Significance of Antibody Screening and Identification in Pretransfusion Testing-A Retrospective Study

Pretransfusion compatibility testing has gone through many changes. To provide safe blood for transfusion does not merely imply thorough testing for infectious markers, but also protection from haemolytic transfusion reactions resulting from alloimmunization against red cell antigens. Continual efforts to improve blood safety have led to introduction of regular screening protocols for detection of unexpected immune antibodies at the various transfusion centre across the globe. The ultimate goal is to determine the exact specificity of the antibody and to provide blood that lacks the corresponding antigen to the patient4. The frequently detected unexpected Blood cell alloantibodies in daily transfusion practice are directed towards the Rh (D, C, E, c& e) and Kell (K) antigens, followed by other blood group antigens of the Duffy, Kidd, MNS& other minor blood group system5. These unexpected antibodies are responsible for acute and delayed haemolytic transfusion reactions as well as haemolytic disease of foetus and newborn5, 6. To determine the frequency of unexpected red cell antibodies, data of antibody screening from Jan 2014 to Dec 2014 were retrieved from case records at department of transfusion medicine, Sakra world hospital, Bangalore and assessed for the presence of alloantibodies. All cases underwent antibody screening and if found positive were subjected to antibody characterization /identification. All antenatal women and only autoantibodies were also included in the study. Antibody screening was performed using commercial cell panel (ID Diacell of Bio-Rad) by Anti human globulin method. In case of a positive antibody screen, further testing was done using extended cell panel, to precisely characterise the unexpected antibody (ies).