熊谷 秀規

BACKGROUND/AIMS: Very early-onset inflammatory bowel disease (VEO-IBD), defined as IBD diagnosed before 6 years of age, is highly influenced by genetic factors. Monogenic IBD is a type of enterocolitis caused by a single pathogenic variant. However, information on Asian patients with VEO-IBD and monogenic IBD is limited. This study investigated real-world data on VEOIBD and monogenic IBD in Japan. METHODS: We evaluated patients with VEO-IBD registered in the Japanese Pediatric Inflammatory Bowel Disease Registry, a multicenter prospective registry study conducted between 2012 and 2021. We categorized patients into monogenic and non-monogenic IBD groups and compared their clinical characteristics and outcomes. RESULTS: Among 703 pediatric patients with IBD, 68 (9.7%) had VEO-IBD. Of these, 26 (38.2%) had ulcerative colitis, 16 (23.5%) had Crohn's disease, 23 (33.8%) had unclassified IBD (IBD-U), and 3 (4.4%) had Behçet's disease. Genetic testing was performed in 25 patients (36.8%), and monogenic IBD was identified in 5 of the 23 patients with IBD-U (7.4% of the VEO-IBD cohort). All 5 monogenic cases presented with an IBD-U phenotype. Monogenic IBD included A20 haploinsufficiency, interleukin-10 receptor subunit alpha deficiency, chronic granulomatous disease, Wiskott-Aldrich syndrome, and Hermansky-Pudlak syndrome. Monogenic IBD was significantly associated with IBD-U phenotype (P= 0.015) and severe infections before 1 year of age (P= 0.004). CONCLUSIONS: Patients with VEO-IBD who present an IBD-U phenotype and have a history of severe infections during infancy should be prioritized for genetic analysis to investigate the possibility of monogenic IBD.

BACKGROUND: Very-early-onset inflammatory bowel disease (VEO-IBD), representing cases diagnosed before age 6 years, is increasing in prevalence. Although VEO-IBD often presents as severe, treatment-resistant disease requiring biologic agents, studies showing the effectiveness of biologics, such as ustekinumab (UST) and vedolizumab (VDZ), remain limited. METHODS: We retrospectively analyzed patients with VEO-IBD treated for at least a year from 13 institutions in Japan, evaluating clinical course including effectiveness of biologics, such as infliximab (IFX), adalimumab (ADL), UST, and VDZ. Patients with monogenic IBD were excluded. Steroid-free clinical remission (SFCR) and treatment persistence were assessed separately for first-line and for second-line or subsequent biologic therapies. RESULTS: We studied 101 VEO-IBD patients (56% male; median age, 3.6 years), including 40 with Crohn's disease, 52 with ulcerative colitis, and 9 with unclassified IBD. Biologics were used in 67 patients, most commonly infliximab (IFX; n = 52), followed by UST (n = 38), adalimumab (ADL; n = 23), and VDZ (n = 21). As first-line therapy, IFX and ADL achieved 1-year SFCR rates of 19% and 46%, with persistence rates of 36% and 48%. Despite being used mainly as second-line or subsequent therapies, UST and VDZ showed 1-year SFCR rates of about 45% and 36%, and maintained persistence of 79% and 46%, respectively, with UST demonstrating higher persistence than TNF-α inhibitors (P < 0.01). No discontinuations due to infusion reactions or other adverse events occurred with UST or VDZ. CONCLUSION: UST and VDZ were effective and well tolerated even when used as second-line or subsequent therapies for VEO-IBD.

BACKGROUND: Peutz-Jeghers syndrome (PJS), a rare genetic disorder characterized by hamartomatous gastrointestinal polyps, poses increased risks of various cancers. Despite the importance of early intervention, the optimal timing for jejunal-ileal polypectomy remains unclear owing to the limited number of comparative studies. METHODS: Herein, we conducted a nationwide survey in Japan and analyzed data from 184 patients with PJS identified through a two-stage sampling process. The initial screening of 2912 medical institutions yielded 1748 facilities, of which 1077 responded to the survey. Time-dependent Cox proportional hazards models and logistic regression analyses were used to examine the association between the timing of jejunal-ileal polypectomy and the risk of surgery for intussusception. RESULTS: Among 184 patients (47.0% women; mean age, 33.5 years), intussusception was the most common complication (67.7%). In the Cox proportional hazards analysis excluding surgeries within 1 year of diagnosis, early jejunal-ileal polypectomy was associated with a reduced risk of surgery for intussusception (adjusted hazard ratio, 0.17; 95% confidence interval [CI] 0.04-0.74, p = 0.018). Logistic regression analysis showed higher odds of surgery in the late treatment group compared with the early treatment group (adjusted odds ratio, 4.26; 95% CI 1.38-13.16, p = 0.012). CONCLUSIONS: Early jejunal-ileal polypectomy may reduce the risk of intussusception in patients with PJS. However, the need for frequent endoscopic procedures must be balanced considering patient burden. These findings support the importance of early intervention and highlight the need for optimized surveillance strategies that consider clinical effectiveness and patients' quality of life.