Kidd Blood Group Genotyping for Thalassemia Patient in Iran

A comparison of serological phenotyping and molecular genotyping for Kell, Kidd, and Duffy antigens in multi-transfused thalassemia patients

BACKGROUND

In multi-transfused thalassemia patients, serological phenotyping fails to test patient's actual blood group antigen profile due to the presence of donor red blood cell (RBC) in the circulation. This limitation of serological tests can be overcome by genotype determination using the polymerase chain reaction (PCR)-based methods. The aim of this study is to compare the serological phenotyping of Kell, Kidd, and Duffy blood group systems with molecular genotyping in the normal blood donors and multi-transfused thalassaemia patients.

MATERIALS AND METHODS

Blood samples from 100 normal blood donors and 50 thalassemia patients were tested using standard serological techniques and PCR-based methods for Kell (K/k), Kidd (Jka/Jkb), and Duffy (Fya/Fyb) blood group systems. The results were compared for concordance.

RESULTS

Genotyping and phenotyping results were 100% concordant for normal blood donors whereas those for thalassemia patients showed 24% discordance. The frequency of alloimmunization in thalassemia patients was 8%. The results of genotyping were used to provide Kell, Kidd, and Duffy matched blood for transfusion therapy to thalassemia patients.

CONCLUSION

The actual antigen profile in multitransfused thalassaemia patients can be reliably determined using genotyping. This would benefit in providing better antigen matched transfusion therapy to such patients hence reducing the rate of alloimmunization.

Comprehensive management of refractory autoimmune hemolytic anemia in pediatric beta-thalassemia major patient: A case report

Introduction

and importance: Autoimmune hemolytic anemia (AIHA) is characterized by the production of antibodies against the red blood cells (RBCs) leading to increased hemolysis. Incidence of AIHA in patients with beta-thalassemia major is 5 of 100 thalassemia patients.

Case presentation

A 15-year-old female patient with refractory AIHA and thalassemia was unresponsive to steroid therapy. In this report, she was treated with cyclosporine and prednisone in addition to leucodepleted packed red cell (PRC). She was successfully got remission during one-year monitoring.

Clinical discussion

Cyclosporine is an immunosuppressive agent that interferes with T-cells activation by inhibiting transcription of cytokines, such as interleukin 2 and interferon-ɣ. Cyclosporine and steroid have synergic effects to prevent antibody production. Nephrotoxicity is one of the most concerning effect in cyclosporine usage, but it rarely develops using doses lower than 5 mg/kgBW/day. In limited resources blood bank with ABO and Rh crossmatch only, leucodepleted PRC transfusion could be an effective way to prevent antibody formation to minor blood group.

Conclusion

Cyclosporine and steroid could be considered for management in refractory AIHA with thalassemia patients. Non-pharmacological therapy such as leucodepleted PRC transfusion and limited donor transfusion could be considered.

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Cyclosporine and steroid may be of benefit in patients with refractory AIHA and beta thalassemia major.

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Leukodepleted PRC transfusion showed protective effect for antibody formation.

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Limited donor transfusion could be beneficial in recurrent transfusion patient.

Blood group genotyping in alloimmunized multi-transfused thalassemia patients from Iran

Objectives

Serological methods may not be reliable for RBC antigen typing, especially in multi‐transfused patients. The blood group systems provoking the most severe transfusion reactions are mainly Rh, Kell, Kidd, and Duffy. We intended to determine the genotype of these blood group system antigens among Iranian alloimmunized thalassemia patients using molecular methods and compare the results with serological phenotyping.

Methods

Two hundred patients participated in this study. Blood group phenotype and genotype were determined using the serological method and PCR‐SSP, respectively. The genotypes of patients with incompatibility between phenotype and genotype were re‐evaluated by RFLP‐PCR and confirmed by DNA sequencing.

Results

Discrepancies between phenotype and genotype results were found in 132 alleles and 83 (41.5%) patients; however, there was complete accordance between the three genotyping methods. Most discrepancies were detected in Rh and Duffy systems with 47 and 45 cases, respectively, and the main discrepancy was in the FY*B/FY*B allele when serologically showed Fy(a+b+). All 39 undetermined phenotypes, due to mixed‐field reactions, were resolved by molecular genotyping.

Conclusion

Molecular genotyping is more reliable compared with the serological method, especially in multi‐transfused patients. Therefore, the addition of blood group genotyping to serological assays can lead to an antigen‐matched transfusion in these patients.