Natural history and clinical features of hepatitis C virus infection during childhood: A nationwide, observational survey in Japan.

AIM: Few data on spontaneous clearance rates of cases of mother-to-child transmission of hepatitis C viral (HCV) infection are available in Japan. Furthermore, the treatment courses of interferon-based and direct-acting antiviral agent (DAA) therapies for children are also unclear. Our aim was thus to clarify the long-term natural progression of HCV infection and the treatment outcomes of children in Japan. METHODS: We conducted a combined multicenter, observational survey involving 65 pediatric institutions in Japan. Pediatric HCV infection cases with patients born between 1973 and 2021 were collected over the 11-year period from 2012 to 2022. A total of 563 patients were enrolled, with 190 excluded for having insufficient laboratory data or treatment information, resulting in 373 eligible cases. RESULTS: Of 328 cases of mother-to-child infection, 34 (10.4%) had spontaneous clearance, with a median time to spontaneous clearance of 3.1 years (range 0.9-7.2 years). Of the total 373 eligible cases, 190 received antiviral therapy (interferon-based therapy, 158; DAA therapy, 32). Sustained virologic response rates after first-line treatment were 75.3% (119/158) and 100% (32/32) for interferon-based therapy and DAA therapy, respectively, with the DAA group showing a shorter time from therapy initiation to viral negativity (2.7 vs. 1.0 months; p = 0.0031). CONCLUSIONS: Approximately 10% of Japanese children infected by mother-to-child transmission achieve spontaneous resolution of HCV infection. Our findings indicate that DAA therapy is safe and highly effective in Japanese children, achieving higher sustained virologic response rates and shorter time to clearance of the virus compared with interferon-based therapy.

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.

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.

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 α4ß7 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.

Inborn errors of bile acid metabolism in Japan.

Bile acids are a category of steroids biosynthesized from cholesterol in the liver. Inborn errors of their metabolism are inherited in an autosomal recessive manner, resulting in enzyme deficiencies affecting the bile acid biosynthetic pathway. These defects in the pathway cause accumulation of unusual bile acids or bile alcohols. Unusual bile acids are highly cytotoxic, causing injury to the liver. These unusual bile acids damage hepatocytes, resulting in cholestatic liver injury beginning in infancy. Except for cerebrotendinous xanthomatosis and some secondary defects, various inborn errors of bile acid metabolism (IEBAM) have been reported from Japan, affecting eight patients including three with 3ß-hydroxy-Δ5 -C27 -steroid dehydrogenase/isomerase deficiency, three with Δ4 -3-oxosteroid 5ß-reductase deficiency, one with oxysterol 7α-hydroxylase deficiency, and one with bile acid-CoA: amino acid N-acyltransferase deficiency. Distinctive laboratory findings in patients with 3ß-hydroxy-Δ5 -C27 -steroid dehydrogenase/isomerase deficiency, Δ4 -3-oxosteroid 5ß-reductase deficiency, and oxysterol 7α-hydroxylase deficiency include normal serum γ-glutamyltransferase and total bile acids concentrations despite presence of cholestasis (elevated serum direct bilirubin) from infancy. Pediatricians and pediatric surgeons who suspect a case of IEBAM should obtain urinary and serum bile acid analyses using gas or liquid chromatography-mass spectrometry as well as genetic analyses. Available treatments include oral cholic acid, chenodeoxycholic acid, glycocholic acid, and ursodeoxycholic acid; fat-soluble vitamin supplementation; and liver transplantation. Early diagnosis and treatment can offer a good outcome.

Pharmacokinetics, Safety, and Efficacy of Glecaprevir/Pibrentasvir in Children With Chronic HCV: Part 2 of the DORA Study.

BACKGROUND AND AIMS: Glecaprevir/pibrentasvir (GLE/PIB) has shown high efficacy and safety in chronic HCV-infected adults and adolescents; data in children were limited. DORA part 2 is a phase 2/3, nonrandomized, open-label study evaluating the pharmacokinetics, efficacy, and safety of a pediatric formulation of GLE and PIB in children ages 3 to < 12 years. APPROACH AND RESULTS: Children with chronic HCV infection, genotype 1-6, with or without compensated cirrhosis, were divided into three cohorts by age-cohort 2 (9 to < 12 years), cohort 3 (6 to < 9 years), and cohort 4 (3 to < 6 years)-and given weight-based doses of GLE and PIB for 8, 12, or 16 weeks. Primary endpoints were sustained virologic response at posttreatment week 12 (SVR12) and steady-state exposure; secondary endpoints were rates of persistent viremia, relapse, and reinfection. Safety and laboratory abnormalities were assessed. Final pediatric dosages determined to be efficacious were 250 mg GLE + 100 mg PIB (in children weighing ≥ 30 to < 45 kg), 200 mg GLE + 80 mg PIB (≥ 20 to < 30 kg), and 150 mg GLE + 60 mg PIB (12 to < 20 kg). Of 80 participants enrolled and dosed, 96% (77/80) achieved SVR12. One participant, on the initial dose ratio, relapsed by posttreatment week 4; no participants had virologic failures on the final dose ratio of GLE 50 mg/PIB 20 mg. Two nonresponders prematurely discontinued the study. Most adverse events (AEs) were mild; no drug-related serious AEs occurred. Pharmacokinetic exposures were comparable to those of adults. CONCLUSIONS: A pediatric formulation of GLE/PIB was highly efficacious and well tolerated in chronic HCV-infected children 3 to < 12 years old.

Serum matrix metalloproteinase-7 in biliary atresia: A Japanese multicenter study.

BACKGROUND: Biliary atresia (BA) is among the commonest indications for liver transplantation (LT) in children. We examined whether serum matrix metalloproteinase-7 (MMP-7) is useful for diagnosis of BA in Japanese infants, and whether serum MMP-7 concentrations before and after Kasai portoenterostomy (KP) predicted LT within a year. METHODS: Subjects under 6 months old at eight pediatric centers in Japan were enrolled retrospectively, including patients with cholestasis and normal controls (NC) without liver disease. Patients with cholestasis were divided into groups representing BA versus cholestasis from other causes (non-BA). Serum samples were collected from patients with BA at diagnosis and 1 and 4 weeks after KP, as well as from non-BA and NC. RESULTS: Serum MMP-7 concentrations were significantly higher in BA at diagnosis (median, 89.1 ng/ml) than in non-BA (11.0; p < 0.001) or NC (10.3; p < 0.001). Receiver operating characteristic (ROC) analysis of MMP-7 for BA versus non-BA yielded an area under the ROC curve of 0.99 (95% confidence interval, 0.96-1.00). An optimal cut-off value of 18.6 ng/ml for serum MMP-7 in diagnosing BA demonstrated sensitivity and specificity of 100% and 90%, respectively. Serum MMP-7 before and 1 week and 4 weeks after KP did not differ significantly between BA requiring only KP and BA requiring LT after KP. CONCLUSION: Serum MMP-7 is a useful marker for diagnosis of BA in Japanese infants, but it could not predict LT within a year.

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.

Qing-Dai for pediatric ulcerative colitis multicenter survey and systematic review.

BACKGROUND: Pediatric ulcerative colitis (UC) is more challenging to treat than adult UC. Qing-Dai therapy is effective in adults but reports of its efficacy in children are unavailable. We conducted a questionnaire survey on Qing-Dai use among pediatric patients with UC in Japan to determine its efficacy and safety. METHODS: Questionnaires were sent to 31 high-volume centers treating pediatric patients with inflammatory bowel disease. The number of patients using Qing-Dai, short-term and long-term effects, and adverse events were assessed. A systematic review of studies on the efficacy and safety of Qing-Dai usage for UC was also performed. RESULTS: Overall, 29/31 facilities (93.5%) responded, Qing-Dai was used in 107 patients with UC, and 84/107 patients (78.5%) initiated treatment. Within 6 months, 81/101 (80.2%) patients had clinical remission, while 59/92 (64.1%) patients had no relapse and 29/92 (31.5%) experienced only one to two relapses yearly. Eighty-seven percent of the patients underwent regular follow ups for adverse events, among whom one patient was diagnosed with pulmonary arterial hypertension (PAH), five with enteritis, and one with headache. In the systematic review, the clinical remission rate was 50-80%, and PAH was observed in 14 of 1,158 patients (1.2%). CONCLUSIONS: Qing-Dai is highly effective in treating pediatric UC. However, Qing-Dai should be administered with caution as it may cause adverse events such as PAH.

Clinical practice guidelines for the management of children with mother-to-child transmitted hepatitis C virus infection.

BACKGROUND: The first guidelines for care of pregnant women carrying the hepatitis C virus (HCV) and their infants were published in 2005 in Japan. Since then, evidence has gradually accumulated worldwide regarding the natural course and treatment of this condition and, especially in recent years, treatment for chronic hepatitis C in adult patients has made great progress. However, the clinical practice policy for children has not been standardized, and new clinical practice guidelines for children with mother-to-child (MTC) transmitted HCV infection have become necessary. METHODS: In the development of the current guideline, we requested cooperation from The Japanese Society for Pediatric Infectious Diseases, The Japan Society of Hepatology, and the Japan Society of Obstetrics and Gynecology. The committee members were recommended and approved by each society to participate in developing the guidelines. The guideline was also created in accordance with the Minds Guide for Practice Guideline Development. The statements were prepared by consensus-building using the Delphi method, based on the comprehensively searched academic papers and guidelines. These articles were retrieved through searching the PubMed, Cochrane Library, and the Igaku Chuo Zasshi databases. RESULTS: Eight clinical questions (CQs) with clinical statements were developed regarding etiology (CQs 1-3), diagnosis (CQs 4 and 5), and treatment (two CQs 6 and 7). In each statement, the consensus rate, evidence level, and recommendation level were determined. CONCLUSION: The guidelines will be helpful in the management of children with hepatitis C MTC transmission.

Assessing liver stiffness with conventional cut-off values overestimates liver fibrosis staging in patients who received the Fontan procedure.

AIM: Patients who undergo the Fontan procedure for complex congenital heart disease are prone to liver cirrhosis. Liver stiffness (LS) reflects liver fibrosis stage in patients with chronic viral hepatitis; however, its accuracy in predicting liver fibrosis stage in Fontan patients is controversial. We aimed to clarify the correlation between LS and liver fibrosis stage in Fontan patients. METHODS: Fifty-eight Fontan patients were prospectively measured for LS with transient elastography. We undertook liver biopsy, cardiac catheterization, and laboratory tests in 22 of these patients (median age, 14.7 years; range, 9.9-32.1 years) with LS > 11.0 kPa (median, 19.2 kPa; range, 12.2-39.8 kPa); these elevated LS values suggest liver cirrhosis. RESULTS: Histologically, all patients showed mild-to-severe portal and sinusoidal fibrosis but no cirrhosis. Statistically, LS did not predict histological liver fibrosis scores (p = 0.175). Liver stiffness was not correlated with central venous pressure (p = 0.456) or with the hepatic venous pressure gradient (HVPG; p = 0.062), although the p value for HVPG was only slightly above the threshold for significance. CONCLUSIONS: Fontan patients are prone to developing both portal and sinusoidal fibrosis. Liver stiffness could be influenced by HVPG, and using the conventional cut-off values for LS overestimates and overtreats liver fibrosis in these patients.

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.

Bile Acid Synthesis Disorders in Japan: Long-Term Outcome and Chenodeoxycholic Acid Treatment.

BACKGROUND: We encountered 7 Japanese patients with bile acid synthesis disorders (BASD) including 3ß-hydroxy-Δ5-C27-steroid dehydrogenase/isomerase (3ß-HSD) deficiency (n = 3), Δ4-3-oxosteroid 5ß-reductase (5ß-reductase) deficiency (n = 3), and oxysterol 7α-hydroxylase deficiency (n = 1) over 21 years between 1996 and 2017. AIM: We aimed to clarify long-term outcome in the 7 patients with BASD as well as long-term efficacy of chenodeoxycholic acid (CDCA) treatment in the 5 patients with 3ß-HSD deficiency or 5ß-reductase deficiency. METHODS: Diagnoses were made from bile acid and genetic analyses. Bile acid analysis in serum and urine was performed using gas chromatography-mass spectrometry. Clinical and laboratory findings and bile acid profiles at diagnosis and most recent visit were retrospectively obtained from medical records. Long-term outcome included follow-up duration, treatments, growth, education/employment, complications of treatment, and other problems. RESULTS: Medians with ranges of current patient ages and duration of CDCA treatment are 10 years (8 to 43) and 10 years (8 to 21), respectively. All 7 patients, who had homozygous or compound heterozygous mutations in the HSD3B7, SRD5B1, or CYP7B1 gene, are currently in good health without liver dysfunction. In the 5 patients with CDCA treatment, hepatic function gradually improved following initiation. No adverse effects were noted. CONCLUSIONS: We concluded that CDCA treatment is effective in 3ß-HSD deficiency and 5ß-reductase deficiency, as cholic acid has been in other countries. BASD carry a good prognosis following early diagnosis and initiation of long-term CDCA treatment.

Paracrine signals regulate human liver organoid maturation from induced pluripotent stem cells.

A self-organizing organoid model provides a new approach to study the mechanism of human liver organogenesis. Previous animal models documented that simultaneous paracrine signaling and cell-to-cell surface contact regulate hepatocyte differentiation. To dissect the relative contributions of the paracrine effects, we first established a liver organoid using human induced pluripotent stem cells (iPSCs), mesenchymal stem cells (MSCs) and human umbilical vein endothelial cells (HUVECs) as previously reported. Time-lapse imaging showed that hepatic-specified endoderm iPSCs (HE-iPSCs) self-assembled into three-dimensional organoids, resulting in hepatic gene induction. Progressive differentiation was demonstrated by hepatic protein production after in vivo organoid transplantation. To assess the paracrine contributions, we employed a Transwell system in which HE-iPSCs were separately co-cultured with MSCs and/or HUVECs. Although the three-dimensional structure did not form, their soluble factors induced a hepatocyte-like phenotype in HE-iPSCs, resulting in the expression of bile salt export pump. In conclusion, the mesoderm-derived paracrine signals promote hepatocyte maturation in liver organoids, but organoid self-organization requires cell-to-cell surface contact. Our in vitro model demonstrates a novel approach to identify developmental paracrine signals regulating the differentiation of human hepatocytes.

Comprehensive Targeted Sequencing Identifies Monogenic Disorders in Patients With Early-onset Refractory Diarrhea.

OBJECTIVES: Causes of early-onset refractory diarrhea include exudative diarrhea associated with very early-onset inflammatory bowel diseases, osmotic or secretory diarrhea, and protein-losing enteropathy. Monogenic disorders are included in these diseases, yet a comprehensive genetic analysis has not been fully established. METHODS: We established targeted gene panels covering all responsible genes for early-onset diarrhea. In total, 108 patients from 15 institutions were enrolled in this study. We collected clinical data from all patients. Seventy-three patients with exudative diarrhea, 4 with osmotic or secretory diarrhea and 8 with protein-losing enteropathy were subjected to genetic analysis. RESULTS: A total of 15 out of the 108 enrolled patients (13.9%) were identified as monogenic. We identified 1 patient with RELA, 2 with TNFAIP3, 1 with CTLA4, 1 with SLCO2A1, 4 with XIAP, 3 with IL10RA, 1 with HPS1, 1 with FOXP3, and 1 with CYBB gene mutations. We also identified 1 patient with NFKB2 and 1 with TERT mutations from the gene panel for primary immunodeficiency syndromes. The patient with refractory diarrhea caused by heterozygous truncated RelA protein expression is the first case identified worldwide, and functional analysis revealed that the mutation affected nuclear factor kappa B signaling. Genotypes were significantly associated with the clinical and pathological findings in each patient. CONCLUSIONS: We identified variable monogenic diseases in the patients and found that genes responsible for primary immunodeficiency diseases were frequently involved in molecular pathogenesis. Comprehensive genetic analysis was useful for accurate molecular diagnosis, understanding of underlying pathogenesis, and selecting the optimal treatment for patients with early-onset refractory diarrhea.An infographic for this article is available at: http://links.lww.com/MPG/B853.

Clinical Features, Molecular Genetics, and Long-Term Outcome in Congenital Chloride Diarrhea: A Nationwide Study in Japan.

OBJECTIVE: To clarify clinical and genetic features of Japanese children with congenital chloride diarrhea (CCD). STUDY DESIGN: This was a multi-institutional, retrospective survey of 616 pediatric centers in Japan with identified patients with CCD between 2014 and 2018. Mutations involving SLC26A3 were detected by Sanger sequencing. RESULTS: Thirteen patients met all entry criteria including mutations in SLC26A3, and 14 patients satisfied clinical diagnostic criteria. Homozygous or compound heterozygous mutations in SLC26A3, including 6 novel mutations, were identified in 13 of these 14 patients (93%). The most common (detected in 7 of 13) was c.2063-1g>t. Median age at diagnosis was 1 day. Nine of the patients meeting all criteria were diagnosed as neonates (69%). Median follow-up duration was 10 years. When studied, 8 patients had <5 stools daily (62%), and all had fewer than in infancy. Only 1 patient had nephrocalcinosis, and 3 (23%) had mild chronic kidney disease. Neurodevelopment was generally good; only 1 patient required special education. Five patients (38%) received long-term sodium, potassium, and chloride supplementation. CONCLUSIONS: Early fetal ultrasound diagnosis and prompt long-term sodium, potassium, and chloride supplementation were common management features. Genetic analysis of SLC26A3 provided definitive diagnosis of CCD. In contrast with previously reported localities, c.2063-1g>t might be a founder mutation in East Asia.

Infantile-onset inflammatory bowel disease in a patient with Hermansky-Pudlak syndrome: a case report.

BACKGROUND: Hermansky-Pudlak syndrome (HPS) is a rare, genetically heterogeneous disorder that manifests oculocutaneous albinism together with bleeding diatheses that reflect a platelet storage pool deficiency. Ten genetic subtypes of this autosomal recessive condition have been described to date. Some patients with Hermansky-Pudlak syndrome type 1, 4, or 6 develop Crohn's-like inflammatory bowel disease at any age including early childhood, but most often in adolescence or young adulthood. Here we report infantile-onset of inflammatory bowel disease in a patient with Hermansky-Pudlak syndrome type 1 who responded to infliximab. CASE PRESENTATION: A Japanese boy, the second child of non-consanguineous healthy parents, was born with chalky white skin, silvery-white hair, and gray eyes, representing oculocutaneous albinism. He developed frequent diarrhea and fever accompanied by weight loss at 6 months, and was diagnosed with Crohn's-like inflammatory bowel disease based on the endoscopic finding of longitudinal ulcerations in the colon and the histopathologic finding of nonspecific chronic inflammation without granulomas at the age of 11 months. Treatment with an elemental diet, salazosulfapyridine, and corticosteroids failed to improve clinical or laboratory abnormalities, and the diarrhea became bloody. At 13 months he began treatment with infliximab, which produced marked improvement followed by clinical remission. Endoscopy at 20 months demonstrated healing of the colonic mucosa. At 22 months he is in sustained clinical remission receiving only infliximab. Because albinism with inflammatory bowel disease suggested Hermansky-Pudlak syndrome, we performed genetic screening using next-generation sequencing in a targeted gene panel analysis for primary immunodeficiency disease and/or inflammatory bowel disease. The patient proved to have a compound heterozygous mutation of the HPS1 gene resulting in Hermansky-Pudlak syndrome type 1. CONCLUSIONS: We consider this report to be the first account of type 1 Hermansky-Pudlak syndrome with infantile-onset of inflammatory bowel disease. Early administration of infliximab was effective. We recommend next-generation sequencing for patients with very early-onset inflammatory bowel disease suspected to be monogenic.

Laboratory values in Japanese children with newly diagnosed inflammatory bowel disease.

BACKGROUND: Laboratory data in children with newly diagnosed inflammatory bowel disease (IBD) have been reported from Europe and North America, but not Asia. The aim of this study was to clarify laboratory data in Japanese children with newly diagnosed IBD, and to compare them with those in Western reports. METHODS: We retrospectively reviewed patients <16 years old, newly diagnosed with ulcerative colitis (UC) or Crohn's disease (CD) at Kurume University Hospital between January 2008 and December 2015. RESULTS: UC and CD patients numbered 31 and 15, respectively. The percentages of patients with normal values for hemoglobin (Hb), platelet count (Plt), albumin (Alb), C-reactive protein (CRP), and erythrocyte sedimentation rate (ESR) in the UC and CD groups were 45% and 47%; 68% and 53%; 84% and 40%; 81% and 7%; and 35% and 0%, respectively. The frequency of normal results for these five tests were similar to Western findings except for the greater frequency of normal CRP in UC. Alb and ESR differed significantly between UC and CD in both mild and moderate-severe cases. Plt, Alb, CRP, and ESR differed significantly between diseases in late-onset IBD, whereas early onset IBD showed no differences. In UC, ESR correlated positively, while Hb and Alb correlated negatively, with disease activity. In CD, CRP and ESR correlated positively with activity. CONCLUSIONS: The proportion of Japanese children with IBD having normal values at diagnosis was mostly similar to that in Western reports. In early onset cases, UC parameters may be similar to CD. Of the five tests, ESR was particularly indicative of disease activity at diagnosis in both pediatric UC and CD.

Regulation of epithelial injury and bile duct obstruction by NLRP3, IL-1R1 in experimental biliary atresia.

BACKGROUND & AIMS: Biliary atresia (BA) results from a neonatal inflammatory and fibrosing obstruction of bile ducts of unknown etiology. Although the innate immune system has been linked to the virally induced mechanism of disease, the role of inflammasome-mediated epithelial injury remains largely undefined. Here, we hypothesized that disruption of the inflammasome suppresses the neonatal proinflammatory response and prevents experimental BA. METHODS: We determined the expression of key inflammasome-related genes in livers from infants at diagnosis of BA and in extrahepatic bile ducts (EHBDs) of neonatal mice after infection with rotavirus (RRV) immediately after birth. Then, we determined the impact of the wholesale inactivation of the genes encoding IL-1R1 (Il1r1-/-), NLRP3 (Nlrp3-/-) or caspase-1 (Casp1-/-) on epithelial injury and bile duct obstruction. RESULTS: IL1R1, NLRP3 and CASP1 mRNA increased significantly in human livers at the time of diagnosis, and in EHBDs of RRV-infected mice. In Il1r1-/- mice, the epithelial injury of EHBDs induced by RRV was suppressed, with dendritic cells unable to activate natural killer cells. A similar protection was observed in Nlrp3-/- mice, with decreased injury and inflammation of livers and EHBDs. Long-term survival was also improved. In contrast, the inactivation of the Casp1 gene had no impact on tissue injury, and all mice died. Tissue analyses in Il1r1-/- and Nlrp3-/- mice showed decreased populations of dendritic cells and natural killer cells and suppressed expression of type-1 cytokines and chemokines. CONCLUSIONS: Genes of the inflammasome are overexpressed at diagnosis of BA in humans and in the BA mouse model. In the experimental model, the targeted loss of IL-1R1 or NLRP3, but not of caspase-1, protected neonatal mice against RRV-induced bile duct obstruction. LAY SUMMARY: Biliary atresia is a severe inflammatory and obstructive disease of bile ducts occurring in infancy. Although the cause is unknown, activation of the innate and adaptive immune systems injures the bile duct epithelium. In this study we found that patients' livers had increased expression of inflammasome genes. Using mice engineered to inactivate individual inflammasome genes, the epithelial injury and bile duct obstruction were prevented by the loss of Il1r1 or Nlrp3, with a decreased activation of natural killer cells and expression of cytokines and chemokines. In contrast, the loss of Casp1 did not change the disease phenotype. Combined, the findings point to a differential role of inflammasome gene products in the pathogenic mechanisms of biliary atresia.

Clinical, Pathologic, and Genetic Features of Neonatal Dubin-Johnson Syndrome: A Multicenter Study in Japan.

OBJECTIVE: To clarify the clinical, pathologic, and genetic features of neonatal Dubin-Johnson syndrome. STUDY DESIGN: Ten patients with neonatal Dubin-Johnson syndrome were recruited from 6 pediatric centers in Japan between September 2013 and October 2016. Clinical and laboratory course, macroscopic and microscopic liver findings, and molecular genetic findings concerning ATP-binding cassette subfamily C member 2 (ABCC2) were retrospectively and prospectively examined. RESULTS: All neonates exhibited cholestasis, evident as prolonged jaundice with or without acholic stools and elevations of serum direct bilirubin as well as γ-glutamyltransferase or total bile acids. Only 38% (3 of 8) of patients who underwent liver biopsy showed a grossly black liver or melanin-like pigment deposits in hepatocytes; their biopsies were performed in early infancy. Immunohistochemically, all liver specimens showed no expression of multidrug resistance-associated protein 2 but increased expression of the bile salt export pump protein. Homozygous or compound heterozygous pathogenic variants of ABCC2 were identified in all patients, representing 11 distinct pathogenic variants including 2 not previously reported. CONCLUSIONS: Immunohistochemical staining of the liver for multidrug resistance-associated protein 2 and molecular genetic analysis of ABCC2 are crucial for accurate diagnosis of neonatal Dubin-Johnson syndrome.