Selenium supplementation in patients undergoing hematopoietic stem cell transplantation: effects on pro-inflammatory cytokines levels

Background: Pro-inflammatory cytokines including tumor necrosis factor alpha (TNF-alpha), interleukin-1 beta (IL-1 beta) and interleukin-6 (IL-6) play an important role in the development of hematopoietic stem cell transplantation (HSCT) complications. We explored the effect of Selenium as an antioxidant and anti-inflammatory agent on pro-inflammatory cytokines levels in HSCT candidates. Findings: Plasma concentrations of TNF-alpha, IL-1 beta and IL-6 were measured in 74 patients from a double-blind, randomized, placebo-controlled study. In both groups, there were 37 patients with median age of 32 years. Patients received oral Se tablets (200 mcg) or placebo twice daily beginning from the first day of high dose chemotherapy (HDC) through 14 days after HSCT. Cytokine levels were determined before starting HDC (prior to first dose of Se), 7 and 14 days after HSCT. Plasma levels of TNF-alpha were not significantly different between Se and control group (P = 0.13). IL-1 levels were similar between two groups (P = 0.88). No significant differences were detected in IL-6 levels between Se and control group (P = 0.96). Conclusion: Selenium had no effect on pro-inflammatory cytokines levels in patients undergoing HSCT. It is likely that earlier initiation and/or larger doses of Se are required to affect inflammatory cytokines significantly.