Efficacy and safety of autologous adipose tissue-derived stem cell therapy for children with refractory Crohn's complex fistula: a Phase IV clinical study

PURPOSE: Autologous adipose tissue-derived stem cells (ASCs) have been proposed for patients with refractory Crohn disease, but research is lacking in pediatric patients. This Phase IV study evaluated the efficacy and safety of ASCs in children with refractory Crohn's fistulae. METHODS: Patients with a refractory Crohn's fistula who did not have conventional therapy for more than 3 months or with a recurrent complex Crohn's fistula were included. All patients were at least 14 years old. Patients with infection, poor condition, or active Crohn disease with a disease activity index of 450 and above were excluded. Five patients were treated with ASCs from 2014 to 2015 in Asan Medical Center. ASC administration was adjusted according to fistula size (1 mL per cm(2)). We evaluated the efficacy and safety 8 weeks after injection and followed patients for 6 months. RESULTS: Fistulae were healed in 4 patients by 8 weeks after ASC injection. Of these 4 patients, 1 had complete fistula closure and sustainability after 6 months. The other 3 with healing effects had less than 50% fistula closure by 6 months. None of these 4 patients have persistent fistulae. One patient had no healing effect, and seton ligation was performed 8 months after ASC injection. There were no adverse effects related to ASC administration. CONCLUSION: ASC therapy is a simple and well-tolerated therapeutic option for children with refractory Crohn's complex fistulae. Complete closure was well-sustained. However, more data from a larger number of patients are needed.