Plasma erythropoietic activity in patients on chronic dialysis with or without kidneys

[Plasma erythropoietin and hematocrit under the influence of chronic hemodialysis treatment (author's transl)]

Hematocrit and plasma ESF titers were determined at 2 to 3 weeks intervals in 21 patients with chronic renal failure prior to and during a 15-weeks' period following initiation of chronic intermittent hemodialysis. While hematocrits increased from 22 to 27%, plasma ESF titers were found unchanged between 31 and 35 mU/ml. It can be excluded therefore that the improvement of erythropoiesis following initiation of dialysis was in part due to an increase in plasma ESF titers. The increased erythropoiesis observed is probably not dependent on increased ESF production. A 30-fold ESF deficit existed in patients with renal failure prior to the initiation of hemodialysis when compared with 5 patients with aplastic anemia (hematocrit 23%, plasma ESF titer 1115 mU/ml). At one exception ESF titers up to 500 mU/ml were found in dialysed patients only in combination with anemia due to acute bleeding or iron deficiency. ESF production is appropiate to the degree of anemia in patients with proper renal function after kidney transplantation.

Plasma erythropoietin assay in patients with chronic renal failure

Using the post-hypoxic mouse method of assay, values for erythropoietin in the plasma of patients with chronic renal failure were equal to, or greater than, normal values. Results suggest that the source of erythropoietin may be primarily extrarenal. Normal renal tissue, provided in the assay by the intact mouse, is required for activation of the hormone. There still remains to be explained the enhanced erythropoietic response to haemorrhage or hypoxia that can occur in anephric man.