Ustekinumab Offers Long-Term Clinical Remission With Safety in Very Early-Onset Inflammatory Bowel Disease

We observed efficacy and safety of ustekinumab in very early-onset inflammatory bowel disease, which has not been previously reported. Clinical remission at 52% was 75%, often persisting beyond 2 years. Further studies including larger numbers of cases are needed to confirm this observation.

Prognosis of pediatric ulcerative colitis after infliximab failure: A multicenter registry-based cohort study

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.

Dried blood spot-based newborn screening for bile acid synthesis disorders, Zellweger spectrum disorder, and Niemann-Pick type C1 by detection of bile acid metabolites

OBJECTIVE

To examine whether it is possible to screen for bile acid synthesis disorders (BASDs) including peroxisome biogenesis disorder 1a (PBD1A) and Niemann-Pick type C1 (NPC1) at the time of newborn mass screening by measuring the intermediary metabolites of bile acid (BA) synthesis.

METHODS

Patients with 3β-hydroxy-ΔSuchy et al. (2021)5-C27-steroid dehydrogenase/isomerase (HSD3B7) deficiency (n = 2), 3-oxo-ΔPandak and Kakiyama (n.d.)4-steroid 5β-reductase (SRD5B1) deficiency (n = 1), oxysterol 7α-hydroxylase (CYP7B1) deficiency (n = 1), PBD1A (n = 1), and NPC1 (n = 2) with available dried blood spot (DBS) samples collected in the neonatal period were included. DBSs from healthy neonates at 4 days of age (n = 1055) were also collected for the control. Disease specific BAs were measured by newly optimized liquid chromatography-tandem mass spectrometry with short run cycle (5-min/run). The results were validated by comparing with those obtained by the conventional condition with longer run cycle (76-min/run).

RESULTS

In healthy specimens, taurocholic acid and cholic acid were the two major BAs which constituted approximately 80% in the measured BAs. The disease marker BAs presented <10%. In BASDs, the following BAs were determined for the disease specific markers: Glyco/tauro 3β,7α,12α-trihydroxy-5-cholenoic acid 3-sulfate for HSD3B7 deficiency (>70%); glyco/tauro 7α,12α-dihydroxy-3-oxo-4-cholenoic acid for SRD5B1 deficiency (54%); tauro 3β-hydroxy-5-cholenoic acid 3-sulfate for CYP7B1 deficiency (94%); 3α,7α,12α-trihydroxy-5β-cholestanoic acid for PBD1A (78%); and tauro 3β,7β-dihydroxy-5-cholenoic acid 3-sulfate for NPC1 (26%). *The % in the parenthesis indicates the portion found in the patient's specimen.

CONCLUSIONS

Early postnatal screening for BASDs, PBD1A and NPC1 is feasible with the described DBS-based method by measuring disease specific BAs. The present method is a quick and affordable test for screening for these inherited diseases.

Safety and efficacy of vedolizumab in pediatric patients with ulcerative colitis: multicenter study in Japan

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.

Incidence and diagnostic performance of ultrasound for perianal abscess or fistula-in-ano in pediatric patients with perianal inflammation

OBJECTIVES

To describe the incidence and diagnostic performance of ultrasound for perianal abscess or fistula-in-ano in pediatric patients with perianal inflammation.

METHODS

We included 45 patients with perianal inflammation who underwent ultrasonography. To demonstrate the diagnostic performance of ultrasound for fistula-in-ano, a definite diagnosis of perianal abscess, and fistula-in-ano was determined as that proven through magnetic resonance imaging (MRI) or computed tomography (CT). The absence or presence of perianal abscess and fistula-in-ano on ultrasonography was recorded.

RESULTS

Among the 45 patients, on ultrasound, perianal abscess and fistula-in-ano were detected in 22 (48.9%) and 30 (68.2%) patients, respectively. Nine patients had MRI or CT and a definite diagnosis of perianal abscess or fistula-in-ano; accuracy, negative predictive value, and positive predictive value of ultrasound for perianal abscess were 77.8% (7/9; 95% confidence interval [CI]: 40.0%-97.1%), 66.7% (2/3; 95% CI: 9.4%-99.2%), 83.3% (5/6; 95% CI: 35.9%-99.6%), and those of fistula-in-ano were 100% (9/9; 95% CI: 66.4%-100%), 100% (8/8; 95% CI: 63.1%-100%), and 100% (1/1; 95% CI: 2.5%-100%), respectively.

CONCLUSIONS

Perianal abscess and fistula-in-ano were detected by ultrasound in half of the patients with perianal inflammation. Accordingly, ultrasound has an acceptable diagnostic performance for perianal abscess and fistula-in-ano.

Clinical outcome of ulcerative colitis with severe onset in children: a multicenter prospective cohort study

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.

Serum leucine-rich alpha-2 glycoprotein and calprotectin in children with inflammatory bowel disease: A multicenter study in Japan

BACKGROUND AND AIM

Serum leucine-rich alpha-2 glycoprotein (LRG) and calprotectin have been studied as disease activity markers in adults with inflammatory bowel disease (IBD). We evaluated them in pediatric IBD patients.

METHODS

Subjects under 17 years old undergoing care at 11 Japanese pediatric centers were retrospectively assigned to 3 groups representing Crohn's disease (CD), ulcerative colitis (UC), and normal controls (NC) with irritable bowel syndrome or no illness. Serum LRG and calprotectin were measured using commercial enzyme-linked immunosorbent assay kits.

RESULTS

We enrolled 173 subjects, including 74 with CD, 77 with UC, and 22 NC. Serum LRG concentrations in active CD (median, 200 μg/mL) were significantly greater than in remission (81 μg/mL; P < 0.001) or NC (69 μg/mL; P < 0.001). Serum calprotectin concentrations in active CD (2941 ng/mL) also were significantly greater than in remission (962 ng/mL; P < 0.05) or NC (872 ng/mL; P < 0.05). Serum LRG concentrations in active UC (134 μg/mL) were significantly greater than in remission (65 μg/mL; P < 0.01) but not significantly greater than in NC (69 μg/mL); serum calprotectin concentrations in active UC (1058 ng/mL) were not significantly different from those in remission (671 ng/mL) or NC (872 ng/mL). In receiver operating characteristic analyses of LRG, calprotectin, C-reactive protein, and erythrocyte sedimentation rate for ability to distinguish active IBD from remission, CD and UC showed areas under receiver operating characteristic curves for LRG (0.77 and 0.70, respectively), exceeding those for calprotectin, C-reactive protein, or erythrocyte sedimentation rate.

CONCLUSIONS

In pediatric IBD, serum LRG may better reflect disease activity than serum calprotectin, particularly in CD.

Expert consensus on vaccination in patients with inflammatory bowel disease in Japan

Immunosuppressive therapies can affect the immune response to or safety of vaccination in patients with inflammatory bowel disease (IBD). The appropriateness of vaccination should be assessed prior to the initiation of IBD treatment because patients with IBD frequently undergo continuous treatment with immunosuppressive drugs. This consensus was developed to support the decision-making process regarding appropriate vaccination for pediatric and adult patients with IBD and physicians by providing critical information according to the published literature and expert consensus about vaccine-preventable diseases (VPDs) [excluding cervical cancer and coronavirus disease 2019 (COVID-19)] in Japan. This consensus includes 19 important clinical questions (CQs) on the following 4 topics: VPDs (6 CQs), live attenuated vaccines (2 CQs), inactivated vaccines (6 CQs), and vaccination for pregnancy, childbirth, and breastfeeding (5 CQs). These topics and CQs were selected under unified consensus by the members of a committee on intractable diseases with support by a Health and Labour Sciences Research Grant. Physicians should provide necessary information on VPDs to their patients with IBD and carefully manage these patients' IBD if various risk factors for the development or worsening of VPDs are present. This consensus will facilitate informed and shared decision-making in daily IBD clinical practice.

Monogenic inflammatory bowel disease with STXBP2 mutations is not resolved by hematopoietic stem cell transplantation but can be alleviated via immunosuppressive drug therapy

STXBP2, encoding syntaxin-binding protein 2, is involved in intracellular organelle trafficking and is associated with familial hemophagocytic lymphohistiocytosis type 5. Although STXBP2 mutations reportedly cause monogenic inflammatory bowel disease, the clinical course and underlying pathogenic mechanisms remain unclear. We identified a novel mutation in STXBP2 [c.1197delC, p.Ala400fs] in a boy with congenital intractable diarrhea and hemophagocytic lymphohistiocytosis (HLH). HLH was treated with intravenous prednisolone, cyclosporine, and dexamethasone palmitate. Hematopoietic stem cell transplantation (HSCT) along with prophylaxis for graft-versus-host-disease was performed at 5 months of age. Additionally, colonoscopies done before and after HSCT showed mild colitis with cryptitis. The patient showed elevated fecal calprotectin levels and persistent diarrhea even after HSCT and required partial parenteral nutrition. While anti-inflammatory treatment reduced diarrhea, it was not completely normalized even after HSCT, suggesting that the pathogenesis of inflammatory bowel disease associated with STXBP2 mutations involves both hyperinflammation and functional epithelial barrier defects.

Small bowel endoscopy for children: Collaboration of capsule endoscopy and device-assisted enteroscopy

Capsule endoscopy (CE) and balloon-assisted enteroscopy (BAE) have become indispensable techniques for the diagnosis and management of small bowel disease in both adult and pediatric cases. However, relevant differences exist in the indications between these cohorts, with body weight and age having particular relevance in decisions for the latter. Both CE and BAE are designed for adult physique and they were not widely used among children. In addition, the types of small intestinal diseases differ between adults and children, and consequently, the indications also differ between them. This review focuses on the issues relevant to pediatric cases and describes the practical application of endoscopy in clinical practice. In conclusion, although there are age and weight restrictions, both CE and BAE are safe and useful devices for use in children, and their indications for use in children are likely to expand in the future.

Role of ultrasound in the diagnosis of very early-onset inflammatory bowel disease in children: a report of three cases

Very early-onset inflammatory bowel disease (VEO-IBD) is defined as IBD onset before 6 years of age and some cases are caused by unique monogenic disorders that require specific treatments such as stem cell transplantation. We identified three children with VEO-IBD of whom two had monogenic disorders. In cases 1 and 2, ultrasound revealed isolated colonic distribution and the loss of wall stratification. In case 3, mesentery inflammation was evident. Bowel ultrasound showed variable findings due to differences in the inflammation distribution within the bowel. In order to diagnose VEO-IBD, sonographersshould carefully evaluate the intestinal wall thickness and stratification and the distribution of inflammation in the intestine and mesentery. These findings may aid the diagnosis of VEO-IBD.

Clostridioides difficile Infection in a Japanese Tertiary Children's Hospital

PURPOSE

Toxins produced by Clostridioides difficile infection (CDI) can cause enteritis and diarrhea. Although the number of pediatric CDI cases is increasing, the clinical management of pediatric CDI, including patient characteristics and prognosis, remains unclear. This study aimed to elucidate the background and clinical course of patients with CDI and evaluate the reliability of diagnostic tests in a tertiary pediatric hospital in Japan.

METHODS

We retrospectively analyzed the clinical data of children diagnosed with CDI between 2011 and 2021 at the Saitama Children's Medical Center in Saitama, Japan.

RESULTS

During the study period, 1,252 C. difficile antigen/toxin tests were performed, and 37 patients were diagnosed with CDI. The main underlying diseases among the patients were hematological and malignant disorders and gastrointestinal diseases, including inflammatory bowel disease (IBD) (59.4%). Two patients (5.4%) had an unremarkable medical history. Among the 37 patients, 27 (73.0%) were immunocompromised, 25 (67.6%) had a history of antibiotic use within the past two months, and 6 (16.2%) were negative on the initial test but were positive on the second test. Finally, 28 patients (75.7%) required primary antibiotic therapy only, and two patients with IBD required additional antibiotic therapy as secondary treatment.

CONCLUSION

The number of pediatric patients with CDI is increasing. Both a comprehensive interview, including underlying diseases and history of antibiotic use, and an understanding of the features of clinical examinations should be emphasized to appropriately diagnose and treat CDI.

Dapsone for Refractory Gastrointestinal Symptoms in Children With Immunoglobulin A Vasculitis

Immunoglobulin A vasculitis (IgAV) is a systemic small-vessel vasculitis. Although corticosteroids (CS) are the primary treatment for gastrointestinal manifestations associated with IgAV, some patients develop refractory or recurrent symptoms such as vomiting and abdominal pain despite CS treatment. Dapsone, a synthetic sulfone antimicrobial, has been used to treat cutaneous purpura in IgAV, but few authors have reported its use for refractory gastrointestinal symptoms. In this retrospective observational study, we describe results in 7 children with IgAV who were treated with dapsone for abdominal pain resistant to CS. Dapsone rapidly relieved abdominal pain in all 7 patients, who then were tapered off CS without relapse. Side effects of mild methemoglobinemia and hemolysis appeared to be manageable with planned monitoring and dose adjustment; a single patient who discontinued dapsone had fatigue and hypoxia associated with methemoglobinemia. No side effects were life-threatening. Dapsone may be considered as a therapeutic option for gastrointestinal symptoms refractory to CS in children with IgAV.

Serum Zinc and Selenium in Children with Inflammatory Bowel Disease: A Multicenter Study in Japan

BACKGROUND

Reports of zinc and selenium deficiencies accompanying inflammatory bowel disease (IBD) mostly have originated from Western countries and concerned adult patients. Whether Japanese children with IBD have similar deficiencies remained unclear.

AIM

We aimed to elucidate differences in serum zinc and selenium concentrations in Japanese children between types of IBD.

METHODS

Children under 17 years old undergoing care at 12 Japanese pediatric centers were retrospectively enrolled between November 2016 and February 2018 to 3 groups representing Crohn's disease (CD), ulcerative colitis (UC), and normal controls (NC) with irritable bowel syndrome or no illnesses. Serum zinc and selenium were measured by atomic absorption spectrophotometry. Zinc and selenium deficiencies were defined by serum concentrations < 70 μg/dL and < 9.5 μg/dL, respectively.

RESULTS

Subjects included 98 patients with CD (median age, 13 years), 118 with UC (11 years), and 43 NC (11 years). Serum zinc and selenium were significantly lower in CD (median, 64 and 12.6 μg/dL respectively) than in UC (69 and 14.6; P < 0.05 and P < 0.001) or NC (77 and 15.7; P < 0.01 and P < 0.001). Zinc deficiency was significantly more prevalent in CD (60.2%) than in NC (37.2%; P < 0.05), but not than in UC (51.7%; P = 0.22). Selenium deficiency was significantly more prevalent in CD (15.3%) than in UC (5.9%; P < 0.05) or NC (0%; P < 0.01).

CONCLUSIONS

In Japanese children under 17 years old, serum zinc and selenium were significantly lower in CD than in UC or NC. Zinc and selenium should be monitored, and supplemented when deficient, in children with IBD, especially CD.

A Systematic Review of Monogenic Inflammatory Bowel Disease

BACKGROUND & AIMS

Advances in genomic technologies have led to increasing reports of monogenic inflammatory bowel disease (IBD). Here, we systematically review the literature to determine the clinical features, genetic profile, and previously used treatment strategies in monogenic IBD.

METHODS

A systematic review of MEDLINE articles published between January 2000 and December 2020 was conducted. A total of 750 individual monogenic IBD cases were identified from 303 eligible articles.

RESULTS

The most frequently reported monogenic IBD genes were IL10RA/B, XIAP, CYBB, LRBA, and TTC7A. In total, 63.4% of patients developed IBD before 6 years of age, 17.4% developed IBD between ages 10 and 17.9 years, and 10.9% developed IBD after age 18. There was a substantial difference between these age groups and the underlying monogenic disorders. Only 31.7% had any history of extraintestinal comorbidity (EIC) before IBD onset, but 76.0% developed at least 1 EIC during their clinical course. The most common EICs were atypical infection (44.7%), dermatologic abnormality (38.4%), and autoimmunity (21.9%). Bowel surgery, biologic therapy, and hematopoietic stem cell transplantation were performed in 27.1%, 32.9%, and 23.1% of patients, respectively.

CONCLUSIONS

Monogenic IBD cases, although rare, have varied extraintestinal comorbidities and limited treatment options including surgery and transplant. Early identification and improved understanding of the characteristics of the genes and underlying disease processes in monogenic IBD is important for effective management.

Deficiency in X-linked inhibitor of apoptosis protein promotes susceptibility to microbial triggers of intestinal inflammation

Inflammatory bowel disease (IBD) is characterized by inappropriate immune responses to the microbiota in genetically susceptible hosts, but little is known about the pathways that link individual genetic alterations to microbiota-dependent inflammation. Here, we demonstrated that the loss of X-linked inhibitor of apoptosis protein (XIAP), a gene associated with Mendelian IBD, rendered Paneth cells sensitive to microbiota-, tumor necrosis factor (TNF)–, receptor-interacting protein kinase 1 (RIPK1)–, and RIPK3-dependent cell death. This was associated with deficiency in Paneth cell–derived antimicrobial peptides and alterations in the stratification and composition of the microbiota. Loss of XIAP was not sufficient to elicit intestinal inflammation but provided susceptibility to pathobionts able to promote granulomatous ileitis, which could be prevented by administration of a Paneth cell–derived antimicrobial peptide. These data reveal a pathway critical for host-microbial cross-talk, which is required for intestinal homeostasis and the prevention of inflammation and which is amenable to therapeutic targeting.

Deficiency in X-linked inhibitor of apoptosis protein promotes susceptibility to microbial triggers of intestinal inflammation

Inflammatory bowel disease (IBD) is characterized by inappropriate immune responses to the microbiota in genetically susceptible hosts, but little is known about the pathways that link individual genetic alterations to microbiota-dependent inflammation. Here, we demonstrated that the loss of X-linked inhibitor of apoptosis protein (XIAP), a gene associated with Mendelian IBD, rendered Paneth cells sensitive to microbiota-, tumor necrosis factor (TNF)–, receptor-interacting protein kinase 1 (RIPK1)–, and RIPK3-dependent cell death. This was associated with deficiency in Paneth cell–derived antimicrobial peptides and alterations in the stratification and composition of the microbiota. Loss of XIAP was not sufficient to elicit intestinal inflammation but provided susceptibility to pathobionts able to promote granulomatous ileitis, which could be prevented by administration of a Paneth cell–derived antimicrobial peptide. These data reveal a pathway critical for host-microbial cross-talk, which is required for intestinal homeostasis and the prevention of inflammation and which is amenable to therapeutic targeting.

Diagnostic accuracy of serum proteinase 3 antineutrophil cytoplasmic antibodies in children with ulcerative colitis

BACKGROUND AND AIM

Serologic markers such as myeloperoxidase (MPO) antineutrophil cytoplasmic antibodies (ANCA) (MPO-ANCA) have been used to screen patients for ulcerative colitis (UC). However, MPO-ANCA shows limited accuracy in Asians. Proteinase 3 ANCA (PR3-ANCA) has performed better at UC diagnosis in Japanese adults than MPO-ANCA. The present study aimed to evaluate usefulness of PR3-ANCA for diagnosis of UC in Japanese pediatric practice.

METHODS

Patients under 17 years old undergoing assessment at 12 Japanese pediatric centers between November 2016 and February 2018 were prospectively enrolled and divided into groups with UC, Crohn's disease (CD), intestinal disease control (IC), and healthy control (HC). Serum PR3-ANCA and MPO-ANCA were analyzed using chemiluminescence enzyme immunoassay kits.

RESULTS

Sera from 367 patients (148 with UC at a median age of 12 years; 120 with CD, 13 years; 56 with IC, 10.5 years; and 43 with HC, 10 years) were examined. Median PR3-ANCA values in UC (1.6 U/mL) were greater than in CD (0.2; P < 0.001), IC (0.15; P < 0.001), and HC (0.1; P < 0.001). In receiver operating characteristic curve analyses, the area under the curve for PR3-ANCA was 0.79, significantly greater than for MPO-ANCA (0.58; P < 0.001). Using a cut-off value of 0.8 U/mL determined from the receiver operating characteristic analyses, PR3-ANCA showed significantly greater sensitivity (64.9%) than MPO-ANCA (cut-off, 0.2 U/mL; sensitivity, 19.6%; P < 0.001) and good specificity (83.6%).

CONCLUSIONS

In Japanese children and adolescents, PR3-ANCA performed better as a serologic marker for diagnosis of UC than MPO-ANCA. To our knowledge, this is the first report of such a comparison.

Novel CARMIL2 loss-of-function variants are associated with pediatric inflammatory bowel disease

CARMIL2 is required for CD28-mediated co-stimulation of NF-κB signaling in T cells and its deficiency has been associated with primary immunodeficiency and, recently, very early onset inflammatory bowel disease (IBD). Here we describe the identification of novel biallelic CARMIL2 variants in three patients presenting with pediatric-onset IBD and in one with autoimmune polyendocrine syndrome (APS). None manifested overt clinical signs of immunodeficiency before their diagnosis. The first patient presented with very early onset IBD. His brother was found homozygous for the same CARMIL2 null variant and diagnosed with APS. Two other IBD patients were found homozygous for a nonsense and a missense CARMIL2 variant, respectively, and they both experienced a complicated postoperative course marked by severe infections. Immunostaining of bowel biopsies showed reduced CARMIL2 expression in all the three patients with IBD. Western blot and immunofluorescence of transfected cells revealed an altered expression pattern of the missense variant. Our work expands the genotypic and phenotypic spectrum of CARMIL2 deficiency, which can present with either IBD or APS, aside from classic immunodeficiency manifestations. CARMIL2 should be included in the diagnostic work-up of patients with suspected monogenic IBD.

A26 A SYSTEMTIC REVIEW OF MONOGENIC INFLAMMATORY BOWEL DISEASE: CLINICAL PHENOTYPE AND GENOTYPE

Background

Advances in genomic technologies have led to an increase in reports of monogenic inflammatory bowel disease (IBD). The majority of the studies on monogenic IBD have focused only on young children aged &lt;6 years. There are no detailed reports containing a comprehensive picture of monogenic IBD with specific numbers on the clinical features, genetic profiles and disease course. Since each gene-specific cause of monogenic IBD is rare, it is difficult to collect cases in a single study even with international cohort studies.

Aims

To elucidate a comprehensive picture of monogenic IBD, we conducted a systematic review of all reported cases of monogenic IBD.

Methods

A systematic review of MEDLINE articles published between January 2000 and December 2019 was conducted. 662 monogenic IBD cases were identified from 273 eligible articles. Data on clinical manifestation, genotype, and management were collected.

Results

The most frequently reported genes causative of monogenic IBD patients were IL10RA, CYBB, IL10RB, and TTC7A (Figure). In total, 64.8% of patients developed IBD before six years old, 15.6% between ages 10 and 17.9 years, and 11.6% at age 18 years or older. Only 32.7% had any history of extra-intestinal manifestation (EIM) before IBD onset. There was substantial difference in the onset age groups and the underlying monogenic disorders. 74.4% developed at least one EIM during their clinical course. The most common EIMs were atypical infection (44.1%), dermatologic abnormality (39.2%), autoimmunity (22.7%) and lymphoid organ abnormality (11.5%). Autosomal recessive (62.8%) was the most common inheritance pattern, and missense-variants (44.3%) were the most identified type of genetic variants. Deletions including CNVs, intronic, synonymous and inversion, which have the possibility to be overlooked by whole exome sequencing were shown in some cases. Bowel surgery, biologics, and hematopoietic stem cell transplantation were performed in 28.3%, 32.8%, and 24.4% of patients, respectively.

Conclusions

Monogenic IBD diagnosis and management is a challenging clinical problem across age groups; the EIMs are more diverse and the management is evidently more difficult compared to non-monogenic IBD. An improved understanding of the characteristics of the genes and underlying disease processes in monogenic IBD is necessary for effective management.

Funding Agencies

CAG, CIHRUehara Memorial Foundation Fellowship

Clinical and Immunological Heterogeneity in Japanese Patients with Gain-of-Function Variants in STAT3

PURPOSE

Germline loss-of-function variants in the signal transducer and activator of transcription 3 (STAT3) gene result in autosomal dominant hyper IgE syndrome, whereas somatic gain-of-function (GOF) variants in STAT3 are associated with some malignancies. In addition, germline GOF variants in STAT3 are linked to disorders involving autoimmunity and lymphoproliferation. In this study, we describe five Japanese families with germline GOF variants in STAT3, including three novel variants. We also present the clinical and immunological characteristics of these patients.

METHODS

Eight patients from five families were enrolled in this study. We performed genetic and immunological analyses, and collected the associated clinical information.

RESULTS

We identified five heterozygous variants in STAT3 using whole-exome sequencing and target gene sequencing. Two of these (E286G and T716M) were previously reported and three (K348E, E415G, and G618A) were novel. A STAT3 reporter assay revealed that all of the variants were GOF. However, the immunological and clinical characteristics among the patients were highly variable.

CONCLUSION

Patients with STAT3 GOF variants exhibited clinical and immunological heterogeneity with incomplete penetrance.

Causes of Melena and Effective Examination Strategies in Children

Background and Aim: Melena, or tarry black stool, is not a rare symptom encountered in pediatric clinical practice, and the bleeding source varies from the upper gastrointestinal tract to the small intestine. Endoscopy is effective in identifying bleeding, but it does not always identify the source of bleeding. Endoscopic examination in children is commonly challenging, and there are no detailed reports about the causes of melena in children. This observational study aimed to validate the cause of melena in children and to investigate more effective and less burdensome examination methods. Methods: We retrospectively reviewed the clinical records of 55 patients who underwent examination for melena. Results: In this research, 38 patients had underlying diseases such as malignancy and severe mental and physical disorders. The bleeding source was identified in 39 patients. The most common final diagnosis was duodenal ulcer (n = 22), and the other diagnoses were gastric ulcer, esophagitis, and esophageal varices. The upper gastrointestinal tract was the most common source of bleeding (n = 34). In five patients, the bleeding source was the small intestine. Vomiting, abnormal abdominal ultrasonography findings, and a hemoglobin level of ≤ 3 g/dL than the lower normal limit were significant factors indicating that the bleeding source can be found on esophagogastroduodenoscopy. Conclusions: The upper gastrointestinal tract was the most common bleeding source of melena in children. As in adults, esophagogastroduodenoscopy is the primary endoscopic method of choice. Furthermore, small bowel capsule endoscopy may be useful in identifying the bleeding source in children without upper gastrointestinal lesions.

Possible mitochondrial dysfunction in a patient with deafness, dystonia, and cerebral hypomyelination (DDCH) due to BCAP31 Mutation

Background

Deafness, dystonia, and cerebral hypomyelination (DDCH) is an X‐linked disorder due to hemizygous mutations of BCAP31.

Methods

We report an 8‐year‐old boy with DDCH who possibly accompanied mitochondrial dysfunction. Clinical evaluation, respiratory chain enzyme assay, and whole exome sequencing analysis were performed.

Results

Mitochondrial dysfunction was suspected by respiratory chain enzyme assay on his cultured skin fibroblasts which showed significantly decreased complex I enzyme activity. Whole exome sequencing analysis revealed a recurrent BCAP31 mutation (c.97C>T:p.Gln33*) which confirmed the diagnosis of DDCH for the patient.

Conclusion

We speculate that mitochondrial dysfunction may be a feature in patients with DDCH.

Advanced Understanding of Monogenic Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) is a group of chronic disorders that cause relapsing inflammation in the gastrointestinal tract and comprise three major subgroups of Crohn's disease (CD), ulcerative colitis (UC), and IBD-unclassified (IBDU). Recent advances in genomic technologies have furthered our understanding of IBD pathogenesis. It includes differentiation rare monogenic disorders exhibiting IBD and IBD-like inflammation (monogenic IBD) from patients with the common polygenic form of IBD. Several novel genes responsible for monogenic IBD have been elucidated, and the number of reports has increased due to advancements in molecular functional analysis. Identification of these pathogenic genetic mutations has helped in elucidating the details of the immune response associated with gastrointestinal inflammation and in providing individualized treatments for patients with severe IBD that is often unresponsive to conventional therapy. The majority of monogenic IBD studies have focused on young children diagnosed <6 years of age (very early-onset IBD); however, a recent study revealed high prevalence of monogenic IBD in older children aged >6 years of age as well. Meanwhile, although patients with monogenic IBD generally show co-morbidities and/or extraintestinal manifestation at the time of diagnosis, cases of IBD developing as the initial symptom with unremarkable prodromal symptoms have been reported. It is crucial that the physicians properly match genetic analytical data with clinical diagnosis and/or differential diagnosis. In this review, we summarize the essential clues that may physicians make a correct diagnosis of monogenic disease, including classification, prevalence and clinical phenotype based on available literatures.

Efficacy and safety of a capsule endoscope delivery device in children

OBJECTIVES

This multicenter, cross-sectional study aimed to elucidate the efficacy and safety of the AdvanCE capsule endoscope delivery device for children in Japan.

METHODS

The present study analyzed 183 cases of small bowel capsule endoscope (SBCE) insertion performed using the AdvanCE in 154 patients aged less than 18 years at participating institutions between 2013 and 2017. Statistical analyses were conducted to identify factors contributing to the completion rate for the entire small intestine examination, small intestine transit time, adverse events and technical issues.

RESULTS

The commonest reason for using the AdvanCE was the patient's inability to swallow the SBCE, which was attributed to young age. SBCE was successfully delivered into the stomach or duodenum in 180 cases and was placed in the duodenum in 90% patients. In 89% patients, the entire small intestine was completely examined, and in 63% patients, findings leading to a new diagnosis or involving changing or maintaining the treatment strategy were obtained. No severe adverse events were observed; however, mild adverse events were observed in 35% patients. No factors considerably contributed to the completion rate for the entire small intestine examination or small intestine transit time and onset of technical issues. The factors that contributed to mild adverse events included intravenous anesthesia, technical issue, and absence of prior insertion of a patency capsule using the AdvanCE.

CONCLUSION

The AdvanCE is well tolerated and effective for children.

Screening of carnitine and biotin deficiencies on tandem mass spectrometry

BACKGROUND

It is important to assess pediatric patients for nutritional deficiency when they are receiving specific interventions, such as enteral feeding. We focused on measurement of C0 and 3-hydroxyisovalerylcarnitine (C5-OH) with tandem mass spectrometry (MS/MS), which is performed as part of the newborn mass screening. The purpose of this study was to investigate the usefulness of MS/MS for screening carnitine and biotin deficiencies.

METHODS

Forty-two children (24 boys, 18 girls) were enrolled between December 2013 and December 2015. Blood tests, including measurement of serum free carnitine via the enzyme cycling method, and acylcarnitine analysis on MS/MS of dried blood spot (DBS), were performed for the evaluation of nutrition status.

RESULTS

Median patient age was 2 years (range, 2 months-14 years). Mean serum free carnitine was 41.8 ± 19.2 μmol/L. In six of the 42 patients, serum free carnitine was <20 μmol/L (range, 4.0-18.7 μmol/L). C0 and C5-OH measured on MS/MS of DBS were 33.8 ± 20.2 nmol/mL and 0.48 ± 0.22 nmol/mL, respectively. There was a strong positive correlation (r = 0.89, P < 0.001) between serum free carnitine and C0 measured on the same day. In one patient on hydrolyzed formula, C5-OH was >1.00 nmol/L. Therapy-resistant eczema was improved by treatment with additional biotin and a non-hydrolyzed formula.

CONCLUSION

C0 and C5-OH, measured on MS/MS of DBS, were useful for screening carnitine and biotin deficiencies.

Difference between early onset and late-onset pediatric ulcerative colitis

BACKGROUND

Early onset pediatric ulcerative colitis (EO-UC) is distinguished from late-onset pediatric ulcerative colitis (LO-UC) by the effects of genetic predisposition, but there have been few reports on the clinical features of EO-UC in Asia.

METHODS

To describe and compare the presentation and disease course of EO-UC (age range, 0-7 years) with those of LO-UC (age range, 8-15 years), we retrospectively analyzed 63 children with UC who had been diagnosed between January 2004 and March 2014 at Saitama Children's Medical Center in Japan.

RESULTS

Ten patients (16%) had EO-UC, and 53 (84%) had LO-UC. All patients in the EO-UC group and 70% in the LO-UC group had pancolitis (P = 0.05). The period from onset to diagnosis was 9.0 ± 14.1 months for EO-UC and 2.6 ± 3.5 months for LO-UC (P < 0.01). The prevalence of extra-intestinal complications at diagnosis was significantly higher for EO-UC than for LO-UC (50% vs 11%, respectively; P < 0.01). There were no significant differences in the use of corticosteroids, immunomodulators, immunosuppressants, or surgical risk between the groups but, in the EO-UC group, only one patient was treated with cytapheresis and none was treated with anti-tumor necrosis factor (TNF-α) antibodies.

CONCLUSIONS

The EO-UC group had a higher incidence of pancolitis, longer diagnostic delay, and more extra-intestinal manifestations than the LO-UC group. Diagnosis and treatment may therefore be slightly more difficult for EO-UC than for LO-UC.

Improved search for nu(mu) --> nu(e) oscillation in a long-baseline accelerator experiment

We performed an improved search for nu(mu) --> nu(e) oscillation with the KEK to Kamioka (K2K) long-baseline neutrino oscillation experiment, using the full data sample of 9.2 x 10(19) protons on target. No evidence for a nu(e) appearance signal was found, and we set bounds on the nu(mu) --> nu(e) oscillation parameters. At Deltam(2)=2.8 x 10(-3) eV(2), the best-fit value of the K2Knu(mu) disappearance analysis, we set an upper limit of sin(2)2theta(mue) < 0.13 at a 90% confidence level.

Search for coherent charged pion production in neutrino-carbon interactions

We report the result from a search for charged-current coherent pion production induced by muon neutrinos with a mean energy of 1.3 GeV. The data are collected with a fully active scintillator detector in the K2K long-baseline neutrino oscillation experiment. No evidence for coherent pion production is observed, and an upper limit of is set on the cross section ratio of coherent pion production to the total charged-current interaction at 90% confidence level. This is the first experimental limit for coherent charged pion production in the energy region of a few GeV.

Evidence for muon neutrino oscillation in an accelerator-based experiment

We present results for nu(mu) oscillation in the KEK to Kamioka (K2K) long-baseline neutrino oscillation experiment. K2K uses an accelerator-produced nu(mu) beam with a mean energy of 1.3 GeV directed at the Super-Kamiokande detector. We observed the energy-dependent disappearance of nu(mu), which we presume have oscillated to nu(tau). The probability that we would observe these results if there is no neutrino oscillation is 0.0050% (4.0 sigma).

Evidence for an oscillatory signature in atmospheric neutrino oscillations

Muon neutrino disappearance probability as a function of neutrino flight length L over neutrino energy E was studied. A dip in the L/E distribution was observed in the data, as predicted from the sinusoidal flavor transition probability of neutrino oscillation. The observed L/E distribution constrained nu(micro)<-->nu(tau) neutrino oscillation parameters; 1.9x10(-3)<Deltam(2)<3.0x10(-3) eV(2) and sin((2)2theta>0.90 at 90% confidence level.

Search for electron neutrino appearance in a 250 km long-baseline experiment

We present a search for electron neutrino appearance from accelerator-produced muon neutrinos in the K2K long-baseline neutrino experiment. One candidate event is found in the data corresponding to an exposure of 4.8 x 10(19) protons on target. The expected background in the absence of neutrino oscillations is estimated to be 2.4+/-0.6 events and is dominated by misidentification of events from neutral current pi(0) production. We exclude the nu(micro) to nu(e) oscillations at 90% C.L. for the effective mixing angle in the 2-flavor approximation of sin((2)2theta(microe)( approximately 1/2sin((2)2theta(13))>0.15 at Deltam(2)(microe)=2.8 x 10(-3) eV(2), the best-fit value of the nu(micro) disappearance analysis in K2K. The most stringent limit of sin((2)2theta(microe)<0.09 is obtained at Deltam(2)(microe)=6 x 10(-3) eV(2).

Angiopoietin 1 inhibits ocular neovascularization and breakdown of the blood-retinal barrier

Several retinal and choroidal diseases are potentially treatable by intraocular delivery of genes whose products may counter or neutralize abnormal gene expression that occurs as part of the diseases. However, prior to considering a transgene, it is necessary to thoroughly investigate the effects of its expression in normal and diseased eyes. An efficient way to do this is to combine tissue-specific promoters with inducible promoter systems in transgenic mice. In this study, we used this approach to evaluate the effects of ectopic expression of angiopoietin-1 (Ang1) in normal eyes and those with ocular neovascularization. Adult mice with induced expression of Ang1 ubiquitously, or specifically in the retina, appeared normal and had no identifiable changes in retinal or choroidal blood vessels or in retinal function as assessed by electroretinography. Increased expression of Ang1 in eyes with severe retinal ischemia or in eyes with rupture of Bruch's membrane significantly suppressed the development of retinal or choroidal neovascularization, respectively. This inhibition of ocular neovascularization is particularly interesting and noteworthy, because overexpression of Ang1 in skin stimulates neovascularization. Ang1 also significantly reduced VEGF-induced retinal vascular permeability. These data suggest that intraocular delivery of ang1 has potential for treatment of ocular neovascularization and macular edema.

Limits on the neutrino magnetic moment using 1496 days of Super-Kamiokande-I solar neutrino data

A search for a nonzero neutrino magnetic moment has been conducted using 1496 live days of solar neutrino data from Super-Kamiokande-I. Specifically, we searched for distortions to the energy spectrum of recoil electrons arising from magnetic scattering due to a nonzero neutrino magnetic moment. In the absence of a clear signal, we found micro(nu)</=(3.6x10(-10))micro(B) at 90% C.L. by fitting to the Super-Kamiokande day-night spectra. The fitting took into account the effect of neutrino oscillation on the shapes of energy spectra. With additional information from other solar neutrino and KamLAND experiments constraining the oscillation region, a limit of micro(nu)</=(1.1x10(-10))micro(B) at 90% C.L. was obtained.