Colton antigen system

{{Short description|Blood antigen system}}

File:Serology interpretation of antibody panel for blood group antigens.jpg. {{further|Blood compatibility testing}}]]

The Colton antigen system (Co) is present on the membranes of red blood cells and in the tubules of the kidneyDenker BM, Smith BL, Kuhajda FP, Agre P. Identification, purification, and partial characterization of a novel Mr 28,000 integral membrane protein from erythrocytes and renal tubules. J Biol Chem 1988;263:15634-15642. {{PMID|3049610}} and helps determine a person's blood type. The Co antigen is found on a protein called aquaporin-1 which is responsible for water homeostasis and urine concentration.King LS, Choi M, Fernandez PC, Cartron JP, Agre P.Defective urinary-concentrating ability due to a complete deficiency of aquaporin-1. N Engl J Med. 2001 Jul 19;345(3):175-9. {{PMID|11463012}}

The Co antigen is important in transfusion medicine. 99.8% of people possess the Co(a) allele. Individuals with Co(b) allele or who are missing the Colton antigen are at risk for a transfusion reaction such as hemolytic anemia or alloimmunization. Antibodies against the Colton antigen may also cause hemolytic disease of the newborn, in which a pregnant woman's body creates antibodies against the blood of her fetus, leading to destruction of the fetal blood cells.Covin RB, Evans KS, Olshock R, Thompson HW. Acute hemolytic transfusion reaction caused by anti-Coa. Immunohematol. 2001 Jun;17(2):45-9. {{PMID|15373591}}