Predictors of renal outcomes in anti-neutrophil cytoplasmic antibody glomerulonephritis

Abstract

Glomerulonephritis associated with anti-neutrophil cytoplasmic antibody (ANCA) vasculitis still has a high prevalence of end-stage renal disease (ESRD), particularly in patients with advanced renal failure at presentation. This study aims to evaluate the clinical and histo- pathological features of renal involvement and investigate factors associated with ESRD. Patients with renal biopsy-proven ANCA-associated glomerulonephritis were included retrospectively over a period of nine years (June 2007 to March 2016). The renal survival, defined as time to reach ESRD, was evaluated based on clinical parameters, histopathological classification, and renal risk score. A total of 37 patients with crescentic glomerulonephritis were included in the study. The average age was 54 ± 16 years (range: 17-80) and 51.3% were female. Twenty-two patients were diagnosed with microscopic polyangiitis and 15 had granulomatosis with polyangiitis. The median glomerular filtration rate at presentation was 16.73 mL/min/1.73 m2. Thirty-five patients (94.5%) had renal failure at presentation and 23 patients (62.1%) required initial hemodialysis (HD) therapy. The pattern of glomerular injury was categorized as sclerotic in 48.6% of cases, crescentic in 24.3%, mixed in 24.3%, and focal class in 2.7%. Regarding renal risk score, we had five patients with low risk, 17 with intermediate risk and 15 with high risk. ESRD occurred in 47% of intermediate-risk group and 66% of the high risk group. During follow-up, 17 patients (45.9%) developed ESRD. Tobacco addiction (P = 0.02), alveolar hemorrhage (P = 0.04), hypertension (P = 0.04), initial HD (P = 0.04), and sclerotic class (P = 0.004) were associated with ESRD. In our patients, a sclerotic class was associated with a higher risk of ESRD, suggesting that histo- pathological classification is potentially an important parameter to predict outcomes in renal disease secondary to ANCA-associated vasculitis.