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

Abstract

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.

Figure 1

(a) Flowchart of patient outcomes at 0-1 year of observation. (b) Flowchart of patient outcomes at >1 year of observation.

Figure 2

(a) Kaplan-Meier plot showing end-stage renal disease-free survival according to histological classification. (b) Kaplan-Meier plot showing patient and end-stage renal disease-free survival according to histological classification.

Figure 3

(a) Kaplan-Meier plot showing end-stage renal disease-free survival in patients aged 70–74.9 years versus ≥75 years. (b) Kaplan-Meier plot showing patient survival in patients aged 70–74.9 years versus ≥75 years. (c) Kaplan-Meier plot showing patient and end-stage renal disease-free survival in patients aged 70–74.9 years versus ≥75 years.