Risk for red cell immunization among thalassemic patients

Background Thalassemia major is a common health problem in Egypt. However, limited data are available on the frequency of red blood cell (RBC) alloimmunization and autoimmunization in transfusion-dependent thalassemia patients. Objectives The primary aim of the current study was to determine the prevalence of alloimmunization and autoimmunization in multitransfused thalassemic patients and to assess potential clinical factors associated with RBC antibody formation. Patients and methods Sixty-five multitransfused thalassemic patients (33 male and 32 female; mean age, 9 years; range 2–37 years) who attended Mansoura University Hospital for Children were included in our study. Antibody screening and identification were carried out with the ID card microtyping system and three-cell and 11-cell panels were used (Serascan Diana 3 and Identisera Diana), respectively. Statistical analysis Statistical analysis was performed using excel program (Microsoft Office, 2010) and statistical package for social science program (SPSS Inc., Chicago, Illinois, USA), version 20. Qualitative data were presented as frequency and percentage. The χ² and Fisher exact tests were used to compare groups. Quantitative data were presented as mean and SD or median and range. The Kolmogrov–Smirnov test was used for testing normality. For comparison between two groups, Student’s t-test or the Mann–Whitney (for nonparametric) were used. Logistic regression analysis was applied for the prediction of development of antibodies (P is significant if ≤0.05 at confidence interval 95%). Results Of 65 patients, 15 cases (23.1%) had been alloimmunized. The majority of alloantibodies were directed against the Kell (12.3%) and Rh systems (6.2%). RBC autoantibodies developed in 9.2% of patients. Only 6.2% of patients had simultaneous alloimmunization and autoimmunization. We found a significant association between RBC immunization and age at first transfusion (P=0.02), splenectomy (P 0.001), and presence of alloimmunization and autoimmunization (P=0.022). Conclusion Red cell alloimmunization is an important risk in thalassemia patients. Most alloantibodies were of the anti-K and the anti-Rh type. Extended phenotype matched blood transfusion for Rh and Kell antigens needs to be explored for preventing alloimmunization in thalassemia patients.