Kell antigen system

[2][3] The KEL gene encodes a type II transmembrane glycoprotein[4] that is the highly polymorphic Kell blood group antigen.

The Kell glycoprotein links via a single disulfide bond to the XK membrane protein[5] that carries the Kx antigen.

Anti-K can also occur following transplacental hemorrhage associated with childbirth making Kell an important concern for hemolytic disease of the newborn.

Similarly, a pregnant woman may develop antibodies against fetal red blood cells, resulting in destruction, anemia, and hydrops fetalis in a process known as hemolytic disease of the newborn (HDN).

Both AIHA and HDN may be severe when caused by anti-Kell antibodies,[10] as they are the most immunogenic antigens after those of the ABO and Rhesus blood group systems.

The XK appears to be required for proper synthesis or presentation of the Kell antigens on the red blood cell surface.

[15] Evidence supports a genetic link between the Kell blood group (on chromosome 7 q33) and the ability to taste phenylthiocarbamide, or PTC, a bitter-tasting thiourea compound.