Monocyte Monolayer Assay as a Predictor of Severity of Hemolytic Disease of the Fetus and Newborn

ABSTRACT

The monocyte monolayer assay (MMA), an in vitro model of in vivo antibody-mediated red blood cell destruction, was previously reported to predict the severity of hemolytic disease of the fetus and newborn accurately when only Rh antibodies and antigen-positive babies were studied. We studied 33 women whose serum contained antibodies with the potential to cause erythroblastosis fetalis; 7 of the 33 women had antibodies other than Rh. None of the babies of the ten women who had consistently negative test results required intrauterine or neonatal transfusions. False-positive MMA results were sometimes found when the fetus was antigen negative. Although the predictive value of a negative MMA was 100%, the efficiency of the MMA was no better than that of the antibody titer. Because of the lack of advantage of the MMA as well as the time and expense it requires, we cannot recommend the general clinical application of this test at this time.