Renal involvement in paediatric systemic vasculitis.

BACKGROUND Primary systemic vasculitis is a rare condition in children, which often has a slowly progressive course with diffuse symptoms and is therefore easily overlooked. Early initiation of treatment can prevent severe kidney disease. The aim of this study was to survey the extent of renal involvement in children with systemic vasculitis at Oslo University Hospital, Rikshospitalet. MATERIAL AND METHOD This observational retrospective study was based on a review of medical records, laboratory results and renal biopsies from first admission to last check-up at Oslo University Hospital, Rikshospitalet, for the period 2000–14. RESULTS A total of 66 children (35 boys) under 18 years of age were treated at the hospital for primary systemic vasculitis in the period in question. Objective signs of renal involvement were found in 39 (59 %) at the first consultation and in 42 (64 %) over the course of the disease. Twenty-nine patients (44 %) underwent renal biopsy. Of the 41 patients with proven renal involvement that were still alive at the time of the last check-up, 12 continued to require treatment for renal impairment. Three patients had undergone renal transplantation, 18 were in remission on immunosuppressive or antihypertensive treatment, while 11 patients had achieved medication-free renal remission. INTERPRETATION There is a high prevalence of renal involvement in paediatric patients treated for systemic vasculitis at Oslo University Hospital, Rikshospitalet. At their final check-up, the majority of patients continue to require treatment and follow-up for kidney disease.