Cytokine profile in intermediate uveitis

Abstract

Abstract Purpose Intermediate uveitis (IU) represents a chronic type of uveitis of unknown cause with the vitreous as the major site of the inflammation. The associated diseases include mostly multiple sclerosis (MS) and sarcoidosis, the majority of cases is idiopathic. The aim of this prospective study was to elucidate intraocular and serum cytokine profiles of patients with IU and relate the laboratory results to clinical features. Methods Aqueous humor (AqH) and serum samples were collected from 39 IU patients in various stages of uveitis activity and from 10 controls with cataract and no uveitis during cataract surgery. The concentration of inflammatory mediators was measured by multiplex immunoassay and included interleukin (IL) 8, 1β, 6, 10, 12p70, TNFα, CCL5/RANTES, CCL3/MIP‐1alpha, CCL4/MIP1‐beta, CCL2/MCP1. Results Serum samples of patients and controls were not distinct; however intraocular samples of IU patients had higher levels of interleukin‐6 (IL 6), interleukin‐8 (IL 8) and MCP 1 than non‐uveitis controls (for all P=<0.05). Intraocular IL6 and IL8 levels exceeded that of serum in 22/39 (56%; P= 0.001) and 29/39 (74%; P= < 0.001) respectively. Active intraocular inflammation and the presence of CME were associated with higher levels of IL 6 and IL 8 than intraocular samples from patients with quiescent uveitis (P=<0.05) and those not affected by CME (P=<0.05). No significant associations were found for other measures cytokines. Conclusion IL 6 and IL 8 are two most abundant cytokines in intraocular environment of patients with IU and their levels were associated with IU activity and the presence of CME. The findings of normal serum levels of proinflammatory cytokines in patients do not support the presence of associated systemic inflammation.