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 antibody-dependent cell-mediated cytotoxicity assay relative to the indirect antiglobulin test titer in the management of Rh D-alloimmunized pregnancies. Study Design: Data from 172 Rh D-alloimmunized pregnancies were analyzed retrospectively. The accuracies of the highest antibody titer and of the highest antibody-dependent cell-mediated cytotoxicity assay result during pregnancy to predict fetal and neonatal Rh disease, defined as the need for intrauterine (n = 30) or neonatal (n = 37) blood transfusion, respectively, were assessed. Results: At different cutoff levels with equal sensitivities the antibody-dependent cell-mediated cytotoxicity assay consistently showed a higher specificity than the antibody titer for the prediction of fetal disease. No difference was found between the receiver operating characteristic curves of the 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 cell-mediated cytotoxicity assay. (Am J Obstet Gynecol 2001;184:1015-20.)