Relevance of ANCA positivity at the time of renal transplantation in ANCA associated vasculitis

Background: Renal transplantation (RTx) is the modality of choice for ESRD due to ANCA associated vasculitis (AAV). The significance of ANCA positivity (ANCA+) at the time of RTx on recurrent disease is controversial. Methods: We evaluated clinical outcomes and predictors of vasculitis relapse in sixteen transplanted AAV patients who were ANCA+ at RTx at a single University Medical Center. Allograft function, vasculitis relapse, and predictors of vasculitis relapse were assessed using descriptive statistics and logistic regression analysis. Results: Our cohort had a median age of 64 years, 88 % Caucasians, 63 % males, 50 % PR3+. All patients were in remission at the time of RTx. Twelve received induction therapy and all were on mycophenolate mofetil, prednisone and tacrolimus. The mean (SD) serum creatinine was 1.2 (0.3) mg/dl at 1 year and 1.8 (1.7) mg/dl at last follow up. Six developed vasculitis relapse at post-transplant. All relapses were treated with escalation in immunosuppression. One non-compliant patient suffered graft loss while the remaining patients achieved remission. In adjusted logistic regression analysis, PR3 ANCA+ patients were two times (OR 2.19, p = 0.71) more likely to experience a relapse compared to MPO ANCA+ patients. Conclusions: This study demonstrates that PR3 ANCA+ patients may be more likely to experience relapse post-transplant. Further investigation of the predictors of vasculitis relapse among AAV patients who are ANCA+ at the time of RTx needs to be pursued.