Serum levels of interleukin-15 and interleukin-10 and their correlation with proliferating cell nuclear antigen in multiple myeloma.

In order to determine prognostic factors characterizing multiple myeloma (MM) cell kinetics, bone marrow proliferative activity and serum Interleukin-10 (IL-10), and Interleukin-15 (IL-15) levels were measured in 40 newly diagnosed MM patients, compared with 10-age and sex-matched-healthy controls. Cell proliferation was evaluated by employing a monoclonal antibody directed against the proliferating cell nuclear antigen (PCNA), whereas IL-10 and IL-15 were measured with quantitative sandwich enzyme immunoassay methods. IL-15, IL-10 and PCNA were higher in the patient group than in controls (P<0.001). IL-10 levels, and PCNA increased significantly with increasing Durie-Salmon disease stage (I-III, P<0.002, and P=0.001, respectively). Serum IL-15 levels in MM stage III patients were elevated in comparison with stages I and II, the difference however, did not reach statistical significance. There was a significant positive correlation between serum IL-15 and IL-10 levels (r: 0.372, P<0.01), and between serum IL-10 and PCNA (r: 0.608, P<0.0001), as well as a positive correlation of serum IL-15 with PCNA, which marginally failed to reach statistical significance. Serum IL-15 levels are elevated in MM patients, increase with advancing stage, and correlate with Il-10 and PCNA. These proliferative factors may be useful in assessing disease progression in MM.