Interleukin-10 Induces Both Plasma Cell Proliferation and Angiogenesis in Multiple Myeloma

In multiple myeloma the angiogenic process is enhanced by various mediators. Among them interleukin-10 (IL-10), secreted mainly by myeloma-associated macrophages seems to participate in myeloma progression with variable manners. The aim of the study was to measure serum levels of IL-10 in various stages of MM patients and to correlate them with various angiogenic cytokines, such as vascular endothelial growth factor and angiopoietin-2 and with known proliferation parameters, such as serum levels of B-cell activating factor and bone marrow infiltration by myeloma plasma cells, in order to explore their clinical significance. We measured serum levels of the above parameters by ELISA in 54 newly diagnosed MM patients. All of them were higher in MM patients and were increasing in parallel with disease progression. Furthermore, IL-10 correlated positively with both angiogenic cytokines and proliferation markers. This correlation of IL-10 with both angiogenic cytokines and markers of disease activity implicates that they all have an important role in MM pathogenesis and progression.