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.

BACKGROUND AND AIM: Peutz-Jeghers syndrome (PJS) and juvenile polyposis syndrome (JPS) are autosomal dominant diseases associated with high cancer risk. In Japan, knowledge about the prevalence and incidence of PJS and JPS is lacking despite being crucial for providing appropriate medical support. We aimed to determine the prevalence and incidence of these diseases. METHODS: In 2022, a nationwide questionnaire survey was conducted to determine the number of patients with PJS or JPS by sex and the number of newly confirmed cases from 2019 to 2021. The target facilities included gastroenterology, pediatrics, and pediatric surgery departments, which were stratified into seven classes on the basis of the total number of beds. We randomly selected target facilities using different extraction rates in each class, resulting in 1748/2912 facilities (extraction rate: 60%) as the final sample. We calculated the estimated number of patients using the response and extraction rates. RESULTS: A total of 1077 facilities responded to the survey. The estimated numbers of patients with PJS and JPS were 701 (95% confidence interval [CI]: 581-820) and 188 (95% CI: 147-230), respectively. The 3-year period prevalences of PJS and JPS were 0.6/100000 and 0.15/100000, whereas the incidences in 2021 were 0.07/100000 and 0.02/100000, respectively. Male patients constituted 53.5% and 59.6% in the PJS and JPS groups, respectively. CONCLUSIONS: We determined the prevalence and incidence of PJS and JPS in Japan for the first time. Further research is needed to obtain more detailed information, including the clinical differences and outcomes in Japan.

BACKGROUND: Although ulcerative proctitis (UP) in children is considered relatively mild, some patients have proximal disease extension and require immunosuppressive treatment. We investigated clinical characteristics and course of refractory UP in a multicenter pediatric cohort. METHODS: Analyzing data obtained between 2013 and 2022 at 10 institutions specializing in pediatric inflammatory bowel disease, we elucidated natural history and factors predicting a need for immunosuppressive UP treatment. We compared patients given immunosuppressants and/or biologic agents (immunosuppressive treatment group) with those given 5-aminosalicylic acid (5-ASA) alone (5-ASA group). RESULTS: Fifty-five patients were followed for 3.5 years. The median Pediatric Ulcerative Colitis Activity Index at diagnosis was 20. The commonest treatment, 5-ASA suppository monotherapy in 40% of patients, showed the worst compliance. Clinical remission was achieved at least once in 95% of all patients. Disease extension beyond the splenic flexure occurred in 51%. Immunosuppressive treatment was given to 37%; biologic agents were used for 18%. Rates of endoscopically demonstrated inflammation, including Ra/Rs at diagnosis and extension beyond the left-sided colon, were higher in the immunosuppressive treatment group (70% vs 38%, P < 0.05; 95% vs 27%, P < 0.0001). The log-rank test and multivariate Cox proportional hazards regression showed that time to first clinical remission exceeding 3 months predicted the need for biologics. CONCLUSION: The typical initial treatment of pediatric UP was 5-ASA suppositories, despite poor compliance. Biologics or other immunosuppressive treatments were needed in 37% of patients. Close follow-up with adjustment of treatment should be considered in children with UP as its clinical course varies.

BACKGROUND AND AIM: Even with increasing numbers of biologic agents available for management of ulcerative colitis (UC), infliximab (IFX) retains an important place in treatment of pediatric patients with this disease. As few reports have addressed outcomes in pediatric UC patients who had to discontinue IFX, we examined clinical course and prognosis after IFX failure in pediatric UC. METHODS: A prospective cohort study of pertinent cases enrolled in the Japanese Pediatric Inflammatory Bowel Disease Registry between 2012 and 2020 was conducted to determine outcomes for pediatric UC patients who received IFX but required its discontinuation during follow-up (IFX failure). RESULTS: Of the 301 pediatric UC patients in the registry, 75 were treated with IFX; in 36 of these, IFX was discontinued during follow-up. Severity of UC at onset and absence of concomitant immunomodulator therapy were significant risk factors for IFX failure (P = 0.005 and P = 0.02, respectively). The cumulative colectomy rate after IFX failure was 41.3% at 1 year and 47.5% at 2 years. Colectomy was significantly more frequent when IFX was discontinued before June 1, 2018, than when IFX was discontinued later (P = 0.013). This difference likely involves availability of additional biologic agents for treatment of UC beginning in mid-2018 (P = 0.005). CONCLUSION: In pediatric UC patients, approximately 50% underwent colectomy during a 2-year interval following IFX failure. Prognosis after IFX failure appeared to improve with availability of new biologic agents and small-molecule drugs in mid-2018.

BACKGROUND: Niemann-Pick disease type C (NPC) is an autosomal recessive inherited and neurodegenerative disorder. Approximately 10% of NPC patients have acute liver failure and sometimes need liver transplantation (LT), and 7% reportedly develop inflammatory bowel disease (IBD). We report the case of a girl with NPC who had a re- accumulation of cholesterol in the transplanted liver and NPC-related IBD. CASE REPORT: The patient underwent living donor liver transplantation (LDLT) due to severe acute liver failure caused by an unknown etiology inherited from her father. At 1 year and 6 months (1Y6M), she developed neurological delay, catalepsy, and vertical supranuclear gaze palsy. The foam cells were found in her skin, and fibroblast Filipin staining was positive; hence, she was diagnosed with NPC. It was identified that her father had NPC heterozygous pathogenic variant. At 2 years, she had anal fissure, skin tag and diarrhea. She was diagnosed with NPC-related IBD, using a gastrointestinal endoscopy. Three years after LT, liver biopsy revealed foam cells and numerous fatty droplets. At 8 years, broken hepatocytes and substantial fibrosis were observed. She died from circulation failure due to hypoalbuminemia at 8Y2M. CONCLUSIONS: In NPC, load of cholesterol metabolism is suggested to persist even after LT. LDLT from NPC heterozygous variant donor was insufficient to metabolize cholesterol overload. In NPC patients, the possibility of cholesterol re-accumulation should be considered when LT is performed. NPC-related IBD should be considered when NPC patients have anorectal lesions or diarrhea.

BACKGROUND: Vedolizumab (VDZ) is a humanized monoclonal antibody that binds to α4β7 integrin expressed in T-lymphocytes and is gut selective. Few studies have evaluated the safety and efficacy of VDZ in pediatric ulcerative colitis (UC) patients, especially from Asia. METHODS: A longitudinal multicenter retrospective study was conducted at 10 Japanese tertiary medical institutions. Patients aged ≤18 years old who received VDZ for UC between January 2019 and July 2021 were enrolled. Information on the clinical characteristics, prior/concomitant treatment, and safety during the observation period was collected. RESULTS: The data obtained from 48 patients (males, n = 30; females, n = 18) were analyzed. The median age at VDZ induction was 14 (range 4-18) years old. VDZ was indicated in 73% of patients as switching from previous biologics due to primary failure, loss of response, and adverse events (AEs) and was the first biologic in 27%. Remission was achieved or maintained at weeks 14, 30, and 54 in 79.2%, 75.0%, and 65.8% of patients, respectively. There were no significant differences between the number of previous biologics exposures and VDZ effectiveness. The hematocrit, serum albumin concentrations, and erythrocyte sedimentation rate (ESR) at baseline differed significantly by VDZ effectiveness. Nine AEs, including infusion reaction, were noted in seven (14.3%) patients. There were no severe AEs related to VDZ administration. CONCLUSIONS: VDZ was safe and effective in children with UC. The hematocrit, albumin, and ESR at VDZ initiation might be predictors for VDZ effectiveness. VDZ may be an important option for pediatric patients and can be used as an alternative to immunomodulators.

BACKGROUND: Peutz-Jeghers syndrome (PJS) is a rare disease characterized by the presence of hamartomatous polyposis throughout the gastrointestinal tract, except for the esophagus, along with characteristic mucocutaneous pigmentation. It is caused by germline pathogenic variants of the STK11 gene, which exhibit an autosomal dominant mode of inheritance. Some patients with PJS develop gastrointestinal lesions in childhood and require continuous medical care until adulthood and sometimes have serious complications that significantly reduce their quality of life. Hamartomatous polyps in the small bowel may cause bleeding, intestinal obstruction, and intussusception. Novel diagnostic and therapeutic endoscopic procedures such as small-bowel capsule endoscopy and balloon-assisted enteroscopy have been developed in recent years. SUMMARY: Under these circumstances, there is growing concern about the management of PJS in Japan, and there are no practice guidelines available. To address this situation, the guideline committee was organized by the Research Group on Rare and Intractable Diseases granted by the Ministry of Health, Labour and Welfare with specialists from multiple academic societies. The present clinical guidelines explain the principles in the diagnosis and management of PJS together with four clinical questions and corresponding recommendations based on a careful review of the evidence and involved incorporating the concept of the Grading of Recommendations Assessment, Development and Evaluation system. KEY MESSAGES: Herein, we present the English version of the clinical practice guidelines of PJS to promote seamless implementation of accurate diagnosis and appropriate management of pediatric, adolescent, and adult patients with PJS.

BACKGROUND: As best practices for treating children with severe-onset ulcerative colitis remain controversial in the era of biologic agents, we prospectively investigated treatments and outcomes in a multicenter cohort. METHODS: Using a Web-based data registry maintained in Japan between October 2012 and March 2020, we compared management and treatment outcomes in an S1 group defined by a Pediatric Ulcerative Colitis Activity Index of 65 or more points at diagnosis with those in an S0 group defined by an index value below 65. RESULTS: Three hundred one children with ulcerative colitis treated at 21 institutions were included, with follow-up for 3.6 ± 1.9 years. Among them, 75 (25.0%) were in S1; their age at diagnosis was 12.3 ± 2.9 years, and 93% had pancolitis. Colectomy free rates in S1 were 89% after 1 year, 79% after 2, and 74% after 5, significantly lower than for S0 (P = 0.0003). Calcineurin inhibitors and biologic agents, respectively, were given to 53% and 56% of S1 patients, significantly more than for S0 patients (P < 0.0001). Among S1 patients treated with calcineurin inhibitors when steroids failed, 23% required neither biologic agents nor colectomy, similarly to the S0 group (P = 0.46). CONCLUSIONS: Children with severe ulcerative colitis are likely to require powerful agents such as calcineurin inhibitors and biologic agents; sometimes colectomy ultimately proves necessary. Need for biologic agents in steroid-resistant patients might be reduced to an extent by interposing a therapeutic trial of CI rather than turning to biologic agents or colectomy immediately.

BACKGROUND: Fermented soybean (natto)-induced hypersensitivity reactions (natto allergy) are rare and can result in late-onset anaphylaxis. The allergen in natto is considered to be poly-γ-glutamic acid (PGA), and marine sports are a risk factor for natto allergy due to epicutaneous sensitization to PGA from cnidarian stings. However, no research on natto allergy in fishery workers has yet been performed. METHODS: We conducted a chart review of inpatients diagnosed with anaphylaxis due to natto at Hokkaido Prefectural Haboro Hospital between April 1, 2009, and August 31, 2020. We also administered self-report questionnaires about food hypersensitivity reactions to Japanese fishery workers, including members of the Kitarumoi Fishery Cooperative Association and part-time workers in this area, from February 1 to May 31, 2021. RESULTS: We found six inpatients (29 inpatients with food-induced anaphylaxis among approximately 11,000 community-dwelling residents) with late-onset anaphylaxis due to natto; all were involved in scallop aquaculture. The questionnaires revealed that 27 participants had natto allergy. We divided the fishery workers into a scallop aquaculture (Scallop) group (n = 211) and other fishery group (n = 106). The Scallop group was significantly associated with natto allergy after adjustments for confounders (OR: 5.73, 95% CI: 1.46-22.56) by logistic regression analysis. In the Scallop group, older age, experience in repairing nets, and a longer length of work experience were significantly related to participants with natto allergy (n = 23), but not participants without natto allergy (n = 181). CONCLUSIONS: Our results indicated an association between scallop aquaculture and natto allergy.

Inflammatory bowel disease (IBD) is a chronic relapsing inflammatory disorder of the intestine. The incidence of IBD is increasing worldwide, including Japan, and in approximately 25% of all affected patients it is diagnosed before 18 years of age. For the health maintenance of such patients, planned transition to adult care systems is essential. Previous Japanese surveys have revealed gaps between adult and pediatric gastroenterologists with regard to their knowledge and perception of health-care transition for patients with childhood-onset IBD. In 2021-2022, several Web workshops to discuss issues related to the transitional care of IBD patients were held by the Ministry of Health, Labour and Welfare of Japan as part of their program for research on intractable diseases. Clinicians experienced in IBD treatment for pediatric and adult patients participated. As a result, this panel of adult and pediatric gastroenterologists developed five consensus statements on the issue of "transfer from pediatric to adult care" and nine statements on the issue of "addressing transitional care (transition program)." To address current gaps in health-care transition for childhood-onset IBD patients, a programmed approach to transition, and better partnerships between pediatric and adult gastroenterologists are indicated. It is hoped that this consensus statement will provide a basis for the development of appropriate guidelines for clinical practice.