Renal Survival in Proteinase 3 and Myeloperoxidase ANCA-Associated Systemic Vasculitis

Background and objectivesThis study evaluated predictors for patient and renal survival in patients with ANCA-associated vasculitis (AAV) with and without renal involvement.Design, setting, participants, & measurementsThere were 273 consecutive AAV patients from January 1990 until December 2007 who were followed until death, loss to follow-up, or December 2010. Based on organ involvement, patients were divided into renal (n=212) and nonrenal groups (n=61). The primary end point was ESRD requiring renal replacement therapy (RRT) or renal transplantation or death.ResultsPatient survival was significantly better in the nonrenal group compared with the renal group (hazard ratio, 0.55; 95% confidence interval, 0.33 to 0.92; P=0.02). In the renal group, renal survival was significantly worse in MPO-ANCA-positive patients (n=65) compared with PR3-ANCA-positive patients (n=138) (hazard ratio, 2.1; 95% confidence interval, 1.11 to 3.8; P=0.01). Of 48 patients who needed RRT at diagnosis, 11 patients (23%) died within 6 months and 14 patients (29%) did not regain renal function. Of all 23 patients who regained renal function after RRT, 7 patients (30%) were temporarily dialysis independent and needed dialysis later (range, 13-63 months). Five patients had a renal relapse in the 6 months before restart of RRT. Of all 203 PR3-ANCA-positive and MPO-ANCA-positive patients with renal involvement, 12 patients (6%) developed ESRD during follow-up. These patients were classified as CKD stage 4 or 5 after initial treatment and eight patients had a renal relapse before becoming dialysis dependent.ConclusionsAAV patients with renal involvement who needed RRT had the worst survival probability. In multivariate analysis, the only major determinants for long-term renal survival were renal function at 6 months and renal relapses.