Erythroid progenitors in paroxysmal nocturnal haemoglobinuria

Abstract
In vitro colony formation of bone‐marrow erythroid progenitor cells in patients with paroxysmal nocturnal haemoglobinuria (PNH) was examined. The numbers of early and late erythroid progenitors (BFU‐E and CFU‐E) showed wide variations; two cases out of eight cases of PNH showed decreased erythroid colony formation, but other cases showed normal or rather increased colony formation of BFU‐E and CFU‐E. The number of erythroid progenitors in patients with PNH may be related to the marrow cellularity.