IL17-related gene polymorphisms associated with orbital inflammatory diseases and their clinical features

Autoimmune-associated orbital inflammation refers to the inflammation of orbital tissues resulting from immune system dysregulation. Interleukin-17 (IL-17) plays a critical role in immune defense, tissue repair, inflammation, and tumor progression. Given its immunomodulatory functions, this study aimed to investigate whether single-nucleotide polymorphisms (SNPs) in IL17-related genes contribute to susceptibility and clinical manifestations of orbital autoimmune diseases. A total of 60 patients with orbital autoimmune disease and 60 healthy controls were recruited. Candidate SNPs in IL17A, IL17F, IL17RA, and IL17RC were selected based on known hotspots, including 500 bp upstream and downstream flanking regions. Associations between SNPs and disease status, as well as clinical features such as pain, diplopia, conjunctival inflammation, and eyelid retraction, were analyzed using chi-square or Fisher's exact tests. The analysis revealed that rs9791323 in the promoter region of the IL17A gene was significantly associated with disease susceptibility (p = 0.045) but not with specific clinical features. Other SNPs were found to correlate with distinct symptoms: in IL17A, rs3804513 was associated with pain (p = 0.012); rs3819024 and rs2275913 with diplopia (p = 0.007 and 0.028, respectively); and rs8193036 with both diplopia (p = 0.002) and eyelid retraction (p = 0.033). In IL17F, rs9463772 was associated with pain (p = 0.005), while rs4715290 and rs11465530 were linked to eyelid retraction (p = 0.014 and 0.030, respectively). Three SNPs in IL17RA-rs4819553, rs4819958, and rs4819554-were significantly associated with conjunctival inflammation (p = 0.012). The IL17RC SNP rs708567 was also related to eyelid retraction (p = 0.049). In conclusion, rs9791323 in IL17A may contribute to disease susceptibility, while other IL17-related SNPs appear to influence specific clinical features. These findings highlight the potential role of IL17 gene variants in both the pathogenesis and phenotypic variability of autoimmune-associated orbital inflammation.