Treatment of small vessel primary CNS vasculitis in children: an open-label cohort study.

Background: There is no treatment protocol or standardised documentation of neurological outcome for patients with small vessel childhood primary angiitis of the CNS, a rare inflammatory brain disease. We aimed to assess a treatment regimen and describe long-term neurological outcomes in a cohort of children with this disorder.

Methods: We did a single-centre open-label cohort study in children with small vessel childhood primary angiitis of the CNS who were less than 18 years old at diagnosis. The treatment protocol consisted of induction therapy with steroids and pulses of intravenous cyclophosphamide followed by maintenance therapy with either azathioprine or mycophenolate mofetil. Clinical and neurological assessments, quality of life measures, and laboratory markers were done at baseline, 3, 6, 9, 12, 18, and 24 months, and every year thereafter. Brain imaging was done at baseline, 6, 12, 18, and 24 months. The primary outcome was the paediatric stroke outcome measure (PSOM) score at 24 months.

Findings: From January, 2002, to December, 2009, 127 patients were enrolled, 19 of whom met the inclusion criteria and were given induction therapy. Median age at diagnosis was 9·8 years (range 5·5-17·8) and median follow-up was 33 months (range 1-86). 14 patients completed induction and received maintenance therapy with azathioprine (n=9) or mycophenolate mofetil (n=5). 13 patients completed 24 months' follow-up, nine of whom had a good neurological outcome by PSOM. Eight of 19 patients experienced disease flares. Four patients achieved remission of disease off medication.

Interpretation: This treatment protocol of immunosuppressive therapy may improve long-term neurological outcome in children with small vessel childhood primary angiitis of the CNS. Identification and appropriate diagnosis of children with the disorder is crucial because with standardised treatment good neurological outcome is a realistic goal.

Funding: None.