Trivioli G, Gopaluni S, Urban ML, et al. - Although rapidly progressive glomerulonephritis is the main renal phenotype of anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV), slow renal disease progression is sometimes reported. These forms have been rarely presented; researchers examined their prevalence, clinicopathological characteristics, and outcome. Individuals with microscopic polyangiitis (MPA) and granulomatosis with polyangiitis followed at seven referral centres were screened and selected those with calculated glomerular filtration rate reduction < 50% over a 6-month period preceding diagnosis. They retrieved data regarding patient features and response to treatment. A total of 856 patients were included in the study. It was considered that AAV may present with slow renal disease progression; this subset is hallmarked by advanced age at diagnosis, positive myeloperoxidase-ANCA, subclinical interstitial lung lesions and chronic damage at kidney biopsy. The results recognize that partial renal recovery may occur following immunosuppression.