Effects of sera from patients with malignant lymphomas on granulocytic progenitor cells (CFU-C): Changes after treatment

Serum from normal subjects, under certain methodologic conditions, increases the colony-forming ability of normal bone marrow. Sera from eight patients with malignant lymphoma reduced the colony-forming ability of normal marrow. The results suggest the presence in these patients of a toxic or inhibitory serum factor rather than the absence of a stimulating factor.Longitudinal studies done in four patients show that this activity is difficult to attribute only to the feedback control of granulopoiesis and that other activities associated with the disease probably intervene.When the effect of sera from three patients on their own marrow and on a normal receptor marrow was compared, the reactivity of their granulocytic progenitor cells (CFU-C) was similar to the reactivity of CFU-C in the normal receptor marrow.Finally, the bone-marrow colony-forming ability of the patients studied and the size of their CFU-C compartment were found to be subnormal or reduced. The significance of these findings together with a serum factor that reduces the colony-forming ability of normal receptor marrow is discussed.