Immunohematology in Patients with Hemoglobinopathies Dr. Wendy Lau Director, Transfusion Medicine,...

Immunohematology in Patients with Hemoglobinopathies

Dr. Wendy LauDirector, Transfusion Medicine,The Hospital for Sick Children,

Associate Medical Director,Canadian Blood Services Central Ontario Region,

Toronto, Ontario, Canada

Objectives

• Three case studies• Present antibody investigation results in

hemoglobinopathy patients• Discuss the challenges of finding compatible

blood in hemoglobinopathy patients with antibodies

• Review lessons learned in unusual cases

Case # 1

• Male born in 1997 in Pakistan• Diagnosed thalassemia major aged 6 mo• Red cell transfusion- monthly with no iron

chelation therapy• Emigrated to Canada in 2001

• Splenomegaly• Anti- HCV Ab +ve Normal LFTs• Rx. RBC transfusion to maintain Hb 90 g/L• Deferoxamine SC 45 mg/kg/day X 7/7• Hep B vaccination

Case # 1

• After 6 mo of deferoxamine• Liver iron content (biopsy) 21.1 11.4 mg Fe/g dry wt• HLA-typing: sibling match identified

• Age 6 years• Plans for BMT• RBC transfusions 2-3 wkly ? Alloantibody• GI consult: HCV RNA +ve genotype 3A Normal LFT

• Age 7 years• ALT 227 AST 110• Liver biopsy: mild focal siderosis + portal fibrosis• Liver enzymes settled

Case # 1 (Immunohematology)

• Age 4 years– Another academic centre: anti-K, anti-Jka

• Age 5 years– Came to Sick Kids– Transfused monthly, K neg Jka neg units

compatible• Age 7 years

– DAT +ve, eluate non-specific, K neg Jka neg units incompatible

– Panel: pan-reactive, auto positive, unable to rule out additional antibodies

– Sent to CBS for further testing

Autoantibody investigations

• Autoantibody may or may not case immune hemolysis

• Children who have not been previously transfused and who have not been pregnant, extensive investigation not necessary

• Acute WAIHA- transfuse small amount and slowly

• Multiply transfuse patients- investigate for alloantibody

Autoantibodies

• Warm-Reactive Autoantibodies– Simple Rh antibodies– Antibodies to common RhD and Rh CE determinants– Antibodies to non-Rh high-prevalence antigens– Antibodies to non-Rh polymorphic gene products (e.g.

N, K, Jka)• Cold-Reactive Antoantibodies

– Most are clinically benign– Anti-I: Mycoplasma pneumonia– Anti-i: infectious mononucleosis– Anti-P (biphasic Donath-Landsteiner antibody):

Paroxysmal Cold Hemoglobinuria (PCH)

Adsorption studies

• Autoadsorption– Cold autoadsorption– Warm autoadsorpion

• Alloadsorption– R1R1, R2R2, rr cells

– Jk(a+b-), Jk(a-b+)– Limitation: antibodies to high prevalence

antigens also adsorbed

Case # 1 (Immunohematology)

– Multiply transfused: no phenotype, not autoadsorption, need alloadsorption

Case # 1 (Immunohematology)• Phenotype unknown: What antibodies can he make?

– Molecular typingRh E/e DNA Genotyping: Result Rh E/eRh c DNA Genotyping: Result Rh cThe patient was tested for the RhE. Rhe, and Rhc alleles. The results

indicate that the patient’s genotype is RhE positive, Rhe positive and Rhc positive.

• Family studies– Mom: C+E-c-e+– Dad: C+E+c+e+– Patient: C+– Transfusion continued with K neg, Jka neg units

Case # 1

• Age 10 years• Rx HCV infection: PEG-IFN & Ribavirin x 24 wks• Complications: hemolytic anemia, neutropenia• Blood bank: Autoantibody + alloantibody• RBC transfusions: every 10-14 days

• 3 months into anti-HCV therapy• Severe IFN/Ribavirin –induced hemolysis Hb 49 g/L• IFN/Ribavirin discontinued• PEG-IFN monotherapy restarted

Case # 1 (Immunohematology)

• Panel pan-reactive

Case # 1

• 4 months anti-HCV therapy• HCV PCR- Neg• IFN stopped• RBC transfusion requirements 2.5- 3 weekly• Liver iron content (MRI) 15 mg Fe/g (ferritin 2220)• Deferoxamine switched to deferasirox (oral chelator)

• Age 11 years• RBC transfusions 3 weekly• Liver iron content (MRI) 5.3 mg Fe/g Ferritin 1300• Liver biopsy: mild fibrosis (0 - 1+)

Case # 1

• Age 11 years– Sibling-donor BMT Bu/Cy/ATG conditioning– Complications: ALT 750, hemorrhagic cystitis– HCV PCR- neg– Engraftment 4 weeks– Blood bank:

• DAT pos (anti-C3D and anti-IgG)• Ab screen- Jk(a)• DAT negative at discharge post- BMT

Case # 1 (update)

• Almost one year post-BMT

• No transfusions for 10 months

• Hb 105

• Ferritin 1419

• Plan: Therapeutic phlebotomy

Case # 2• Male born in 2003 in Nigeria

• Diagnosed SCD aged 7 mo• Recurrent painful VOC• No RBC transfusion

• Age 2 years• Emigrated to Canada• Transcranial Doppler (TCD) velocities:

– MCA 244/201– dICA 110/210

• Brain MRI: T2 hyperintense area in Lt parietal, no restricted diffusion

• Parents resisted prescribed chronic RBC transfusion therapy

Case # 2

• Age 4 years• TCD MCA 201/187• Sleep study: obstructive sleep apnea• Underwent tonsillectomy & adenoidectomy• Pre-operative RBC transfusion (first)

– Blood Gp A POS Ab screen- NEG

• Age 5 years• TCD MCA: 217/173 dICA:

118/247• RX options presented to parents

– Chronic RBC transfusions to keep Hb S < 30% (preferred)– Hydroxyurea therapy

Case # 2

• Transfusion history– April 08

• transfusion # 2 Ab screen: Anti-S DAT neg– May 08

• DAT- pos anti- C3D pos anti-IgG neg• DAT- neg in June 08

– Aug 08• Ab screen : anti-S, anti-Jk(b), unidentified Ab (?autoAb)

– Dec 08• Anti-S, anti-Jk(b)

Case # 2 (Nov 2008)

Case # 2 (Nov 2008)

Case # 2 (Feb 2009)

Case # 2 (Feb 2009)

HTLA

• High-titre, low avidity (low antigen) antibodies• Serologically difficult antibodies with Limited

Clinical Significance (nuisance antibodies)• Knops antibodies, anti-Csa (Cost-Stirling),

anti-Yka (York), anti-Chido/Rodgers, anti-Yta (Cartwright), anti-JMH (John Milton Hagen)

• Ch and Rg antigens: polymorphisms in C4 (complement), in vitro neutralization, anaphylactic reactions from plasma products and platelets

• anti-Yta: may be clinically significant

Case # 2 (Feb 2009)

Case # 2 (Mar 2009)

Case # 2 (June 2009)

Case # 2 (Aug 2009)

Case # 2 (Sept 2009)

Case # 2 (Nov 2009)