Intraocular cytokine environment in active Behcet uveitis

center dot PURPOSE: To determine cytokine profiles in aqueous humor and peripheral blood from patients with Behcet uveitis. center dot DESIGN: Prospective, experimental, and case-control study. center dot METHODS: Aqueous humor and peripheral blood samples from 24 patients with Behcet uveitis, 28 patients with other causes of endogenous uveitis, and 20 healthy subjects after uncomplicated cataract surgery were obtained. Cytokines (interferon gamma (IFN-gamma), interleukin [IL]-2, IL-4, IL-10, IL-12, IL-15, and tumor necrosis factor alpha (TNF-alpha)) were measured by enzyme-linked immunosorbent assay and compared be tween the uveitis groups. center dot RESULTS: Aqueous interferon gamma (IFN-gamma) levels were higher in patients with Behcet uveitis in contrast to higher concentrations of IL-4 in patients without Behcet uveitis. Aqueous levels of tumor necrosis factor alpha (TNF-alpha) were higher in patients with Behcet uveitis than in patients without Behcet uveitis. Aqueous and serum IL-10 were detected in all patients without Behcet uveitis, but were below detection limits in all patients with Behcet uveitis. Furthermore, IL-15 was exclusively increased in the aqueous humor of Behcet uveitis. The aqueous IL-2 or IL-12 levels were similar regardless of the presence of Behcet uveitis. center dot CONCLUSIONS: Our results showed that an extreme Th1 polarization, a high proinflammatory condition, a low immunosuppressive status, and the presence of natural killer (NK) or CD8(+) T cell-activating cytokine were unique features in aqueous humor with Behcet uveitis, suggesting that different immunopathogenic mechanisms may be involved in the ongoing intraocular inflammation of Behcet uveitis.