Decreased in vivo and in vitro erythropoiesis induced by plasma of ten patients with thymoma, lymphosarcoma, or idiopathic erythroblastopenia.

Abstract

Summary Plasma was collected from 10 patients with severe anemias of a variety of etiologies, and their effect on in vivo erythropoiesis and nucleoprotein and heme synthesis in human bone marrow cultures was studied. The pathological factor in most cases appeared to be immunoglobulin G. Demonstration of the effect of this inhibitor was often dependent upon dilution of plasma to reduce the concentration of erythropoietin or upon its separation from the erythropoietin content of the plasma sample, since the presence of the latter in high concentrations tended to mask the effect of the inhibitor. Plasma (and extracts thereof) collected from patients with lymphomatous disease and thymoma appeared to be a more potent inhibitor of erythropoiesis. An extract of thymoma also displayed potent erythropoietic inhibitory effect. The results appeared to indicate that the effective immunoglobulin damaged erythroblasts much as serum antibodies damage circulatory erythrocytes in autoimmune hemolytic anemia, leading to the clinical picture of erythroblastopenia.