Recent advances in immunohematology.

Knowledge of the biochemistry and genetics of erythrocyte blood group antigens has been growing rapidly over the past several years. Last year, the molecular basis for the major Rh blood group antigens was delineated. In addition, the genetic and biochemical bases of several other blood group antigens were identified. One of the most interesting matches of blood group antigens to a functional membrane protein was that of the Diego antigens to the erythrocyte anion channel (band 3) protein. In addition, knowledge of the molecular basis of blood group antigens is now leading rapidly to the usefulness of molecular techniques in identifying blood group genotypes and even blood group antibody specificities. This knowledge has also broadened our understanding of the pathogenesis of erythrocyte disorders associated with null blood group phenotypes. The diagnosis and treatment of autoimmune hemolytic anemia has seen slow but steady progress. New techniques appear promising as methods for distinguishing clinically important from benign autoantibodies. The molecular targets for erythrocyte autoantibodies were also largely identified. Treatment of autoimmune hemolytic anemia is also slowly being improved with the use of agents such as intravenous gammaglobulin, danazol, and immunosuppressive agents, all of which have also been important in the treatment of autoimmune thrombocytopenic purpura.