Effect of splenectomy on circulating haematopoietic progenitors in myelofibrosis.

The effect of splenectomy on peripheral blood CFU-GM and BFU-E numbers was studied in a patient with myelofibrosis. The numbers of CFU-GM and BFU-E were twice as high in the splenic venous blood as in the peripheral blood. The number of CFU-GM in peripheral blood decreased to 20% and that of BFU-E to 7% of the presplenectomy level at 1 wk after the operation. The progenitor numbers recovered to reach the presplenectomy level within 4-6 w after splenectomy. This effect of splenectomy was different from that seen in 3 patients with Hodgkin's disease, in whom increased numbers of progenitors were observed after a small initial notch.