Evidence that inhibition of erythropoiesis is important in the anemia of chronic renal failure.

Previous studies have documented that serum from patients with chronic renal failure is capable of inhibiting erythropoiesis in vitro. Few data, however, link this finding with the pathophysiology of the anemia of uremia. To study this, we correlated hematocrits from uremic patients with the degree to which serum from these patients inhibited erythropoiesis, using two different in vitro systems. We studied patients receiving hemodialysis and patients with varying degrees of uremia not receiving dialysis and did serial studies on patients in whom long-term hemodialysis was initiated. Study of patients with varying degrees of renal failure showed that levels of inhibitor developed and increased as renal failure worsened and the hematocrit level fell. Finally, we found a fall in inhibitor level in those patients who had an increase in hematocrit after long-term hemodialysis. We interpret these data as evidence that inhibition of erythropoiesis is involved in the anemia of chronic renal failure.