The effect of serum from patients with chronic renal failure on erythroid colony growth in vitro.

Considerable evidence suggests that insufficient EP production and the presence of a toxic factor inhibiting erythropoiesis are two major factors responsible for the production of anemia in patients with CRF. The toxic factor can be detected in a number of tissue culture systems. In order to evaluate its mechanism of action in a proliferation-dependent system, we studied the formation of erythroid colonies in plasma clots containing normal serum and CRF serum, using normal mouse marrow cells as the target organ. Fewer colonies were found in cultures containing uremic serum. This effect was greater as the concentration of serum was increased. No differences were found in the size or morphology of colonies formed. Addition of urea and creatinine to normal sera did not affect their ability to support colony growth. Uremic sera had no effect on white cell colony growth in the plasma clot system. We conclude that materials inhibitory to erythroid proliferation are present in CRF serum.