Studies in polycythemia after kidney transplantation.

Mononuclear cells from peripheral blood of six patients with polycythemia after kidney transplantation were studied in methyl cellulose cultures using fetal calf serum with and without adding erythropoietin. Parallel tests were run with "synthetic medium". The data obtained were compared to those of patients with polycythemia vera and normal subjects. The erythropoietin independent proliferation in synthetic medium typical for polycythemia vera could not be found in patients with renal grafts. However, in the preparations with fetal calf serum without erythropoietin, a formation of erythroid colonies could be detected suggesting an increased sensitivity or proliferation of erythropoietically determined stem cells in patients with transplanted kidneys.