Inactivation of Kell blood group antigens by 2-aminoethylisothiouronium bromide.

Human red cells incubated with a solution containing 6% 2-aminoethylisothiouronium bromide (AET) lose activity of antigens that are part of, or related to, the Kell blood group system. However, Kx antigen is not inactivated. Studies on a wide range of other blood-group antigens show no other evidence of changes and AET appears to react specifically with red-cell membrane structures that have Kell activity. The AET procedure produces an artificial K0 red cell that can be used in blood group serology, and allows easy recognition of antibodies that are associated with the Kell system. AET has been used by other workers to produce a red cell that has many serological and biochemical characteristics of a PNH cell. Our studies on red cells from PNH patients have not shown any changes in Kell blood-group antigens.