Biologic therapy in primary systemic vasculitis of the young.

Objectives: To describe the biologic treatment regimens and report the efficacy and safety of biologic therapies in a multicentre series of children with primary systemic vasculitis (PSV).

Methods: This was a retrospective descriptive case series of children with PSV treated with biologic therapy between February 2002 and November 2007. Primary retrospective outcome assessment measures were: daily corticosteroid dose; Birmingham Vasculitis Activity Score (BVAS); and adverse events (including infection rate).

Results: Twenty-five patients median age 8.8 (range 2.4-16) years; 11 male with active PSV (n = 6 with anti-neutrophil cytoplasmic antibody associated vasculitides, n = 11 with polyarteritis nodosa, n = 7 with unclassified vasculitis and n = 1 with Behçet's disease) were treated with biologic agents including infliximab (n = 7), rituximab (n = 6), etanercept (n = 4), adalimumab (n = 1) or multiple biologics sequentially (n = 7). Overall, there was a significant reduction in BVAS from a median of 8.5 (range 5-32) at start of therapy to 4 (range 0-19) at median 32 months follow-up (P = 0.003) accompanied by significant reduction in median daily prednisolone requirement from 1 (range 0.2-2) to 0.25 (range 0-1) mg/kg/day, P = 0.000. For those receiving multiple biologic agents sequentially, a similar clinical improvement was observed with corticosteroid sparing. Infections occurred in 24%, the most severe in those receiving infliximab.

Conclusion: Our data provide retrospective evidence of efficacy of these agents, and highlight the associated infectious complications. Further multicentre standardization of treatment protocols and data collection to inform clinical trials of biologic therapy in systemic vasculitis of the young is required.