The role of Interleukin-17A and Interleukin-17E in multiple myeloma patients

BACKGROUND Tumor growth in multiple myeloma (MM) is regulated by the cytokine networks which are produced by myeloma cells and the microenvironment of the bone marrow. Interleukin-17 (IL-17) is implicated in the increased angiogenesis in the bone marrow of MM. Recent studies reported elevated levels of interleukin 17A (IL-17A) in the sera of patients with advanced stages according to Durie-Salmon classification. MATERIAL/METHODS We compared the concentration of IL-17A and IL-17E in the blood serum of 34 newly diagnosed MM patients with healthy subjects' sera. We also evaluated the concentration of IL-17A and IL-17E in the blood serum of MM patients and the relation to the percentage of plasma cells and other clinical parameters. The concentration of IL-17E and IL-17A of healthy subjects and patients with MM was assessed by enzyme-linked immunosorbent assay (ELISA). RESULTS Our data confirm that IL-17A and IL-17E serum levels were significantly higher in all MM patients and also in patients with advanced stage compared with healthy subjects. We found the correlation between serum levels of IL-17A in MM patients and percentage of plasma cells. Our results also showed that if serum levels of IL-17E were higher in MM patients, the percentage of plasma cells and beta-2-microglobulin levels were lower. CONCLUSIONS The IL-17 family of cytokines may suppress or promote tumor growth. There seems to be some balance between the effects of IL-17A and IL-17E. The role of increased levels of IL-17E needs further investigation to understand its role in the pathobiology of MM.