A pediatric case of infliximab-resistant ulcerative colitis successfully treated using vedolizumab

Pediatric ulcerative colitis is likely to be more severe than adult ulcerative colitis. Failure to thrive should be considered during therapy. A 10-year-old boy was diagnosed with ulcerative colitis based on his clinical presentation and colonoscopy and biopsy results. The administration of 5-aminosalicylic acid and prednisolone resulted in remission ; however, the symptoms reappeared after the discontinuation of prednisolone. Then, infliximab was administered ; however, the patient was resistant to it and appeared to be dependent on prednisolone. Vedolizumab, a monoclonal antibody against α4β7 integrin, was administered, which resulted in rapid remission. A steady decrease in prednisolone followed, and remission was maintained even after prednisolone discontinuation. Vedolizumab may be effective in pediatric patients with moderate-to-severe refractory ulcerative colitis. Vedolizumab prevents lymphocytes from binding to MAdCAM-1, which is selectively expressed in the gastrointestinal submucosa, leading to the mitigation of the systemic side effects of immunosuppression, such as infections. In Japan, vedolizumab use is not yet approved for use in children, but its effectiveness and safety in children is expected to be investigated in the future.