Anti-Blood Group Kell Antigen antibody [MM0435-12X3]

Supplementary info

Activity summary

The Blood Group Kell Antigen also known as Kell protein is a type II transmembrane glycoprotein with a mass of approximately 93 kDa. It exists on the surface of red blood cells (RBCs) and has enzymatic activity specifically as a zinc endopeptidase. The primary expression site for Kell protein is the erythrocyte membrane where it functions in processing various polypeptides through its enzymatic action. There are different phenotypes like Kell positive and Kell negative and antibodies such as anti-Kell and anti-K are significant in immunohematology.

Biological function summary

The Kell protein facilitates the degradation of endothelin precursors. It belongs to the neprilysin (M13) family of zinc endopeptidases playing a critical part in modulating vasoactive peptides. Normally the Kell protein forms a complex with another protein called XK an integral membrane protein. When properly functioning this Kell-XK complex maintains RBC integrity and membrane flexibility essential for normal cellular operations and lifespan.

Pathways

The Kell antigen influences pathways involved in cardiovascular regulation and cellular movement. It has connections with the vasoregulatory pathway where it interacts with endothelins. The breakdown of endothelin precursors by Kell reduces the levels of these potent vasoconstrictors. The protein also has an indirect association with members of the endothelin-converting enzyme family which further processes these peptides into active forms.

Associated diseases and disorders

The Kell antigen plays an important role in conditions like transfusion reactions and hemolytic disease of the newborn (HDN). In transfusion medicine incompatibility with Kell positive blood can lead to antibody production resulting in hemolytic reactions. Anti-Kell antibodies such as anti-K and anti-Kell are particularly implicated in HDN where the maternal immune response targets the Kell antigen on fetal erythrocytes. The XK protein related to Kell through the disease mechanism is also involved and mutations in XK can cause McLeod syndrome further complicating blood group antigen relationships.