International Society of Blood Transfusion recently recognized thirty-three (33) blood group systems. Apart from ABO and Rhesus system, many other types of antigens have been noticed on the red cell membranes. Blood grouping and cross-matching is one of the few important tests that the anaesthesiologist orders during perioperative period. Therefore, a proper understanding of the blood group system, their clinical significance, typing and cross-matching tests and current perspective are of paramount importance to prevent transfusion-related complications. Nevertheless, the knowledge on blood group system is necessary to approach blood group-linked diseases which are still at the stage of research. This review addresses all these aspects of the blood groups system.
Keywords: ABO blood groups, Rhesus blood group screening., antibody typing, blood group system
