CRP and anti-neutrophil cytoplasmic antibody-associated vasculitis: I read the article by Atas et al. about the association between C-reactive protein (CRP) to albumin ratio (CAR) with disease activity in patients suffering from antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV).1 These findings are important because there is not enough data yet to make a firm conclusion regarding the value of CAR measurement in AAV.