Interleukin 8 gene polymorphism is associated with increased risk of nephritis in cutaneous vasculitis

Objective. To assess the influence of interleukin-8 (IL-8), epithelial cell-derived neutrophil-activating peptide (ENA-78), and regulated upon activation normal T cell expressed and secreted (RANTES) gene polymorphisms in the susceptibility and clinical expression of patients fulfilling classification criteria for Henoch-Schönlein purpura (HSP). Methods. Fifty patients (25 men) from Northwest Spain with primary cutaneous vasculitis classified as HSP according to proposed criteria were studied. All patients were required to have had at least 2 years' followup. Patients and ethnically matched controls were genotyped for IL-8, ENA-78, and RANTES gene polymorphisms. Results. No allele or genotype differences between patients fulfilling HSP classification criteria and controls were observed for any of the chemokines. However, a significantly increased frequency of allele A of the IL-8 gene polymorphism was found in patients with HSP who developed renal manifestations compared with patients without renal involvement (p = 0.02; pcorr = 0.036). Moreover, the genotype distribution in HSP patients with and without renal involvement showed statistically significant differences (p = 0.02). Conclusion. In unselected patients with cutaneous vasculitis, carriage of IL-8 allele A influences the susceptibility to renal involvement.