難治性潰瘍性大腸炎に対する新しい内科治療―インフリキシマブの効果と位置づけ

The Effect of Anti-TNF-αAntibody in Refractory Ulcerative Colitis

要旨　当院でインフリキシマブ投与を行った難治性潰瘍性大腸炎28例の導入療法効果および維持療法の成績，安全性を検討した．インフリキシマブ投与は導入に0，2，6週の3回投与，維持投与は8週ごとの投与を基本とした．追跡不能1例を除いた27例全体での導入療法の有効率は63.0％，投与目的別ではタクロリムス不応・再燃40.0％，ステロイド抵抗85.7％，ステロイド依存57.1％，そのほかの難治例100％の有効率を示した．計画的維持投与を行っている症例では，導入療法で寛解となった8例中6例が寛解を維持しており，2例は再燃を認めたが，再導入療法や投与期間短縮にて再び寛解を維持している．副作用は1例で投与時反応により投与を中止した．以上の結果から，インフリキシマブは難治性潰瘍性大腸炎に対する治療として，寛解導入および寛解導入例での寛解維持に有用な薬剤であることが示された．

　To assess the effectiveness of anti-TNF（tumor necrosis factor）-αantibody（infliximab）in the short- and long-term and its safety in patients with ulcerative colitis, we analyzed 28 patients who were treated with infliximab at Keio University Hospital. Infliximab（5mg/kg body weight）was administered at 0,2 and 6 weeks, and every 8 weeks thereafter.

　Overall efficacy of induction therapy was 63.0％. When looking at indications for infliximab administration, efficacies including remission and improvement were 40.0％, 85.7％, 57.1％and 100％ for tacrolimus-refractory, steroid-refractory, steroid-dependent and others, respectively. Among patients who were administered infliximab as maintenance therapy, 6 of 8 patients who achieved remission with induction therapy remained in remission. The other 2 patients, who had relapsed, achieved remission with re-induction therapy or adjustment of the administration schedule. One patient developed infusion reaction which required discontinuation of the therapy.

　Our results suggested that infliximab therapy was safe and effective for induction and maintaining remission of ulcerative colitis refractory to conventional medical treatment.