Evaluation of TNF-α and IL-1β polymorphisms in Taiwan Chinese patients with pterygium

Purpose: Pterygium, a complex disease, is associated with ultraviolet radiation, immunoinflammatory process, genetic factors, and virus infection. Ultraviolet radiation induces secretion of proinflammatory cytokines by the ocular surface epithelium, inflammatory cells in the tear fluid, or both. Among these cytokines, tumour necrosis factor (TNF)α and interleukin (IL)-1β activate pterygium body fibroblasts, resulting in a phenotype capable of expressing various proteinases associated with extracellular matrix remodelling, angiogenesis, and fibroblast proliferation, which are important for pterygium formation and recurrence. The genetic factor was proposed to play a role in pterygium formation, but there were few studies to clarify this proposition. For investigating genetic factors, the association between pterygium and TNF-α and IL-1β polymorphisms is evaluated in this study. Methods: A total of 128 pterygium patients and 103 volunteers without pterygium were enrolled in this study. Polymerase chain reaction-based analysis was used to resolve the TNF-α-308 promoter, IL-1β-511 promoter, IL-1β exon 5, and IL-1 receptor antagonist (IL-1 Ra) polymorphisms. Results: There were no significant differences in the frequency of genotypes and alleles of TNF-α-308 promoter, IL-1β-511 promoter, IL-1β exon 5, and IL-1 Ra polymorphisms between both groups. Conclusions: The correlation between pterygium and TNF-α-308 promoter, IL-1β-511 promoter, IL-1β exon 5, and IL-1 Ra polymorphisms does not exist and those polymorphisms are not useful genetic markers for pterygium susceptibility. Further studies on other polymorphisms or haplotypes of TNF-α and IL-1β are necessary.