Three cases of pregnancies in which the mother had more than one type of antibody capable of causing hemolytic disease of the fetus and newborn (HDFN) have been recently reported in the Indian Journal of Hematology and Blood Transfusion.
Red blood cell (RBC) alloantibodies are antibodies that target antigens not present in the RBCs of the person who carries them but that can be present in the RBCs of other humans. When the immune system of an alloantibody carrier comes into contact with RBCs carrying the targeted antigen, alloantibodies can destroy the RBCs in question, as observed in HDFN.
Alloantibodies targeting the RhD antigen are the most commonly associated with severe HDFN; however, many other antigens in the RBC membrane can also be targeted by alloantibodies. Furthermore, there are instances in which more than one type of alloantibody can be present in the same individual.
“The presence of multiple alloantibodies, especially if one is masking the other, leads to diagnostic dilemma and delay in transfusion therapy of patients,” the authors wrote.
The first case involved a four-day-old baby brought to the emergency room with yellow coloration of the skin; laboratory analysis showed severe anemia and elevated bilirubin. Both the mother and baby were A RhD positive. However, further testing revealed that the mother had both anti-E and anti-alloantibodies. The physicians concluded the anemia was caused by HDFN and administered treatment with significant improvement.
The second case was similar to the first, involving a seven-day-old baby presented to the emergency room due to yellowish coloration of the skin, with further investigations revealing severe anemia and a maternal history of a stillbirth in the first pregnancy. Both mother and baby were O-negative. However, extensive testing revealed the presence of anti-E and anti-S antibodies in the maternal serum, which led to the HDFN diagnosis.
In the third case, the HDFN diagnosis was made through antibody screening during pregnancy; the mother was found to have anti-M and anti-D alloantibodies. The pregnancy was closely monitored, and a healthy baby was delivered
“The above cases highlight the importance of universal antenatal antibody screening despite Rh D status,” the authors wrote. “It is important to look for clinically significant alloantibodies other than anti-D and correctly identify the culprit antibody, especially,when it is masked by the other multiple alloantibodies,”.
