Erythropoietin in renal transplant recipients: studies based on recombinant human erythropoietin radioimmunoassay.

In posttransplant patients, modest increases in endogenous EPO induce erythropoiesis similar to that observed in uremic patients who are given large doses of exogenous rHuEPO that generate vastly higher circulating EPO levels. Moreover, once it is initiated, erythropoiesis may be sustained by normal levels of EPO. These observations raise the possibility that the restoration of renal function may alter the EPO-erythropoiesis response pattern. It is also possible that the resolution of uremic anemia is dependent on factors in addition to the level of circulating EPO.