Antibody characterization against erythrocytic antigens on hemolytic disease of the newborn (HDN)

Abstract

This study’s goals were: (1) raise incidence and characterize the alloantibodies against erythrocytic antigens, in the serum from 2,126 pregnant women, served at CAISM, in the period from January 2014 to June 2015 and (2) investigate the maternal alloantibodies adherence in fetal red blood cells, in 76 samples from umbilical cord blood. Irregular antibodies in the maternal serum were investigated by the agglutination method in micro gel column, employing previously typed red blood cell panels (Diamed, USA). Maternal alloantibodies were checked in the fetal red blood cells, employing gel columns with polyclonal human antiglobulin and, after elution, by acid glycine or freezing and defrosting; then, their identification was undertaken. Erythrocytic sensitization was observed in 130 (6.1%) pregnant women, but only 85 (4.0%) carried clinically relevant antibodies for HDN. In 91.8% of the relevant cases, the incompatibility in the Rh system was the responsible for generating antibodies, highlighting the anti-D antibody (81.2%). Material antibodies joint to the fetal erythrocytes were observed in 18 (23.7%) cases. In 83.3%, they were directed to the Rh system antigens, exclusively, or associated to the A or B antigens. In 1 (5.6%) case, there was the identification of the anti-Fya antibody, related to the Duffy system. It was possible to conclude that, despite of the immunoprophylaxis, the allosensitization for D antigen is still relevant in our environment. In addition to that, it is necessary, along the pregnancy, to investigate the anti-A and anti-B antibodies, from the IgG class, as well as other systems, such as Duffy, with the purpose of minimize the HDN occurrence.