannabinoids persist in the body for longer than

a few days so it is important that the urine sample is collected at a time soon after drug ingestion. Where the

purpose of the test is related to employment, child-custody, medico-legal or forensic issues, the service

provided by Clinical Biochemistry is unsuitable. In particular there will be no “chain of custody” as would

be required for use of a result as evidence. The laboratory will be able to suggest the name of a suitable

laboratory for such analyses.

Elastase (Faecal)

Please refer to Faecal Elastase

Electrophoresis (Serum)


Reference Range: please refer to Immunoglobulins

Notes: The main use of serum electrophoresis is in screening for myeloma. On electrophoresis, the various

serum proteins are separated and visualised by staining. Monoclonal or polyclonal immunoglobulin bands

may be visualised and immunosuppression may also be detected. If abnormal bands are detected for the first

time, further tests will be done to type any monoclonal bands. Monoclonal bands can be quantitated (“M-

band quantitation”) as a tumour marker. Electrophoresis may also be useful in detection of deficiency or

phenotypic variation in α-1-Antitrypsin. For electrophoresis of CSF in the diagnosis of demyelinating

disease, see 'Oligoclonal bands'.

Ethanol

Specimen Type: Fluoride tube (yellow top)


Notes: When poisoning by other alcohols such as methanol or ethylene glycol is suspected, measure serum

osmolality and consult the laboratory about sending a sample to the Poisons Unit for specific assay. An

ethanol concentration of 14.5 mmol/L is equivalent to 80 mg/100ml, the UK legal drink drive limit for

alcohol. This analytical service is suitable for clinical purposes only, not for medico-legal or forensic use.

Ethosuximide



Notes: Sample should be taken just before the next dose. It is now accepted that measurement of

ethosuximide is not needed or clinically helpful in most patients. If you think this test is needed, please

consult the laboratory. (Dr Anthony Norden - ext. 6820). Average plasma half-life is 50 hours; time to steady

state 10 days.


Reviewed: 07/06/10

Ethylene Glycol



Notes: Sample should be taken without delay. If urgent analysis is needed, arrangements should be made by

the physician by phoning Guys' Poisons Unit and arranging a taxi to rush the sample to Guys'. If it is

anticipated that regular measurements of ethanol level will be needed during treatment, please phone the

local laboratory to arrange this. The same sample and the same arrangements are needed if methanol

poisoning is suspected. Serum osmolality can be used to estimate the total concentration of such poisons but

this does not differentiate between methanol, ethylene glycol and ethanol.

Faecal Elastase

Specimen Type: single random stool sample in sterillin container

Reference Range: 200 to >500µg Elastase/g Faeces

Notes: Pancreatic elastase E1 forms part of the exocrine secretions of the pancreas and remains undegraded

during intestinal transit. Intraindividual variation of Faecal Elastase (FEL) is small and has been shown to

reflect the secretory capacity of the pancreas and may thus be used to aid the diagnosis or exclusion of

pancreatic exocrine insufficiency. A reduced FEL concentration may be associated with chronic pancreatitis,

cystic fibrosis, pancreatic tumour and diabetes mellitus. Moderate to mild pancreatic exocrine insufficiency

is associated with FEL concentrations of 100 to 200µg Elastase/g Faeces. Severe pancreatic exocrine

insufficiency is associated with FEL concentrations of <100 µg Elastase/g Faeces.

Ferritin


Reference Range: 22 – 322µg/L (Adult Male)

10 – 292µg/L (Adult Female)

Notes: Request either 'iron deficiency' or 'iron overload' studies. The acute phase reaction markedly affects

serum Ferritin and Transferrin concentrations. Because of this, CRP is always measured in order to detect

any acute phase response. If there is an acute phase response, serum Ferritin is uninterpretable; the Ferritin

concentration is not correlated with the CRP concentration. Where iron deficiency is suspected, the

appropriate tests are serum Ferritin and CRP. Measurement of iron and iron-binding capacity is obsolete.

Where iron overload is suspected, the appropriate tests are serum ferritin, iron, transferrin and CRP. DNA

tests for haemochromatosis genes are available.

FK506





Reviewed: 07/06/10

time after transplantation. For queries on appropriate target levels, please refer to the relevant clinical team.

Cut off time is 10.00 am for same day analysis (Monday to Saturday). NO SUNDAY SERVICE.

Folate (Red Cell)

Specimen Type: EDTA whole blood (red top)

Reference Range: > 250 µg/L

Free Haemoglobin

Specimen Type: 5ml clotted blood (brown top only)

Reference Range: See notes below

Notes: Assayed routinely Monday to Friday in a daily batch – samples should arrive for same day results by

12:00 hrs. An urgent service is offered on Saturday morning; samples should arrive in Clinical Biochemistry,

Level 4, Pathology block by 11:00 hrs otherwise samples will not be analysed until Monday as there is NO

SUNDAY SERVICE. Units are mg/dL but no specific reference range has been quoted for this group of

patients, as there are a range of pumps having different acceptable ranges for free Haemoglobin. The

individual patient monitoring of the free Haemoglobin level is used to assess their status

Free T3 (Free Triiodothyronine)


Reference Range: 3.0 – 7.5 pmol/L

Notes: Free T3 is a sensitive and specific test for hyperthyroidism, including relapsing thyrotoxicosis but it is

not sensitive or specific in hypothyroidism. Assay is performed once a week.

Free T4 (Free Thyroxine)



Age Range: Reference Range (pmol/l):

0 – 4days no reference range given

4 days – 2.5 months 10.4 – 22.7

>2.5 months – Adult 10 – 19.8

Notes: If TSH is outside the normal reference range, free T4 will be measured automatically. Please contact

the laboratory if you suspect hypopituitarism.

Fructose Intolerance

A DNA test is available to confirm the diagnosis of hereditary fructose intolerance. Please phone the

laboratory (3151) in advance to discuss this test.


Reviewed: 07/06/10

FSH (Follicle-Stimulating Hormone)


Reference Range: see Tables below

Approximate FSH normal ranges in adults:

Patient Group: Normal Range (U/L):

Adult men aged 20-60 1.0 - 10.1

Men over 60 1.5 - 15.0

Adult women in the follicular phase 2.9 - 8.4

Women with established menopause 21 - 140

Approximate FSH normal ranges in children:

Puberty Stage Males Females

Mean ±sd (U/L)

Infancy 1.03 ± 1.17 7.27 ± 4.16

Tanner 1 0.97 ± 0.59 2.16 ± 1.14

Tanner 2 2.75 ± 1.84 3.44 ± 1.58

Tanner 3 2.94 ± 1.55 4.88 ± 2.11

Tanner 4 4.47 ± 1.88 6.19 ± 2.55

Tanner 5 7.64 ± 2.50 4.92 ± 2.31

(Neely, E.K. et al. (1995), J Paediatr; 127, 40 - 52)

Notes: FSH varies through the menstrual cycle but in women having menstrual cycles it is best to take the

sample around day 8 (mid-follicular phase). Normal Reference Range varies markedly with stage of sexual

development and from day to day in the menstrual cycle. Normal ranges are related more to stage of sexual

development than to chronological age. The ranges below are thus only an indication of what is normal.

At the approach of the menopause, FSH rises before LH. In the perimenopausal period, FSH concentrations

over 100 U/L are common. At the approach of puberty, FSH rises from childhood concentrations before LH

does. In primary gonadal failure in children, concentrations of FSH and LH do not rise until puberty.

GAL-1-PUT (Galactose-1-Phosphate Uridyl Transferase)

Specimen Type: Guthrie card



Reviewed: 07/06/10

Notes: Mark the card very clearly 'GAL1PUT'. This is a screening test or galactosaemia. This is a red cell

enzyme and therefore the result will be unreliable if the patient has had a blood transfusion in the last six

weeks.

Gastrin & other Gut Hormones

Specimen Type: 2 X 4.5 ml EDTA tube, “on-ice”

Reference Range: < 40 pmol/L (Gastrin)

Patient Preparation: The patient must fast completely (not even water)

overnight. H2 blockers should be stopped for 72 hr and

Proton Pump Inhibitors such as Omeprazole should be

stopped for 2 weeks before taking the sample

Notes: Specimen MUST now be collected into “blue” transfusion EDTA tubes (as Trasylol is now no longer

available). Place the tube on ice and rush it to the laboratory. Visible haemolysis invalidates the assay.

Request either 'Gastrin' for Gastrin alone or 'gut hormone profile'.

The gut hormone profile consists of Gastrin, Glucagon, VIP (Vasoactive Intestinal Polypeptide), PP

(Pancreatic Polypeptide), Neurotensin and Somatostatin. GAWK (Chromogranin) is an optional extra.

Best advice: always send patient to OPD Blood Tests for correct Gastrin and gut hormone samples.

Gaucher's disease enzymes

Notes: Diagnostic Enzyme: β-Glucosidase (see White Cell enzymes).

Monitoring Treatment: Chitotriosidase.

GAWK

Specimen Type: As Gastrin

Reference Range: < 200 pmol/L

Patient Preparation: As Gastrin

Note: Please request GAWK by using “Gut Hormone Profile”. The acronym GAWK is derived from Gly-

Ala-Trp-Lys.

Glucagon




Notes: Please request Glucagon by using “Gut Hormone Profile”.

Glucose (Blood, Serum or CSF)

Specimen Type: Fluoride (Yellow) tube


Reviewed: 07/06/10

Reference Range: 3.5 – 5.5 mmol/L (Fasting)

3.5 – 9.0 mmol/L (Non-Fasting)

2.5 – 5.3 mmol/L (CSF)

Notes: Glucose can also be measured on serum or heparinised plasma but the glucose will be lower because

the cells continue to consume glucose after venepuncture unless there is fluoride present. When CSF glucose

is measured it must always be in a fluoride tube and it is advisable to take a blood sample for glucose at the

same time. Protein can be measured on the same CSF sample.

Glucose Tolerance Testing (Oral) – GTT

Principle

Diabetes mellitus is a disease of glucose and lipid metabolism caused by an absolute or relative lack of

insulin. It can be diagnosed by the finding of a raised fasting glucose (>7 mmol/l) on two or more occasions

together with symptoms such as thirst and polyuria. However some patients may need to have a test of

glucose handling in order to either diagnose diabetes or to indicate some degree of glucose intolerance that

may indicate a predisposition to develop diabetes later in life. These findings may also indicate an increased

risk of cardiovascular disease. The diagnostic criteria are shown in the table below.

The test itself consists of measurements of glucose after an overnight fast and a second measurement 2 hours

after taking 75g of glucose

Criteria for diagnosis of Diabetes Mellitus from WHO; World Health Organisation/International Diabetes

Federation, Definition and Diagnosis of Diabetes Mellitus and Intermediate Hyperglycaemia, 2006.

Diabetes Mellitus WHO Criteria

Fasting plasma glucose ≥ 7.0 mmol/L OR

2-hour plasma glucose* ≥ 11.1 mmol/L

Impaired Glucose Tolerance (IGT)

Fasting plasma glucose < 7.0 mmol/L AND

2-hour plasma glucose* ≥ 7.8 and < 11.1 mmol/L

Impaired Fasting Glucose

Fasting plasma glucose 6.1 to 6.9 mmol/L and (if measured)

2-hour plasma glucose* < 7.8 mmol/L

*venous plasma glucose 2-hour after ingestion of 75g oral glucose load

* if 2-hour plasma glucose is not measured, status is uncertain as diabetes or IGT cannot be excluded.

Testing

• Test preceded by ≥3 days of normal, unrestricted diet (>150 g carbohydrate daily) with normal

physical activity.

• Carbohydrate rich meal (30–50 g) on night before test.

• Overnight fast of 8–14 hours; drink only water.


Reviewed: 07/06/10

• Record any factors that may affect interpretation of test such as medication, inactivity, infection,

gestation of pregnancy, acute psychological stress etc.

• Collect fasting (and all other) samples in 5.5ml fluoride oxalate tube. If other tests are requested at

the same time take the brown and/or white tubes first

• Timing of test (0 hours) starts at beginning of glucose drink.

• Adults ingest 410 ml of Lucozade™ Energy Original or 75g glucose in 250–300 ml water over 5

minutes.

• Children ingest 10ml/kg body weight up to a maximum of the adult dose

• No smoking during test.

• Take blood sample at 2 hours

• Ideally take sample from warmed vein on back of hand (antecubital fossa samples may be artificially

lower).

• An indwelling 'butterfly' or conventional cannula can be left in situ throughout the test (affix in place

and dress); flush with saline after taking fasting sample, then draw at least 10 ml and discard before

drawing sample for assay tube.

Invalid test

• If the patient is unable to drink all of the lucozade or vomits soon after taking the drink the test will

be invalid and will need to be repeated on another day.

γγγγ-Glutamyl Transferase (GGT)




1 – 7 days 21 – 145 15 – 127

8 – 30 days 19 – 150 13 – 120

1 – 3 months 13 – 126 13 – 120

4 – 6 months 4.0 – 80 11 – 106

7 – 12 months 6.0 – 32 6.0 – 50

1 – 3 years 1.0 – 12 1.0 – 12

4 – 6 years 4.0 – 14 4.0 – 14

7 – 9 years 7.0 – 17 7.0 – 17

10 – 11 years 10.0 – 21 10.0 – 19

12 – 13 years 10.0 – 33 8.0 – 17

14 – 15 years 6.0 – 25 8.0 – 19

16 – 19 years 5.0 – 25 5.0 – 19

> 19 years < 51 < 31

Ghoshal A.K., Soldin S.J. (2003), Clin Chim Acta ;331: 135- 46.


Reviewed: 07/06/10

Glycosaminoglycans (Mucopolysaccarides)

Please refer to “Mucopolysaccarides”

Growth Hormone


Reference Range: Not Applicable for random specimens

Units: ug/L (as from 01/10/08)

Notes: In normal individuals, growth hormone concentrations are higher when fasting than when fed and

rises in stress. In fed unstressed normal individuals, growth hormone can be undetectable. In screening for

acromegaly measure GH about 2 hours after a carbohydate-rich meal. The definitive test is a glucose

tolerance test with growth hormone assay. When pituitary failure is suspected, a random growth hormone is

of little value as it can be very low in normal individuals. If failure of growth hormone production is to be

tested formally, the insulin tolerance test is used. In children suspected of growth hormone deficiency, it may

be helpful to take a sample when the child has fasted overnight and then exercised vigorously for 20 minutes

(Exercise Test protocol). However, a formal stimulation test is usually needed; the clonidine test is preferred.

For various timed tests requiring growth hormone assay request 'growth hormone series'.

Gut Hormone Profile




Notes: Request 'gut hormone profile'. The gut hormone profile consists of Gastrin, Glucagon, VIP

(Vasoactive Intestinal Polypeptide), PP (Pancreatic Polypeptide), Neurotensin and Somatostatin.

Haemoglobin A1c


Reference Range: 4.9 – 6.3 % (Non Diabetic Adults)

(Lower in pregnancy)

Notes: N.I.C.E. suggest a target of 7.5 % or lower in diabetic patients. See N.I.C.E. website for specific

details.

Haptoglobin



Notes: Lowering of Haptoglobin is a sensitive indicator of in vivo haemolysis.

HCG (Human Chorionic Gonadotrophin) (Serum)


Reviewed: 07/06/10


Reference Range: Up to 4.0 U/L in non-pregnant subjects

Notes: Comparison of serum and CSF concentrations may help to identify a CNS lesion secreting HCG.

HCG (CSF)





HCG.

HDL Cholesterol (see Full Lipid Profile)



should now follow the NSF guidelines. See for


Notes: HDL Cholesterol is provided as part of the 'Full Lipid profile' and the patient should be fasting. Total

cholesterol can be used for screening and in this case the patient does not need to fast.

Heavy Metals

Specimen Type: EDTA whole blood (red top) plus a random plain urine


Notes: A variety of heavy metals can cause poisoning and they can be measured for diagnostic purposes or

for monitoring industrial workers who are exposed to these toxins. Seek advice by phoning 3153 or 3151.

Homocystine (Urine or Plasma)

Specimen Type: Plain Urine or Lithium Heparin Plasma (orange top)


Handbook

Notes: Used in the investigation of suspected homocystinuria. Plasma homocystine is less commonly

needed. The sample required is heparinised plasma rushed to the laboratory. Please phone the laboratory

(ext. 57130 or 3160) in advance as the blood sample has to be deproteinised immediately upon arrival.

Homovanillic acid (HVA) (Urine)

Specimen Type: 24-hour urine (acid) or Random urine

Reference Range: 12 – 53 µmol/24 hours (24- hour collection)

See Table below (Random urine collection, children)


Reviewed: 07/06/10

Reference Ranges for children on Spot Urine:

Age VMA/Creatinine Ratio

(µmol/mmol creatinine)

HVA/Creatinine Ratio (µmol/mmol

creatinine)

Up to 2 years old 0.0 – 11.8 0.0 – 20.3

2 to 7 years old 0.0 – 8.6 0.0 – 12.3

8 to 15 years old 0.0 – 3.6 0.0 – 5.3

16 years old and over 0.0 – 3.6 0.0 – 4.4

Notes: Used for the investigation of Neuroblastoma HVA/Creatinine ratio can be measured if 24-hour urine

collection is impractical. HVA has no diagnostic use in adults but may be secreted in some Neuroblastomas

in preference to VMA. For detailed information on specimen collection please refer to the document located

on the Intranet site: http://connect/media/pdf/l/g/PIN1296_urinecollection_VMA_1.pdf

17-Hydroxyprogesterone (17-OHP)


Reference Range: < 12 nmol/L (Adults)

< 5 nmol/L (Children)

Notes: Please call the laboratory to arrange priority assay for salt wasting neonates. The sample must not be

taken before 48 hours after birth. 17-Hydroxyprogesterone can also be measured in saliva for monitoring

replacement therapy in children. In patients suspected of 'non-classical CAH' (late onset, mild type), first do

a basal 9am sample. If it is markedly raised, then do a short synacthen test measuring 17-hydroxy

progesterone at 0, 30 and 60 minutes. Results affected by stress.

25-Hydroxy Vitamin D (Vitamin D)


Reference Range: Not Applicable – see Action Limits in table below

!! Note Change of Units !!

Action Limit (nmol/L) Comments

30 – 50 Vitamin D concentration is suboptimal and treatment may be required if

clinically indicated.

15 - 30 Represents moderate Vitamin D deficiency, treatment usually required.

Below 15 Represents severe deficiency, treatment required.

Notes: from 7th

June 2010, there will be a Change of Units and a Change in Methodology.


Reviewed: 07/06/10

We are taking this opportunity to change our reported units from ug/L to nmol/L in accordance with a recent

UK directive to harmonize pathology reports. Please beware of this unit change when comparing test results

issued prior to the 7th

June 2010 to results generated after this date.

From the 7th June 2010, the 25OH-Vitamin D method will change from Immunoassay to Mass

Spectrometry. The new method will fully detect 25OHD2 (ergocalciferol), unlike the previous method. In

patients that are not taking 25OHD2 the results correlate very well; results are directly comparable with the

old method in this patient group. We will be reporting both 25OHD2 and 25OHD3 concentrations.

5-Hydroxyindolacetic acid (5-HIAA) (Urine)


Reference Range: 11 – 37 µmol/24 hours (Adults)

0 – 4 µmol/mmol creatinine (5HIAA/Creatinine)

Notes: The patient must be on a diet low in indoles, serotonin and indole precursors for the 24 hours before

and the 24 hours during the urine collection. For detailed information, please refer to the document located

on the Intranet site: http://connect/media/pdf/2/p/PIN1615_urine_for_5-HIAA_measurement.pdf

Immunoglobulins


Reference Range: IgG 6.0 – 13.0 g/L (Adult)

IgA 0.8 – 3.7 g/L (Adult)

IgM 0.4 – 2.2 g/L (Adult)

See table below (Children)

Age IgG (g/L) IgA (g/L) IgM (g/L)

Cord Blood 5.2 - 18.0 <0.02 0.02 - 0.20

0-2 Weeks 5.0 -17.0 0.01 - 0.08 0.05 - 0.20

2-6 Weeks 3.9 - 13.0 0.02 - 0.15 0.08 - 0.40

6-12 Weeks 2.1 - 7.7 0.05 - 0.40 0.15 - 0.70

3-6 Months 2.4 - 8.8 0.10 - 0.5 0.2 - 1.0

6-9 Months 3.0 - 9.0 0.15 -0.7 0.4 - 1.6

9-12 Months 3.0 - 10.9 0.20 - 0.7 0.6 - 2.1

1-2 Years 3.1 - 13.8 0.3 - 1.2 0.5 - 2.2

2-3 Years 3.7 - 15.8 0.3 - 1.3 0.5 - 2.2

3-6 Years 4.9 - 16.1 0.4 - 2.0 0.5 - 2.0


Reviewed: 07/06/10

Age IgG (g/L) IgA (g/L) IgM (g/L)

6-9 Years 5.4 - 16.1 0.5 - 2.4 0.5 - 1.8

9-12 Years 5.4 - 16.1 0.7 - 2.5 0.5 - 1.8

12-15 Years 5.4 - 16.1 0.8 - 2.8 0.5 - 1.9

Insulin






Reference Range: Less than 60 pmol/L (fasting adults with normal BMI)

Less than 200 pmol/L (neonates)

Notes: Samples should be collected when the patient is fasting or showing signs of hypoglycaemia. Assays

are performed on a weekly basis; please contact the laboratory if urgent analysis is required. Insulin

concentrations rise rapidly if glucose is given or food is ingested. Interpretation of insulin concentrations in

samples with normal or raised blood glucose concentrations is difficult. Sample haemolysis is known to

artefactually lower insulin levels.

In babies, it is difficult to achieve the equivalent of a fasting state in adults. Insulin concentrations in babies

are very variable and reference ranges are not well defined.

One sample is usually sufficient for insulin and c-peptide / proinsulin if required.

Insulin-like growth factor 1 (IGF-1)


Reference Range: Depends on age, stage of puberty and on nutrition.

Intact Proinsulin






Reference Ranges: Intact: up to 7 pmol/L,

(fasting adults with normal BMI)

Notes : Measurement of proinsulins may be useful in the investigation of insulinoma.

32-33 split proinsulin assay is not routinely available – please phone the laboratory to discuss if required.

Iron (Serum)


Reviewed: 07/06/10



Notes: Investigations of Iron status should be separated into either investigation for Iron deficiency or Iron

overload. Please indicate this on the request form. For Iron-deficiency, the appropriate tests are Ferritin and

CRP. CRP is needed to check for an acute phase response which if present will affect Ferritin and

Transferrin concentrations. Measurement of Iron and Iron-binding capacity is obsolete in this context. For

Iron overload, the appropriate tests are Ferritin, Iron, Transferrin and CRP. In suspected Iron poisoning

serum, Iron is required and is available as an urgent test.

Krabbe's Enzyme (Galactocerebrosidase)

Specimen Type: Lithium Heparin blood (orange top)


Handbook

Notes: Telephone laboratory to arrange (ext 57130 or 6172). The assay is performed on a leukocyte

preparation.

Lactate (Plasma, CSF)

Specimen Type: Fluoride (Yellow) on ice



0 – 2 months 1.0 – 3.5 1.0 – 3.5

3 months – 1 year 1.0 – 3.3 1.0 – 3.3

2 – 18 years 1.0 – 2.4 1.0 – 2.4

> 18 years 0.1 – 1.8 0.1 – 1.8


Notes: The sample must reach the laboratory promptly.

Lactate Dehydrogenase (LDH)




1 – 30 days 200 – 714 210 – 681

1 – 3 months 177 – 422 170 – 399

4 – 6 months 150 – 425 177 – 399

7 – 12 months 144 – 415 170 – 370

1 – 3 years 184 – 323 184 – 323

4 – 6 years 173 – 316 173 – 316

7 – 9 years 157 – 267 157 – 267

10 – 15 years 157 – 260 144 – 250


Reviewed: 07/06/10


16 – 19 years 130 – 244 130 – 239

> 19 years 120 – 240 120 – 240


Notes: Because of high concentrations in red cells, even slight haemolysis will increase serum LDH. The test

offered is total LDH. LDH isoenzymes are sometimes measured but are not offered by the laboratory.

Laxative Screen

Specimen Type: 50ml Plain Urine


Notes: It is usually helpful to discuss the test with the laboratory (3151) prior to collecting the sample.

Low-density Lipoprotein Cholesterol (LDL) (see FLP)



should now follow the NSF guidelines. See for


Notes: LDL cholesterol is calculated using the Friedwald formula from total cholesterol, HDL cholesterol

and triglyceride concentrations. The patient must have fasted overnight. This test is offered only as part of

the 'full lipid profile'.

Lead


Reference Range: < 0.5 µmol/L (Unexposed adults and children)

Notes: Concentrations below 1.8 µmol/L are unlikely to be associated with toxicity. Zinc Protoporphyrin is

also measured on each sample.

Leptin



Reference Range: Reference range is dependant upon sex and BMI

See Table below.

Sex BMI (kg/m2) Median

(ng/ml)

minimum.

(ng/ml)

maximum

(ng/ml)

n

Male <25

35-30

30-35

>35

2.5

4.7

9.5

15.5

0.1

0.5

2.1

7.8

22.8

26.3

36.7

31.7

278

375

98

8

Female <25 8.9 0.2 45.8 535


Reviewed: 07/06/10

Sex BMI (kg/m2) Median

(ng/ml)

minimum.

(ng/ml)

maximum

(ng/ml)

n

25-30

30-35

>35

18.9

32.3

52.4

3.0

8.1

11.9

65.7

79.1

137.4

348

126

60

Notes : Measurement of leptin may be useful in the investigation of obese subjects for the rare clinical

condition of leptin deficiency.

Liver Function Tests


Reference Ranges (Adult): Albumin: 30 – 51 g/L

Total Bilirubin* 0 -17 µmol/L

ALT: 2.10 – 2.50 mmol/L

Alkaline Phoshatase: 30 – 135 U/L

* Age-related reference ranges apply

Notes: The Liver Function Test is a profile that consists of Albumin, Total Bilirubin, ALT and Alkaline

Phosphatase analyses.

Luteinising Hormone (LH)


Reference Range: See Tables below

Notes: LH varies through the menstrual cycle but in women having menstrual cycles it is best to take the

sample around day 8 (mid-follicular phase). Normal Reference Range varies markedly with stage of sexual

development and from day to day in the menstrual cycle. Normal ranges are related more to stage of sexual

development than to chronological age. The ranges below are thus only an indication of what is normal.

Patient Group Normal Range (U/L)

Adult Men aged 20 - 60 1.5 - 6.3

Men aged over 60 1.5 - 10.0 U/L

Adult Women in the follicular phase 1.3 - 8.4

Women with established menopause 16 - 75

Notes: At the approach of the menopause, FSH rises before LH. In the perimenopausal period, FSH

concentrations over 100 U/L are common. At the approach of puberty, FSH rises from childhood

concentrations before LH does. In primary gonadal failure in children, concentrations of FSH and LH do not

rise until puberty.

Puberty stage Males Females


Reviewed: 07/06/10

Mean ±sd (U/L) Mean ±sd (U/L)

infancy 1.60 ± 3.22 0.16 ± 0.25

Tanner 1 0.05 ± 0.05 0.03 ± 0.03

Tanner 2 1.80 ± 1.30 0.71 ± 1.04

Tanner 3 1.86 ± 1.41 2.10 ± 2.33

Tanner 4 2.65 ± 1.81 3.67 ± 2.22

Tanner 5 2.76 ± 1.12 2.88 ± 2.68

Approximate LH normal ranges in children (Neely, E.K. et al. (1995), J Paediatr; 127, 40 - 52)

Light Chain Quantification

Specimen Type: 24-hour urine (plain)


Notes: This is test is also referred to as 'quantitative Bence Jones Protein' and is used as a tumour marker in

patients who have a myeloma secreting predominantly light chains.

Lipid Profile (FLP)



should now follow the NSF guidelines. See, for


Notes: The patient must have fasted overnight. This profile consists of Total Cholesterol, HDL Cholesterol,

calculated LDL Cholesterol and total Triglycerides.

Lithium

Specimen Type: 5ml clotted blood (brown or white top), pre-dose

Therapeutic Range: 0.4 – 1.0 mmol/L

Notes: The best time to take the sample is 12 hours after the last dose. For control of acute mania the

recommended therapeutic range is 0.8 - 1.2 mmol/L. At concentrations above 1.2 mmol/L toxicity is likely

to occur eventually. At concentrations above 1.5 mmol/L toxic symptoms are highly likely. Lithium is

cleared by the kidneys so any renal impairment may precipitate toxicity. Average serum half-life 18 - 36 hrs;

time to steady state about 7 days.

Magnesium




Reviewed: 07/06/10


7 – 30 days 0.5 – 1.1 0.5 – 1.1

1 month – 1 year 0.7 – 1.1 0.7 – 1.1

1 – 12 years 0.7 – 1.0 0.7 – 1.0

13 – 15 years 0.7 – 1.0 0.7 – 0.9

> 15 years 0.7 – 1.0 0.7 – 1.0


Myeloma screen and M-band Quantification


Reference Range: see Immunoglobulins

Notes: In the initial investigation of Myeloma, request 'electrophoresis'. If present, any monoclonal bands

will be immunotyped. Sequential quantification of Myeloma proteins in individual patients is useful to

follow progress, but only after the Myeloma protein has been typed. Screening for Bence-Jones protein

(monoclonal free light chains) requires an early morning urine.

Mercury


or 50 ml of early morning urine in a plain bottle.

Reference Ranges: < 20 nmol/L (Blood) (Unexposed adults)

< 5 nmol/mmol Creatinine (Urine) (Unexposed adults)

Notes: For industrial workers exposed to mercury, maximum concentrations should be: Blood 95 nmol/L;

Urine 45 nmol/mmol Creatinine. It is not appropriate to measure mercury if the only exposure is to dental

fillings (see Br Dent J 1997 182 455). If the test is for regular monitoring of workers exposed to mercury, the

samples are to be sent to the Health and Safety Executive.

Metals, Heavy

Specimen Type: EDTA whole blood (red top) plus random urine (plain)


Notes: A variety of heavy metals can cause poisoning and they can be measured for diagnostic purposes or

for monitoring industrial workers who are exposed to these toxins. Seek advice by telephone ext. 3151.

Methanol



Notes: Sample should be taken without delay. If urgent analysis is needed, arrangements should be made by

the physician by phoning Guys' Poisons Unit and arranging a taxi to rush the sample to Guys'. If it is

anticipated that regular measurements of Ethanol level will be needed during treatment, please phone the

local laboratory to arrange this. The same sample and the same arrangements are needed if Ethylene Glycol

poisoning is suspected. Serum osmolality can be used to estimate the total concentration of such poisons but

this does not differentiate between Methanol, Ethylene glycol and Ethanol.


Reviewed: 07/06/10

Methotrexate


Therapeutic Range: < 0.1 µmol/L (72 hours post-dose)

Notes: Available only for monitoring in-patients treated with high-dose Methotrexate. This is not a routine

test and the clinician is expected to phone the laboratory in every case to make the arrangements for assay of

the timed samples. Over weekends and public holidays it may not be possible to provide the assay at all and

samples which arrive late in the day may have to wait until morning when there is enough staff to carry out

the assay. This means that the clinician should plan to start the treatment so that samples are taken at a time

when the laboratory can offer support. The test is not sensitive enough for patients taking low-dose

Methotrexate, e.g. for psoriasis.

Micro-Albumin (ACR)

Specimen Type: Random urine (plain)

Reference Range: < 2.5 mg/mmol Creatinine

Notes: Used in diabetics and others where very small amounts of Albumin excretion into urine are

significant. In the case of Proteinuria, request 'urine protein'.

ββββ2-Microglobulin


Reference Range: 0.8 – 2.5 mg/L

Note: Used in renal failure patients and as a prognostic indicator in Myeloma.

Micronutrient Profile

For those on long-term total parenteral nutrition only, it may be helpful to measure a range of trace elements

and vitamins. Before deciding on this test, phone 3151.

Mucopolysaccharides (Glycosaminoglycans)

Specimen Type: Random urine (plain)


Handbook 2007

Note: Used in investigation of suspected mucopolysaccharidosis.

Noradrenaline (Plasma)


Reference Range: 100 – 900 ng/L (Noradrenaline)



Reviewed: 07/06/10



Noradrenaline (Urine)

For further information regarding urinary noradrenaline, please see “Catecholamines (Urine)”

Neurone-specific Enolase (NSE)

Specimen Type: Lithium Heparin blood (orange tube)

Reference Range: 0 – 13 µg/L

Notes: NSE is a tumour marker, which is of some value in Neuroblastoma cases.

Neurotensin


Reference Range: < 40 pmol/L (Gastrin)











Occult Blood (Faecal)

Specimen Type: Hema-screen™ card


Notes: The sample is collected and applied to a special card; these are obtained from the laboratory.

Oestradiol


Reference Range: Vary with the stage of the menstrual cycle and in

children with the stage of puberty

Follicular phase: 100 – 750 pmol/L

Midcycle peak: 500 – 1500 pmol/L


Reviewed: 07/06/10

Postmenopausal: < 110 pmol/L approximately

Men aged 20 - 60: < 180 pmol/L

Children: Pre-pubescent (Tanner stage 1): < 55 pmol/L

Notes: In the investigation of infertility, the sample should ideally be taken on about day 8 of the menstrual

cycle, i.e. in the follicular phase. In girls, concentrations rise in Tanner stage 2 and are then similar to adult

follicular phase concentrations. In boys, concentrations remain in the prepubescent range until Tanner stage

4 by which time they approach adult male concentrations. During the menstrual cycle, Oestradiol rises

slowly during the follicular phase with concentrations correlating with the number and size of developing

follicles. There is a sharp peak of Oestradiol at midcycle accompanied by a high LH and moderately raised

FSH. Concentrations then fall but soon rise again as the corpus luteum develops. At the end of the cycle

Oestradiol concentrations fall reaching low concentrations just before menstruation. In menopausal women

Oestradiol concentrations overlap with those in the normal follicular phase and thus measuring Oestradiol is

not very helpful. The assay is specific for Oestradiol and does not measure Ethinyl Oestradiol. It does

measure the Oestradiol released from Oestradiol patches or implants.

Organic Acids (Urine)

Specimen Type: Random urine (Plain)


Handbook

Osmolality (Serum, Urine)

Specimen Type: 5ml clotted blood (brown or white top) or random urine.

Reference Range: 280 – 300 mOsm/kg (Serum)

Not Applicable (Urine)

Notes: Urine osmolality depends on fluid intake, therefore, a reference range, as such, does not exist. On an

average fluid intake, urine osmolality is normally over 300 mOsm/kg. In clinical practice, the terms

osmolarity and osmolality can be used interchangeably. Strictly, osmolarity is milliosmoles per litre of

solution whereas osmolality, or osmotic pressure, is milliosmoles per kilogram of water.

Calculated Osmolality

Serum osmolality can be calculated reasonably accurately from concentrations of serum components

(provided they are all expressed in mmol/L) using the following formula:

Serum Osmolality = 2 X (Sodium + Potassium) + Glucose + Urea

Urine osmolality can be calculated from the following formula, but the error is greater than for serum:

Urine Osmolality = 2 X (Sodium + Potassium) + Urea – 10

Oxalate (Plasma)


Reference Range: 0 – 10 µmol/L (Plasma)


Reviewed: 07/06/10

Notes: Oxalate assay is only available for patients with primary Hyperoxaluria and is not usually appropriate

in investigation of other patients with renal Calculi.

Oxalate (Urine)

Specimen Type: 24-hour urine (Acid)

Reference Range: 100 – 460 µmol/24 hrs (Urine)

1 – 38 µmol/mmol creatinine (Oxalate/Creatinine)

Notes: Oxalate assay is only available for patients with primary Hyperoxaluria and is not usually appropriate

in investigation of other patients with renal Calculi.

Pancreatic Polypeptide (PP)













Pancreolauryl Test

This test is obsolete and has been replaced by the measurement of Elastase in a small sample of faeces.

Paracetamol


Reference Range: Not Applicable –see Graph overleaf

Notes: The interpretation of the result should be made using the graph (below), which was obtained from the

British National Formulary handbook, and the time of the sample relative to the dose. At 4 hours, after the

ingestion of paracetamol, a serum concentration over 196.4 mg/L is predictive of severe liver damage. At 10

hours, a serum concentration over 71.0 mg/L indicates a similar risk level. Earlier measurements can confirm

that paracetamol was taken but because of the influence of the post-absorption peak, it is not possible to use

the level to infer the amount ingested and hence whether or not treatment is needed. Once a treatment


Reviewed: 07/06/10

decision is made, there is no need for further measurements. There is no need clinically to measure

paracetamol later than 24 hours from the time of ingestion as paracetamol is completely cleared by this time.

At this late stage, only liver and renal function tests are indicated. Patients taking enzyme-inducing drugs,

including alcohol, may develop toxicity at lower concentrations as indicated by the 'high risk' line on the

graph.


Reviewed: 07/06/10


Reviewed: 07/06/10

Paraprotein Studies


Reference Ranges: see Immunoglobulins

Notes: Myeloma bands are detected by electrophoresis. Any abnormal bands found will be typed and

quantified.

Parathyroid Hormone (PTH)


Reference Range: 14 – 72 ng/L

Notes: Request simultaneous calcium assay on clotted sample.

PARC



Reference Range: 10 – 150 ng/ml

Notes : This test is used for monitoring the treatment of patients with Gaucher’s disease.

pH (Arterial Blood)

Specimen Type: Heparinised Blood Gas Syringe

Reference Range: 36 – 45 nmol/L (pH: 7.35 - 7.44)

Notes: Arterial blood pH is measured as part of the blood gas profile and is usually expressed as hydrogen

ion concentration.

pH = -log10[H+]

E.g. if hydrogen ion concentration is 36 nmol/L = 36 x 10-9

mol/L then

pH = -log10(36 x 10-9

) = 7.44

pH (Urine)

Notes: Urine pH is normally measured using a dipstick on the ward. It is important to test it immediately it

has been voided as the pH changes on standing. When an accurate pH is needed, the sample must be rushed

to the laboratory for IMMEDIATE measurement with a pH meter.

Phenobarbitone



Reviewed: 07/06/10

Therapeutic Range: 40 – 170 µmol/L (Adults)

50 – 100 µmol/L (Children)

Notes: The sample should be taken just before the next dose. Half-life (Adults): 96 hours; Time to Steady

State (Adults): 20 days; Half-life (Children): 67 hours; Time to Steady State (Children): 12 days.

Phenytoin


Therapeutic Range: 25 - 70 µmol/L

Notes: The sample should be taken just before the next dose. Half-life (Adults): 13-46 hours; Time to Steady

State (Adults): 14 days

Phytanic acid


Reference Range: 0 – 10 µmol/L (Less than 1 year old)

0 - 15 µmol/L (Older than 1 year old)

Notes: Used in the investigation of suspected Peroxisomal disorders, including Refsum's disease.

Phosphate (Serum) (see BFT)




0 – 30 days 0.90 – 2.26 1.00 – 2.49

31 – 90 days 1.00 – 2.13 1.00 – 2.32

3 – 12 months 1.00 – 2.13 1.00 – 2.20

13 – 24 months 1.00 – 2.00 1.00 – 2.03

2 – 13 years 1.00 – 1.90 1.00 – 1.90

13 – 16 years 1.00 – 1.71 1.00 – 1.78

16 – 18 years 1.00 – 1.65 1.00 – 1.55

> 18 years 0.8 – 1.4 0.8 – 1.4


Phosphate (Urine)


Reference Range: 16 – 32 mmol/24 hr

Porphyrins

Specimen Type: Random plain urine (for screening)

10ml EDTA blood (red tops) (detailed investigation if

screening is positive)

Reference Range: Not Applicable (for screening)

Notes: It is most important that all samples be immediately protected from light: e.g. wrap in dark paper or


Reviewed: 07/06/10

aluminium foil or place in a brown envelope or box. A screening test done on fresh urine or faeces is

adequate for screening and to exclude acute Porphyria in a patient with symptoms. For more extensive

studies and quantification of Porphyrins, samples are sent to a reference laboratory. Please telephone ext.

3151 for further information.

Potassium (Serum) (U&E, E&C)




0 – 1 week 3.2 – 5.7 3.2 – 5.7

1 week – 1month 3.4 – 6.2 3.4 – 6.2

1 – 6 months 3.5 – 5.8 3.5 – 5.8

6 months – 1year 3.5 – 6.3 3.5 – 6.3

> 1 year 3.3 – 4.7 3.3 – 4.7

> 18 years 3.4 – 5.0 3.4 – 5.0


Potassium (Urine)

Specimen Type: Random urine or 24-hour urine in a plain bottle

Reference Range: 20 – 60 mMol/24hrs (on normal Potassium intake).

Notes: Concentrations in random urine are a poor guide to excretion rate and will depend on water excretion

rate.

Primidone



Notes: The sample should be taken just before the next dose. Primidone is partially metabolised to

Phenobarbitone so it may be necessary to measure Phenobarbitone as well. Half-life is 8 hours; time to

steady state 2 days.

Pristanic Acid

Specimen Type: EDTA blood sample (red top)

Reference Range: 0 – 1 µmol/L (Less than 1 year old)

0 – 2 µmol/L (Older than 1 year old)

Notes: Used in the investigation of peroxisomal disorders.

Progesterone


Reference Range: At concentrations between 20 and 80 nmol/L normal

ovulation is probable and it likely to be release of a


Reviewed: 07/06/10

single ovum. At concentrations over 80 nmol/L multiple

ovulation becomes increasingly probable.

Notes: The sample should be taken on day 21 of the menstrual cycle. In the case of longer or shorter cycles,

the sample should be taken 7 days before menstruation

Proinsulin

Specimen Type: Lithium Heparin blood (orange tube) on ice, plus

Fluoride-Oxalate (yellow) tube for glucose; rush to the

laboratory

Reference Range: < 7 pmol/L (Fasting Adults of normal BMI)

Notes: Take the sample when the patient is hypoglycaemic along with insulin analysis for the investigation

of insulinoma.

Prolactin


Reference Ranges: < 375 mU/L (Male)

< 619 mU/L (Female)

Notes: Prolactin is released very readily by minor stress. If the result is raised but below 1000 mU/L it is

most likely to be due to stress and it is recommended to take another sample. Prolactin is also raised in the

following conditions: Primary hypothyroidism: typical concentrations are up to 1200 mU/L, Pregnancy:

concentrations rise early after conception and soon reach concentrations of 1000-3000 mU/L.

Phenothiazines, some antidepressives, Cimetidine: Concentrations can be up to 4000 mU/L. If these

conditions are excluded, prolactin concentrations over 1000 mU/L are more likely to be pathological and

over 2000 mU/L a prolactinoma may be visible in CAT scan.

Protein, Total (Serum)




1 – 60 days 40 – 76 36 – 70

61 – 180 days 40 – 70 40 – 76

181 days – 1 year 42 – 79 46 – 78

1 – 6 years 60 – 80 60 – 78

7 – 9 years 63 – 81 63 – 81

10 – 19 years 64 – 86 64 – 86

> 19 years 63 – 83 63 – 83


Notes: This test is rarely needed in diagnosis and in general, it is better to request albumin and

immunoglobulins separately or, where myeloma is suspected, electrophoresis. It can be useful to measure


Reviewed: 07/06/10

protein in other fluids, the same method is used and only a plain tube is needed. Request "fluid protein" and

fluid.

Protein, Total (Urine)

Specimen Type: 24-hour plain urine

Reference Range: < 0.25 g/24 hr

Notes: There are separate tests for Albumin excretion rate and Albumin/Creatinine ratio, which are used to

monitor 'Microalbuminuria' in diabetics. Similarly, a plain bottle is needed.

Protein, Total (CSF)

Notes: Please refer to CSF Protein.

PSA (Prostate specific Antigen)


Reference Range: This is age-dependent due to the increased likelihood of

benign prostatic hypertrophy with increasing age

Age (Years) Reference Range

(µg/L)

up to 49 up to 2.7

50 - 59 up to 3.9

60 - 69 up to 5.0

Above 69 up to 7.2

Interpretation:

Prostatitis can produce concentrations up to around 40 but the level falls slowly as the Prostatitis improves.

Concentrations up to about 12 are most likely to indicate benign Prostatic Hypertrophy (BPH) but do not

exclude early carcinoma. Concentrations up to about 20 suggest that any carcinoma is early and confined to

the capsule. Concentrations over 20 strongly suggest carcinoma and by a level of 80, widely disseminated

carcinoma is probable.

Notes: Digital rectal examination does not significantly affect PSA concentration.

Pseudocholinesterase & Cholinesterase (Serum)



Notes: Measurements of serum cholinesterase are used to screen for sensitivity to suxamethonium which

may cause ‘scoline apnoea’. It is often useful to follow these measurements by genotyping. To ensure that

this can be done, patients should be consented for molecular genetic studies at the time that the enzyme

measurement is requested. The fact of consent to genetic studies should be recorded in the notes and on the

request. In cases of organophosphorus poisoning, the test used is serum/red cell acetylcholinesterase for

which EDTA whole blood is needed.


Reviewed: 07/06/10

Pyruvate

Notes: Lactate/pyruvate ratio is included in some protocols for the investigation of mitochondrial disorders.

However since a normal lactate/pyruvate ratio does not exclude mitochondrial disease and further

investigation of increased ratios is required to elucidate the type of mitochondrial disease, measurement of

pyruvate is not recommended. For further discussion on the investigation of mitochondrial disorders please

call ext. 57130 or 6172.

Rapamycin






Renin

Specimen Type: 5 ml EDTA whole blood (red top) – NOT on ice

Reference Range: 5.4 – 6.0 mU/L (Upright)

5.4 – 30.0 mU/L (After 1 hours rest)

Patient Preparation

Notes: Sodium intake and posture have marked effects on the Renin-Aldosterone system. Patients should be

on a normal Sodium intake of 100-150 mmol/day. There are two different protocols for measuring renin but

both require measurement of Aldosterone at the same time. For 'initial investigation' the patient must remain

seated quietly for not less than 10 minutes and the sample should be taken without standing up. For more

reliable results, the patient must lie flat in bed overnight and should not get up. A blood sample is then taken

at about 9 am with the patient still lying flat. The patient then stands or walks about for exactly 30 minutes

and a second sample is taken.

Notes: Dependent on posture, volaemic status and salt intake. Beta blockers suppress and ACE inhibitors

increase renin concentrations. Concentrations are much higher in the first few weeks of life and

concentrations then fall rapidly followed by a slower fall with age until adult ranges are reached at about age

6 years.

Reducing Substances in Faeces

Specimen Type: Small, fresh sample of faeces


Notes: Please telephone ext. 3151 for interpretation

Salicylate


Reviewed: 07/06/10


Therapeutic Range: 207 – 276 mg/L (High Dose Therapy)

Notes: A concentration of greater than 497 mmol/L in adults or greater than 304 mg/L in children is an

indication that forced alkaline diuresis should be considered.

There may be delayed absorption of salicylate and in a few patients with significant serum concentrations of

salicylate it may be useful to measure it a second time to establish whether it is rising or falling. If it is

falling, there is no need for further measurements. In high dose aspirin therapy, a value of 276 mg/L should

be reached; tinnitus may be a useful guide to therapy.

SGOT (AST)



Notes: Aspartate aminotransferase analysis is obsolete in modern clinical practice as it is too unspecific,

being present in roughly equal amounts in liver, heart and muscle. As a cardiac enzyme, it is of very low

specificity and sensitivity when compared to the alternatives. Its only use now is for research projects and

drug trials that follow protocols originating in the USA.

SGPT (ALT)



Notes: This enzyme was formerly called Serum Glutamate-Pyruvate Transaminase (SGPT). Its modern name

is Alanine Aminotransferase (ALT). Raised ALT activity is suggestive of hepatocellular damage.

SHBG (Sex Hormone Binding Globulin)


Reference Range: 13 – 71 nmol/L (Males)

18 – 114 nmol/L (Females)

Notes: SHBG is the serum protein that binds both Testosterone and Oestradiol. Measurement of SHBG may

be helpful when serum total Testosterone is borderline as it allows correction for states of high and low

SHBG, which may affect total Testosterone concentrations. It is believed that it is free Testosterone that is

biologically important. Its assay is not indicated when the serum Testosterone is normal nor is it helpful in

men complaining of impotence. SHBG is raised in hyperthyroidism and lowered in hypothyroidism but the

changes are relatively small.

Sirolimus




Reviewed: 07/06/10




Sodium (Serum) (U&E, E&C)


Reference Ranges: 135 – 145 mmol/L

Notes: Sodium can be measured in a variety of fluids. No preservatives are needed. For blood, use a brown

top tube (serum) and for urine and other fluids use a plain bottle.

Sodium (Urine)

Specimen Type: Random or 24 hr Urine (Plain)

Reference Ranges: 50 – 200 mmol/24hr

Notes: Sodium can be measured in a variety of fluids. No preservatives are needed. For blood use a brown

top tube (serum) and for urine and other fluids use a plain bottle.

Solvent Screen

Specimen Type: Lithium Heparin blood (orange top)


Notes: The blood tube must be completely full with no air bubble. Do not use any tube containing a gel (e.g.

brown tube) as the gel contains xylene.

Somatomedin (IGF-1, Insulin-like Growth Factor)

Please refer to IGF - 1

Somatostatin

Specimen Type: as Gastrin









Reviewed: 07/06/10





Steroid Profile

Specimen Type: 24-hr Urine collection (Plain)

Reference Range: Please telephone ext. 3151 for information

Notes: In the case of infants, collect as much urine as possible over a period of time. Ideally, 25 ml is the

minimum acceptable volume if there is to be a chance of getting a diagnostic result. The steroid metabolites

are analysed by GLC and this often enables the nature of an enzyme defect in the steroid pathways to be

determined. However, this is a very expensive and difficult assay so please phone Dr Anthony Norden, ext

6820 to arrange it and do not assume that a result can be obtained on a tiny amount of dilute urine.

Sugars in Faeces - Please See “Reducing Substances in Faeces”.

Sweat Test

Specimen Type: Sweat collected in Wescor Macroduct tube

Reference Range: See interpretation below

Interpretation: > 60 mmol/L: supports diagnosis of cystic fibrosis

40 – 60 mmol/L: suggestive but NOT diagnostic of

cystic fibrosis

< 40 mmol/L: normal, low probability of cystic

fibrosis

Notes: Sweat tests are arranged by the Chest Clinic at Addenbrookes Hospital (telephone ext. 2645)

Tacrolimus






Testosterone


Reference Ranges: 8.0 - 29.0 nmol/L (Adult Males)

Up to 3.0 nmol/L (Adult Females)

See Table below (Infants)


Reviewed: 07/06/10

Notes: In adult males as a group, the average testosterone level declines steadily with age above the age of

50 years but this fall is not seen in all individuals. The female reference range quoted is for women who have

menstrual cycles. In post-menopausal women, concentrations are in the lower part of this range but there is

considerable overlap.

Reference Ranges in infancy and puberty (approximate)

Age Males Females

Median (Range) (nmol/L)

1 day 6.9 (2.1 - 19.8) 1.6 (0.7 - 2.7)

1 week 0.9 (0.5 - 1.7) 0.5 (0.2 - 1.2)

1 - 4 months 6.2 (1.7 - 12.5) 0.2 (0.1 - 0.7)

4 - 12 months 0.2 (0.1 - 1.35) 0.2 (0.1 - 0.7)

1 year to puberty 0.2 (0.1 - 0.7) 0.2 (0.1 - 0.7)

Notes: In infancy, boys have higher testosterone concentrations than girls for about the first 4 months but

after 6 months, concentrations are the same in boys and girls until the start of puberty, but there is

considerable individual variation.

Reference Ranges for testosterone in puberty (approximate)

Puberty Stage Males Females

Median (Range) (nmol/L)

Tanner 1 0.4 (up to 0.8) 0.4 (up to 0.5)

Tanner 2 0.6 (up to 2.4) 0.7 (up to 1.0)

Tanner 3 1.8 (0.5 - 9.7) 1.0 (up to 1.0)

Tanner 4 5.9 (3.6 - 19) 1.7 (0.5 - 2.5)

Tanner 5 12.1 (8.0 - 32) 1.3 (0.5 - 2.5)

Notes: The appearance of pubic and other hair (adrenarche) is more related to adrenal androgens than to

testosterone which is primarily of gonadal origin. Some young men do not reach full adult testosterone

concentrations until their late teens.

Theophylline (Aminophylline)


Therapeutic Range: Refer to Notes below, (usually target < 50 µmol/L) (Adults)

30 – 70 µmol/L (Children)


Reviewed: 07/06/10

Notes: Many patients will respond at concentrations of less than 50 µmol/L. Titrate to clinical response.

Some patients, however, may require concentrations up to, but not more than, 90 µmol/L. The time at which

it is appropriate to begin monitoring serum theophylline concentrations is dependent on the treatment regime

used. If intravenous treatment is used, then monitoring should begin 1 to 2 days after the initiation of

treatment. If oral modified-release tablets are used, then monitoring should commence 5 days following the

initiation of treatment.

Blood specimens should be collected:

• at least 4-6 hours post dose (for oral modified-release tablets)

• 4 to 6 hours after starting infusion (for intravenous Loading Dose)

• at 14 - 20 hours (for intravenous Maintenance Dose)

Average plasma half-life: Neonates 24 hrs; Children 4 hrs; Adults (non-smokers) 9 hrs; Adults (smokers) 4

hrs.

Thiamine (Vitamin B1) and Transketolase


Reference Ranges: Please telephone ext. 3151 if required

Notes: Please telephone the laboratory before taking the sample. In cases of thiamine deficiency, Erythrocyte

Transketolase can be measured, as this enzyme requires thiamine as a cofactor. It is essential to telephone in

advance to arrange this test as the sample has to be transported to a distant laboratory in a taxi.

Thyroglobulin


Reference Range: 0.0 – 1.0 µg/L (Thyroglobulin)

0 – 46 kU/L (Anti-Thyroglobulin Antibodies)

75 – 115 % (Recovery)

Thyroid function tests (TSH, Thyrotrophin)


Reference Range: 0.35 – 5.5 mU/L (TSH)

Note: TSH concentrations are difficult to interpret in the first few days of life due to post-natal TSH surge.

Laboratory Policy on Thyroid Function Tests

All samples where thyroid function is requested will have TSH measured. If the TSH result is outside the

Normal Reference Range (i.e. < 0.35 mU/L or > 5.5 mU/L), or if the patient is under age 15 years, then free

T4 is measured. If there is an indication that the patient may have a condition in which the normal

relationship between TSH and Free T4 is changed, e.g. Pituitary disorder or current active treatment of

Hyperthyroidism, then free T4 is also measured. In suspected Hyperthyroidism with borderline Free T4 and

suppressed TSH, Free T3 may be helpful. In other cases, if TSH is normal, other Thyroid function tests will

not be carried out. However if you believe you need free T4 or free T3 in a particular patient, please call the


Reviewed: 07/06/10

laboratory to discuss your request. Thyroid function screening of ill patients is not recommended, as there is

a significant incidence of falsely low or high TSH due to physiological causes.

Free T3 (Free Triiodothyronine)



Notes: Free T3 is a sensitive and specific test for hyperthyroidism, including relapsing thyrotoxicosis but it is

not sensitive or specific in hypothyroidism. Assay is performed once a week.

Free T4 (Free Thyroxine)



Notes: If TSH is outside the normal reference range, free T4 will be measured automatically. Please contact

the laboratory if you suspect hypopituitarism. Please refer to Laboratory Policy on Thyroid Function Tests

above.

Total Bilirubin (see LFT)




0 – 1 day < 87 < 87

1 – 2 days < 123 < 123

3 – 5 days < 176 < 176

1 month – 18 years < 14 < 14

> 18 years < 17 < 17


Notes: Total bilirubin is part of the LFT profile. Total bilirubin and Conjugated (direct) bilirubin, often

referred to as “Split Bilirubin” is rarely required and must be requested separately.

Total Iron Binding Capacity (TIBC)



Notes: The old 'indirect' measure of TIBC is obsolete. Request either 'iron deficiency studies' or 'iron

overload studies'. Direct measurement of Transferrin is a substitute for TIBC.

TPMT


Reviewed: 07/06/10



Notes: Please do not place on ice or separate, as whole blood is needed. Please telephone ext. 3151 to

arrange. The enzyme is involved in the metabolism of Thiopurines such as Azathioprine. Genetically-

determined variation in concentrations of TPMT occur: Low TPMT can result in toxicity and high TPMT

can result in reduced effectiveness of the drug due to enhanced metabolism.

Transferrin




1 – 30 days 0.86 – 1.74 0.83 – 1.76

31 – 182 days 0.94 – 2.71 1.11 – 2.58

183 – 365 days 1.52 – 2.96 1.26 – 3.03

1 – 3 years 1.67 – 3.04 1.29 – 3.17

4 – 6 years 1.72 – 2.91 1.49 – 3.31

7 – 9 years 1.29 – 2.93 1.59 – 3.05

10 – 12 years 1.15 – 3.16 1.58 – 3.13

13 – 5 years 1.47 – 3.10 1.64 – 3.24

16 – 18 years 1.65 – 2.89 1.54 – 3.44

> 18 years 1.9 – 3.5 1.9 – 3.5


Notes: Transferrin is the serum iron-transport protein. Request either 'Iron deficiency studies' or Iron

overload studies'. Carbohydrate-deficient Transferrin is not available as a marker of alcohol abuse.

Carbohydrate-deficient Transferrin is available to aid diagnosis of inherited abnormalities of protein

glycosylation. Desialylated Transferrin (also known as 'tau-protein') was used to distinguish CSF from serum

or nasal secretions τ-protein. Tau-protein analysis has been superseded by Beta Trace analysis.

Triglycerides


Reference Range: For adults, interpretation of triglycerides and other lipid

results should now follow the NSF guidelines. See for


For adolescents, age related reference ranges apply – see

Table below.


0 – 1 week 0.21 – 1.97 0.29 – 1.80

1 week – 1 month 0.42 – 3.15 0.37 – 3.05

1 month – 3 months 0.47 – 3.15 0.38 – 3.84

1 – 3 years 0.28 – 1.34 0.28 – 1.34


Reviewed: 07/06/10


4 – 6 years 0.34 – 1.24 0.34 – 1.24

7 – 9 years 0.29 – 1.39 0.29 – 1.39

10 – 11 years 0.25 – 1.48 0.42 – 1.51

12 – 13 years 0.25 – 1.56 0.40 – 1.40

14 – 15 years 0.36 – 1.78 0.41 – 1.46

Ghoshal A.K., Soldin S.J. (2003), Clin Chim Acta ; 331: 135- 46.

Notes: A full lipid profile may be more helpful than Triglycerides alone.

Troponin I



Age Range Males (ug/L) Females (ug/L)

0-30 days 0 – 8.4 0 – 8.4

31-90 days 0 – 0.7 0 – 0.7

3-6 months 0 – 0.5 0 – 0.5

7-12 months 0 – 0.3 0 – 0.3

>1 year < 0.1 < 0.1

Ghoshal A.K., Soldin S.J. (2003), Clin Chim Acta ; 331: 135- 46.

Notes: In suspected acute coronary syndrome (ACS), Troponin I is measured on presentation and at 12 hours

post-event. Concentrations up to 0.3 mg/ml may indicate mild myocardial damage. Concentrations > 0.3

mg/ml indicate definite myocardial damage. Troponin I concentrations peak 12 - 18 hours post-event and

remain elevated for 10 - 12 days. (For re-infarction, see Cardiac Enzymes).

Thyroid Stimulating Hormone (TSH)


Reference Range: 0.35 – 5.5 mU/L

Note: TSH concentrations are difficult to interpret in the first few days of life due to post-natal TSH surge.

Urea (Serum) (BUN)



Age Range Males (mmol/l) Females (mmol/l)

0 – 4 days 1.1 – 6.8 1.1 – 6.8

5 days – 2 years 2.1 – 6.1 2.1 – 6.1

3 – 12 years 2.9 – 6.4 2.9 – 6.4

13 – 18 years 3.2 – 7.5 3.2 – 7.5

> 18 years < 7.5 < 7.5

Ghoshal A.K., Soldin S.J. (2003), Clin Chim Acta; 331: 135-46.


Reviewed: 07/06/10

Notes: Urea is requested separately and is not part of the “U&E” profile. Urea concentrations can be raised

by protein intake, including that resulting from an upper gastrointestinal bleed.

Urea (Urine)

Specimen Type: Random or 24-hour Plain Urine

Reference Range: 330 – 500 mmol/24 hours

Uric acid (Serum)




1 – 30 days 0.071 – 0.291 0.077 – 0.369

1 – 3 months 0.077 – 0.315 0.077 – 0.345

4 – 6 months 0.083 – 0.381 0.077 – 0.369

7 – 12 months 0.083 – 0.399 0.083 – 0.3369

1 – 3 years 0.101 – 0.297 0.101 – 0.297

4 – 6 years 0.131 – 0.280 0.131 – 0.280

7 – 9 years 0.113 – 0.297 0.113 – 0.297

10 – 11 years 0.137 – 0.321 0.178 – 0.280

12 – 13 years 0.161 – 0.404 0.178 – 0.345

14 – 15 years 0.143 – 0.470 0.178 – 0.345

16 – 19 years 0.238 – 0.518 0.178 – 0.351

>19 years 0.20 – 0.45 0.15 – 0.35


Uric acid (Urine)

Specimen Type: 24-hour collection in a plain bottle

Reference Range: 3 – 12 mmol/24 hr

Valproate



Notes: Valproate assay is not available to monitor the treatment of Epilepsy, as there is no useful relationship

between serum drug level and therapeutic efficacy. In exceptional cases, assay may be useful to demonstrate

lack of compliance, or, when it is used for other therapeutic purposes. To arrange this please telephone 3151.

Vasopressin

Please contact the laboratory on ext. 3151


Reviewed: 07/06/10

Very Long Chain Fatty acids


Reference Ranges: See Table below

Cn (Units)

< One Year 1 – 10 Years > 10 Years

C22 (µmol/L) 21 – 103 33 – 96 31 – 98

C24 (µmol/L) 22 – 87 25 – 71 24 – 66

C26 (µmol/L) 0.05 – 1.97 0.15 – 0.91 0.15 – 0.91

C24/C22 Ratio (Not Applicable) < 1.15 < 1.01 < 0.96

C26/C22 Ratio (Not Applicable) < 0.028 < 0.026 < 0.022

Notes: Used in the investigation of suspected peroxisomal disorders.

VIP (Vasoactive Intestinal Peptide)













Vitamin A, Vitamin E and Carotenoids

Specimen Type: 5ml clotted blood (white top ONLY) or

5ml plasma (Lithium Heparin - Orange top) or

(EDTA – Red top)

Reference Ranges: 1.0 – 3.0 µmol/L (Vitamin A)

15 – 45 µmol/L (Vitamin E)

14 – 60 µg/L (α-Carotene)

90 – 310 µg/L (β-Carotene)

Notes: Please telephone 3151 to arrange this test. Vitamin A, Vitamin E and Carotenoids form a profile that

are usually assayed together. Protect specimen from light, avoid haemolysis and do NOT collect blood in a

brown top gel tube.


Reviewed: 07/06/10

Thiamine (Vitamin B1)


Reference Ranges: Please telephone ext. 3151 if required

Notes: Please telephone the laboratory before taking the sample. In cases of thiamine deficiency, Erythrocyte

Transketolase can be measured, as this enzyme requires thiamine as a cofactor. It is essential to telephone in

advance to arrange, as samples have to be transported to a distant laboratory by taxi.

Vitamin B12


Reference Range: 211 – 911 ng/L

Vitamin C (Ascorbic Acid)

Specimen Type: 5ml EDTA blood (red top), on ice


Notes: Plasma vitamin C level may be useful but represents recent dietary intake rather than overall vitamin

C status. Low plasma concentrations precede onset of clinical symptoms by many weeks. Please phone in

advance as a special preservative has to be prepared. Specimens must be brought quickly to the laboratory

following collection. Ascorbic Acid analysis is offered on a project basis only.

25-Hydroxy Vitamin D (Vitamin D)


Reference Range: Not Applicable – see Action Limits in table below

!! Note Change of Units !!

Action Limit (nmol/L) Comments

30 – 50 Vitamin D concentration is suboptimal and treatment may be required if

clinically indicated.

15 - 30 Represents moderate Vitamin D deficiency, treatment usually required.

Below 15 Represents severe deficiency, treatment required.

Notes: from 7th

June 2010, there will be a Change of Units and a Change in Methodology.

We are taking this opportunity to change our reported units from ug/L to nmol/L in accordance with a recent

UK directive to harmonize pathology reports. Please beware of this unit change when comparing test results

issued prior to the 7th

June 2010 to results generated after this date.

From the 7th June 2010, the 25OH-Vitamin D method will change from Immunoassay to Mass

Spectrometry. The new method will fully detect 25OHD2 (ergocalciferol), unlike the previous method. In


Reviewed: 07/06/10

patients that are not taking 25OHD2 the results correlate very well; results are directly comparable with the

old method in this patient group. We will be reporting both 25OHD2 and 25OHD3 concentrations.

VMA (Vanillyl Mandelic acid) (Urine)

Specimen Type: 24-hour urine (acid) or Random urine

Reference Ranges: 9 – 40 µmol/24 hours (24- hour collection)

Approximate Reference Ranges (Children, Spot Urine):

Age VMA/Creatinine Ratio

(µmol/mmol creatinine)

HVA/Creatinine Ratio (µmol/mmol

creatinine)

Up to 2 years old 0.0 – 11.8 0.0 – 20.3

2 to 7 years old 0.0 – 8.6 0.0 – 12.3

8 to 15 years old 0.0 – 3.6 0.0 – 5.3

16 years old and over 0.0 – 3.6 0.0 – 4.4

Notes: Urine Catecholamines are a more sensitive test for Phaeochromocytoma. Urine VMA is used for the

investigation of Neuroblastoma in children. VMA/Creatinine ratio can be measured on a shorter collection.

However, shorter collections reduce the sensitivity of the test.

The following drugs are known to cause interferences: MAO inhibitors and others, which reduce

Catecholamine metabolism; drugs which reduce Noradrenaline uptake such as Phenothiazines,

Procholorperazine; Dopamine (though the effect is greater on HVA than VMA) and Methydopa; Beta

blockers especially Labetalol and Sotolol. For detailed information on specimen collection please refer to the

document located on the Intranet site http://connect/media/pdf/l/g/PIN1296_urinecollection_VMA_1.pdf

White Cell Enzymes

Specimen Type: 10 ml EDTA whole blood (red top)

Do NOT put the sample on ice


Notes: A group of enzymes used in the diagnosis of Lysosomal storage diseases. In each case, the

arrangements and sample requirements are the same but the clinical details must be stated so that the correct

enzymes are assayed. It is absolutely essential to arrange the test before the patient arrives as the specimen

has to be transported to a specialist laboratory and processed immediately on arrival. Telephone ext. 57130

to make the arrangements. Assays available include the enzymes for the following Lysosomal disorders:

Aspartylglucosaminuria, Fabry's, Fucosidosis, Gaucher's, GMI-Gangliosidosis, Krabbe, α-Mannosidosis, β-

mannosidosis, Metachromatic Leucodystrophy, Niemann-Pick A and B, Sandhoff's, Schindler's, Sly's, Tay-

Sachs, Wolman's.

Zinc

Specimen Type: 5ml clotted blood (white top ONLY)

Do NOT use a brown top gel tube for zinc.


Reviewed: 07/06/10


Notes: Zinc is bound to Albumin in serum and thus concentrations are affected by changes in Albumin level.

For example, serum Zinc may be slightly low in a severe acute phase reaction due to the low Albumin level,

but this does not mean the patient is Zinc-deficient. Zinc and Magnesium are useful proxies for deficiency of

other trace elements. Only in rare cases is it useful to measure other trace elements directly. To arrange this,

telephone the laboratory on ext. 3151.

Documents

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