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)