Relapse rate and outcome of ANCA-associated small vessel vasculitis after transplantation

Background. Anti-neutrophil cytoplasm antibody-associated systemic vasculitis (AASV) is a rare disease and frequently leads to end-stage renal disease (ESRD). Potentially fatal disease activity can develop after the onset of ESRD or in transplanted patients despite the immunosuppressive effects of uraemia and rejection prophylaxis, respectively, leading to concern that such patients may have greater morbidity and mortality. Methods. To assess the outcome of patients with AASV following kidney transplantation, a retrospective analysis was performed of nine patients with AASV at our unit who received renal transplants between 1987 and 2000. The renal survival of the patients was compared with a control population who received kidney transplants over the same period for causes other than AASV and diabetes mellitus. Results. Nine patients with the diagnosis of AASV (five patients with Wegener's granulomatosis and four with microscopic polyangiitis) received eight cadaveric grafts and one live-related graft after a mean of 44 months from the start of dialysis. These patients had a mean age of 49.2 years at time of transplantation and they were followed up for a mean of 62 months post-transplantation. Two patients with Wegener's granulomatosis suffered a vasculitic relapse affecting the upper respiratory tract at 40 and 50 months posttransplantation, corresponding to a relapse rate of 0.04 per patient per year. The renal transplant function of vasculitis patients compared with 18 non-diabetic control patients who were transplanted at the same time was better in the vasculitis patients at some time points (P=0.054 at 6 months). Conclusions. There is a substantial relapse rate in the AASV population, especially affecting the upper respiratory tract and with increasing duration of follow-up. Nonetheless, renal transplantation is a good option for the treatment of vasculitis patients and their outcome compares favourably with that of other non-diabetic patients following transplantation.