The rate and control of baseline red cell production in hematologically stable patients with uremia.

It is generally accepted that the anemia of uremia is caused by decreased production of erythropoietin. Nevertheless, the erythropoietin titers are not lower than but equal to or higher than in normal non-anemic individuals. To examine this discrepancy, erythrokinetic studies were made of 22 hematologically stable dialysis patients without clinical or laboratory evidence of extrarenal inflammation, infection, or neoplastic disorders. The red cell life span was normal in 14, and because of stable hematocrits, their daily rate of red cell production had to equal their daily rate of red cell destruction, which could be determined by dividing the red cell mass by red cell life span. These rates were about one half the rates of normal stable individuals, despite the same or higher erythropoietin titers. This suggests that the anemia of uremia is caused in part by a decreased bone marrow response to endogenous erythropoietin.