The relationship between interleukin-3-like activity and basophil production in chronic myeloid leukemia patients

Increased basophil proliferation has been reported in patients with chronic myeloid leukemia (CML) both in vivo and in vitro. In this study we have examined the relationship between the release of interleukin-3-like activity (IL-3-LA) by mononuclear cells derived from CML patients and the development of basophils under culture conditions. The results indicate that cells from CML patients produce a high percentage of basophils under the applied experimental conditions. The IL-3-LA in the conditioned medium (CM) of these patients was much lower than that of the controls. Incubation of cells from CML patients with CM containing IL-3-LA resulted in its absorption, whereas cells from control subjects did not absorb the factor. This result may explain the discrepancy between the high basophil production and the low IL-3-LA observed in the CML patients and may indicate that leukemic cells possess receptors for IL-3-LA.