Blocking of antigen caused by Anti-K antibody

Abstract

Hemolytic disease of the fetus and newborn due to anti-K antibodies is rare, but it can cause severe fetal anemia. A correct evaluation of immunohematological tests is important for providing the proper treatment. One of the complications in laboratory determination can be obtaining a false negative result of typing an erythrocyte antigen in a sample of fetal or newborn blood, due to an antibody blocking the antigen. This can be pointed out by the result of a strongly positive direct antiglobulin test and the absence of the antigen corresponding to the identified antibody. This case report describes the situation we encountered when preparing an intrauterine transfusion for a pregnant woman with a Kell positive fetus and anti-K antibody.