What Is the Rhesus Factor?

The Rh factor, also known as the Rhesus Factor, is also read as the Rh antigen, because it has the same name as the antigen on the rhesus red blood cells, and was originally discovered in 1940. According to the presence or absence of Rh factors on human blood red blood cells, two types of blood, Rh negative and Rh positive, can be distinguished. This blood group system becomes the Rh blood group system. Its clinical significance is second only to the ABO blood group system. There are six types of antigens in the Rh blood group system, namely C, c, D, d, E, and e. Among them, d antigen has no antiserum, so only five can be detected. Among the six antigens, the D antigen is the strongest and has the highest pathogenicity, accounting for more than 80% of the Rh factors. Therefore, anti-D serum is often used to determine Rh blood type in clinical practice. According to the introduction of relevant data, Rh-positive blood types account for about 99.7% of the Han and most ethnic groups in China, and about 90% for individual ethnic minorities. In some ethnic groups abroad, the Rh-positive blood group is about 85%, of which the Rh-negative blood group is about 15% in European and American Caucasians.