The prevalence, alloimmunization risk factors, antigenic exposure, and evaluation of antigen‐matched red blood cells for thalassemia transfusions: a 10‐year experience at a tertiary care hospital

Abstract

The prevalence, alloimmunization risk factors, antigenic exposure, and evaluation of antigen-matched red blood cells for thalassemia transfusions: a 10-year experience at a tertiary care hospital BACKGROUND: Hemoglobin E-β 0 thalassemia and homozygous β 0 -thalassemia are the most common chronic transfusion-dependent thalassemias in Thailand. Patients with these conditions can experience clinical complications such as RBC alloimmunization. In this study we aimed to determine the prevalence, alloimmunization risk factors, antigenic exposure, and evaluation of antigen-(C, c, E, e, Mi a ) matched RBC transfusion. STUDY DESIGN AND METHODS: Thalassemia patients were recruited from a tertiary care hospital for 10 years from 2008 to 2017. The medical records of transfusion history were reviewed for red cell phenotype both of patients and donors, number of units transfused, and type of alloantibodies. RESULTS: A total of 383 thalassemia patients were identified (178 males and 205 females). The frequency of RBC alloantibodies was 19.3%. Some patients tested positive for more than one antibody type. Autoantibodies were detected in nine individuals. Anti-E (49 [39.5%]), anti-Mi a (24 [19.4%]), and anti-c (19 [15.3%]) were the most common antibodies detected. A high rate of alloimmunization was found in splenectomized patients. Risk of alloimmunization increased when more total units of blood had been transfused. A trend toward low alloimmunization rates was noted in the antigen-matched RBC group, where 3.5% (5/143) of patients were alloimmunized. Anti-E and anti-Mi a , which may be naturally occurring, were identified in this group.CONCLUSION: Thai patients are more prone to develop antibodies against the Rh and Mi a than to the Kell blood group antigens.

Phenotype frequencies of Rh (C, c, E, e), M, Mia and Kidd blood group systems among ethnic Thai blood donors from the north‐east of Thailand

“…This implies that there are few susceptible M (−) individuals who are at risk of producing anti‐M through incompatible transfusion or pregnancy. In accordance with our previous work, anti‐M is of low frequency in transfused patients, representing 1.60% of all common clinically relevant antibody specificity (Romphruk et al, ). This contrasts with the 10% frequency of positive antibody in pregnant Caucasian women (De Young‐Owens, Kennedy, Rose, Boyle, & O'Shaughnessy, ).…”

“…Anti‐Mi a is the second‐most commonly found alloantibody in Asians but is uncommon in Caucasians. Recently, we found this alloantibody to be common in north‐east Thailand (19.40%) (Romphruk et al, ). The presence of anti‐Mi a is associated with HLA‐DRB1*09 (Chu et al, ), an allele common in our population (7.10%) (Romphruk et al, ).…”

“…In addition, haemoglobin E‐β 0 ‐thalassaemia and homozygous β 0 ‐thalassaemia are the most common chronic transfusion‐dependent thalassaemias in Thailand. The prevalence of alloimmunization in thalassaemia patients at our Blood Transfusion Center has been detected to be 19.3% (Romphruk et al, ). The detection of RBC phenotypes either among patients who required chronic transfusions or donors would be useful to reduce alloimmunization and haemolytic transfusion reactions.…”

“…Finally, our study reports the highest known frequency of CCDEe phenotype (5.40%). The most common alloantibodies in Thai patients are anti‐E (39.50%) and anti‐E combined with anti‐c (25.30%), which are produced in transfused R 1 R 1 patients (Romphruk et al, ). Thus, these alloimmunized patients should receive antigen‐negative blood (E antigen‐ and c antigen‐negative).…”

“…At our Blood Transfusion Center, antigen‐matched RBC programme for thalassaemia patients has been, since 2008, 65.6% of all patients had received Rh (D, C, c, E, e) antigen‐matched and 19.2% received Mi a antigen‐matched RBCs. Based on the outcome after implemented, a trend towards low alloimmunization rates was noted in the antigen‐matched RBC group, where 3.5% of patients were alloimmunized (Romphruk et al, ). Moreover, a phenotype database of blood donors also has been established at our Blood Center which can provide the rare blood type such as Jk(a−b−) and antigen‐negative compatible blood to patients with multiple alloantibodies.…”