FETAL PROTEINS AND CHRONIC TREATMENT WITH LOW-DOSE ERYTHROPOIETIN

The potential stimulating effect of erythropoietin on the production o f fetal proteins (FPs) has not been explored in human subjects. Theref ore, the plasma levels of fetal fibrinogen (FF), carcinoembriogenic an tigen (CEA), alpha-fetoprotein (AFP), and fetal hemoglobin (HbF) were measured in 12 uremic hemodialyzed patients before the first administr ation and after 1, 2, and 3 months of low-dose erythropoietin (r-Hu-EP O; 45 U/kg body wt IV, thrice weekly). Such a treatment efficaciously increased total hemoglobin (Hb). CEA and AFP increased from 5.8 +/- 1. 1 ng/ml and 2.9 +/- 0.9 ng/ml to the final value of 43.2 +/- 3.9 ng/ml and 8.7 +/- 1.1 ng/ml, respectively, in the absence of detectable neo plastic diseases. The levels of FF did not change. HbF levels increase d from <3% of Hb to the peak value of 48% at the end of the first mont h; subsequently, a progressive reduction in HbF was observed. Similar changes were detected in the reticulocyte count (RET). A striking corr elation was found between HbF and RET (r = 0.8633, p < 0.0001), indica ting that the increment in HbF was dependent on the erythroid activity . In conclusion, this study evidences broader than expected effects of erythropoietin on the synthesis of FP and suggests that (1) r-Hu-EPO markedly increases HbF in a condition of suppressed bone marrow activi ty, (2) the measurement of the cell proliferation markers CEA and AFP is unreliable during r-Hu-EPO therapy, and (3) the prothrombotic state associated with chronic r-Hu-EPO treatment in patients with uremia ca nnot be attributed to the presence of FF.