Blood group antigens in health and disease.

PURPOSE OF REVIEW

Blood group antigens are polymorphic, inherited structures located on the surface of the red blood cell. They have long played an important role in identifying matched blood products for transfusion. Recent studies have identified varied and important functions for some of these molecules in cell physiology and human pathology.

RECENT FINDINGS

Many novel functions associated with blood group antigens have recently been identified. These include contributing to erythrocyte membrane structural integrity, transport of molecules through the membrane, and complement regulation as well as acting as adhesion molecules, receptors for extracellular ligands, and enzymes. Importantly, deficiency of these membrane components is associated with certain red cell disorders. Furthermore, as the same components are expressed in a variety of non-erythroid cells, deficiency of these proteins can also result in various other pathologies.

SUMMARY

Novel functions for red cell membrane components carrying blood group antigens are being identified. These findings are providing new molecular insights into the pathophysiology of both red cell disorders as well as various related pathologies in other organ systems.