Associations of the IL-1B level, IL-1A and IL-1B gene polymorphisms and ankylosing spondylitis risk in a Chinese Han population

Introduction: The aim of this study was to investigate the effect of interleukin (IL)-1A and IL-1B gene polymorphisms on ankylosing spondylitis (AS) susceptibility in a Chinese population. Additionally, we examined the association of IL-1B level with different genotype of rs2853550 polymorphism and clinicopathological features of AS patients. Materials and methods: The IL-1B concentration in plasma was determined by an enzyme-linked immunosorbent assay. The IL-1A rs3783546, IL-1A rs3783550 and IL-1B rs2853550 gene polymorphisms were determined by using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Results: Our data indicated that the average plasma IL-1B concentration in the AS patients was markedly higher than in the control samples. Subgroup analyses suggested that there was no significant association between plasma IL-1B concentration and sex, age, HLA-B27, C-reactive protein (CRP), or grade of the sacroiliac joint in AS patients. We also found that the IL-1B rs2853550 AG genotype showed significantly correlation with an increased risk of AS. In comparing AS patients to control participants, elevated plasma concentrations were observed in AS patients while significant differences were found between the IL-1B rs2853550 AA genotypes. There is a negative correlation between the IL-1A rs3783550 and IL-1A rs3783546 polymorphisms in the AS patients in relation to controls. Conclusions: The IL-1B concentration in plasma was markedly higher in cases and AA genotype carriers. Furthermore, IL-1B rs2853550 AG was a genetic contributor to AS risk in a Chinese population.