No association of G-463A myeloperoxidase gene polymorphism with MPO-ANCA-associated vasculitis.

BACKGROUND: The activation of neutrophils and monocytes by ANCA, resulting in the release of reactive oxygen species and proteases like myeloperoxidase (MPO), is essential to the pathogenesis of ANCA-associated vasculitis. As the A allele of the G-463A MPO gene polymorphism is associated with diminished activity of MPO, it is conceivable that the presence of this allele protects against MPO-ANCA-associated vasculitis. METHODS: Allelic frequencies of the G-463A polymorphism were studied in 119 ANCA-associated vasculitis patients, 48 with MPO-ANCA and 71 with proteinase 3 (PR3)-ANCA. RESULTS: Allelic frequencies of MPO G-463A promoter polymorphism did not differ between MPO-ANCA- and PR3-ANCA-associated vasculitis patients. Moreover, allelic distribution was similar to that of the normal population. CONCLUSIONS: The data suggest that G-463A polymorphism does not seem to contribute to either MPO-ANCA- or PR3-ANCA-associated vasculitis formation.