Wacrenier S, Riou J, Jourdain P, et al. - Researchers analyzed a large cohort of ANCA-associated vasculitis (AAV) with renal involvement (AAV-RI) patients, to determine the link between lymphocyte counts and outcomes in this sample. By using the Maine-Anjou AAV registry, 145 patients were analyzed. Among participants, a lower kidney function at baseline and more likelihood of needing kidney replacement therapy was observed in those with lymphopenia at diagnosis. Lymphopenic patients experienced a lower end-stage kidney disease-free survival. Overall, findings showed a correlation of lymphopenia with the severity of AAV glomerulonephritis at diagnosis. Poor renal outcome was also predicted by lymphopenia. Overall, lymphopenia could serve as a simple as well as cost-effective biomarker to evaluate renal prognosis at AAV-RI diagnosis.