Erythroid colony formation in primary thrombocythaemia: evidence of hypersensitivity to erythropoietin

Abstract

In a group of 14 patients with primary thrombocythemia (PT), the study of erythropoietic colony formation in vitro showed the development of so-called endogenous colonies, namely colonies with no added erythropoietin (Ep), in all but 1 case. In the presence of added Ep, the colony formation increased slightly in the PT group, but the rise in the control group was so pronounced that any statistical difference between the 2 groups disappeared. No endogenous colonies were observed in cases of secondary thrombocytosis. PT apparently is a myeloproliferative disorder and establishes that some erythroid progenitors show the same high sensitivity to Ep as that found in polycythemia vera; in the patients studied, there was no apparent involvement of erythropoiesis.