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.

The impact of treatment on the psychological burden of mothers of children with chronic hepatitis C virus infection: a multicenter, questionnaire survey.

Mothers of children with chronic hepatitis C virus (HCV) infection experience anxiety about the health of their children. In this study we assessed an impact of treating children with chronic HCV infection on the psychological burden of their mothers. This was a multicenter, questionnaire survey conducted at six institutions in Japan.

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.

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.

Primary Immunodeficiencies Associated With Early-Onset Inflammatory Bowel Disease in Southeast and East Asia.

Background: Causes of early-onset inflammatory bowel disease (IBD) vary, and primary immunodeficiency diseases (PIDs) are associated with early-onset IBD as monogenic disorders.

Aim: This review investigates the prevalence, clinical manifestation, genetic profile, and treatment of patients with early-onset IBD in Southeast and East Asia.

Methods: A systemic review of articles reporting PID patients associated with early-onset IBD in Southeast and East Asia was conducted.

Interim analysis of a multicenter registry study of COVID-19 patients with inflammatory bowel disease in Japan (J-COSMOS).

Background: The spread of coronavirus disease 2019 (COVID-19) had a major impact on the health of people worldwide. The clinical background and clinical course of inflammatory bowel disease (IBD) among Japanese patients with COVID-19 remains unclear.

Methods: This study is an observational cohort of Japanese IBD patients diagnosed with COVID-19.

A nationwide survey concerning the mortality and risk of progressing severity due to arterial and venous thromboembolism in inflammatory bowel disease in Japan.

Background: The mortality and risk factors of severe disease and death due to arterial and venous thromboembolism (ATE and VTE, respectively) in patients with inflammatory bowel disease (IBD) remain unclear, especially in Asia.

Aims: This study aimed to reveal the mortality and risk factors of TE in IBD patients in Japan.

Methods: In the primary surveillance, responses to questionnaires regarding the number of cases of severe TE and TE-associated death in IBD patients in a span of over the past 10 years were obtained from 32 institutions in Japan.

Assessment of Adenosine Triphosphatase Phospholipid Transporting 8B1 (ATP8B1) Function in Patients With Cholestasis With ATP8B1 Deficiency by Using Peripheral Blood Monocyte-Derived Macrophages.

Adenosine triphosphatase phospholipid transporting 8B1 (ATP8B1) deficiency, an ultrarare autosomal recessive liver disease, includes severe and mild clinical forms, referred to as progressive familial intrahepatic cholestasis type 1 (PFIC1) and benign recurrent intrahepatic cholestasis type 1 (BRIC1), respectively. There is currently no practical method for determining PFIC1 or BRIC1 at an early disease course phase. Herein, we assessed the feasibility of developing a diagnostic method for PFIC1 and BRIC1.

Nationwide survey of pediatric gastrointestinal endoscopy in Japan.

Background And Aim: The implementation rates of pediatric gastrointestinal endoscopy are increasing with advancements in the devices used and pediatricians' skills. As part of the Japan Pediatric Endoscopy Study Group, we aimed to investigate the rates of pediatric gastrointestinal endoscopy use and the associated adverse events through a nationwide survey.

Methods: A questionnaire was sent to 630 institutions in Japan.

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.

Association between Passive Smoking from the Mother and Pediatric Crohn's Disease: A Japanese Multicenter Study.

Smoking is a risk factor for adult-onset Crohn's disease (CD). Although passive smoking from family members is a major concern, especially in pediatric CD, the number of existing epidemiological studies is limited. This multicenter case-control study aimed to assess the effects of familial smoking on pediatric CD.

Current role of colonoscopy in infants and young children: a multicenter study.

Background: To evaluate the role of colonoscopy in infants and young children and clarify the distribution of colonoscopy-requiring diseases in this age group.

Methods: Cohorts of colonoscopies performed at three children's hospitals in Japan between April 2011 and March 2016 including infants and children younger than six years of age were retrospectively reviewed.

Results: In total, 453 colonoscopies were performed in 276 infants and young children.

Clinical features of chronic enteropathy associated with SLCO2A1 gene: a new entity clinically distinct from Crohn's disease.

Background: Chronic enteropathy associated with SLCO2A1 gene (CEAS) is a hereditary disease caused by mutations in the SLCO2A1 gene and characterized by multiple small intestinal ulcers of nonspecific histology. SLCO2A1 is also a causal gene of primary hypertrophic osteoarthropathy (PHO). However, little is known about the clinical features of CEAS or PHO.

Assessment of ATP8B1 Deficiency in Pediatric Patients With Cholestasis Using Peripheral Blood Monocyte-Derived Macrophages.

Progressive familial intrahepatic cholestasis type 1 (PFIC1), a rare inherited recessive disease resulting from a genetic deficiency in ATP8B1, progresses to liver failure. Because of the difficulty of discriminating PFIC1 from other subtypes of PFIC based on its clinical and histological features and genome sequencing, an alternative method for diagnosing PFIC1 is desirable. Herein, we analyzed human peripheral blood monocyte-derived macrophages (HMDM) and found predominant expression of ATP8B1 in interleukin-10 (IL-10)-induced M2c, a subset of alternatively activated macrophages.

Natural history of chronic hepatitis B virus infection in children in Japan: a comparison of mother-to-child transmission with horizontal transmission.

Background: It is necessary to evaluate the natural history of children with hepatitis B virus (HBV) infection in each country to consider their long-term management.

Methods: A multi-center observational study of children with chronic HBV infection who were diagnosed at age ≤15 years was carried out in 18 hospitals in Japan.

Results: We reviewed children with HBV infection including 381 with mother-to-child transmission (MTCT) and 154 with horizontal transmission, genotype C being the most prevalent virus genotype (83%).

Hepatocellular carcinoma in children and young patients with chronic HBV infection and the usefulness of alpha-fetoprotein assessment.

The aims of the study were to elucidate the clinical characteristics of patients who developed hepatocellular carcinoma (HCC) related to persistent HBV infection since childhood and to investigate usefulness of assessing alpha-fetoprotein (AFP) in this population. A nationwide multicenter survey of children with chronic HBV infection was performed. Among 548 patients, 15 patients developed HCC at the median age of 15 years (range 9-36), including 13 males and 2 females.

Targeted Sequencing and Immunological Analysis Reveal the Involvement of Primary Immunodeficiency Genes in Pediatric IBD: a Japanese Multicenter Study.

Purpose: Pediatric inflammatory bowel disease (IBD) is a heterogeneous disorder caused by multiple factors. Although genetic and immunological analyses are required for a definitive diagnosis, no reports of a comprehensive genetic study of a Japanese population are available.

Methods: In total, 35 Japanese patients <16 years of age suffering from IBD, including 27 patients aged <6 years with very early-onset IBD, were enrolled in this multicenter study.

Pediatric-onset Chronic Nonspecific Multiple Ulcers of Small Intestine: A Nationwide Survey and Genetic Study in Japan.

We performed a Japanese nationwide survey of pediatric-onset chronic nonspecific multiple ulcers of the small intestine between January 2000 and July 2013 in 176 institutions of pediatric surgery or pediatric gastroenterology and clarified the clinical features associated with genetic abnormalities in the Solute Carrier Organic Anion Transporter Family, Member 2A1 (SLCO2A1) gene. A total of 4 cases (3 girls and 1 boy) were diagnosed in this series, which had to be differentiated from Crohn disease, Behçet disease, tuberculosis, or drug-induced enteropathy. Clinical symptoms appeared in infants and accurate diagnosis required several years.

Pediatric Patient and Parental Anxiety and Impressions Related to Initial Gastrointestinal Endoscopy: A Japanese Multicenter Questionnaire Study.

Objective. To assess anxiety among pediatric patients and their parents related to initial gastrointestinal endoscopy. Methods.

Selective expansion of donor-derived regulatory T cells after allogeneic bone marrow transplantation in a patient with IPEX syndrome.

IPEX syndrome is a rare and fatal disorder caused by absence of regulatory T cells (Tregs) due to congenital mutations in the Forkhead box protein 3 gene. Here, we report a patient with IPEX syndrome treated with RIC followed by allogeneic BMT from an HLA-matched sibling donor. We could achieve engraftment and regimen-related toxicity was well tolerated.

Association of IL28B polymorphisms with virological response to peginterferon and ribavirin therapy in children and adolescents with chronic hepatitis C.

Aim: The objective of the current study was to find baseline predictive factors of response to therapy with pegylated interferon and ribavirin (PEG-IFN/RBV therapy) in children and adolescents with chronic hepatitis C.

Methods: IL28B genotype and mutations in the core of hepatitis C virus (HCV) were analyzed in 30 patients treated with PEG-IFN/RBV for HCV infection. The initial rate of decrease in the viral load was assessed during the first 2 weeks of treatment.