Peiyu Chen

Fibrosis is an important pathological change in inflammatory bowel disease (IBD), but the mechanism has yet to be elucidated. WNT2B high‑expressed fi

Norovirus infection is the leading cause of foodborne gastroenteritis worldwide, causing more than 200,000 deaths each year. As a result of a lack of reproducible and robust in vitro culture systems and suitable animal models for human norovirus (HuNoV) infection, the pathogenesis of HuNoV is still poorly understood. In recent years, human intestinal enteroids (HIEs) have been successfully constructed and demonstrated to be able to support the replication of HuNoV. The NLRP3 inflammasome plays a key role in host innate immune responses by activating caspase1 to facilitate IL-1β and IL-18 secretion and N-GSDMD-driven apoptosis, while NLRP3 inflammasome overactivation plays an important role in the development of various inflammatory diseases. Here, we found that HuNoV activated enteric stem cell-derived human intestinal enteroids (HIEs) NLRP3 inflammasome, which was confirmed by transfection of Caco2 cells with full-length cDNA clones of HuNoV. Further, we found that HuNoV non-structural protein P22 activated the NLRP3 inflammasome and then matured IL-1β and IL-18 and processed the cleavage of gasdermin-D (GSDMD) to N-GSDMD, leading to pyroptosis. Besides, berberine (BBR) could ameliorate the pyroptosis caused by HuNoV and P22 by inhibiting NLRP3 inflammasome activation. Together, these results reveal new insights into the mechanisms of inflammation and cell death caused by HuNoV and provide potential treatments.

Sclerosing mesenteritis is a rare fibroinflammatory disorder of unknown etiology that primarily affects the mesentery of the small intestine during late adult life. Only about twenty pediatric cases have been reported to date, but none has been reported in Chinese children. A 5-year-old Chinese male presented with a 4-week history of recurrent bloating, abdominal pain, anorexia and vomiting. On admission, physical examination showed a severely distended abdomen. Biochemical investigations showed a slightly increased C-reactive protein, and normal serum levels of electrolytes and erythrocyte sedimentation rate. An abdominal film showed small intestine obstruction and massive ascites. An exploratory laparotomy revealed widespread inflammatory fibrotic adhesions between the bowel and the abdominal wall, thickening of the small bowel and massive ascites. During a prolonged hospital course, a 2nd surgery (4 months after 1st exploratory laparotomy) was performed in order to close the ileostomy and revealed that the bowel was still severely edematous, with very tight adhesions between the bowel and the abdominal wall. Histopathological examination of excised mesentery and nodules showed chronic inflammatory cell infiltration, fat necrosis and fibrosis. A diagnosis of sclerosing mesenteritis was finally established. Prednisolone at 2 mg/kg was started and he experienced rapid clinical improvement in 4 weeks. Sclerosing mesenteritis is extremely rare in children and often misdiagnosed due to its nonspecific clinical manifestation. It is important to be aware of sclerosing mesenteritis when evaluating a child with intractable abdominal pain, bloating, intestinal obstruction and massive ascites.

Background: Refractory esophageal stricture (RES) may be attributed to food allergy. Its etiology and pathogenesis are not fully understood. Identification of novel genetic variants associated with this disease by exome sequencing (exome-seq) may provide new mechanistic insights and new therapeutic targets. Methods: To identify new and novel disease-associating variants, whole-exome sequencing was performed on an Illumina NGS platform in three children with RES as well as food allergy. Results: A total of 91,024 variants were identified. By filtering out ‘normal variants’ against those of the 1000 Genomes Project, we identified 12,741 remaining variants which are potentially associated with RES plus food allergy. Among these variants, there are 11,539 single nucleotide polymorphisms (SNPs), 627 deletions, 551 insertions and 24 mixture variants. These variants are located in 1370 genes. They are enriched in biological processes or pathways such as cell adhesion, digestion, receptor metabolic process, bile acid transport and the neurological system. By the PubMatrix analysis, 50 out of the top 100 genes, which contain most variants, have not been previously associated with any of the 17 allergy-associated diseases. These 50 genes represent newly identified allergy-associated genes. Those variants of 627 deletions and 551 insertions have also not been reported before in RES with food allergy. Conclusions: Exome-seq is potentially a powerful tool to identify potential new biomarkers for RES with food allergy. This study has identified a number of novel genetic variants, opening new avenues of research in RES plus food allergy. Additional validation in larger and different patient populations and further exploration of the underlying molecular mechanisms are warranted.

Cow’s milk is the most common cause of food-protein-induced enterocolitis syndrome (FPIES). The aim of this study was to examine the clinical features and treatment outcomes of infants with severe FPIES to cow’s milk. We reviewed all infants ≤12 months of age who were hospitalized and diagnosed with severe FPIES to cow’s milk between 1 January 2011 and 31 August 2014 in a tertiary Children’s Medical Center in China. Patients’ clinical features, feeding patterns, laboratory tests, and treatment outcomes were reviewed. A total of 12 infants met the inclusion criteria. All infants presented with diarrhea, edema, and hypoalbuminemia. Other main clinical manifestations included regurgitation/vomiting, skin rashes, low-grade fever, bloody and/or mucous stools, abdominal distention, and failure to thrive. They had clinical remission with resolution of diarrhea and significant increase of serum albumin after elimination of cow’s milk protein (CMP) from the diet. The majority of infants developed tolerance to the CMP challenge test after 12 months of avoidance. In conclusion, we reported the clinical experience of 12 infants with severe FPIES to cow’s milk, which resulted in malnutrition, hypoproteinemia, and failure to thrive. Prompt treatment with CMP-free formula is effective and leads to clinical remission of FPIES in infants.

Eosinophilic colitis is a well recognized clinical entity mainly associated with food allergies. Empiric treatment options include dietary allergen exclusion (extensively hydrolyzed protein formula and elimination diet), anti-allergy medications (antihistamines and leukotriene receptor antagonists) and corticosteroids. We evaluated the effectiveness of dietary antigen exclusion on clinical remission of eosinophilic colitis in infants and young children. We retrospectively reviewed charts of all infants and children ≤3 years of age who were diagnosed with eosinophilic colitis (defined as mucosal eosinophilia ≥20 hpf⁻¹) from 1 January 2011 to 31 December 2013 at a tertiary children’s hospital in China. Forty-nine children were identified with eosinophilic colitis. Elemental formula, simple elimination diet or combination therapy resulted in clinical improvement in 75%, 88.2% and 80% of patients, respectively. In conclusion, eosinophilic colitis in infants and children ≤3 years of age responded well to dietary allergen exclusion.

With increasing prevalence of childhood obesity, non-alcoholic fatty liver disease (NAFLD) has emerged as the most common cause of liver disease among children and adolescents in industrialized countries. It is generally recognized that both genetic and environmental risk factors contribute to the pathogenesis of NAFLD. Recently, there has been a growing body of evidence to implicate altered gut microbiota in the development of NAFLD through the gut-liver axis. The first line of prevention and treatment of NAFLD in children should be intensive lifestyle interventions such as changes in diet and physical activity. Recent advances have been focused on limitation of dietary fructose and supplementation of antioxidants, omega-3 fatty acids, and prebiotics/probiotics. Convincing evidences from both animal models and human studies have shown that reduction of dietary fructose and supplement of vitamin E, omega-3 fatty acids, and prebiotics/probiotics improve NAFLD.

Congenital sucrase-isomaltase deficiency (CSID) is a rare genetic disorder. The prevalence of CSID in Chinese population is unknown and no single case has been reported. Sucrose tolerance tests were performed in three children suspected of CSID. Glucose tolerance tests were performed to exclude glucose malabsorption. Blood glucose was measured at fasting and at 30 min, 60 min, 120 min, and 180 min of the study. Gastrointestinal symptoms were recorded up to 4 hours after the study. From December 2008 to June 2011, three children, ranging from 16 to 19 months old, were referred to our tertiary children’s hospital due to chronic watery diarrhea and failure to thrive. Laboratory investigations including complete blood counts, ESR, CRP, and serum immunoglobulins were normal. Routine stool culture for bacteria and exam for parasites were negative. Upper endoscopy, colonoscopy and histology were unremarkable. All children failed lactose-free and amino acid-based formulas. All three children had flat sucrose tolerance tests and began to have watery stool 2–4 hours after feeding sucrose test solution. The glucose tolerance tests were normal and no children developed watery stools up to 4 hours after feeding glucose test solution. This is the first case series of CSID in Chinese children. The diagnosis of CSID can be made based on clinical suspicion and sucrose tolerance test. CSID is probably an under-diagnosed or misdiagnosed disease in Chinese children and should be considered in children with chronic watery diarrhea.

Introduction: Duodenal duplication is a rare congenital malformation and has been reported as a rare cause of recurrent acute pancreatitis. Hemorrhagic ascites has been reported in only one case of duodenal duplication. Case presentation: An 11-year-old Chinese girl presented with abdominal pain, hematemesis and dark stools. On admission, an abdominal examination revealed a moderately distended abdomen with diffuse tenderness. Biochemical investigations showed increased serum levels of amylase, lipase, and urine amylase. An abdominal computed tomography scan and magnetic resonance imaging scan revealed an enlarged and heterogeneous pancreas with poorly delineated borders. There was a cystic lesion measuring 25mm × 48mm × 28mm, located between the descending portion of her duodenum and the head of her pancreas. There were massive effusion signals in her abdominal cavity. An exploratory laparotomy was performed. A tubular cyst measuring 32mm × 52mm × 30mm was found in the second part of the duodenum, next to the head of her pancreas. The anterior wall of the duplication cyst was resected and anastomosis of the remaining cyst to the duodenum was performed for drainage. Histopathological examination of the excised cyst wall showed duodenal mucosa, submucosa and muscle coats, indicative of a duodenal duplication. Conclusions: It is important to be aware of duodenal duplication when evaluating a patient with recurrent acute pancreatitis accompanied by massive hemorrhagic ascites.

Background: Numerous diagnostic tests are available to detect Helicobactor pylori (H. pylori). There has been no single test available to detect H. pylori infection reliably. We evaluated the accuracy of a new fluorescence quantitative PCR (fqPCR) for H. pylori detection in children. Methods: Gastric biopsy specimens from 138 children with gastritis were sent for routine histology exam, rapid urease test (RUT) and fqPCR. ¹³C-urea breath test (¹³C-UBT) was carried out prior to endoscopic procedure. Gastric fluids and dental plaques were also collected for fqPCR analysis. Results: 38 children (27.5%) were considered positive for H. pylori infection by gold standard (concordant positive results on 2 or more tests). The remaining 100 children (72.5%) were considered negative for H. pylori. Gastric mucosa fqPCR not only detected all 38 H. pylori positive patients but also detected 8 (8%) of the 100 gold standard-negative children or 11 (10.7%) of the 103 routine histology-negative samples. Therefore, gastric mucosa fqPCR identified 46 children (33.3%) with H. pylori infection, significantly higher than gold standard or routine histology (P13C-UBT alone or in combination to detect H. pylori infection in children with chronic gastritis. Either gastric fluid or dental plaque PCR is as reliable as ¹³C-UBT for H. pylori detection.