PREDICTING THE SEVERITY OF HEMOLYTIC-DISEASE OF THE NEWBORN - AN ASSESSMENT OF THE CLINICAL USEFULNESS OF THE CHEMILUMINESCENCE TEST

The ability of the chemiluminescence test (CLT) to predict the severit y of haemolytic disease of the newborn (HDN) was determined in 80 allo immunized pregnant women who delivered antigen-positive babies, In 54 cases of alloimmunization to D, results from the CLT showed better cor relation with fetal outcome than anti-D concentration measured by Auto Analyzer (r = 0 . 70 and 0 . 36 respectively). Results from the CLT pe rmitted a threshold level of antibody activity (30%) below which 15/20 babies were unaffected or had mild disease, and only one required tra nsfusion therapy in utero. CLT results above 30% were associated with moderate or severe disease in all cases, Results from the AutoAnalyzer proved a less reliable predictor of disease severity; three women wit h anti-D levels > 20 iu/ml delivered unaffected babies, and two women with anti-D levels < 10 iu/ml delivered babies who bad required transf usion in utero, The clinical usefulness of the CLT derives from the po ssibility of avoiding invasive monitoring procedures in women with hig h levels of anti-D which is relatively non-functional.