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Presented at Belfast City Hospital Physician's Meeting. Topic - A case of Focal Segmental Glomerulosclerosis with all the complications of nephrotic syndrome and transplant recurrence of FSGS.
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Challenging Nephrotic Syndrome
Dr Richard McCroryST3 Renal Medicine
BCH Physician’s Meeting
Outline
• A patient with a challenging case history • Key clinical features of nephrotic syndrome• Some recent research• Some hope for the patient (at the end!)
Our Challenging Case - Ms LF
19 year old femalePresented January 2005 to Local Hospital3 week history of:
– lower limb swelling to mid thigh– polyuria
GP dipped urine - ++++ protein on dipstick
Lab Results at Presentation
Hb 161 g/LWhite Cells 8.7Platelets 419
Total protein 47 g/L, Albumin 12g/L24 hour Urinary Protein – 5.4 g/24h
Cholesterol 10 mmol/l
140 4.4 7.4103 28 71
Clinical diagnosis – nephrotic syndrome
• Oedema• Hypoalbuminaemia• Proteinuria (> 3.5 g/24hr)
• Frequent associations with nephrotic syndrome– hyperlipidaemia– thromboembolism
Glomerular structure facilitating ultrafiltration
The Glomerular Filtration Barrier
Ronco P. JCI. 2007 117(8):2079-82.
Failure of the Filtration Barrier in Nephrotic Syndrome
Why is there oedema with nephrotic syndrome?
Plasma colloid oncotic pressure↓ Oedema and Intravascular volume↓
Intravascular volume↓® Stimulation of antidiuretic hormone (ADH )
® H2O and Na+ retention® GFR ↓
® Activation of Renin Angiotensin Aldosterone H2O and Na+ retention
H2O and Na+ Retention → Aggravates Oedema
Classifying Nephrotic Syndrome
Diseases with antibody-mediated mechanismse.g., lupus erythematosus, membranous nephropathy
Diseases that are associated with metabolic disorderse.g., diabetes, plasma cell disorders, amyloidosis
Diseases caused by abnormal glomerular cell functione.g. minimal change glomerulonephritis
Differential diagnosis of nephrotic syndrome in an adult1
• Membranous nephropathy• Minimal change disease• Focal segmental glomerulosclerosis (FSGS)• Lupus nephritis• Membranoproliferative nephritis• IgA nephropathy• Amyloidosis
• Adults with nephrotic syndrome need a renal biopsy to establish a diagnosis
1Rivera F, et al. Spanish Registry of Glomerulonephritis.Kidney Int. 2004;66(3):898
Management: Feb-Mar 2005
• oral prednisolone 60mg daily• rash with captopril, switched to candesartan.• initial rapid reduction in proteinuria 5g/24h to 1.6g/24h• serum albumin improved from 12g/L to 36g/L• stable kidney function
Rationale for ACEi / ARB in treating Proteinuric Renal Disease
PAng II
Ang II
An
g I
I
Efferent arteriolar vasoconstriction
Podocyte Injury and Cytoskeleton Remodelling
May 2005
• prednisolone reduced to 60mg alternate days– proteinuria promptly relapsed (>5g/24 hours)– serum albumin fell to 18 g/L
• nephrotic syndrome remitted again with increasing steroid– albumin rose to 33 g/L– but becoming cushingoid– candesartan dose escalated up to 8mg daily and prednisolone reduced– decision made to perform native renal biopsy
June 2005 – Biopsy Report
• ‘The biopsy shows a mild degree of mesangial proliferation…however, it still falls within the category of minimal change disease.’
• ‘There is no evidence of tubular atrophy or acute tubular necrosis. There is no interstitial inflammation or fibrosis.’
Pathological diagnosis – minimal change disease
• No obvious histological features on light microscopy despite clinical problems associated with nephrotic syndrome
Minimal change disease
• Usually idiopathic• Associations with NSAID use and lymphoma
• Management of oedema and proteinuria– Loop diuretics– ACE inhibitor (or ARB)
• Immunosuppression if symptomatic and protracted– Steroids
June 2005 – June 2006
• Unable to get below 17.5mg prednisolone / day without return of hypoalbuminaemia– candesartan increased to 16mg– frank nephrotic syndrome in November
• Eventually...– urinary Protein <1g/24h– no limb oedema for ~4 months
However - August 2006
++++ Protein on DipstickAlbumin 10 g/LCreatinine 84 umol/L
• Thus far 8 relapses of nephrotic syndrome with severe hypoalbuminaemia in 18 months and dependent on steroids...
What next?
Clinical Practice Guideline for GlomerulonephritisPublished June 2012
“Helping clinicians know and better understand the evidence (or lack of evidence) that determines
current practice.”
Guideline 5.2 for Frequently Relapsing/Steroid Dependent MCD
5.2.1: We suggest oral cyclophosphamide 2–2.5 mg/kg/d for 8 weeks. (2C)
5.2.2: We suggest calcineurin inhibitors (CNIs) for FR/SD MCD patients who have relapsed despite cyclophosphamide, or for people who wish to preserve their fertility. (2C)
5.2.3: We suggest MMF 500–1000 mg twice daily for 1–2 years for patients who are intolerant of corticosteroids, cyclophosphamide, and CNIs. (2D)
Treatment Strategy
• Started on cyclophosphamide 100mg daily– Remission within 3 weeks!
• Overlapping therapy with ciclosporin 75mg bd and then cyclophosphamide stopped– One episode of pyelonephritis requiring hospital admission and
associated with AKI – recovered
• ACR fell to 45 mg/mmol in Nov ‘06
Complications of NS - Infection
Nephrotic patients liable to infection because : Loss of immunoglobulin in urine Oedema fluid acts as a culture medium Use of immunosuppressive agents in management Malnutrition / Negative Nitrogen Balance
Recurrent Upper Airways Infection, peritonitis, cellulitis and UTI may be seen.
Organisms: Encapsulated (Pneumococci, Haemophilus Influenzae)Gram negative (e.g. E.coli)
2007 – ‘Annus Horribilis’
13 grams proteinuria
Treatments tried (and failed)• Prednisolone
– Cushingoid– Osteoporotic Bones– Borderline Blood Sugars
• Ciclosporin• Mycophenolate
– Severe GI symptoms on escalating dose
• Diuretics / ACE inhibitors + Angiotensin Blockers– Recurrent Hypovolaemia on trying to increase dose
• Rituximab – Tried as ‘rescue therapy’ in minimal change disease presenting in children– Some evidence of efficacy in small cohorts of adults– Albumin improved from 5g/L to 11 g/L
From Bad to Worse...
April 2009
• Commenced on haemodialysis for management of AKI episode
– Severe hypoalbuminaemia and heavy proteinuria persisted with no response to all treatments
– Declining GFR possibly secondary to hypovolaemia and medication effects
• but progressive chronic kidney disease is not a feature of MCD)
• and remained dialysis dependent 3 months later
Diagnosis Revisited – August 2009
• ‘The biopsy shows well developed focal segmental glomerulosclerosis with complete sclerosis of 4 out of the 10 glomeruli and segmental sclerosis in a further 5. This is associated with a moderate degree of tubular atrophy and interstitial fibrosis. There is also evidence of acute tubular necrosis. Hypertensive vascular changes are also seen.
Focal Segmental Glomerulosclerosis
• On light microscopy the presence in some but not all glomeruli (hence the name focal) of segmental areas of mesangial collapse and sclerosis
Classifications of FSGS: Aetiology
Primary– ‘Idiopathic’
Secondary– Toxins– Genetic Abnormalities (Slit Diaphragm Proteins)– Infections (HIV Associated Nephropathy, Erythrovirus)– Obesity– Heroin Nephropathy– Drug Toxicity (Pamidronate)
Diagnosis revised
• FSGS can be challenging to diagnose (sampling error i.e. in the renal biopsy none of the glomeruli demonstrate sclerosis)
• FSGS may be primary disorder or can occur as a secondary response to nephron loss (as is reflux nephropathy) or previous glomerular injury.
• Differentiating between primary and secondary FSGS is important for therapy
• Primary FSGS may respond to immunosuppression whereas secondary FSGS does not
• Secondary FSGS is best treated with drugs like ACEi that lower the intraglomerular pressure
Progress on Dialysis
Ongoing– Malnutrition secondary to negative nitrogen balance (albumin
<20g/L despite supplements and intra-dialytic nutrition)– Nephrotic Range Proteinuria (>20g/24hours)
March 2010Admitted from dialysis unit with acute shortness of breath. CTPA notes pulmonary arterial filling defects
Complications of NS - Hypercoagulability
1 ↑concentration of I,II, V,VII,VIII,X and fibrinogen2 Urinary losses of regulatory anticoagulant substances: anti-
thrombin III3 Decreased fibrinolysis4 Higher blood viscosity (overaggressive diuresis)5 Increased platelet aggregation
Classic Recognised Complication – Renal Vein Thrombosis
2010 – The Final Straw
Bilateral Nephrectomy
But there’s more...
10/3/2013Received offer for deceased donor renal transplantDonor
– 15 year old male, COD – Intracranial Haemorrhage– Creatinine at retrieval 82 umol/L– Mismatch 1-1-0
Following negative crossmatch → Proceeded to surgery
Post-Operative Creatinine: D0-D6
‘Mischief, thou art afoot...’
• Day 3 Post Transplant– urinary Albumin/Creatinine Ratio
• 500 mg/mmol (≈ 5 g/24h)
First Transplant clinic– diarrhoea and Nausea from anti-rejection drugs– postural Hypotension on examination– polyuric, ++++ protein on dipstick
Laboratory Results
19/3/2013
Albumin 41 g/L
20/3/2013(and 3 litres IV Fluids later)
Albumin 33 g/LUrine ACR back - 500
133 5.6 16.1108 17 130
135 5.8 15.5107 22 141
Primary FSGS – A soluble factor Involved
1980’s• Injecting serum from a patient with recurrent FSGS induced
proteinuria in rats
Recurrent FSGS after Transplantation
• Proteinuria may herald the development of FSGS even if a
biopsy does not show glomerular abnormalities.
• 20–40% risk of FSGS recurrence
• 40–50% with FSGS recurrence lose their grafts
Factors influencing the risk of recurrence of FSGS
Increased RiskChildhood OnsetRapid progression to
uraemia in original disease
Patients with pre-transplant nephrectomy
Living DonorWhite RaceElderly Donor
Reduced RiskFamilial FSGSNon-nephrotic proteinuria
in original diseaseBlack Race
Ponticelli, NDT 2010
Clinical Course Post-Transplant
• 5 sessions of plasma exchange– Clear ‘soluble factor’
• Maximised ACEi early– Stabilise podocytes
• Given 1 dose rituximabSo far...Complete remission of proteinuria, Creatinine
120 umol/L
Resolution of Recurrent Focal Segmental Glomerulosclerosis after Retransplantation
Gallon et al, NEJM 2012
Learning points from this case
• Nephrotic syndrome (a clinical triad of proteinuria, hypoalbuminaemia and oedema)
• Nephrotic syndrome has potentially life threatening consequences (thromboembolism, malnutrition, infection)
• Management is often challenging with inconsistent response to immunosuppression
• If no response to therapy reconsider the original diagnosis (further renal biopsy)
• Primary FSGS has a high risk of recurrence in renal transplant but may respond to plasmapheresis
• The soluble marker causing FSGS remains to be identified