Background: Juvenile idiopathic arthritis is the most common chronic rheumatic disease of childhood, with a significant genetic component. Polymorphisms in proinflammatory cytokine genes are potential contributors to disease susceptibility. The aim of this study was to investigate the association between tumor necrosis factor-alpha (TNF-α)-308G>A (rs1800629), interleukin-1 beta (IL-1β)-511C>T (rs16944), and interleukin-6 (IL-6)-174G>C (rs1800795) variants and juvenile idiopathic arthritis in a Turkish cohort.
Methods: A case-control study was conducted involving 57 juvenile idiopathic arthritis patients and 50 age- and sex-matched healthy controls. Genotyping was performed using polymerase chain reaction-restriction fragment length polymorphism. Genotype and allele distributions were compared between groups, and associations with clinical parameters (erythrocyte sedimentation rate, C-reactive protein, disease subtype) were assessed.
Results: A significant association was found between the IL-1β-511C>T polymorphism and juvenile idiopathic arthritis. The CC genotype was significantly more frequent in patients compared to controls (24.6 vs. 2.0%; p=0.004), and the C allele demonstrated a trend toward association (p=0.051). In contrast, no significant differences were observed in the genotype or allele frequencies of the TNF-α-308G>A or IL-6-174G>C variants between patients and controls. Furthermore, none of the studied polymorphisms were associated with erythrocyte sedimentation rate, C-reactive protein levels, or specific disease subtypes.
Conclusion: This study identifies the IL-1β-511C>T polymorphism as a significant risk factor for juvenile idiopathic arthritis in the Turkish population, underscoring the role of the IL-1 pathway in disease pathogenesis. These findings contribute to the understanding of the ethnic-specific genetic architecture of juvenile idiopathic arthritis and suggest IL-1β as a potential candidate for further functional and pharmacogenetic studies.