Renal-limited vasculitis in children: a single-center retrospective long-term follow-up analysis.

Pauci-immune renal limited vasculitis (RLV) is a rare and aggressive autoimmune disease. We retrospectively analyzed the renal outcome of 6 children with biopsy proven RLV. Median age at diagnosis was 10.6 years (range 7.1 - 14.5) and the median follow-up was 4.4 years (range 2.3 - 6.6). At diagnosis, 5 patients were given induction therapy (methylprednisolone + cyclophosphamide pulses) followed by maintenance treatment (prednisolone + azathioprine) while 1 patient received maintenance treatment only. After induction, 4 patients either retained or recovered normal renal function, and 1 patient, in whom short-term plasma exchange was prescribed to try to rescue her renal function, became free from dialysis. Repeated biopsy showed no disease activity; however, renal scarring was evident in all renal specimens. At last follow-up, 2 patients had normal renal function, 3 patients had mild renal insufficiency, and 1 patient had advanced renal failure. In addition, 5 patients were treated for hypertension. Our case series suggests that an initial favorable response to immunosuppressive therapy might not necessarily prevent the occurrence of renal scarring and highlights the importance of regular follow-up.