Granulomatosis with polyangiitis (GPA) is a form of autoimmune vasculitis that is associated with the presence of anti-neutrophil cytoplasmic antibodies directed against proteinase 3 (PR3). In this episode, Véronique Witko-Sarsat, Nathalie Thieblemont, and Katherine Martin discuss their work, which shows that PR3 expression was enhanced on the surface of apoptotic neutrophils from patients with GPA. PR3-expressing apoptotic neutrophils were found to promote pro-inflammatory responses and prevent the development of regulatory T cells. Moreover, the authors show that this immune dysregulation was also present in patients with GPA. Together, the results of this study provide important insight into the pathogenesis of GPA.
