[Significance of alloantibodies other than anti-D hemolytic disease of the fetus and newborn (HDF/N)].

OBJECTIVE: Because of immunoprophylaxis, the proportion between HDF/N caused by anti-D and other antibodies have changed. We assessed HDF/N due to non anti-D among women with antibodies detected during a screening programme.

MATERIAL AND METHODS: Blood samples from 507 women with antibodies were examined for Ig class of antibody, specificity, the titer by routine serological tests and for functional activity by chemilumine-scence test (CLT). The father's and fetal/newborn's blood was also examined.

RESULTS: Among 507 women, anti-D was detected in 231 (45.5%), non-anti-D (potentially clinically important) in 106 (21%), and in 170 (33.5%) IgM of various specificity regarded as clinically benign. The first and last group will not be discussed. Among 106 cases with non anti-D in 46 (43%) antibodies reacted with antigens from Rh system (C,c,E,e,G,Rh17), in 35 (33%) with K and k (only 1), and in 25 (24%) with other antigens. Feto-maternal incompatibility was found in 50 cases. HDF/N was diagnosed as: mild (without treatment) in 27 (54%) cases, moderate (phototerapy and/or top-transfusions) in 12 (24%), severe (exchange transfusions) in 4 (8%) and very severe (intrauterine transfusions, oedema and death) in 7 (14%) cases.

CONCLUSIONS: Among 337 women with clinically significant antibodies, in 106 cases, they reacted with a non-D antigen. 37% of mothers had children with HDF/N, including two rare cases due to anti-Rh17 and anti-G. Most had mild/moderate HDF/N, however 22% severe/very severe due to anti-c, -E, -K, two of them died in utero. The CLT results were helpful in prognosing the severity of HDF/N.