Abstract
Abstract: :
Purpose: Uveitis is one of the late complications of systemic leptospirosis. Our previous study confirmed the aetiology by demonstrating the presence of pathogenic leptospiral DNA in aqueous humor and specific anti–leptospiral antibodies in serum. However, it was not possible to isolate the spirochaete from aqueous humor. The present study is to determine the profile of infiltrating cells and the levels of cytokines in aqueous humor. Methods: Aqueous humor and blood samples were collected from patients with leptospiral uveitis. The infiltrating cells in aqueous humor were characterized using Giemsa staining. Cytometric Bead Array for human inflammatory and Th1/Th2 cytokines was used to identify the cytokines present in aqueous humor and serum. The identified cytokines were quantified by sandwich ELISA. Phacolytic uveitis and age–related cataract patients were included as controls. Results: Predominant infiltrations of neutrophils as well as significant increase in the levels of protein and inflammatory cytokines, IL–6 and IL–8 were observed in aqueous humor of leptospiral uveitis patients. However, none of the key cytokines for Th1/Th2 response were detected. The IL–6 and IL–8 levels were significantly higher in aqueous humor than in the serum samples of the same leptospiral uveitis patients, thereby indicating the local production of these cytokines. Phacolytic uveitis was characterized by a high proportion of "activated" macrophages and increased levels of inflammatory cytokines (IL–6 and IL–8) in aqueous humor. However, none of the above finding were noted in cataract controls. Conclusions: The selective infiltration of neutrophils, the presence of the IL–6, IL–8 and the absence of Th1/Th2 cytokines indicate that leptospiral uveitis is an inflammatory condition, that is not mediated by T–cells. Comparison of these results with studies on animal models suggests that leptospiral uveitis may be endotoxin mediated. However, further analysis is essential to elucidate the role of leptospiral lipopolysaccharide in inducing uveitis.
Keywords: uveitis-clinical/animal model • cytokines/chemokines • aqueous