ERYTHROPOIETIN COURSE IN NEWBORNS WITH RH HEMOLYTIC-DISEASE TRANSFUSED AND NOT TRANSFUSED IN-UTERO

This study reports the Hb, erythropoietin (Epo), and reticulocyte cour se at different postnatal ages (range, 8-83 d) of 56 blood samples fro m 30 newborns (range, one or two blood samples from each newborn) with erythroblastosis fetalis (18 intrauterine transfused (IUTd) and 12 no n-IUTd). Hb, Epo, and reticulocyte values were not statistically diffe rent in IUTd and non-IUTd cases. As age increased, decreasing Hb value s and increasing Epo levels were observed. The reticulocyte count was relatively low in all but six cases. There was an inverse correlation between Epo and Hb (r = -55, p < 0.001), but no correlation was found between Hb and reticulocytes or between Epo and reticulocytes. When gr oups were formed on the basis of Hb levels, anemic newborns showed hig her serum Epo than did nonanemic patients (p < 0.02). In the present s tudy we found a significant increase in Epo levels in anemic newborns without a rise in the reticulocyte count. These results suggest that o ther mechanisms, rather than low Epo production, could be involved in the pathogenesis of this anemia. Persisting anti-D antibodies, probabl y at a medullary level, may destroy erythrocyte precursors, leading to anemia with a low reticulocyte count.