ABO HEMOLYTIC-DISEASE OF THE NEWBORN - RELATIVE DIAGNOSTIC-VALUE OF THE COOMBS AND ELUTION TESTS

A decision to establish early treatment for hemolytic disease in the newborn is usually based upon results of the Coombs test. In order to evaluate a possible advantage of using the Elution test to help in the diagnosis of the hemolytic state, samples of cord blood from 197 consecutive newborns with ABO incompatibility were studied. Hemolysis occurred in 41. Each test (Coombs and Elution) was positive in 26 patients, for a total of 35 positive results and a combined sensitivity of 85%. False positives ocurred in 24 of 156 patients with Coombs test and in 30 for the Elution test. Thus, combined results of both test would have suggested a need for phototherapy in 72 of 197 patients when in fact it was needed for only 41. Conversely, 13 patients with hemolytic disease were missed by both tests. The negative predictive value of both tests combined was 95% which is useful for clinical practice.