Moderate hemolytic disease of the newborn due to anti-Hr0 in a mother with the D--/D-- phenotype
109 Hemolytic disease of the newborn (HDN) due to anti-Hr 0 antibody is typically severe and often fatal. We report a case of moderate HDN due to anti-Hr 0 in a woman with the D--/D--phenotype. A 33-yearold woman delivered her second child who was mildly jaundiced. The highest level of bilirubin was 26.1 mg/dL on the third day postpartum and the hemoglobin concentration was 14.0 g/dL. The newborn recovered after phototherapy and no mental retardation was noticed after 1 year of follow up. An
... of follow up. An exchange transfusion was excluded due to the lack of a compatible donor and the physical condition of the mother precluded blood donation. The maternal RBCs were D+C-c-E-e-; only G and Rh29 of the Rh system were expressed. Thus, her probable phenotype was D--/D--. Her alloantibody was identified as anti-Hr 0 (anti-Rh17) as it reacted with all red blood cells (RBCs) but not her own, other D---RBCs, and Rh null RBCs. The results of the antibody titer (64) and activity in a chemiluminescense test (CLT; 34%) were consistent with a moderate HDN. Family studies were negative for the D--/D--phenotype and consanguinity was not proved. This is the first described case of moderate HDN due to anti-Hr 0 . The result of antibody activity in the CLT might be helpful in predicting the severity of HDN in other rare HDN cases. Immunohematology 2000;16:109-111. Key Words: hemolytic disease of the newborn (HDN), anti-Hr 0 , anti-Rh17, D--/D--phenotype D--/D--is a rare red blood cell (RBC) phenotype that carries the D antigen without C, c, E, and e. Individuals with the D--/D--phenotype may become alloimmunized to Rh system antigens by transfusion or pregnancy. The most common antibody identified in alloimmunized D--/D--mothers is anti-Hr 0 (anti-Rh17), which usually results in hemolytic disease of the newborn (HDN). HDN due to anti-Hr 0 is rare and all published cases were severe. 1-4 We report a case of moderate HDN due to anti-Hr 0 .