It is still not clear how advances in the management of antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) have impacted long-term outcomes. We undertook this study to examine changes over 25 years in long-term clinical outcomes, including the impact of renal function at diagnosis (a potential marker of time to disease detection) and the duration of cyclophosphamide use in AAV patients with renal involvement.
We included ANCA-positive patients with biopsy-proven AAV diagnosed between 1985 and 2009 who were followed up in the Glomerular Disease Collaborative Network inception cohort. Outcomes included the composite outcome of end-stage renal disease (ESRD) or death as well as relapse. Cox proportional hazards or competing risks regression models were adjusted for potential baseline confounders.
Data from 554 patients were included in the analysis. There was a decreasing 5-year risk of ESRD or death over time (P < 0.001 by log rank test for trend). After adjustment for baseline characteristics, the risk of relapse was similar across the time periods (P = 0.45 by test for trend). Serum creatinine level at baseline was the only significant predictor of an increased risk of ESRD or death (hazard ratio 1.11 per 1 mg/dl of serum creatinine [95% confidence interval 1.04-1.18], P = 0.002).
In patients with renal disease secondary to AAV, over 25 years the risk of ESRD or death has decreased but the risk of relapse has not changed. A higher serum creatinine level at diagnosis is associated with a higher risk of ESRD or death, suggesting that earlier disease detection is potentially an important measure to improve outcomes in AAV.