Abstract
Background Recently, infliximab dependency has been described. Aim To assess frequency of ID in 82 consecutive Crohn's disease children treated with infliximab 2000-2006 and to describe clinical and genetic predictors of long-term infliximab response.
Methods A phenotype model of infliximab dependency was used to assess treatment response: 'immediate outcome' (30 days after infliximab start) - complete/partial/no response. 'Long-term outcome': (i) prolonged response: maintenance of complete/partial response; (ii) infliximab dependency: relapse 12 months to sustain response. Polymorphisms TNF-308 A>G, TNF-857 C>T, Casp9 93 C>T, FasL-844 C>T, LTA 252 C>T and CARD15 (R702W, G908R, 1007fs) were analysed.
Results Ninety-four per cent of children obtained complete/partial response. In long-term outcome, 22% maintained prolonged response, 12% had no response, while 66% became infliximab dependent.
Perianal disease and no previous surgery were associated with infliximab dependency (OR 5.34, 95% CI: 1.24-22.55; OR 6.7, 95% CI: 1.67-26.61). No association was found with studied polymorphisms.
The cumulative probability of surgery 50 months after starting infliximab was 10% in infliximab dependency, 30% in prolonged responders and 70% in nonresponders (P = 0.0002). Conclusions Sixty-six per cent of children became infliximab dependent.
Perianal disease and no surgery prior to infliximab were associated with infliximab dependency phenotype.