Rh Antigen D (D)

The Rh antigen, specifically the D antigen, is a protein found on the surface of red blood cells. Its presence or absence determines whether an individual is classified as Rh positive or Rh negative. It is clinically significant in transfusion medicine and obstetrics due to its high immunogenicity, leading to hemolytic transfusion reactions and hemolytic disease of the newborn. The precise physiological function of Rh proteins remains unclear but may involve ammonium transport across red cell membranes and maintenance of membrane integrity.

Other names

Rh factorRHD proteinRhD antigen

Anti-D immunoglobulin binds to RhD-positive fetal red blood cells in the maternal circulation, preventing the mother's immune system from recognizing them and producing anti-D antibodies. Blood transfusion interactions involve antigen-antibody reactions that lead to hemolysis.