Alloimmunization and autoimmunization in transfusion dependent thalassemia major patients: Study on 319 patients

Abstract

Background:The development of anti-red blood cell antibodies (both allo-and autoantibodies) remains a major problem in thalassemia major patients. We studied the frequency of red blood cell (RBC) alloimmunization and autoimmunization among thalassemia patients who received regular transfusions at our center and analyzed the factors, which may be responsible for development of these antibodies.Materials and Methods:The study was carried out on 319 multiply transfused patients with β-thalassemia major registered with thalassemia clinic at our institute. Clinical and transfusion records of all the patients were examined for age of patients, age at initiation of transfusion therapy, total number of blood units transfused, transfusion interval, status of splenectomy or other interventions. Alloantibody screening and identification was done using three cell and 11 cell panel (Diapanel, Bio-rad, Switzerland) respectively. To detect autoantibodies, autocontrol was carried out using polyspecific coombs (IgG + C3d) gel cards.Results:Eighteen patients out of total 319 patients (5.64%) developed alloantibodies and 90 (28.2%) developed autoantibodies. Nine out of 18 patients with alloantibodies also had autoantibodies. Age at first transfusion was significantly higher in alloimmunized than non-immunized patients (P = 0.042). Out of 23 alloantibodies, 52.17% belonged to Rh blood group system (Anti-E = 17%, Anti D = 13%, Anti-C = 13%, Anti-Cw = 9%), 35% belonged to Kell blood group system, 9% of Kidd and 4% of Xg blood group system.Conclusion:Alloimmunization was detected in 5.64% of multitransfused thalassemia patients. Rh and Kell blood group system antibodies accounted for more than 80% of alloantibodies. This study re-emphasizes the need for RBC antigen typing before first transfusion and issue of antigen matched blood (at least for Rh and Kell antigen). Early institution of transfusion therapy after diagnosis is another means of decreasing alloimmunization.

A Study of Irregular Antibodies in 200 Multi - Transfused Patients

“…This finding is supported by some of the earlier studies done by Alick et al, Dhawan et al, Vishinski E et al & Jensen LS et al who have found a strong correlation between the numbers of blood units transfused and alloantibody formation. [11,14,20,22] CONCLUSION: By considering the results of present and other reference Indian studies, blood banks of India should go for universal type and screen policy for finding the prevalence of alloantibodies in general patient and donor population. The indigenous development of local cell panels would be a better option to ensure adequate supplies of reagent red cells and introduction of type and screen policy for all the patients.…”

“…[11,18,19] Anti c was detected in four patients, Anti-D in four, Anti-N in three, anti-C in two and Anti-M, Anti e in one patient each. Anti-c and anti-D (27%) were the most common antibodies in our study, which is comparable to Thakral et al (38.8%).…”

“…(Figure 3) In the present study, there was an absence of anti-Kell antibody in all subjects which was similar to the findings of the study done by Thakral et al while other studies found anti Kell antibodies. [11,13,15,18] This could be due to differences in blood group antigen frequencies in different populations. According to the study on blood donors of the South Gujarat, Kell antigen positivity was found to be 6%.…”

“…[14] Similar results was also found by Dhawan et al (22%cases had dual allo antibodies). [11] Since pre-transfusion antibody screening in patients' samples is not a routine practice in India, these patients might have received antigen mismatched blood leading to formation of multiple alloantibodies.…”

Splenectomy for β-Thalassemia Major in Resource Challenged Settings: Often a Hobson’s Choice!

“…Nevertheless, when annual transfusion requirement rises above 200 ml/kg/y of pure red cells, splenectomy is one of several strategies to reduce the rate of iron-loading [2]. Splenectomy leads to a higher prevalence of autoantibodies [9]. Whether splenectomy has a bearing on the outcome of allogeneic stem-cell transplantation in patients with TM is not well-defined [10].…”