Question

A 50 year old male is seen in his physician’s office for a routine checkup. His spleen shows enlargement and his blood work shows hemolytic anemia with bilirubinemia. His wife states the patient has been “off” lately for no apparent reason. He tends to have muscle pulsations in the afternoon to late evening that do not stop until he goes to sleep. Additional blood work is ordered along with a type and screen. His haptoglobin levels are decreased, and his physician orders two units of packed RBCs. His antibody screen results show he has a weakened expression of Kell antigens. What type of Kell antigens should not be expressed in patients with this diagnosis?

Answer 1

The Kell antigens are a group of antigens on the human red blood cell surface. They are important as they determine the blood type. They are targetted by the autoimmune or alloimune diseases which destroy the red blood cells.

Hemolytic amemia occurs when the body produces an antibody against a blood group antigen on its own red blood cells. These antibodies kill the RBCs resulting in anemia. Kell can be noted as K, k or Kp. The Kell antigens are peptides found within the kell protein which is a zinc dependent endopeptidase which is responsible for cleaving endothelin- 3.

There are 25 types of kell antigen which have been specified. Of these the K antigen is the most clinically significant Kell antigen. So, patients showing the above mentioned diagnosis should not have the the K antigen.