Transcript Immunohematology in Patients with Hemoglobinopathies final pt 1

Immunohematology in Patients
with Hemoglobinopathies
Dr. Wendy Lau
Director, 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
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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
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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
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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 typing
Rh E/e DNA Genotyping:
Result Rh E/e
Rh c DNA Genotyping:
Result Rh c
The 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
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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
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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
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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)
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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
– dICA
244/201
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
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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
• RX options presented to parents
dICA: 118/247
– 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)