PRTN3 and anti-neutrophil cytoplasmic antibody-associated vasculitis: Stratifying participants with small to medium sized vessel vasculitis (GPA, MPA, EGPA, PAN, and UCV) for the absence or presence of ANCA-specific antibodies, we find that inflammatory measures track more closely with disease course in individuals with PR3-AAV and to a lesser extent, ANCA-negative vasculitis.