The CD18 AvaII polymorphic site not associated with Henoch-Schönlein purpura

Henoch-Schönlein purpura (HSP) is an immune complex-mediated systemic vasculitis. Its genetic etiology remains unknown. CD18, the subunit of integrin beta2 in leukocytes, has essential roles in the expression and function of ITGB2, mediating immune responses. CD18 has been proved to be associated with some systemic vasculitides, such as microscopic polyangiitis and Churg-Strauss syndrome. We aimed to assess the influence of CD18 AvaII polymorphism (rs235326, C->T) in the incidence of HSP and determine its possible implication in severe systemic complications by studying 73 patients with HSP and 156 controls in China. Our results showed that AvaII polymorphism was not associated with HSP susceptibility (odd ratio (OR)=0.48, 95% confidence interval (CI)=0.53-1.39, p=0.63) or with HSP nephritic syndrome (OR=0.88, 95%CI=0.35-2.06, p=0.90). Moreover, we did not observe any significant association between serum parameters, such as CRP, IgA, IgE, C3 and C4, and HSP severity. In conclusion, our results suggested that CD18 AvaII is not associated with HSP susceptibility and its clinical outcomes.