Interleukin-10 and Gp130 cytokines in human multiple myeloma.

Interleukin (IL)-10 is a critical cytokine involved in the terminal differentiation of B cells into plasma cells. IL-10 is also involved in multiple myeloma, a malignant plasma cell disorder. IL-6 and, more generally the cytokines activating the gp130 IL-6 transducer, are major survival and proliferation factors of myeloma cells. IL-10 is also a growth factor of malignant plasma cells, produced by myeloma cells from about half the patients and is detected in the plasma of patients with plasma cell leukemia or solitary plasmacytoma. The myeloma cell growth activity of IL-10 is mediated through a gp130 cytokine, oncostatin M (OSM), that is frequently produced by myeloma cells. Myeloma cells fail to express OSM receptors but IL-10, by inducing it, confers on them the sensitivity to OSM.