Bone Marrow Colony Stimulating Activity in Human Sera. RESULTS OF TWO INDEPENDENT SURVEYS IN BUFFALO AND MELBOURNE*

Abstract

In two independent surveys, 1188 sera from 947 normal persons or patients with various diseases were tested for their capacity to stimulate mouse bone marrow cells to proliferate in vitro and form cell colonies. Ninety‐eight per cent of sera from normal persons had no colony stimulating activity. Colony stimulating activity was detected in sera from 15 to 70 per cent of patients with: (1) leukaemia and allied diseases, particularly in the advanced stages and active phases of the diseases, (2) proliferative diseases of leukopoiesis, and (3) non‐bacterial infections. Regardless of the source of the active serum, all colonies stimulated initially contained granulocytic cells and later contained phagocytic mononuclear cells.