Serum levels of leptin in multiple myeloma patients and its relation to angiogenic and inflammatory cytokines

Background: Leptin, apart from the regulation of food intake, has been implicated in hematopoiesis, the immune response and angiogenesis. Leptin has been found to be decreased in various hematological malignancies. In the present study leptin was measured in multiple myeloma (MM) patients before and after treatment and correlated with other angiogenic molecules and markers of disease activity. Methods: Serum leptin, vascular endothelial growth factor (VEGF), basic fibroblast growth factor (b-FGF), interleukin-1 beta (IL-1beta), beta 2 microglobulin (beta(2)M) and C-reactive protein (CRP) were measured in 62 newly diagnosed MM patients, 22 of whom obtaining disease stabilization after treatment. The same parameters were measured in 20 healthy controls. Disease stage was defined according to the Durie-Salmon criteria. Results: Leptin, VEGF, b-FGF, IL-1beta, and beta(2)M were significantly higher in newly diagnosed MM patients than in controls (p<0.05). VEGF, b-FGF, IL-1beta, beta(2)M, CRP but not leptin increased with advancing stage of disease (p<0.01). All parameters decreased significantly following treatment (p<0.001). Although IL-1beta correlated positively with VEGF, beta(2)M, b-FGF and CRP, leptin did not correlate with any of the measured parameters. Conclusion: Leptin serum levels do not reflect disease severity in MM. However, there seems to be a decrease in leptin following treatment, which may be associated with an alteration in the metabolic state or the chemokine milieu.