Intraocular Interleukin-17 and Proinflammatory Cytokines in HLA-A29–Associated Birdshot Chorioretinopathy

Abstract

To determine the levels of 23 immune mediators in paired aqueous humor (AqH) and serum samples from patients with birdshot chorioretinopathy (BSCR). Single-centre case-control study. 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. 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. 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.