Diego antigen system

Diego antigen system is a blood group system that consists of 22 antigens. It was first discovered in 1955 by Landsteiner and Levine, who named it after the patient in whom the first antigen was identified. The Diego antigen system is significant in transfusion medicine and population genetics.

History

The Diego antigen system was discovered when a previously unidentified antibody was found in the serum of a patient named Diego. This antibody was reacting against an antigen in the red blood cells of a large proportion of American Indians and people of East Asian descent, but was absent in people of European descent. This antigen was named "Di(a)" and the antibody "anti-Di(a)".

Antigens

The Diego blood group system consists of 22 antigens. The most clinically significant of these are Di(a) and Di(b), which are responsible for hemolytic disease in newborns and transfusion reactions. The other 20 antigens are less common and have less clinical significance.

Genetics

The Diego antigens are encoded by the SLC4A1 gene, which is located on chromosome 17. This gene also encodes the anion exchanger 1 (AE1) protein, which is responsible for the transport of bicarbonate and chloride ions across the red blood cell membrane.

Clinical significance

The Diego antigen system is significant in transfusion medicine, as antibodies to the Diego antigens can cause transfusion reactions. It is also significant in population genetics, as the distribution of the Diego antigens varies between different populations. For example, the Di(a) antigen is found in a high proportion of people of East Asian and American Indian descent, but is rare in people of European descent.

See also

• Blood group system
• Antigen
• Transfusion reaction
• Hemolytic disease of the newborn