Significant of Molecular Genotyping over Serological Phenotyping Techniques in Determination of Blood Group Systems among Multiple Transfused Patients and Blood Donors to Prevent Alloimmunization - Abstract
Erythrocyte serological phenotyping is very important in determining the identity of suspected alloantibodies and also to facilitate the identification of antibodies that may be formed in the future. Serological phenotyping is a conventional method which is based on the presence of visible haemagglutination or haemolysis. This technique has some limitations in successful determination oblood group due to presence of donor red blood cell in the circulation of recent multiple transfused patients, taking certain medications or some diseases condition which may alter the erythrocyte composition, this make accurate determination of blood group of such patients to be time consuming and difficult to interpret. It is often more complicated to determine the blood group, if direct antiglobulin test of such patients were positive and there is no direct agglutinating antibody. Molecular Genotyping of blood group systems led to the understanding of the molecular basis of many blood group antigens, many blood group polymorphisms are associated with a single point mutation in the gene encoding of protein carrying the blood group antigen. This knowledge allows the use of molecular testing to predict the blood group antigen profile of an individual and to overcome the limitations of conventional serological blood group phenotyping. Determination of blood group polymorphism at the genomic level facilitates the resolution of clinical problems that cannot be addressed by serological techniques. Applications of blood group genotyping for red cell
blood group antigens affecting several areas of medicine which includes identification of fetuses at risk for haemolytic disease of the newborn and candidates for Rh-immune-globulin, to determine antigen types for which currently available antibodies are weakly reactive, to determine blood group of patients who had recent multiple transfusion, to increase the reliability of repositories of antigen negative RBCs for transfusion, to select appropriate donor for bone marrow transplantation, to provide transfusion support for highly alloimmunized patients, to resolve ABO and Rh discrepancies, to confirm sub group of A2 status of kidney donors, to provide comprehensive typing for patients with haematological diseases requiring chronic transfusion and oncology patients receiving monoclonal antibody therapies that interfere with pretransfusion testing.