Expression of interleukin 1 beta receptors on blast cells in acute myeloblastic leukemia: comparison with interleukin...

We describe here the presence of a single class of interleukin 1 beta (IL-1 beta) receptors on the surface of blast cells freshly obtained from eight acute myeloblastic leukemia patients and one chronic myelocytic leukemia patient in blast crisis. Blast cells possessed a low number of high-affinity receptors (range, less than 10-173 receptors/cell) with a Kd of 1.8-12.8 x 10(-10) M. At the same time, we have investigated the effects of IL-1 on the growth of leukemic blast progenitors, and a significant heterogeneity of responsiveness was observed. IL-1 beta (1 ng/ml) enhanced blast colony formation in six patients. No significant effect was observed by addition of up to 100 ng/ml of IL-1 beta in the remaining three patients. No significant correlation was observed between the receptor number, receptor affinity, and the cellular responsiveness to IL-1; in some acute myeloblastic leukemia cases with apparent IL-1 receptors, no proliferation response to added IL-1 was observed. Our data show that IL-1 alone can enhance blast colony formation and that lack of responsiveness to IL-1 in some acute myeloblastic leukemia patients is not related to the absence of IL-1 receptors on blast cells.