Prognosis and Histological Classification in Elderly Patients with ANCA-Glomerulonephritis: A Registry-Based Cohort Study

BACKGROUND: The value of a histologic classification scheme to classify patients with anti-neutrophil cytoplasmic antibody-associated glomerulonephritis (ANCA-GN) into focal, mixed, crescentic, and sclerotic types for predicting risk of end-stage renal disease (ESRD) is well documented. However, the prognostic value of histological classification specifically in elderly patients (≥70 years) with ANCA-GN has not previously been investigated. METHODS: Patients with biopsy-verified pauci-immune necrotizing glomerulonephritis were identified from the Norwegian Kidney Biopsy Registry between 1991 and 2012 and those ≥70 years of age at the time of diagnosis and having positive anti-neutrophil cytoplasmic antibody serology were included in this study. The incidence rate of ESRD and/or death was determined by linking the study cohort to the Norwegian Renal Registry and the Population Registry of Norway. The ESRD-free survival and patient survival were compared between the 4 histological types. RESULTS: Of the 81 patients included, 20 progressed to ESRD and 34 died. The 1-year and 5-year ESRD-free survival varied between histological groups (p = 0.003) as follows: focal, 97% and 97%, respectively; mixed, 70% and 57%; crescentic, 76% and 63%; and sclerotic, 49% and 49%. Patient survival did not differ significantly between groups (p = 0.30). CONCLUSION: Histological classification in elderly patients with ANCA-GN is useful for predicting ESRD but not survival.