LAUSR

A 17-year-old boy with X-linked inhibitor of apoptosis (XIAP) deficiency was referred to our hospital for hematopoietic stem cell transplantation (HSCT). He was diagnosed as having Crohn’s disease (CD) and he had been treated with various treatments for CD. Nevertheless, clinical remission had never been achieved and genetic analysis revealed XIAP deficiency 6 years after the diagnosis of CD. Before HSCT, colonoscopy revealed a stricture of the ileocecal valve with an active ulcer (Fig. 1a), in addition to active multiple ulcers in his large intestine (Fig. 1b,c). One month after HSCT, the ulcers were healing (Fig. 1e,f); however, the stricture progressed (Fig. 1d). Consequently, he developed bowel obstruction 3 months after HSCT (Fig. 2). His symptoms improved with fasting, and we decided to perform endoscopic balloon dilation (EBD) by referring to the strategy used to treat strictures in patients with CD. We first dilated the stricture using 8 mm through-the-scope balloon (Fig. 3a,d). We performed the second EBD 1 month after the first EBD and the third EBD 3 months after the second EBD, which dilated the stricture up to 10 and 12 mm, respectively (Fig. 3b,e). After the third EBD, the colonoscope could be advanced through the stricture (Fig. 3c,f). Throughout the patient’s clinical course, no complications of EBD occurred. After the third EBD, his abdominal symptoms have not relapsed without any dietary restrictions. XIAP deficiency is a rare primary immunodeficiency and gastrointestinal lesions in XIAP deficiency are similar to CD. For patients with CD, EBD is known to be a standard procedure for intestinal strictures. However, the safety and efficacy of EBD for patients with XIAP deficiency remain unknown. Our case suggests that EBD could be an effective and safe procedure for intestinal strictures after HSCT in patients with XIAP deficiency.