Studies on the Haematopoietic Stem Cells in Primary Myelofibrosis

—In vitro colony forming capacity of the peripheral blood, the spleen, the splenic arterial and venous blood—

Abstract

In vitro colony forming capacity of the peripheral blood, spleens, splenic arterial and venous blood in three patients with primary myelofibrosis (PM) was studied. The culture was carried out according to the method of Robinson and Pike.
Considerable increase of CFU-c was observed in the peripheral blood of all three patients.
Extramedullary haematopoiesis was histologically detectable in the spleens of two splenectomized patients, and numbers of CFU-c were more elevated in the spleens of patients with PM than two patients with stomach cancer.
White blood cells and CFU-c in the splenic venous blood increased more than splenic arterial blood in one patient with PM.
These results suggest that a part of granulocytic stem cells probably proliferates in the spleen and goes out into the circulation.