Very early-onset inflammatory bowel disease (IBD) in infancy is a different disease entity from adult-onset IBD; one form of interleukin-10 receptor mutations. J Hum Genet. 2014;59:337-341. [PMID: 24785691 DOI: 10.1038/jhg.2014.32]

Distribution of epithelial endoplasmic reticulum stress-related proteins in adult and pediatric Crohn's disease: Association with inflammation and fibrosis

BACKGROUND/AIMS

Intestinal strictures in Crohn's disease (CD), driven by fibrosis remain challenging to treat. Current treatments focus on inflammation, but are less effective against fibrosis. Endoplasmic Reticulum Stress-Related Proteins, including Protein disulfide isomerases (PDIs), may contribute to fibrosis; their roles in CD remain unclear. This study investigated the distribution of AGR2, BiP, PDIA6, ERP44 in intestinal epithelium and their association with fibrosis and inflammation in pediatric and adult CD.

METHODS

We retrospectively analyzed 224 patients (2009-2023). CD patients with and without strictures, non IBD controls, and ulcerative colitis patients were compared. Immunohistochemistry assessed Endoplasmic Reticulum Stress-Related protein distribution in epithelium. H&E and Masson's trichrome staining evaluated inflammation and fibrosis. Correlations between protein distribution, inflammation and fibrosis were examined.

RESULTS

AGR2 and BiP were increased in fibro-inflammatory and fibrotic intestinal epithelial tissues, especially in pediatric-onset CD. ERP44 was associated with fibrosis exclusively in pediatric CD. PDIA6 was upregulated in CD compared to non IBD, without fibrosis association. Distinct protein distribution patterns were observed between pediatric and adult CD, and between ileum and colon.

CONCLUSIONS

Distinct patterns of AGR2, BiP, PDIA6, and ERP44 in fibrotic and inflammatory intestinal tissues suggest potential roles in CD-associated fibrosis, warranting exploration as biomarkers or therapeutic targets.

Charge-based immunoreceptor signalling in health and disease

Immunoreceptors have crucial roles in sensing environmental signals and initiating immune responses to protect the host. Dysregulation of immunoreceptor signalling can therefore lead to a range of diseases, making immunoreceptor-based therapies a promising frontier in biomedicine. A common feature of various immunoreceptors is the basic-residue-rich sequence (BRS), which is a largely unexplored aspect of immunoreceptor signalling. The BRS is typically located in the cytoplasmic juxtamembrane region of immunoreceptors, where it forms dynamic interactions with neighbouring charged molecules to regulate signalling. Loss or gain of the basic residues in an immunoreceptor BRS has been linked to severe human diseases, such as immunodeficiency and autoimmunity. In this Perspective, we describe the role of BRSs in various immunoreceptors, elucidating their signalling mechanisms and biological functions. Furthermore, we highlight pathogenic mutations in immunoreceptor BRSs and discuss the potential of leveraging BRS signalling in engineered T cell-based therapies.

Development of Anti-Inflammatory Agents Utilizing DC-SIGN Mediated IL-10 Secretion in Autoimmune and Immune-Mediated Disorders: Bridging Veterinary and Human Health

DC-SIGN (dendritic cell-specific intercellular adhesion molecule-3-grabbing non-integrin) is a C-type lectin receptor expressed on dendritic cells and M2 macrophages, playing a key role in immune regulation and pathogen recognition. Its ability to mediate anti-inflammatory effects by interacting with specific ligands triggers pathways that suppress pro-inflammatory responses and promote tissue repair, making it a potential therapeutic target for inflammatory and autoimmune diseases. DC-SIGN homologs in various animal species share structural similarities and perform comparable immune functions, offering valuable insights into its broader application across species. By recognizing carbohydrate ligands on pathogens, DC-SIGN facilitates immune modulation, which can be harnessed for developing therapies aimed at controlling inflammation. In veterinary medicine, autoimmune and inflammatory diseases, such as rheumatoid arthritis and inflammatory bowel disease, represent significant challenges, and the anti-inflammatory properties of DC-SIGN could provide new therapeutic options to improve disease management and enhance animal health. Future investigations should focus on the structural and functional analysis of DC-SIGN homologs in various species, as well as the development of preclinical models to translate these findings into clinical interventions bridging veterinary and human health.

Gut-microbiota-based ensemble model predicts prognosis of pediatric inflammatory bowel disease

Developing microbiome-based markers for pediatric inflammatory bowel disease (PIBD) is challenging. Here, we evaluated the diagnostic and prognostic potential of the gut microbiome in PIBD through a case-control study and cross-cohort analyses. In a Korean PIBD cohort (24 patients with PIBD, 43 controls), we observed that microbial diversity and composition shifted in patients with active PIBD versus controls and recovered at remission. We employed a differential abundance meta-analysis approach to identify microbial markers consistently associated with active inflammation and remission across seven PIBD cohorts from six countries (n = 1,670) including our dataset. Finally, we trained and tested various machine learning models for their ability to predict a patient's future remission based on baseline bacterial composition. An ensemble model trained with the amplicon sequence variants effectively predicted future remission of PIBD. This research highlights the gut microbiome's potential to guide precision therapy for PIBD.

Early Onset Inflammatory Bowel Disease Due to Immunodeficiency as a Result of ICOS Gene Homozygous Mutation

INTRODUCTION

Inflammatory bowel disease (IBD) is classified as very early-onset IBD (VEO-IBD) if it occurs before age six. VEO-IBD may progress with more severe and resistant inflammation findings in the gastrointestinal and non-gastrointestinal systems.

CASE REPORT

We describe the clinical presentation of a 4-year-old female presenting with recurring episodes of bloody diarrhea, vomiting, abdominal pain, fever, arthritis, erysipelas, and bilateral ankle pain. Monogenic primary immunodeficiency (PID) was suspected due to her age, different clinical findings and the presence of atypical gastroscopic findings and deep transmural ulcerations resembling Crohn's disease. The gene analysis showed a homozygous mutation in the inducible T cell co-stimulator (ICOS) deficiency genes.

DISCUSSION/CONCLUSION

This case presentation shares our clinical experience and demonstrates the link between IBD progression and ICOS deficiency.

Infantile inflammatory bowel disease in three Syrian infants: a case series

BACKGROUND

Inflammatory bowel diseases, consisting of Crohn's disease and ulcerative colitis, are chronic bowel relapsing inflammatory disorders. Inflammatory bowel diseases begin rarely in infants. Approximately 25% of patients with inflammatory bowel diseases present before the age of 20 years. Very early-onset inflammatory bowel disease occurs before the age of 6 years; infantile inflammatory bowel diseases occurs before the age of 2 years, and is extremely rare in infants under 1 year of age.

CASE PRESENTATION

Herein, we report a case series of 7-month-, 11-month-, and 12-month-old Syrian infants that presented with diarrhea, hematochezia, and pale appearance and were finally diagnosed with infantile inflammatory bowel disease and treated.

CONCLUSIONS

Early diagnosis and ruling out infantile inflammatory bowel diseases despite its rarity are recommended. Over and above that, new drugs such as vedolizumab, golimumab, and less invasive treatment methods should also be taken into consideration for better response and adequate remission with improved quality of life.

Heterozygous variants of NOD2, IL10RA, PLA2G6 and COL7A1 correlate with Crohn's disease

To identify candidate pathogenic genes of early-stage Crohn's disease (CD) and predict potential roles of genetic factors in CD, we performed whole exome sequencing on a child with early-stage Crohn's disease (CD) and her parents (core family), found that the patient carried heterozygous variants of 4 genes: NOD2 c. 2257 C > T, IL10RA c. 301 C > T, PLA2G6 c. 2029 C > T, COL7A1 c. 3190 G > A. Heterozygous variants of NOD2, IL10RA, PLA2G6 and COL7A1, intestinal inflammatory response is triggered, normal intestinal wall tissue damage, leading to CD phenotype.

Etiology of IBD-Is It Still a Mystery?

Inflammatory bowel diseases (IBD), including colitis ulcerosa and Crohn's disease, are chronic diseases of the gastrointestinal tract for which the cause has not been fully understood. However, it is known that the etiology is multifactorial. The multidirectional network of interactions of environmental, microbiological and genetic factors in predisposed persons lead to an excessive and insufficiently inhibited reaction of the immune system, leading to the development of chronic inflammation of the gastrointestinal walls, the consequence of which is the loss of the function that the intestine performs, inter alia, through the process of fibrosis. Detailed knowledge of the pathways leading to chronic inflammation makes it possible to pharmacologically modulate disorders and effectively treatthese diseases. In this review, we described the primary and adaptive immune system response in the gut and the known immune pathogenetic pathways leading to the development of IBD. We also described the process leading to intestinal tissue fibrosis, which is an irreversible consequence of untreated IBD.

Treatment patterns of anti-tumour necrosis factor-alpha and prognosis of paediatric and adult-onset inflammatory bowel disease in Korea: a nationwide population-based study

BACKGROUND

The global prevalence of inflammatory bowel disease (IBD) is increasing. However, population-level data are scarce for Asian populations.

AIMS

To outline and compare paediatric and adult IBD incidence and prevalence data in Korea, describe prescription patterns, and analyse outcomes of anti-tumour necrosis factor (anti-TNF) use in a nationally representative cohort METHODS: IBD was identified based on the presence of Rare and Intractable Disease diagnosis codes for Crohn's disease (CD) and ulcerative colitis (UC). We calculated age-based prevalence and incidence, and examined prescription patterns. We used a Cox proportional hazard model to calculate the hazard ratio (HR) for undergoing surgery.

RESULTS

The prevalence of CD increased between 2006 and 2015, particularly among those aged 10-19 years (12.7-35.5 patients per 100,000 people). The use of anti-TNF agents increased from 3.2% to 22.9% in paediatric CD patients. Early use of an anti-TNF agent increased 25-fold in CD patients. Further, CD patients aged 0-14 years were most likely to undergo fistulectomy (HR, 2.63; 95% confidence interval [CI], 1.73-3.97). Children with UC had a higher risk of undergoing surgery (HR, 3.01; 95% CI, 1.33-6.83) than adults. Early use of an anti-TNF agent in CD patients was associated with lower odds of surgery than late-stage use.

CONCLUSION

The prevalence of IBD has increased over time, especially among paediatric patients. Given the magnitude of paediatric IBD disease burden, a multi-faceted approach is needed for early detection and vigilant monitoring to aim for better prognosis.

Interleukin-10 regulates goblet cell numbers through Notch signaling in the developing zebrafish intestine

Cytokines are immunomodulatory proteins that orchestrate cellular networks in health and disease. Among these, interleukin (IL)-10 is critical for the establishment of intestinal homeostasis, as mutations in components of the IL-10 signaling pathway result in spontaneous colitis. Whether IL-10 plays other than immunomodulatory roles in the intestines is poorly understood. Here, we report that il10, il10ra, and il10rb are expressed in the zebrafish developing intestine as early as 3 days post fertilization. CRISPR/Cas9-generated il10-deficient zebrafish larvae showed an increased expression of pro-inflammatory genes and an increased number of intestinal goblet cells compared to WT larvae. Mechanistically, Il10 promotes Notch signaling in zebrafish intestinal epithelial cells, which in turn restricts goblet cell expansion. Using murine organoids, we showed that IL-10 modulates goblet cell frequencies in mammals, suggesting conservation across species. This study demonstrates a previously unappreciated IL-10-Notch axis regulating goblet cell homeostasis in the developing zebrafish intestine and may help explain the disease severity of IL-10 deficiency in the intestines of mammals.

Cytomegalovirus Colitis in Immunocompetent and Immunocompromised Children: A 2-Center Study

BACKGROUND

Data about cytomegalovirus (CMV) colitis in children are scarce. We aimed to describe the characteristics of childhood CMV colitis in terms of risk factors, clinical symptoms, diagnosis, therapeutic approaches, and outcomes.

METHODS

Inflammatory bowel disease (IBD) and non-IBD patients with CMV colitis diagnosed by histology and tissue CMV PCR at 2 tertiary centers between January 2017 and November 2019 were studied. Clinical and laboratory data were retrieved from medical records. Underlying conditions, immune status, response to therapy and outcomes were described and followed up to 6 months after diagnosis.

RESULTS

A total of 16 children (8 non-IBD, 7 ulcerative colitis and 1 Crohn's disease) with CMV colitis were included. All patients had persistent diarrhea (bloody in 13 cases). There was a significant age difference between IBD and non-IBD children (P < 0.05). The final diagnosis in 1 patient was immunodeficiency with a mutation in JAK1 gene. Three children were categorized as apparently immunocompromised and 4 children as apparently immunocompetent. Ulcer was not visible in 2 children from the non-IBD group. The mean fecal calprotectin level of IBD children was significantly higher than that of non-IBD children (376.12 ± 231.21 µg/g vs. 160.96 ± 69.94 µg/g, P < 0.05). After follow-up, 1 patient died because of another reason. Ganciclovir was used in 14 of 16 children for 3 weeks and the treatment was continued with valganciclovir in selected 6 children.

CONCLUSIONS

CMV colitis is a rare but overlooked cause of prolonged diarrhea in immunocompetent and immunocompromised children. CMV colitis might present without any ulcer formation at colonoscopy in infants.

Autosomal recessive 333 base pair interleukin 10 receptor alpha subunit deletion in very early-onset inflammatory bowel disease

BACKGROUND

Interleukin 10 receptor alpha subunit (IL10RA) dysfunction is the main cause of very early-onset inflammatory bowel disease (VEO-IBD) in East Asians.

AIM

To identify disease-causing gene mutations in four patients with VEO-IBD and verify functional changes related to the disease-causing mutations.

METHODS

From May 2016 to September 2020, four young patients with clinically diagnosed VEO-IBD were recruited. Before hospitalization, using targeted gene panel sequencing and trio-whole-exome sequencing (WES), three patients were found to harbor a IL10RA mutation (c.301C>T, p.R101W in one patient; c.537G>A, p.T179T in two patients), but WES results of the fourth patient were not conclusive. We performed whole-genome sequencing (WGS) on patients A and B and reanalyzed the data from patients C and D. Peripheral blood mononuclear cells (PBMCs) from patient D were isolated and stimulated with lipopolysaccharide (LPS), interleukin 10 (IL-10), and LPS + IL-10. Serum IL-10 levels in four patients and tumor necrosis factor-α (TNF-α) in the cell supernatant were determined by enzyme-linked immunosorbent assay. Phosphorylation of signal transducer and activator of transcription 3 (STAT3) at Tyr705 and Ser727 in PBMCs was determined by western blot analysis.

RESULTS

The four children in our study consisted of two males and two females. The age at disease onset ranged from 18 d to 9 mo. After hospitalization, a novel 333-bp deletion encompassing exon 1 of IL10RA was found in patients A and B using WGS and was found in patients C and D after reanalysis of their WES data. Patient D was homozygous for the 333 bp deletion. All four patients had elevated serum IL-10 levels. In vitro, IL-10-stimulated PBMCs from patient D failed to induce STAT3 phosphorylation at Tyr705 and only minimally suppressed TNF-α production induced by LPS. Phosphorylation at Ser727 in PBMCs was not affected by LPS or LPS + IL-10 in both healthy subjects and in patient D.

CONCLUSION

WGS revealed a novel 333-bp deletion of IL10RA in four patients with VEO-IBD, whereas the WES results were inconclusive.

Infantile Inflammatory Bowel Disease in a Three-Month-Old-Boy

Very early-onset inflammatory bowel disease (VEO-IBD) and infantile IBD occur in children aged less than six years and less than two years, respectively. Since childhood-onset IBD seems to be a more aggressive and rapidly progressive disease than adult-onset IBD, it should therefore be diagnosed and treated immediately. Here, we report a case of infantile IBD in a three-month-old infant with clinical and biochemical manifestations. The diagnosis was confirmed with histopathological evidence. The patient had been treated successfully with both mesalazine and prednisolone and with mesalazine alone on follow-up.

Case Report: A Novel Compound Heterozygous Mutation in IL-10RA in a Chinese Child With Very Early-Onset Inflammatory Bowel Disease

Very early-onset inflammatory bowel disease (VEO-IBD) is defined as IBD diagnosed in children younger than 6 years of age. VEO-IBD is often associated with a monogenic etiology or primary immune deficiency. Here, we report the case of a 7-month-old Chinese girl diagnosed with VEO-IBD who had a variant in the interleukin-10 receptor A (IL-10-RA) gene. The patient presented with recurrent fevers, abdominal pain, diarrhea, perianal abscesses, and oral ulcers. Whole-exome sequencing (WES) identified a novel compound heterozygote mutation, c.395T>G (p.Leu132Arg)/ex.1del (p.?), in the IL-10RA gene of the patient. The missense mutation c.395T>G (p.Leu132Arg) was inherited from her mother, and ex.1del (p.?) was inherited from her father. Neither mutation has been reported previously. The IL-10RA function of the patient was defective, as demonstrated by a failure of signal transducer and activator of transcription 3 (STAT3) activation in peripheral blood mononuclear cells (PBMCs) stimulated with recombinant IL-10. The patient underwent matched unrelated peripheral blood hematopoietic stem cell transplantation (HSCT), and the clinical manifestations were dramatically improved. In summary, we identified a novel compound heterozygote mutation, c.395T>G (p.Leu132Arg)/ex.1del (p.?), in IL-10RA that caused VEO-IBD in a Chinese child, which further expands the mutational spectrum of IL-10RA.

Intestinal Microbes in Autoimmune and Inflammatory Disease

Autoimmune diseases and chronic inflammatory disorders are characterized by dysregulated immune responses resulting in excessive and uncontrolled tissue inflammation. Multiple factors including genetic variation, environmental stimuli, and infection are all thought to contribute to continued inflammation and pathology. Current evidence supports the microbiota as one such factor with emerging data linking commensal organisms to the onset and progression of disease. In this review, we will discuss links between the microbiota and specific diseases as well as highlight common pathways that link intestinal microbes with multiple autoimmune and inflammatory diseases.

Pediatric Inflammatory Bowel Disease in Asia: Epidemiology and natural history

Pediatric inflammatory bowel disease (PIBD) in Asia, once considered a rare entity, has seen a sharp increase in incidence over the preceding decade. However, there is a paucity of epidemiological data on PIBD in Asia, and the true disease burden is difficult to estimate due to the lack of national disease registries, prospective databases and the fact that much of existing published data are limited to single-center experiences. This sets the stage for examining recent published data on epidemiological trends and its natural history. Hence, we reviewed the relevant published literature on PIBD in order to summarize the epidemiological data in the Asian populations and compare it with the data available from the other population including Western population. Our review demonstrates that the rapid surge in PIBD incidence across Asian centers lies in contrast to the plateauing albeit high incidence rates in larger established Western cohorts. Important epidemiological trends observed across emerging Asian literature are the higher rates of perianal involvement at disease onset amongst pediatric Crohn's disease (CD) patients, a higher proportion of early-onset disease and the over-representation of the Indian ethnicity in multi-ethnic cohorts. A number of issues currently limit a robust comparison and hence the way forward would be to advocate the recognition of PIBD as an increasingly important public health problem with the need to establish robust disease registries.

Pediatric inflammatory bowel disease: Is it really uncommon in Asian children?

Background/Aim

Inflammatory bowel disease (IBD) is said to be rare in Asian children, and there is scarce information from India. We therefore analyzed our experience of pediatric IBD.

Methods

Prospectively maintained data of 105 consecutive children [median age 12 (IQR:7–14) years, 71 males] with IBD from July 2001 through June 2016 were retrospectively analyzed. Their detailed clinical features, endoscopic appearance, histopathology, and treatment outcomes were recorded. For Crohn's disease (CD), disease phenotype and disease location were assessed as per Paris classification.

Results

Disease spectrum includes ulcerative colitis (UC), 55 (52%); CD, 43 (41%); and IBD‐unclassified, 7 (7%). There was a significant increase in the number of cases in the last 5 years compared to the previous 10 years (63 vs. 42, r² = 0.96). Most UC cases (75%) had extensive/pancolitis, 74% of CD had colonic/ileocolonic disease, and 65% had inflammatory phenotype. Fever, growth failure, pain in abdomen, and need for surgery were significantly more frequent in CD than in UC (P < 0.0001). Over a median follow up of 19 (IQR: 7–48) months, remission was achieved in 48 of 51 (94%) UC patients and in 24 of 34 (70.6%) CD patients; an immunomodulator was required to maintain remission in 67% of UC cases. In CD, there was a significant reduction in the use of empirical antitubercular therapy (76%, P = 0.008) with time, and disease progressed in three.

Conclusions

IBD is not uncommon, and the incidence seems to be increasing among Indian children. UC is more common than CD and is more often an extensive disease. CD is mainly an inflammatory phenotype. The majority of children with IBD required an immunomodulator to maintain remission.

Effectiveness and safety of biologics in pediatric inflammatory boweldisease: Real-life data from the Sicilian Network

BACKGROUND

Biological therapies have modified the disease course of pediatric inflammatory bowel disease (IBD) and are routinely used in clinical practice. Our observational study aims to evaluate effectiveness and safety of biologics in IBD.

METHOD

Clinical benefit and safety data of 93 children with IBD, receiving biologics (Infliximab - IFX, Adalimumab - ADA, Golimumab - GOL) from January 2013 to December 2017, were extracted from the cohort of the Sicilian Network of IBD.

RESULTS

Among 87 children aged 7-17 years (63 Crohn's disease [CD], 24 Ulcerative colitis [UC]), 101 out of 108 biologic treatments were considered. Evaluation of 74 biologic treatments in CD patients at 26, 52, 104 weeks showed clinical benefit rates of 84.2%, 93.3%, 66.7% with IFX (n= 38) and 88.9%, 84.4%, 65.2% with ADA (n= 36). Biologic treatments (n=27) evaluated in the UC group at 26, 52, 104 weeks, led to clinical benefit rates of 85.7%, 83.3%, 50% in IFX subgroup (n=21) and 40%, 50%, 33% in the ADA subgroup (n=5), respectively. One patient treated with GOL showed 100% clinical benefit at 26 and 52 weeks. Overall adverse events (AEs) rate was 9.25%. Six younger children, <6 years, receiving 8 treatments (4 ADA, 4 IFX) presented a clinical remission rate of 75% at 12 weeks and 25% at 52 weeks. AEs rate was 25% in this group.

CONCLUSION

Our data show that biologic therapy in children, even at a younger age, is effective in allowing long-term remission with a good safety profile.

An analysis and survey of interleukin-10 receptor mutation in inflammatory bowel disease (IBD) in the first Iranian IBD cohort

Background

Early-onset inflammatory bowel disease (IBD) is classified into Crohn’s disease (CD), ulcerative colitis (UC) and unclassified disorders, which has a chronic, relapsing course and can result in substantial long-term morbidity. IBD is a multifactorial disorder with genetic susceptibility, immunological predisposition and environmental triggers. The objective of this study was to generally determine the prevalence of IL10R mutation in IBD patients in Isfahan, Iran. We performed sequencing of all exons in IL10RA and IL10RB in a cohort of IBD patients and healthy controls.

Methods

Total DNA contents of 76 patients and 50 healthy controls were extracted from whole blood and polymerase chain reaction (PCR) amplifications and sequencing of whole exons in IL10R were performed.

Results

Overall, we determined 13 single nucleotide polymorphisms (SNPs) in all IL10R genes. Of them, rs3135932 and rs2229113 of the IL10RA1 gene, in exons 4 and 7, respectively, were significantly associated with IBD occurrence in patients.

Conclusions

Our results also confirmed that early-onset IBD could be attributed to a synergistic effect of several variant alleles of the genes encoding IL10 receptors. These variants, alone, could only give rise to a sub-clinical manifestation of IBD.

[Construction of rat interleukin-10 adenoviral vector and its expression in bone marrow mesenchymal stem cells]

OBJECTIVE

To construct the recombinant adenoviral vector carrying the rat interleukin-10 (rIL-10) gene, and to investigate whether it is stably expressed in bone marrow mesenchymal stem cells.

METHODS

The rIL-10 gene was amplified by PCR from template rIL-10 cDNA, and the recovered 656 bp rIL-10 DNA fragment was cloned into pcDNA3.1 to construct pcDNA3.1-IL-10. Then HEK293 cells were transfected with pcDNA3.1-IL-10 and adenoviral vector for homologous recombination, and sequencing and PCR were used to evaluate whether recombination was successful. HEK293 cells were lysed by repeated freeze-thaw cycles, and bone marrow mesenchymal stem cells were infected with the virus solution containing the rIL-10 gene. Western blot was used to measure the expression of rIL-10 in bone marrow mesenchymal stem cells.

RESULTS

Sequencing and PCR verified that the rIL-10 adenoviral vector was successfully constructed, with a virus titer of 4×10⁹ PFU/mL. The expression of IL-10 was detected after bone marrow mesenchymal stem cells were infected by the virus solution containing the rIL-10 gene.

CONCLUSIONS

The constructed rIL-10 recombinant adenovirus can mediate the stable expression of rIL-10 gene in bone marrow mesenchymal stem cells, which provides a basis for gene transplantation therapy of inflammatory bowel disease.

Candidiasis associated with very early onset inflammatory bowel disease: First IL10RB deficient case from the National Iranian Registry and review of the literature

Defects in interleukin-10 (IL10) and interleukin-10 receptors (IL10R) are closely related to very early onset (infantile) inflammatory bowel disease (VEO-IBD). In the present study, we report a novel homozygous null mutation within interleukin-10 receptor B (IL10RB) gene in a child presenting with severe VEO-IBD. In accordance with previous reports, our patient manifested with chronic diarrhea, failure to thrive, intermittent fever and multiple anal ulcers associated with Candidiasis. Homozygous null mutation within IL10RB gene (c.92C > T, p.S31P) affecting the extracellular domain of protein was discovered in this patient. In conclusion, the diagnosis of IL-10R gene mutations should always be considered as a possible cause of refractory diarrhea and failure to thrive. Mutation analysis could help detect the genetic defects associated with these clinical manifestations and to determine the most appropriate treatment option for patients affected by this disease.

Genetic Studies of Inflammatory Bowel Disease-Focusing on Asian Patients

The pathogenesis of inflammatory bowel disease (IBD) is not well-understood; however, increased and persistent intestinal inflammation, due to inappropriate immune responses that are caused by interactions between genetic factors, gut microbiota, and environmental factors, are thought to lead to IBD. Various studies have identified more than 240 genetic variants related to IBD. These genetic variants are involved in innate and adaptive immunity, autophagy, defective bacterial handing, interleukin-23 and 10 signaling, and so on. According to several epidemiological and clinical studies, the phenotypes and clinical course of IBD differ between Asians and Europeans. Although the risk loci for IBD typically overlap between Asians and Westerners, genetic heterogeneity has been detected in many loci/genes, such as NOD2/CARD15, TNFSF15 and human leukocyte antigen, contributing to the risk of IBD. Thus, although common pathways exist between Westerners and Asians in the development of IBD, their significance may differ for individual pathways. Although genetic studies are not universally applicable in the clinical field, they may be useful for diagnosing and categorizing IBD, predicting therapeutic responses and toxicity to drugs, and assessing prognosis by risk modeling, thereby enabling precision medicine for individual patients.

Current concepts in pediatric inflammatory bowel disease; IL10/IL10R colitis as a model disease

Inflammatory bowel disease (IBD) is a heterogeneous group of disorders composed mainly of ulcerative colitis (UC) and Crohn's disease (CD) and undetermined IBD. The peak incidence of occurrence is mainly beyond the pediatric age group. Recent knowledge about genetic factors had been strongly linked to pediatric IBD (PIBD). Recent advances in genomic technologies have prompted the identification of genetic defects underlying rare, very early-onset IBD (VEO-IBD) as a disease subgroup noted especially in populations with higher consanguinity rates. A better understanding of key players in the complex homeostasis of the immune system in the gut and illustrating the relationships between intestinal microbiome, systemic immune dysregulation and primary immunodeficiency have received growing recognition over the years. In this article, we provide a review of the key players of the immunity of the gut, compare between adult and pediatric IBD as an interesting module to investigate the relationship between monogenic and multifactorial/polygenic diseases, list genetic mutations confirmed to be linked to VEO IBD and summarize the scientific work that led to the discovery of one of the monogenic mutations related to infantile colitis, namely IL10 and IL10 receptor defects.

Novel Compound Heterozygote Mutation in IL10RA in a Patient With Very Early-Onset Inflammatory Bowel Disease

BACKGROUND

Very early-onset inflammatory bowel disease (VEO-IBD) is often associated with monogenetic disorders. IL-10RA deficiency is one of the major causal mutations in VEO-IBD. Here, we aimed to identify the causal mutation associated with severe IBD in a 1-year-old patient, validate the pathogenicity of the mutation, and characterize the mutant protein.

METHODS

To identify the causal mutation, targeted exome sequencing (ES) was performed using the genomic DNA from the patient. To validate the pathogenicity, IL-10RA functional tests were performed using the patient's peripheral blood mononuclear cells (PBMCs). Additionally, flow cytometry analysis, confocal microscopy on overexpressed green fluorescent protein-fused mutants, and computational analysis on the structures of IL-10RA proteins were performed.

RESULTS

We identified a novel compound heterozygote mutation p.[Tyr91Cys];[Pro146Alafs*40] in the IL10RA gene of the patient. The missense variant p.Tyr91Cys was previously identified but not functionally tested, and a frameshift variant, p.Pro146Alafs*40, is novel and nonfunctional. PBMCs from the patient showed defective signal transducer and activator of transcription 3 activation. The p.Tyr91Cys mutant protein failed to properly localize on the plasma membrane. The p.Tyr91Cys mutation seems to disrupt the hydrophobic core structure surrounding the tyrosine 91 residue, causing structural instability.

CONCLUSIONS

Targeted ES and linkage analysis identified novel compound heterozygous mutations p.[Tyr91Cys];[Pro146Alafs*40] in the IL10RA gene of a child with severe VEO-IBD. p.Tyr91Cys proteins were functionally defective in IL-10RA signaling and failed to properly localize on the plasma membrane, probably due to its structural instability.

Clinical aspects and treatments for pediatric inflammatory bowel disease

The incidence of pediatric inflammatory bowel disease (IBD) is increasing worldwide, especially in the developing countries. It differs from adult disease in clinical manifestations, especially with regard to genetic predisposition in monogenic IBD. Pediatric disease also have a tendency to show more aggressive inflammation and greater extent of lesion. Newer drugs such as antitumor necrosis factor-α have been known to make a difference in treating pediatric IBD. Recent studies suggested that the patients with high risk factors might have some benefits from earlier use of biologics. To achieve treatment goals such as relieving symptoms, optimizing growth, and improving quality of life while minimizing drug toxicity, more research is needed to develop tools for risk stratification in the use of biologics for pediatric IBD.

Clinical Aspects and Treatments for Pediatric Inflammatory Bowel Diseases

The incidence of pediatric inflammatory bowel disease (IBD) is increasing worldwide, especially in the developing countries. It differs from adult disease in clinical manifestations, especially with regard to genetic predisposition in monogenic IBD. Pediatric disease also have a tendency to show more aggressive inflammation and greater extent of lesion. Newer drugs such as anti-tumor necrosis factor α have been known to make a difference in treating pediatric IBD. Recent studies suggested that the patients with high risk factors might have some benefits from earlier use of biologics. To achieve treatment goals such as relieving symptoms, optimizing growth, and improving quality of life while minimizing drug toxicity, more research is needed to develop tools for risk stratification in the use of biologics for pediatric IBD.

Recent Advance in Very Early Onset Inflammatory Bowel Disease

Recent studies on pediatric inflammatory bowel disease (IBD) have revealed that early-onset IBD has distinct phenotypic differences compared with adult-onset IBD. In particular, very early-onset IBD (VEO-IBD) differs in many aspects, including the disease type, location of the lesions, disease behavior, and genetically attributable risks. Several genetic defects that disturb intestinal epithelial barrier function or affect immune function have been noted in these patients from the young age groups. In incidence of pediatric IBD in Korea has been increasing since the early 2000s. Neonatal or infantile-onset IBD develops in less than 1% of pediatric patients. Children with "neonatal IBD" or "infantile-onset IBD" have higher rates of affected first-degree relatives, severe disease course, and a high rate of resistance to immunosuppressive treatment. The suspicion of a monogenic cause of VEO-IBD was first confirmed by the discovery of mutations in the genes encoding the interleukin 10 (IL-10) receptors that cause impaired IL-10 signaling. Patients with such mutations typically presented with perianal fistulae, shows a poor response to medical management, and require early surgical interventions in the first year of life. To date, 60 monogenic defects have been identified in children with IBD-like phenotypes. The majority of monogenic defects presents before 6 years of age, and many present before 1 year of age. Next generation sequencing could become an important diagnostic tool in children with suspected genetic defects especially in children with VEO-IBD with severe disease phenotypes. VEO-IBD is a phenotypically and genetically distinct disease entity from adult-onset or older pediatric IBD.

Compound heterozygous mutations in IL10RA combined with a complement factor properdin mutation in infantile-onset inflammatory bowel disease

OBJECTIVES

Inflammatory bowel diseases (IBDs) are chronic and multifactorial diseases resulting from a complex interaction of host genetic factors and environmental stimuli. Although many genome-wide association studies have identified host genetic factors associated with IBD, rare Mendelian forms of IBD have been reported in patients with very early onset forms. Therefore, this study aimed to identify genetic variants associated with infantile-onset IBD.

PARTICIPANTS AND METHODS

We obtained genomic DNA from whole blood samples of a male patient with infantile-onset IBD and nonconsanguineous Korean parents. Whole-exome sequencing was performed using trio samples. Then, we analyzed the data using susceptibility genes for monogenic forms of IBD and various immunodeficiencies and protein structural analysis.

RESULTS

The patient who presented with oral aphthous ulcers at the age of 14 days suffered from severe colitis and was refractory to medical treatment. Compound heterozygous mutations in IL10RA (p.R101W; p.T179T) were found in the patient. In addition, a hemizygous mutation in complement factor properdin (CFP) (p.L456V) located on the X-chromosome was detected, inherited from the patient's mother. Protein structural modeling suggested impaired properdin subunit interactions by p.L456V that may hamper protein oligomerization required for complement activation.

CONCLUSION

This study identified compound heterozygous mutations in IL10RA combined with a hemizygous CFP mutation in infantile-onset IBD by using whole-exome sequencing. CFP p.L456V may exacerbate symptoms of infantile-onset IBD by disturbing oligomerization of properdin.

Salivary Gland Extract of Kissing Bug, Triatoma lecticularia, Reduces the Severity of Intestinal Inflammation through the Modulation of the Local IL-6/IL-10 Axis

Triatomines are known for their role as vectors of the causative agent of Chagas disease. The occurrence of an arsenal of molecules in their saliva is able to suppress vertebrate immune responses. Thus, it is reasonable to assume that the presence of molecules with therapeutic potential in their saliva is able to constrain inflammation in immune-mediated diseases. Thus, mice were exposed to dextran sulfate sodium (DSS) in drinking water uninterruptedly during 6 consecutive days and treated with T. lecticularia salivary gland extract (SGE) (3, 10, or 30 μg) or vehicle (saline) (n = 6/group). At the highest dose (30 μg), an improvement in clinical outcome and macroscopic aspects of the intestine were observed. This observation was followed by amelioration in histopathological aspects in the colon especially when the doses of 10 and 30 μg were used. Regardless of the concentration used, treatment with T. lecticularia SGE significantly reduced the levels of the inflammatory cytokine IL-6 in the intestine. The production of the anti-inflammatory cytokine IL-10 was positively impacted by the concentrations of 3 and 30 μg. Our results suggest that the presence of molecules in the T. lecticularia SGE is able to attenuate clinical outcome and colon shortening and improve intestinal architecture besides reducing the production of IL-6 and inducing a local production of IL-10 in the intestine.

Recent advance in very early-onset inflammatory bowel disease

Recent studies on pediatric inflammatory bowel disease (IBD) have revealed that early-onset IBD has distinct phenotypic differences compared with adult-onset IBD. In particular, very early-onset IBD (VEO-IBD) differs in many aspects, including the disease type, location of the lesions, disease behavior, and genetically attributable risks. Neonatal or infantile-onset IBD develops in less than 1% of pediatric patients. Children with infantile-onset IBD have high rates of affected first-degree relatives and severe disease course. The suspicion of a monogenic cause of VEO-IBD was first confirmed by the discovery of mutations in the genes encoding the interleukin 10 (IL-10) receptors that cause impaired IL-10 signaling. Patients with such mutations typically presented with perianal fistulae, shows a poor response to medical management, and require early surgical interventions in the first year of life. To date, 60 monogenic defects have been identified in children with IBD-like phenotypes. The majority of monogenic defects presents before 6 years of age, and many present before 1 year of age. Next generation sequencing could become an important diagnostic tool in children with suspected genetic defects especially in children with VEO-IBD with severe disease phenotypes. VEO-IBD is a phenotypically and genetically distinct disease entity from adult-onset or older pediatric IBD.

Copy number variations and founder effect underlying complete IL-10Rβ deficiency in Portuguese kindreds

Mutations in interleukin-10 receptor (IL-10R) genes are one cause of very early-onset inflammatory bowel disease with perianal lesions, which can be cured by hematopoietic stem cell transplantation. Using a functional test, which assesses responsiveness of peripheral monocytes to IL-10, we identified three unrelated Portuguese patients carrying two novel IL-10RB mutations. In the three patients, sequencing of genomic DNA identified the same large deletion of exon 3 which precluded protein expression. This mutation was homozygous in two patients born from consanguineous families and heterozygous in the third patient born from unrelated parents. Microsatellite analysis of the IL10RB genomic region revealed a common haplotype in the three Portuguese families pointing to a founder deletion inherited from a common ancestor 400 years ago. In the third patient, surface expression of IL-10R was normal but signaling in response to IL-10 was impaired. Complementary DNA sequencing and next-generation sequencing of IL10RB locus with custom-made probes revealed a ≈ 6 Kb duplication encompassing the exon 6 which leads to a frameshift mutation and a loss of the TYK2-interacting Box 2 motif. Altogether, we describe two novel copy number variations in IL10RB, one with founder effect and one preserving cell surface expression but abolishing signaling.

High-Throughput Chip Assay for Investigating Escherichia coli Interaction with the Blood-Brain Barrier Using Microbial and Human Proteome Microarrays (Dual-Microarray Technology)

Bacterial meningitis in neonates and infants is an acute lethal disease and occurs in response to microbial exploitation of the blood-brain barrier (BBB), resulting in the intracranial inflammation. Several pathogens, such as Escherichia coli ( E. coli), can cause this devastating disease; however, the underlying molecular mechanisms by which these pathogens exploit the BBB remain incompletely understood. To identify important players on both the pathogen and host sides that govern the E. coli-BBB cell interactions, we took advantage of the E. coli and human proteome microarrays (i.e., HuProt) as an unbiased, proteome-wide tool for identification of important players on both sides. Using the E. coli proteome microarrays, we developed a unique high throughput chip-based cell probing assay to probe with fluorescent live human brain microvascular endothelial cells (HBMEC, which constitute the BBB). We identified several transmembrane proteins, which effectively bound to live HBMEC. We focused on YojI protein for further study. By probing the HuProt arrays with YojI, interferon-alpha receptor (IFNAR2) was identified as one of its binding proteins. The importance of YojI and IFNAR2 involved in E. coli-HBMEC interactions was characterized using the YojI knockout bacteria and IFNAR2-knock down HBMEC and further confirmed by E. coli binding assay in HBMEC. This study represents a new paradigm (dual-microarray technology) that enables rapid, unbiased discovery of both pathogen and host players that are involved in pathogen-host interactions for human infectious diseases in a high throughput manner.

Neonatal Presentation of Unremitting Inflammatory Bowel Disease

Very-early-onset inflammatory bowel disease (VEO-IBD) has a distinct phenotype and should be considered a specific entity. VEO-IBD presents with very severe clinical pictures and is frequently known by an indeterminate colitis whose clinical remission is unmanageable. This study examines the case of a neonate with VEO-IBD, not responding to medical and surgical treatment. A 7-day-old Iranian female neonate presented with severe bloody diarrhea, poor feeding, abdominal distention, and dehydration suggesting severe proctocolitis due to an allergy to the protein in cow's milk. The condition did not respond to the elimination of diet for 1 month. Infections, celiac disease, and cystic fibrosis were excluded. Immunological investigations were negative, but antineutrophil cytoplasmic antibodies were positive. Due to the neonate's persistent symptoms and failure to thrive, upper and lower endoscopies were performed, showing ulcerative colitis. At the age of 4 months, she presented with signs and symptoms of toxic colitis and acute intestinal perforation, which prompted an emergency laparotomy. Due to the necrosis of the colon, hemicolectomy and colostomy were done. The patient was resuscitated and rehabilitated and was given glucocorticoid and mesalamine. We believe that the incidence of this problem is increasing, as is shown by the rise in the number of children under 10 years old being diagnosed. These patients require more aggressive therapeutic interventions than older IBD patients to achieve complete remission because they are more likely to have extensive colonic disease.

Computational Protein Phenotype Characterization of IL10RA Mutations Causative to Early Onset Inflammatory Bowel Disease (IBD)

The deleterious amino acid substitution mutations in IL-10 receptor alpha gene are most frequently reported in several autoimmune diseases including early onset-inflammatory bowel disease (IBD). Despite the important role of IL-10 RA in maintaining immune homeostasis, the specific structural and functional implications of these mutations on protein phenotype, stability, ligand binding and post translational characteristics is not well explored. Therefore, this study performed the multidimensional computational analysis of IL10RA missense variations causative to pediatric or early onset inflammatory bowel disease (<5 years of age). Our computational algorithmic screening identified the deleterious nature of p. W45G, p. Y57C, p. W69G, p.T84I, p.Y91C, p.R101W, p.R117C, and p.R117H, IBD causative IL10-RA mutations. The sensitivity and specificity analysis of different computational methods showed that CADD outperform SIFT, PolyPhen 2.0, FATHMM, LRT, MetaLR, MetaSVM, PROVEAN and Condel in predicting the pathogenicity of IL10RA mutations. Our three-dimensional protein modeling assays showed that the point mutations cause major drifts in the structural plasticity of IL10 RA molecule and negatively influence its stability. Findings from molecular docking analysis have shown that these point mutations decrease the binding affinity of IL10RA toward IL10 and may likely to disturb the IL10 signaling pathway. This study provides an easy frame work for phenotypic characterization of mutant IL10RA molecule in terms of structure, flexibility and stability aspects. Our approach may also add a new dimension to conventional functional biology assays in quickly studying IL10 RA mutations and also for designing and developing inhibitors for mutant IL10RA molecule.

Phenotype and Management of Infantile-onset Inflammatory Bowel Disease: Experience from a Tertiary Care Center in China

BACKGROUND

Infantile-onset inflammatory bowel disease (IBD) comprises rare and clinically severe disorders. We examined the phenotypes and genetic causes of patients with infantile-onset IBD from a tertiary medical center.

METHODS

We enrolled 38 patients with infantile-onset IBD and applied standardized treatment with medical, surgical, and supportive care. Targeted sequencing and whole-exome sequencing were performed. Clinical data were retrieved from medical records.

RESULTS

Median age of onset of disease was 12.5 (interquartile range: 7.0-30.0) days. All patients had diarrhea, whereas 18 (47.4%) patients reported hematochezia. Thirteen (34.2%) patients had oral ulcers, 15 (39.5%) patients had perianal abscess, and 9 (52.9%) female patients had rectovaginal fistula. Six (18.8%) patients had intestinal strictures and 4 (12.1%) patients had perforation. Twelve (31.6%) patients underwent surgical procedures. Median age of surgery was 272.5 days, and cumulative probability for surgery during first year was 32.1%. One-year mortality of patients was 25.9%. Sequencing showed 24 (63.2%) patients had causative IL10RA mutations, 1 patient had EPCAM mutation, 1 patient had TNFAIP3 mutation, and 1 patient had LRBA mutation, whereas causative mutations cannot be identified in the other 11 (28.9%) patients. Umbilical cord blood stem cell transplantation has been applied to 8 cases with IL10RA mutations, of whom 5 (71.4%) patients have achieved clinical remission.

CONCLUSIONS

Patients with infantile-onset IBD had severe phenotype and early onset. Medical, surgical interventions with supportive care are essential. High-throughput sequencing ensures appropriate treatment. Hematopoietic stem cell transplantation can be performed in selected patients with IL10RA mutations (see Video Abstract, Supplemental Digital Content 1, http://links.lww.com/IBD/B657).

Genetic association and epistatic interaction of the interleukin-10 signaling pathway in pediatric inflammatory bowel disease

AIM

To study the genetic association and epistatic interaction of the interleukin (IL)-10 and IL-10/STAT3 pathways in pediatric inflammatory bowel disease (IBD).

METHODS

A total of 159 pediatric inflammatory IBD patients (Crohn’s disease, n = 136; ulcerative colitis, n = 23) and 129 matched controls were studied for genetic association of selected single nucleotide polymorphisms (SNPs) of the IL-10 gene and the genes IL10RA, IL10RB, STAT3, and HO1, from the IL-10/STAT3 signaling pathway. As interactions between SNPs from different loci may significantly affect the associated risk for disease, additive (a) and dominant (d) modeling of SNP interactions was also performed to examine high-order epistasis between combinations of the individual SNPs.

RESULTS

The results showed that IL-10 rs304496 was associated with pediatric IBD (P = 0.022), but no association was found for two other IL-10 SNPs, rs1800872 and rs2034498, or for SNPs in genes IL10RA, IL10RB, STAT3, and HO1. However, analysis of epistatic interaction among these genes showed significant interactions: (1) between two IL-10 SNPs rs1800872 and rs3024496 (additive-additive P = 0.00015, Bonferroni P value (Bp) = 0.003); (2) between IL-10RB rs2834167 and HO1 rs2071746 (dominant-additive, P = 0.0018, Bp = 0.039); and (3) among IL-10 rs1800872, IL10RB rs2834167, and HO1 rs2071746 (additive-dominant-additive, P = 0.00015, Bp = 0.005), as well as weak interactions among IL-10 rs1800872, IL-10 rs3024496, and IL-10RA (additive-additive-additive, P = 0.003; Bp = 0.099), and among IL10RA, IL10RB, and HO1 genes (additive-dominant-additive, P = 0.008, Bp = 0.287).

CONCLUSION

These results indicate that both the IL-10 gene itself, and through epistatic interaction with genes within the IL-10/STAT3 signaling pathway, contribute to the risk of pediatric IBD.

Mutations in Interleukin-10 Receptor and Clinical Phenotypes in Patients with Very Early Onset Inflammatory Bowel Disease: A Chinese VEO-IBD Collaboration Group Survey

BACKGROUND

Interleukin-10 (IL10) signaling plays an important role in the pathogenesis of very early onset inflammatory bowel disease (VEO-IBD) in children. However, little is known about the role of the IL10 axis in children with VEO-IBD in China.

METHODS

The Chinese VEO-IBD Collaboration Group was created to collect clinical and genetic data from patients deficient in IL10 and the IL10 receptor. High-throughput sequencing was performed to identify mutations in these genes.

RESULTS

We identified 32 compound heterozygous mutations and 9 homozygous mutations in IL10 receptor subunit alpha and 1 homozygous mutation in IL10 receptor subunit beta. Among these mutations, 10 novel mutations were identified, and 6 pathogenic mutations had been previously described. In patients with IL10 receptor subunit alpha mutations, c.301C>T (p.R101RW) and c.537 G>A (p.T179T) were the most common mutations. For 88.1% of the patients, the initial symptom was diarrhea, with a time of onset of 10.4 ± 8.0 days. Oral ulcers were the first symptom in 23.8% of the patients, with a time of onset of 9.7 ± 2.8 days. Extraintestinal manifestations included perianal abscesses (22/42), perianal fistulas (23/42), oral ulcers (20/42), and recurrent eczema (15/42). Twelve patients underwent enterostomy. These patients also had lower average Z scores in height-for-age and weight-for-age. Various treatment strategies were used, including fecal microbiota transplantation; however, only hematopoietic stem cell transplantation was efficacious.

CONCLUSIONS

This study identified genotypes and phenotypes of Chinese VEO-IBD infants with IL10 receptor mutations. Our study expands the current knowledge on the involvement of the IL10 axis in patients with VEO-IBD.

IL-10 and IL-10 Receptor Mutations in Very Early Onset Inflammatory Bowel Disease

Very early onset inflammatory bowel disease (VEO-IBD) is a unique disease entity with a complex genetic susceptibility in affected patients. Next-generation gene sequencing techniques have revealed various monogenetic mutations contributing to the pathogenesis of VEO-IBD, including interleukin 10 (IL-10) and IL-10 receptor (IL-10R) mutations. In this article, we reviewed the features of and effective therapeutic options for VEO-IBD with IL-10 and/or IL-10R mutations. The IL-10 signal pathway inhibits the release of several key cytokines and thereby has a significant anti-inflammatory effect in the gastrointestinal tract. Mutations of the genes encoding IL-10 and/or IL-10R have been detected in VEO-IBD patients among myriad populations throughout the world. VEO-IBD patients with IL-10 or IL-10R mutations often present with repeated bouts of bloody diarrhea, marked weight loss, growth retardation, and recurrent perianal problems, including abscesses, fistulas, and significant fissures. Moreover, some patients may have folliculitis and present with pulmonary infections. While the therapeutic efficacy of immunosuppressants is typically poor in these patients, allogeneic hematopoietic stem cell transplantation (HSCT) has been reported to improve symptoms significantly. However, the long-term prognosis of VEO-IBD patients with IL-10 or IL-10R gene mutations treated with HSCT requires further exploration to verify the efficacy and safety of this treatment. We concluded that clinicians should recognize the clinical phenotype of VEO-IBD, as mutational analysis of the IL-10 pathway can support the diagnosis and prompt early treatment of this complicated disease.

Variable outcome in infantile-onset inflammatory bowel disease in an Asian cohort

AIM

Infantile-onset inflammatory bowel disease (IO-IBD) with the onset of disease before 12 mo of age, is a different disease entity from childhood IBD. We aimed to describe the clinical features, outcome and role of mutation in interleukin-10 (IL-10) and interleukin-10 receptors (IL-10R) in Asian children with IO-IBD.

METHODS

All cases of IO-IBD, defined as onset of disease before 12 mo of age, seen at University Malaya Medical Center, Malaysia were reviewed. We performed mutational analysis for IL10 and IL10R genes in patients with presenting clinical features of Crohn’s disease (CD).

RESULTS

Six [13%; CD = 3, ulcerative colitis (UC) = 2, IBD-unclassified (IBD-U) = 1] of the 48 children (CD = 25; UC = 23) with IBD have IO-IBD. At final review [median (range) duration of follow-up: 6.5 (3.0-20) years], three patients were in remission without immunosuppression [one each for post-colostomy (IBD-U), after standard immunosuppression (CD), and after total colectomy (UC)]. Three patients were on immunosuppression: one (UC) was in remission while two (both CD) had persistent disease. As compared with later-onset disease, IO-IBD were more likely to present with bloody diarrhea (100% vs 55%, P = 0.039) but were similar in terms of an associated autoimmune liver disease (0% vs 19%, P = 0.31), requiring biologics therapy (50% vs 36%, P = 0.40), surgery (50% vs 29%, P = 0.27), or achieving remission (50% vs 64%, P = 0.40). No mutations in either IL10 or IL10R in the three patients with CD and the only patient with IBD-U were identified.

CONCLUSION

The clinical features of IO-IBD in this Asian cohort of children who were negative for IL-10 or IL-10R mutations were variable. As compared to childhood IBD with onset of disease after 12 mo of age, IO-IBD achieved remission at a similar rate.

A Synonymous Variant in IL10RA Affects RNA Splicing in Paediatric Patients with Refractory Inflammatory Bowel Disease

Interleukin-10 receptor [IL10R] mutations are associated with severe childhood inflammatory bowel disease [IBD]. Two unrelated patients who died of very early-onset severe IBD and sepsis were identified as harbouring the same compound heterozygous mutations in IL10RA [p.R101W; p.T179T]. A third patient was found to be homozygous for p.T179T. The missense change of p.R101W has been reported. The synonymous change of p.T179T, with a minor allele frequency of 0.035% in the population, was novel. The p.T179T mutation was located before the 5' splice donor site, leading to exon skipping and out-of-frame fusion of exons 3 and 5, causing altered STAT3 phosphorylation in IL10-induced peripheral blood mononuclear cells. The patient developed colitis at 6 years of age, the oldest reported age of onset among patients with IL10RA mutations, and did not suffer from perianal disease. We report three paediatric patients with a rare, synonymous p.T179T variant causing a splicing error in IL10RA.

Viral Infection of the Central Nervous System Exacerbates Interleukin-10 Receptor Deficiency-Mediated Colitis in SJL Mice

Theiler´s murine encephalomyelitis virus (TMEV)-infection is a widely used animal model for studying demyelinating disorders, including multiple sclerosis (MS). The immunosuppressive cytokine Interleukin (IL)-10 counteracts hyperactive immune responses and critically controls immune homeostasis in infectious and autoimmune disorders. In order to investigate the effect of signaling via Interleukin-10 receptor (IL-10R) in infectious neurological diseases, TMEV-infected SJL mice were treated with IL-10R blocking antibody (Ab) in the acute and chronic phase of the disease. The findings demonstrate that (i) Ab-mediated IL-10 neutralization leads to progressive colitis with a reduction in Foxp3+ regulatory T cells and increased numbers of CD8+CD44+ memory T cells as well as activated CD4+CD69+ and CD8+CD69+ T cells in uninfected mice. (ii) Concurrent acute TMEV-infection worsened enteric disease-mediated by IL-10R neutralization. Virus-triggered effects were associated with an enhanced activation of CD4+ T helper cells and CD8+ cytotoxic T lymphocytes and augmented cytokine expression. By contrast, (iii) IL-10R neutralization during chronic TMEV-infection was not associated with enhanced peripheral immunopathology but an increased CD3+ T cell influx in the spinal cord. IL-10R neutralization causes a breakdown in peripheral immune tolerance in genetically predisposed mice, which leads to immune-mediated colitis, resembling inflammatory bowel disease. Hyperactive immune state following IL-10R blockade is enhanced by central nervous system-restricted viral infection in a disease phase-dependent manner.

Comprehensive mutation screening for 10 genes in Chinese patients suffering very early onset inflammatory bowel disease

AIM

To perform sequencing analysis in patients with very early-onset inflammatory bowel disease (VEO-IBD) to determine the genetic basis for VEO-IBD in Chinese pediatric patients.

METHODS

A total of 13 Chinese pediatric patients with VEO-IBD were diagnosed from May 2012 and August 2014. The relevant clinical characteristics of these patients were analyzed. Then DNA in the peripheral blood from patients was extracted. Next generation sequencing (NGS) based on an Illumina-Miseq platform was used to analyze the exons in the coding regions of 10 candidate genes: IL-10, IL-10RA, IL-10RB, NOD2, FUT2, IL23R, GPR35, GPR65, TNFSF15, and ADAM30. The Sanger sequencing was used to verify the variations detected in NGS.

RESULTS

Out of the 13 pediatric patients, ten were diagnosed with Crohn's disease, and three diagnosed with ulcerative colitis. Mutations in IL-10RA and IL-10RB were detected in five patients. There were four patients who had single nucleotide polymorphisms associated with IBD. Two patients had IL-10RA and FUT2 polymorphisms, and two patients had IL-10RB and FUT2 polymorphisms. Gene variations were not found in the rest four patients. Children with mutations had lower percentile body weight (1.0% vs 27.5%, P = 0.002) and hemoglobin (87.4 g/L vs 108.5 g/L, P = 0.040) when compared with children without mutations. Although the age of onset was earlier, height was shorter, and the response to treatment was poorer in the mutation group, there was no significant difference in these factors between groups.

CONCLUSION

IL-10RA and IL-10RB mutations are common in Chinese children with VEO-IBD. Patients with mutations have an earlier disease onset, lower body weight and hemoglobin, and poorer prognosis.

Integrin CD11b attenuates colitis by strengthening Src-Akt pathway to polarize anti-inflammatory IL-10 expression

Interleukin-10 (IL-10) plays a central role in regulation of intestinal mucosal homeostasis and prevention of inflammatory bowel disease (IBD). We previously reported that CD11b(hi) regulatory dendritic cells (DCs) can produce more IL-10, and CD11b can negatively regulate Toll-like receptors (TLRs)-induced inflammatory responses in macrophages. However whether CD11b and its signaling can control autoimmunity via IL-10 production remains unclear. Here we found that CD11b deficient (Itgam(-/-)) mice were more susceptible to dextran sulfate sodium (DSS)-induced colitis, with more tumor necrosis factor α (TNF-α) while less IL-10 production. CD11b inhibited nuclear factor-kappa B (NF-κB) while promoted activator protein 1 (AP-1) activation through activating sarcoma oncogene (Src), leading to decreased TNF-α while increased IL-10 production. Src interacted with and promoted c-casitas B lineage lymphoma proto-oncogene (c-Cbl)-mediated degradation of the inhibitory subunit p85 of phosphatidylinositol 3-kinase (PI3K). Importantly, Src inhibitor dasatinib aggravated DSS-induced colitis by decreasing IL-10 while increasing TNF-α in vivo. Therefore, CD11b promotes IL-10 production by activating Src-Akt signal pathway. An axis of CD11b-Src pathway is important in balancing homeostasis of TLR-induced pro-inflammatory and anti-inflammatory responses.

Detecting inflammation in the unprepared pediatric colon - how reliable is magnetic resonance enterography?

BACKGROUND

Pediatric inflammatory bowel disease frequently affects the colon. MR enterography is used to assess the small bowel but it also depicts the colon.

OBJECTIVE

To compare the accuracy of MR enterography and direct visualization at endoscopy in assessing the colon in pediatric inflammatory bowel disease.

MATERIALS AND METHODS

We included children with inflammatory bowel disease who had undergone both MR enterography and endoscopy, and we restrospectively assessed the imaging and endoscopic findings. We scored the colonic appearance at MR using a total colon score. We then compared scores for the whole colon and for its individual segments with endoscopy and histology.

RESULTS

We included 15 children. An elevated MR colonic segmental score predicted the presence of active inflammation on biopsy with a specificity of 90% (95% confidence interval [CI] 79.5-96.2%) and sensitivity of 60% (CI 40.6-77.3%); this compares reasonably with the predictive values for findings at colonoscopy - specificity 85% (CI 73.4-92.9%) and sensitivity 53.3% (CI 34.3%-71.6%). Accuracy did not change significantly with increasing bowel distension.

CONCLUSION

MR-derived scores had comparable accuracy to those derived during visualization at colonoscopy for detecting biopsy-proven inflammation in our patient group. MR enterography might prove useful in guiding biopsy or monitoring treatment response. Collapse of a colonic segment did not impair assessment of inflammation.

Novel exonic mutation inducing aberrant splicing in the IL10RA gene and resulting in infantile-onset inflammatory bowel disease: a case report

Background

Although deleterious mutations in interleukin-10 and its receptor molecules cause severe infantile-onset inflammatory bowel disease, there are no reports of mutations affecting this signaling pathway in Japanese patients. Here we report a novel exonic mutation in the IL10RA gene that caused unique splicing aberrations in a Japanese patient with infantile-onset of inflammatory bowel disease in association with immune thrombocytopenic purpura and a transient clinical syndrome mimicking juvenile myelomonocytic leukemia.

Case presentation

A Japanese boy, who was the first child of non-consanguineous healthy parents, developed bloody diarrhea, perianal fistula, and folliculitis in early infancy and was diagnosed with inflammatory bowel disease. He also developed immune thrombocytopenic purpura and transient features mimicking juvenile myelomonocytic leukemia. The patient failed to respond to various treatments, including elemental diet, salazosulfapyridine, metronidazole, corticosteroid, infliximab, and adalimumab. We identified a novel mutation (c.537G > A, p.T179T) in exon 4 of the IL10RA gene causing unique splicing aberrations and resulting in lack of signaling through the interleukin-10 receptor. At 21 months of age, the patient underwent allogeneic hematopoietic stem cell transplantation and achieved clinical remission.

Conclusions

We describe a novel exonic mutation in the IL10RA gene resulting in infantile-onset inflammatory bowel disease. This mutation might also be involved in his early-onset hematologic disorders. Physicians should be familiar with the clinical phenotype of IL-10 signaling defects in order to enable prompt diagnosis at an early age and referral for allogeneic hematopoietic stem cell transplantation.

Electronic supplementary material

The online version of this article (doi:10.1186/s12876-016-0424-5) contains supplementary material, which is available to authorized users.

Genomic architecture of inflammatory bowel disease in five families with multiple affected individuals

Currently, the best clinical predictor for inflammatory bowel disease (IBD) is family history. Over 163 sequence variants have been associated with IBD in genome-wide association studies, but they have weak effects and explain only a fraction of the observed heritability. It is expected that additional variants contribute to the genomic architecture of IBD, possibly including rare variants with effect sizes larger than the identified common variants. Here we applied a family study design and sequenced 38 individuals from five families, under the hypothesis that families with multiple IBD-affected individuals harbor one or more risk variants that (i) are shared among affected family members, (ii) are rare and (iii) have substantial effect on disease development. Our analysis revealed not only novel candidate risk variants but also high polygenic risk scores for common known risk variants in four out of the five families. Functional analysis of our top novel variant in the remaining family, a rare missense mutation in the ubiquitin ligase TRIM11, suggests that it leads to increased nuclear factor of kappa light chain enhancer in B-cells (NF-κB) signaling. We conclude that an accumulation of common weak-effect variants accounts for the high incidence of IBD in most, but not all families we analyzed and that a family study design can identify novel rare variants conferring risk for IBD with potentially large effect size, such as the TRIM11 p.H414Y mutation.