Anti-jka antibodies and hemolytic disease of the newborn
The numerous antigens on the surface of red blood cells have been placed into groups.
Many people are familiar with the Rhesus (Rh) group as it is the most clinically relevant.
However the non-Rh groups such as Kell, MNS and Kidd have assumed increasing importance as the incidence of Rh-D sensitization has decreased in the population with the use of Rh gamma globulins preventing an Rh negative mother from developing Rh negative antibodies following the birth of an Rh positive child.
Sensitization to Rh antigens (non-D ) is still responsible for the largest proportion of hemolytic disease in the newborn.
Jka and Jkb antigens:
First reported in 1951 and 1953 respectively.
Anti-Jka and anti-Jkb can both show dosage and are notorious for their evanescence: antibody titres that rise after stimulation but quickly drop, often to undetectable levels.
Kidd system antibodies, (like the well known Rh antibodies) have also been implicated in delayed and immediate Haemolytic Transfusion Reactions and Haemolytic Disease of the Newborn.
The first reported case of hemolytic disease of the newborn (HDN) secondary to anti-Jka was reported by Allen et al in 1951, and the antibody was named after the mother of the affected child, Mrs. Kidd. The newborn had erythroblastosis fetalis, and testing of Mrs. Kidd’s serum identified a previously unknown antibody (Jka) with a titer of 1:64. It was first thought that the cause of hemolysis was due to the additional presence of anti-Kell antibodies. Later, Mrs. Kidd’s son was grouped as Kell antigen negative, leaving the presumed cause of hemolytic disease as anti-Jka antibodies.
- bilirubin levels
- direct and indirect coombs test
- exchange blood transfusion