MONOCYTE MONOLAYER ASSAY AS A PREDICTOR OF SEVERITY OF HEMOLYTIC-DISEASE OF THE FETUS AND NEWBORN

The monocyte monolayer assay (MMA), an in vitro model of in vivo antib ody-mediated red blood cell destruction, was previously reported to pr edict the severity of hemolytic disease of the fetus and newborn accur ately when only Rh antibodies and antigen-positive babies were studied . We studied 33 women whose serum contained antibodies with the potent ial to cause erythroblastosis fetalis; 7 of the 33 women had antibodie s other than Rh. None of the babies of the ten women who had consisten tly negative test results required intrauterine or neonatal transfusio ns. 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 antibo dy titer. Because of the lack of advantage of the MMA as well as the t ime and expense it requires, we cannot recommend the general clinical application of this test at this time.