Blood groups polymorphisms in patients with multiple transfusions and patients with autoimmune hemolytic anemia: implications in immune response and transfusion practice.

Abstract

The knowledge of blood group antigens is essential to transfusional practice, because antibodies against those antigens can be a major problem in the clinic, mainly in the cases of patients with hemoglobinopathies or others diseases that require blood transfusions. Blood group genotyping can contribute significantly in the quality of the phenotyped transfused blood, especially in multi-transfused patients. Based on this one of our goal is establish a specific genotyping protocol for patients with myelodysplasia and autoimmune hemolytic anemia (AIHA), using real time PCR and microarray techniques, with the objective of avoid hemolytic transfusion reactions and red blood cell (RBC) alloimmunization after transfusion. However, the alloimmunization do not occur in all incompatibility cases for all polytransfused patients groups and according with the literature, some polytransfused patients groups are more responders to allogenic transfusions than others. A possible explication to selective answer for these antigens is the genetic predisposition to alloimmunization that can be related with HLA phenotype. So, another goal is to analyze a possible association between HLA-DRB1 and the immune response to a variety of blood group antigens. Based on the difficult of obtain compatible blood to autoimmune hemolytic anemia patients and that the RBC antigen expression can be decreased in the red cell surface of AIHA patients in the active phase of the disease, we have also the objective to determine the blood group antigen expression in those patients to associate the auto-antibody identity to the antigen that was lost or had decreased expression in the red cell membrane.