ABSTRACT
Our aim was to investigate the effects of hyaluronan on inflammatory cytokines in the synovial fluid of patients with knee osteoarthritis. The study was single blind, placebo-controlled, and randomized. We administered hyaluronan to 22 patients in the study group and placebo to 19 in the control group. Enzyme-linked immunosorbent assay was used to determine the levels of cytokines. Both HA and placebo caused a significant decrease in interleukin (IL)-6 levels (P=0.0001 and P=0.04, respectively). But it was more significant in the study group. However, IL-8 and tumor necrosis factor alpha (TNF-alpha) levels did not change in either group (P>0.05). The amount of effusion decreased significantly in the study group (P=0.001) but not in the control group (P=0.133). It can be concluded that hyaluronan considerably decreased IL-6 levels, which correlated with clinical improvement, but had no effect on IL-8 and TNF-alpha levels in synovial fluid. However, larger studies with longer follow-up periods are needed to explain the effect of hyaluronan on cytokines.