Clinical Prognostic Factors of Renal Outcome in Anti-neutrophil Cytoplasmic Autoantibody (ANCA)-associated Glomerulonephritis in Elderly Patients

Background: The purpose of the present study was to determine clinical prognostic factors on renal survival in 37 older patients with antineutrophil cytoplasmic autoantibody-associated pauci-immune necrotizing crescentic glomerulonephritis (ANCA-associated GN) who underwent renal biopsy at our Department between January 1996 and December 2000.

Methods: The date of renal biopsy was used as the start date for entry into the study. Age, gender, 24 h proteinuria, serum creatinine level, blood pressure and ANCA were evaluated. The end-point for renal survival analysis was the start of chronic dialysis.

Results: Twenty-six (70%) patients showed varying degrees of renal insufficiency, nine (24%) patients required dialysis, 13 (35%) were hypertensive (BP > or =140/90 mmHg) and 33 (89%) had proteinuria. During follow-up (31.73+/-17.39 months), 16% of the patients (6/37) developed end-stage renal disease (ESRD). The actuarial renal survival rate for all patients was 92% at 1 year and 76% at 3 years, for Wegener's granulomatosis 80% at 1 and 3 years, for microscopic polyangiitis 85% at 1 and 3 years, and for renal limited disease (GN) 75% at 1 and 37% at 3 years. Age (P = 0.024), arterial hypertension (P = 0.018), proteinuria (P = 0.037) and serum cre-atinine > or =400 micro mol/l (P = 0.047) were the most important risk factors for ESRD.

Conclusion: The actuarial renal survival rate in elderly patients with ANCA-associated GN was 92% at 1 year and 76% at 3 years. Older age, arterial hypertension, proteinuria and serum creatinine > or =400 micro mol/l related to ESRD.