Pathogenesis of the anemia of Shay Chloroleukemia

The pathogenesis of anemia of the Shay chloroleukemia (SCL) was studied in rats following SC, IP and IV inoculation of chloroma cells. Little difference in survival was noted regardless of the route of inoculation. A decrease in hamatocrit occurred in all SCL rats during approximately the final 48 hours of the disease; however, the anemia was more severe in SC- and IP-inoculated terminal rats than in SCL rats inoculated IV. A reduction in the numbers of normal cellular elements was noted in the femoral bone marrow of most terminal rats studied which was found to correlate inversely with the leukemic blast cell content of the marrow. No correlation was observed between the erythroblast content of the marrow and the degree of anemia. The number of erythroblasts varied from greatly reduced to normal in terminal SCL rats despite severe anemia. Moreover, the greatest reduction of both normal marrow cellularity and erythroblast numbers was observed in IV inoculated rats which consistently displayed the highest hematocrits in the terminal stage of the disease. Thus, the terminal anemia appears to be due primarily to excessive red cell loss. The decrease in erythroblasts, when observed, was most striking in the orthochromatophilic and polychromatophilic stages of erythroid maturation.