The aim of this study is to report the efficacy of infliximab, a monoclonal antibody directed against tumor necrosis factor alpha which is used for both treatment of refractory pediatric Crohn disease (CD) and induction of remission.

Among pediatric patients who were diagnosed with CD at Samsung Medical Center between March 2001 and August 2007, a total of 16 patients were given infliximab to treat conventional therapy-resistant refractory CD and severe active CD for induction of remission. Patients needing maintenance therapy were treated with an infliximab infusion every 8 weeks, and fistulizing CD patients occasionally received the infusion upon the condition that a fistula developed. The efficacy of treatment was assessed by comparing the Pediatric Crohn Disease Activity Index (PCDAI), Hct, ESR, CRP, and serum albumin levels using paired t-test.

The male/female ratio was 13:3, and the median age was 13 years (range, 21 months~15 years). The patients included 7 cases of therapy-resistant refractory CD, 7 cases of severe active CD, and 2 cases of fistulizing CD. Mean PCDAI before infliximab therapy was 34.19±14.96, and mean follow-up PCDAI within 2 to 4 weeks after the last infusion was significantly lower, at 6.88±10.31 (p=0.000). Hematological markers such as ESR (p=0.000), serum albumin (p=0.016), and CRP (p=0.009) also improved significantly after infusion. Remission was achieved in 2 of 4 patients refractory to conventional therapy. Among 3 steroid-dependent patients, 2 were able to discontinue steroid therapy, and dose reduction was possible in 1 patient. Remission after top-down therapy without prior use of other immunomodulators was achieved in 6 weeks in all 7 of the patients who had severe CD. Nine of ten refractory fistulizing CD patients also showed improvement after infliximab therapy.

Infliximab was effective in pediatric refractory CD for induction of remission and maintenance therapy, as well as in severe CD for top-down induction therapy. Furthermore, infliximab has contributed to steroid cessation and dose reduction. Long-term follow-up evaluation is needed to determine safety and efficacy of infliximab in the future.