Clinical value of an antibody-dependent cell-mediated cytotoxicity assay in the management of Rh D alloimmunization

OBJECTIVE: The aim of this study was to evaluate the clinical value of an a ntibody-dependent cell-mediated cytotoxicity assay relative to the indirect antiglobulin test titer in the management of Rh D-alloimmunized pregnancie s. STUDY DESIGN: Data from 172 Rh D-alloimmunized pregnancies were analyzed re trospectively. The accuracies of the highest antibody titer and of the high est antibody-dependent cell-mediated cytotoxicity assay result during pregn ancy to predict fetal and neonatal Rh disease, defined as the need for intr auterine (n = 30) or neonatal (n = 37) blood transfusion, respectively, wer e assessed. RESULTS: At different cutoff levels with equal sensitivities the antibody-d ependent cell-mediated cytotoxicity assay consistently showed a higher spec ificity than the antibody titer for the prediction of fetal disease. No dif ference was found between the receiver operating characteristic curves of t he 2 tests for the prediction of neonatal disease. CONCLUSIONS: Selection of patients for referral and invasive testing for Rh D alloimmunization may be improved with the use of an antibody-dependent c ell-mediated cytotoxicity assay.