The PTPN22 620W allele is a risk factor for Wegener's granulomatosis

Objective. Analyses of families with multiple autoimmune disorders have revealed a functional polymorphism, 620W, in the intracellular tyrosine phosphatase gene PTPN22 as a predisposing factor for type 1 diabetes, seropositive rheumatoid arthritis, systemic lupus erythematosus, and Hashimoto thyroiditis, and the presence of the PTPN22 protein appears to herald the development of autoantibodies in these disorders. This study therefore examined whether the functionally relevant PTPN22 polymorphism is associated with Wegener's granulomatosis (WG). Methods. A population-based study was performed for the PTPN22 polymorphism in 199 patients with WG and in 399 healthy individuals. The R620W variation was investigated by simple restriction fragment-length polymorphism analysis. Results. The PTPN22 620W allele frequency was significantly increased in antineutrophil cytoplasmic antibody (ANCA)-positive WG patients compared with healthy controls (P < 0.001). The association was particularly striking in patients with kidney, lung, eye, and peripheral nervous system involvement (i.e., those with generalized WG). Conclusion. The PTPN22 620W allele appears to be involved in the pathogenesis of WG, and ANCA positivity seems to be the hallmark.