Effect of Disease Activity at Three and Six Months After Diagnosis on Long-Term Outcomes in Antineutrophil Cytoplasmic Antibody-Associated Vasculitis.
OBJECTIVE: The treatment of antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) aims to suppress disease activity and prevent subsequent disease flare. This study sought to explore the association of early disease control with long-term outcomes to validate early disease control as an end point for future clinical trials in AAV. METHODS: Data from 4 European Vasculitis Society inception clinical trials in AAV (1995-2002) and subsequent data on long-term outcomes from the trial data registry were studied. Clinical parameters in patients with AAV at baseline and at 3 and 6 months after diagnosis were assessed to study the long-term risk of death and end-stage renal failure (ESRF). At 6 months, outcomes were defined based on a disease status of either sustained remission (remission by 3 months, sustained to 6 months), late remission (remission after 3 months and by 6 months), relapsing disease (remission by 3 months but relapse by 6 months), or refractory disease (no remission by 6 months). RESULTS: Of the 354 patients with AAV who were followed up for a median of 5.7 years, 46 (13%) developed ESRF, 66 (18.6%) died, and 89 (25.1%) had either died or developed ESRF. At 6 months, predictors of the composite end point of death or ESRF were as follows: age (hazard ratio [HR] 1.02, 95% confidence interval [95% CI] 1-1.05; P = 0.012), estimated glomerular filtration rate (HR 0.94, 95% CI 0.92-0.95; P < 0.001), and disease status at 6 months (late remission, HR 2.94, 95% CI 1.1-7.85 [P = 0.031]; relapsing disease, HR 8.21, 95% CI 2.73-24.65 [P < 0.001]; refractory disease, HR 4.89, 95% CI 1.96-12.18 [P = 0.001]). Similar results were observed when these analyses were performed separately for death and for ESRF. CONCLUSION: The results of this study suggest that disease status at 3 and 6 months following the diagnosis of AAV may be predictive of the long-term risk of mortality and ESRF, and therefore these may be valid end points for induction trials in AAV. The current findings need to be validated in a larger data set.