Alloimmunization to Red Cells and the Association of Alloantibodies Formation with Splenectomy Among Transfusion-Dependent β-Thalassemia Major/HbE Patients

Abstract

Severe hemolytic anemia in b-thalassemia major and b-thalassemias/HbE (b-TM) patients requires giving blood transfusions. Chronic blood transfusions lead to iron overload consequence with organs damage and risk of alloantibody-formation. This study evaluates the prevalence of red cell alloimmunization and estimates the risk of alloantibody-formation in chronic transfusion-dependent b-TM patients. This cross sectional study was conducted on 143 b-TM patients receiving regular transfusions. We tried to determine the frequency, types and factors influencing red cell alloimmunization in these transfusiondependent b-TM patients. Median age of 25 (17.5 %) alloantibody-formation b-TM patients was 19.0 years (inter quartile 15.5-24.0 years). The alloantibodies were Anti-Rh (E) (13.1 %), Anti-Rh (D) (0.7 %). Thirty-four patients (23.8 %) of the sample had splenectomies of which 10 (29.4 %) had alloantibody-formation. The interval from first transfusion to antibody development varied from 1.5 to 14 years. Alloantibody-formation correlated with splenectomy and splenectomy correlated with number of transfusion (p \ 0.005). In multiple logistic regression used to estimate the risk of alloantibodies formation with splenectomy; OR and 95 % CI were 2.88 (1.07-7.80), p = 0.037 after adjusting for other co-variates. The rate of red cell alloimmunization was 17.5 % and splenectomy associated with increased alloantibody-formation in these transfusion-dependent b-TM patients.

Comparison of deferasirox and deferoxamine effects on iron overload and immunological changes in patients with blood transfusion-dependent β-thalassemia

“…Moreover, beta-thalassemia major and intermedia are associated with several immunological disorders due to defect in phagocytosis, opsonization, lymphocyte functions, and immunoglobulin levels;[ 13 ] these changes were linked to the iron overload, splenectomy, and recurrent exposure to the foreign antigens through repeated blood transfusion. [ 14 ]…”

Alloimmunization against Rh and Kell blood groups antigens is the main obstacle for blood transfusion in transfusion dependent thalassemia patients in Iran

“…Similar to Iran the most common antibodies against transfused red blood cells were anti-Rh and anti-Kell antibodies in other countries [14][15][16][17][18][19][20][21][22]. The rate of alloimmunization varies between these countries from ~4% in India and Pakistan to ~75% in Kuwait [16,21,22].…”

“…Similar to Iran, conventional tube method is the most commonly used method for antibody detection and identification in other countries [23][24][25][26]. Although as low as 0.7% of autoantibody was reported in other countries, most studies reported a significantly higher incidence of autoimmunization in other countries [18,[22][23][24][25]. In Kell blood group system, the most commonly alloantibodies directed against K antigen [14,[18][19][20].…”

“…Although as low as 0.7% of autoantibody was reported in other countries, most studies reported a significantly higher incidence of autoimmunization in other countries [18,[22][23][24][25]. In Kell blood group system, the most commonly alloantibodies directed against K antigen [14,[18][19][20]. In Rh blood group system, majority of antibody directed against D, E and C antigens (Table 3).…”

Alloimmunization in thalassemia patients

“…Nevertheless, the high rate of alloimmunization among the patients is still observed. [2] The problem might be due to the limitation of the availability of minor blood group matching feasibility among small blood banks in remote areas where many thalassemia patients live. According to a recent report by Jansuwan et al ., it was found that “splenectomy is associated with increased alloantibody formation.”[2] It might be an additional clue that there is a requirement for special minor blood group matching for the thalassemia patients with postsplenectomy status.…”