Ahn SS, et al. - In this retrospective analysis of 160 patients with antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV), researchers tested neutrophil to lymphocyte ratio (NLR) at diagnosis as a measure for estimating vasculitis activity and poor prognosis during follow-up. They obtained information on clinical and laboratory data at diagnosis. They formed three groups of AAV patients based on tertile, and defined the lower limit of each highest tertile as the optimal cut-off (5.9 for NLR and 15.0 of Birmingham vasculitis activity score for severe AAV). Based on the findings, they concluded that vasculitis activity at diagnosis can be estimated by NLR at diagnosis in patients with AAV. Moreover, in these subjects, the prediction of relapse during follow-up can be predicted by NLR at diagnosis.