Adverse transfusion reactions means harmful effects of transfusion other than expected proper effect. This may occur since blood transfusion is a sort of transplant of other's blood tissue. Typical acute adverse reaction is a hemolytic reaction due to an incompatible transfusion. It is also well-known the mother may exhibit alloimmunization to antigens on fetal red blood cells (RBC), and the fetus may be affected by maternal antibodies provoked by previous pregnancies, by previous or present allologous blood transfusions, or by the ongoing pregnancy.
We determined immunoglobulin subclasses using elution procedure and direct antiglobulin test for the RBC antibodies obtained from three patients with hemolytic disease of the newborn, and a non-pregnant woman with hemolytic reaction due to the Jra-incompatible transfusion.
The IgG antibodies were identified three subclasses except IgG4. In subjects alloimmunized to RBC, anti-RBC antibody-bearing B lymphocytes can be demonstrated by observing ‘rosettes’. The rosetting could be demonstrated in two of the four women immunized by pregnancy and blood transfusion.