Intraocular interleukin-17 and proinflammatory cytokines in HLA-A-29-associated birdshot chorioretinopathy

Purpose: To determine the levels of 23 immune mediators in paired aqueous humor (AqH) and serum samples from patients with birdshot chorioretinopathy (BSCR). Design: Single-centre case-control study. Methods: A multiplex immunoassay was used to determine the levels of 23 immune mediators (T-cell, proinflammatory, and vascular-active mediators) in paired AqH and serum of 16 BSCR patients. The AqH of 11 age-related cataract controls served as controls. Results: AqH levels of the T-cell mediators interleukin (IL)-2 (P =.044) and IL-17 (P =.039) and proinflammatory mediators IL-1β (P =.032), IL-6 (P =.034), and tumor necrosis factor α (P =.041) were elevated compared with that of age-related cataract controls. The elevated intraocular levels of IL-1β, IL-17, and tumor necrosis factor α in BSCR samples were higher than their concurrent serum levels. A significant positive correlation of intraocular mediators was noted between IL-17 and both IL-2 (r = 0.744; P <.0001) and IL-23 (r = 0.921; P <.0001) and between IL-2 and IL-23 (r = 0.776; P <.0001). AqH levels of vascular-active mediators were not distinct between the groups. Conclusions: BSCR patients have elevated intraocular levels of proinflammatory and T cell-associated cytokines. Our results suggest the novel pathogenic concept that BSCR is an autoimmune inflammatory disease restricted to the eye and associated with elevated IL-17.