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.