Antineutrophil cytoplasmic antibodies and their relationship with disease activity and presence of staphylococcal superantigens in nasal swabs in patients having granulomatosis with polyangiitis: results of a study involving 115 patients from a single center

Abstract

There was no detectable evidence for the association between ANCA level and the presence of SAgs. Although monitoring ANCA levels as a marker of disease activity may be clinically relevant, GPA management cannot proceed on the basis of ANCA levels alone. Key Points • ANCA concentration usually correlates with GPA activity, although in half of patients, ANCAs persist despite effective treatment and clinical remission. • ANCA values of 138 Ru/ml seem to be an indicator of active disease with high specificity, but low sensitivity. • Although there is a relevance for ANCA monitoring as a marker of disease activity, GPA management cannot be based on ANCA levels alone. • The suspected clinical correlation between ANCA formation and SAg presence in nasal swabs is not obvious and requires further investigations.