Serum interleukin-17 and its relationship to angiogenic factors in multiple myeloma

BackgroundInterleukin-17 (IL-17) is a CD4 T-cell-derived mediator of angiogenesis that stimulates vascular endothelial cell migration and regulates the production of a variety of proangiogenic factors, such as tumor necrosis factor-α (TNF-α) and vascular endothelial cell growth factor (VEGF). Angiogenesis is implicated in the progression of multiple myeloma (MM).MethodsWe measured serum levels of IL-17, TNF-α, and VEGF, as well as microvessel density (MVD) in 40 untreated MM patients.ResultsLevels of IL-17 in the sera of patients with MM were higher than those in matched controls; however, the difference did not reach statistical significance. Serum levels of both TNF-α and VEGF in MM patients were significantly higher than those in controls (p < 0.001 in both instances). Levels of IL-17 in MM patients, both stage II and stage III, were significantly higher than those of stage I patients (p = 0.001 and p < 0.001, respectively). Similarly, higher values of VEGF (p < 0.001), TNF-α (p < 0.001), and MVD (p < 0.035) were associated with advanced disease stage. Serum values of IL-17 in MM patients correlated positively not only with VEGF (Spearman's rho = 0.606) and TNF-α (r = 0.552; p < 0.001 in both instances), but also with MVD (r = 0.385, p = 0.014). In addition, a positive correlation was found between serum values of VEGF and TNF-α (r = 0.657, p < 0.001), MVD and VEGF (r = 0.353, p = 0.026), and between MVD and TNF-α (r = 0.506, p = 0.001) in MM patients.ConclusionThese results suggest that IL-17 plays a role in the promotion of angiogenesis and associated disease progression in MM.