Cytokine Changes in the Aqueous Humor in Rubella-Related Fuchs Heterochromic Iridocyclitis

This retrospective study is aimed at determining the correlation between cytokine levels and virus status in the aqueous humor of 38 patients with Fuchs heterochromic iridocyclitis (FHI) with/without a viral presence between May 2017 and January 2020. The levels of cytokines were analyzed in the groups with and without virus-related FHI. Among the patients, 50% had rubella virus, 5.26% had cytomegalovirus, and 2.63% had herpes simplex virus infections. The expression of interleukin-6 (IL-6) and IL-8 was significantly higher, and that of basic fibroblast growth factor (bFGF) was significantly lower in the virus-positive group than in the virus-negative group (P = 0.015, P = 0.001, and P = 0.001, respectively). Although there was no significant difference in the mean expression of vascular cell adhesion protein 1 (VCAM-1), IL-10, and vascular endothelial growth factor (VEGF), that of VCAM-1 and IL-10 was higher (M = 1338 and M = 1390, respectively; M = 6.225 and 10.600, respectively) and that of VEGF was lower (M = 134.5 and M = 38.70, respectively) in the virus-positive group than in the virus-negative group. Similar findings were observed for the expressions of IL-6, IL-8, and bFGF in the rubella-positive and rubella-negative groups. Viral presence was highly related to FHI, especially that of the rubella virus. High levels of inflammatory cytokines and low levels of neovascularization-related factors are involved in rubella-related FHI. These study findings could be helpful in the diagnosis and treatment of FHI.