Novel de novo mutations of the interleukin-10 receptor gene lead to infantile onset inflammatory bowel disease

A Systematic Review of Mendelian Pyoderma Gangrenosum: Clinical and Genetic Characteristics in 120 Published Patients

Pyoderma gangrenosum (PG) is a rare neutrophilic dermatosis characterised by sterile, recurrent ulcers with a predominantly multifactorial aetiology. However, in a small subset of patients carrying highly penetrant Mendelian mutations in single genes, PG presents as a part of a genetic syndrome. This study aimed to systematically review Mendelian susceptibilities to PG and summarise the clinical and genetic characteristics of patients. Search criteria encompassed case reports, case series and other original articles focusing on causal sequence variants associated with PG pathogenicity. We screened 1577 articles and selected 79 studies, encompassing 120 PG patients and 19 distinct genes, for quantitative analysis. The most prevalent mode of inheritance was autosomal dominant, and the mean age of onset was 23.39 ± 19.76 years. Seventeen of 19 genes are categorised under the Inborn Errors of Immunity (IEI) compiled by the International Union of Immunological Societies (IUIS). According to this, the most reported genes (37%) belong to 'Autoinflammatory Disorders.' All 19 genes were linked to cutaneous ulcers, with PSTPIP1 and MEFV being the only genes associated with all three lesion types (cutaneous, anogenital, mucosal). PSTPIP1 was the most frequently reported PG-related gene, followed by MEFV, ITGB2, NOD2, NFKB1, RAG1, JAK2, and NCSTN. Pseudomonas aeruginosa was the most frequently identified infectious agent in PG skin lesions. This study identifies at least 19 genes associated with PG susceptibility, emphasising the crucial role of genetic factors in disease pathogenesis. Gaining insight into the genetic basis and molecular mechanisms involved may facilitate the development of more targeted therapeutic strategies for PG.

Risk factors for stoma and incision complications of enterostomy in children with very early-onset inflammatory bowel disease: a prospective cohort study

Enterostomy is utilized to mitigate severe clinical symptoms in children with very early-onset inflammatory bowel disease (VEO-IBD) and to provide a window for stem cell transplantation. Nevertheless, the incidence of postoperative complications is significant, and there is currently a lack of research exploring the risk factors associated with complications related to the stoma and incision following the procedure. The objective of this study is to investigate the risk factors for stoma and incision complications after enterostomy in patients with VEO-IBD. From January 2015 to December 2023, 49 children with VEO-IBD who underwent enterostomy were enrolled in the study. Demographic characteristics, blood biochemical indices, weighted Pediatric Crohn's Disease Activity Index (wPCDAI), and enterostomy-related information were prospectively collected. Multivariate logistic regression was employed to identify the risk factors for ostomy and incision-related complications. All 49 included VEO-IBD children had interleukin-10 (IL-10) signaling defects, with 27 (55.1%) having stomal-related complications and 10 (20.4%) had incision complications after enterostomy. Univariate analysis revealed that wPCDAI (OR, 1.03; 95% CI, 1.00-1.07; P = 0.05) showed a tendency towards statistical significance in the occurrence of ostomy complications. Weight-for-age Z-score (WAZ) (OR, 0.57; 95% CI, 0.39-0.84; P = 0.004), height-for-age Z-score (HAZ) (OR, 0.57; 95% CI, 0.37-0.88; P = 0.01), type of surgery (OR, 0.12; 95% CI, 0.03-0.56, P = 0.007), C-reactive protein (CRP) (OR, 1.02; 95% CI, 1.01-1.04; P = 0.007), and wPCDAI (OR, 1.08; 95% CI, 1.01-1.14; P = 0.009) demonstrated statistical significance in the occurrence of incision complications. However, multivariate binary logistic regression did not reveal any statistically significant factors.

CONCLUSION

Although emergency surgery is unavoidable, our study suggests that improving nutritional status, reducing CRP levels, and increasing preoperative wPCDAI scores may help reduce post-enterostomy stoma and incision complications in VEO-IBD children with interleukin-10 (IL-10) signaling defects. Further large-scale studies are needed to confirm these findings.

WHAT IS KNOWN

• Enterostomy is commonly used to manage severe symptoms in children with VEO-IBD and to provide a window for stem cell transplantation. • The incidence of postoperative complications, including stoma and incision-related issues, is significant in these patients.

WHAT IS NEW

• This study identifies potential risk factors for stoma and incision complications following enterostomy in children with VEO-IBD, particularly those with IL-10 signaling defects. • Factors such as nutritional status (WAZ and HAZ), CRP levels, type of surgery, and the wPCDAI were found to be associated with stoma and incision complications in univariate analysis, although multivariate analysis did not show statistical significance for these factors.

Assessment of Anti-inflammatory Efficacy of Acupuncture in Patients with Inflammatory Bowel Disease: A Systematic Review and Meta-analysis

BACKGROUND

Inflammation has a significant role in the onset and progression of inflammatory bowel disease (IBD). Increasing attention has been paid to the use of acupuncture in IBD patients; however, its regulatory effects on inflammatory factors in IBD still require validation. Here, we systematically evaluated the effects of acupuncture on inflammatory factors in IBD patients.

METHODS

Eight electronic databases were searched for studies that met the inclusion criteria. After evaluating the quality of the studies selected by two reviewers, the meta-analysis was performed to assess the efficacy of acupuncture in IBD patients and the impact on inflammatory factors (TNF-α, IL-1, IL-8 and IL-10).

RESULTS

Four randomized controlled trials with a total of 228 patients satisfied the inclusion criteria. Acupuncture has a positive therapeutic impact on IBD (MD = 1.22, 95% CI [1.07, 1.39], P =0.003). Moreover, it regulates the levels of TNF-α (MD =-60.58, 95% CI [-100.30, -20.89], P =0.003), IL-8 (MD =-56.40, 95% CI [-60.02, -52.14], P<0.00001) and IL-10 (MD =35.96, 95% CI [11.02, 60.91], P =0.005) in IBD patients. However, the P value of meta-analysis in IL-1 great than 0.05.(MD =-27.90, 95% CI [-97.82, 42.02], P =0.11).

CONCLUSION

Acupuncture has a positive therapeutic impact on IBD and can effectively regulate inflammatory factors in IBD patients. TNF-α, IL-8 and IL-10 are more appropriate inflammatory indicators for clinically evaluating the anti-inflammatory response in the blood of IBD patients by acupuncture.

Elevated IgA and IL-10 levels in very-early-onset inflammatory bowel disease secondary to IL-10 receptor deficiency

OBJECTIVE

To report two patients with very-early-onset inflammatory bowel disease (VEOIBD) secondary to interleukin-10 receptor (IL-10R) mutations, explore immunophenotyping data and plasma cytokine profile on these cases compared to healthy controls, and describe the phenotype of IL-10/IL-10R mutations based on a literature review.

CASE DESCRIPTION

We report on two female infants referred to our tertiary center at the age of ten months, with severe colonic and perianal disease, as well as significant malnutrition, who had shown limited response to usual inflammatory bowel disease (IBD) therapy agents. In the first case, whole-exome sequencing (WES) revealed a homozygous (c.537G>A/p.T179T) mutation in exon 4 of the IL-10RA gene, while in the second patient, compound heterozygosity was identified, also in the IL-10RA gene (chr11:117.859.199 variant A>G/p.Tyr57Cys and chr11: 117.860.335 variant G>T/p.Val123Leu). Both patients underwent hematopoietic cell transplantation (HCT). Immunological work-up of these patients revealed increased IL-10 plasma levels and increased IgA.

COMMENTS

Our case reports disclose novel findings on plasma cytokine profile in IL-10R deficiency, and we describe the severe phenotype of IL-10/IL-10R deficiency that should be recognized by physicians.

Canagliflozin, an SGLT-2 inhibitor, ameliorates acetic acid-induced colitis in rats through targeting glucose metabolism and inhibiting NOX2

BACKGROUND

Inflammatory bowel disease is defined as chronic noninfectious inflammation of the gastrointestinal tract, including ulcerative colitis and Crohn's disease. Its incidence and predominance have increased globally, with no effective agents for preventing its recurrence or treatment until now.

AIM

The current study aimed to investigate the possible role of canagliflozin (CANA), a sodium-glucose co-transporter-2 inhibitor (SGLT-2), to prevent and treat acetic acid (AA)-induced colitis in a rat model.

METHODS

Colitis was induced in male Wistar rats by intrarectal instillation of 1 ml of 4% (v/v) AA. Rats were treated orally with either CANA (30 mg/kg/day, p.o.) for 10 days before or after colitis induction or sulfasalazine (360 mg/kg/day, p.o.) for 10 days before colitis induction.

RESULTS

AA resulted in a significant increase in disease activity index, colonic weight over length ratio, colon macroscopic damage score, and histological signs of colitis. All of these effects were significantly decreased by CANA administration. Additionally, CANA markedly inhibited AA-induced oxidative stress and inflammatory responses by significantly reducing the up-regulated levels in malondialdehyde, total nitrite, NF-κB, interleukin-1β, and TNF-α, and significantly increasing the down-regulated levels in reduced glutathione, superoxide dismutase, and interleukin-10. CANA significantly inhibited caspase-3 level while rescued survivin expression in colons. Finally, CANA reduced the elevated levels of pyruvic acid and G6PDH activity, as well as the levels of p22phox and NOX2 in the AA-induced colitis.

CONCLUSION

Our findings provide novel evidence that CANA has protective and therapeutic effects against AA-induced colitis by the impact of its antioxidant, anti-inflammatory, and anti-apoptotic effects.

Secondary causes of inflammatory bowel diseases

Inflammatory bowel diseases (IBD), conventionally consist of Crohn's disease (CD) and ulcerative colitis. They occur in individuals with high risk genotype for the disease in the setting of appropriate environmental factors. The pathogenesis of IBD involves a dysregulated autoimmune response to gut dysbiosis, which in turn is triggered due to exposure to various inciting environmental factors. But there is no clearly defined etiology of IBD and this type of disease is termed as "idiopathic IBD", "classic IBD", or "primary IBD". We reviewed the current medical literature and found that certain etiological factors may be responsible for the development of IBD or IBD-like conditions, and we consider this form of de novo IBD as "secondary IBD". Currently known factors that are potentially responsible for giving rise to secondary IBD are medications; bowel altering surgeries and transplantation of organs, stem cells or fecal microbiome. Medications associated with the development of secondary IBD include; immunomodulators, anti-tumor necrosis factor alpha agents, anti-interleukin agents, interferons, immune stimulating agents and checkpoint inhibitors. Colectomy can in some cases give rise to de novo CD, pouchitis of the ileal pouch, or postcolectomy enteritis syndrome. After solid organ transplantation or hematopoietic stem cell transplantation, the recipient may develop de novo IBD or IBD flare. Fecal microbiota transplantation has been widely used to treat patients suffering from recurrent Clostridium difficile infection but can also causes IBD flares.

Tregopathies: Monogenic diseases resulting in regulatory T-cell deficiency

Monogenic diseases of the immune system, also known as inborn errors of immunity, are caused by single-gene mutations resulting in immune deficiency and dysregulation. More than 350 diseases have been described to date, and the number is rapidly expanding, with increasing availability of next-generation sequencing facilitating the diagnosis. The spectrum of immune dysregulation is wide, encompassing deficiencies in humoral, cellular, innate, and adaptive immunity; phagocytosis; and the complement system, which lead to autoinflammation and autoimmunity. Multiorgan autoimmunity is a dominant symptom when genetic mutations lead to defects in molecules essential for the development, survival, and/or function of regulatory T (Treg) cells. Studies of "Tregopathies" are providing critical mechanistic information on Treg cell biology, the role of Treg cell-associated molecules, and regulation of peripheral tolerance in human subjects. The pathogenic immune networks underlying these diseases need to be dissected to apply and develop immunomodulatory treatments and design curative treatments using cell and gene therapy. Here we review the pathogenetic mechanisms, clinical presentation, diagnosis, and current and future treatments of major known Tregopathies caused by mutations in FOXP3, CD25, cytotoxic T lymphocyte-associated antigen 4 (CTLA4), LPS-responsive and beige-like anchor protein (LRBA), and BTB domain and CNC homolog 2 (BACH2) and gain-of-function mutations in signal transducer and activator of transcription 3 (STAT3). We also discuss deficiencies in genes encoding STAT5b and IL-10 or IL-10 receptor as potential Tregopathies.

Flow Cytometric-Based Analysis of Defects in Lymphocyte Differentiation and Function Due to Inborn Errors of Immunity

The advent of flow cytometry has revolutionized the way we approach our research and answer specific scientific questions. The flow cytometer has also become a mainstream diagnostic tool in most hospital and pathology laboratories around the world. In particular the application of flow cytometry has been instrumental to the diagnosis of primary immunodeficiencies (PIDs) that result from monogenic mutations in key genes of the hematopoietic, and occasionally non-hematopoietic, systems. The far-reaching applicability of flow cytometry is in part due to the remarkable sensitivity, down to the single-cell level, of flow-based assays and the extremely user-friendly platforms that enable comprehensive analysis, data interpretation, and importantly, robust and rapid methods for diagnosing PIDs. A prime example is the absence of peripheral blood B cells in patients with agammaglobulinemia due to mutations in BTK or related genes in the BCR signaling pathway. Similarly, the development of intracellular staining protocols to detect expression of SAP, XIAP, or DOCK8 expedites the rapid diagnosis of the X-linked lymphoproliferative diseases or an autosomal recessive form of hyper-IgE syndrome (HIES), respectively. It has also become evident that distinct cohorts of PID patients exhibit unique “lymphocyte phenotypic signatures” that are often diagnostic even prior to identifying the genetic lesion. Flow cytometry-based sorting provides a technique for separating specific subsets of immune cells such that they can be studied in isolation. Thus, flow-based assays can be utilized to measure immune cell function in patients with PIDs, such as degranulation by cytotoxic cells, cytokine expression by many immune cells (i.e., CD4⁺ and CD8⁺ T cells, macrophages etc.), B-cell differentiation, and phagocyte respiratory burst in vitro. These assays can also be performed using unfractionated PBMCs, provided the caveat that the composition of lymphocytes between healthy donors and the PID patients under investigation is recognized. These functional deficits can assist not only in the clinical diagnosis of PIDs, but also reveal mechanisms of disease pathogenesis. As we move into the next generation of multiparameter flow cytometers, here we review some of our experiences in the use of flow cytometry in the study, diagnosis, and unraveling the pathophysiology of PIDs.

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.

Vinpocetine Ameliorates Acetic Acid-Induced Colitis by Inhibiting NF-κB Activation in Mice

The idiopathic inflammatory bowel diseases (IBD) comprise two types of chronic intestinal disorders: Crohn's disease and ulcerative colitis. Recruited neutrophils and macrophages contribute to intestinal tissue damage via production of ROS and NF-κB-dependent pro-inflammatory cytokines. The introduction of anti-TNF-α therapies in the treatment of IBD patients was a seminal advance. This therapy is often limited by a loss of efficacy due to the development of adaptive immune response, underscoring the need for novel therapies targeting similar pathways. Vinpocetine is a nootropic drug and in addition to its antioxidant effect, it is known to have anti-inflammatory and analgesic properties, partly by inhibition of NF-κB and downstream cytokines. Therefore, the present study evaluated the effect of the vinpocetine in a model of acid acetic-induced colitis in mice. Treatment with vinpocetine reduced edema, MPO activity, microscopic score and macroscopic damage, and visceral mechanical hyperalgesia. Vinpocetine prevented the reduction of colonic levels of GSH, ABTS radical scavenging ability, and normalized levels of anti-inflammatory cytokine IL-10. Moreover, vinpocetine reduced NF-κB activation and thereby NF-κB-dependent pro-inflammatory cytokines IL-1β, TNF-α, and IL-33 in the colon. Thus, we demonstrate for the first time that vinpocetine has anti-inflammatory, antioxidant, and analgesic effects in a model of acid acetic-induced colitis in mice and deserves further screening to address its suitability as an approach for the treatment of IBD.

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.

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.

Umbilical Cord Blood Transplantation Corrects Very Early-Onset Inflammatory Bowel Disease in Chinese Patients With IL10RA-Associated Immune Deficiency

BACKGROUND

Hematopoietic stem cell transplantation is considered the only curative therapy for very early-onset inflammatory bowel disease with specific immune defects, such as interleukin-10 receptor deficiency. We performed reduced-intensity conditioning before umbilical cord blood transplantation in patients with interleukin-10 receptor-A deficiency.

METHODS

We enrolled 9 very early-onset inflammatory bowel disease patients with typical manifestations. We diagnosed the patients with interleukin-10 receptor-A deficiency by whole-exome sequencing. Umbilical cord blood transplantation was performed in all 9 patients. Eight patients received the reduced-intensity conditioning regimen, and 1 patient received the myeloablative conditioning regimen.

RESULTS

All 9 patients received transplantation between the ages of 6 months to 43 months (average, 16.8 months) with body weights ranging from 3 to 10.4 kg (average, 6.6 kg). The patients displayed complete chimerism at 2-8 weeks after transplantation; 6 patients achieved complete remission without evidence of graft-vs-host disease or infections; 1 patient died of chronic lung graft-vs-host disease at 6 months post-transplantation; and the other 2 patients died of sepsis post-transplantation because of unsuccessful engraftments. Severe malnutrition and growth retardation associated with interleukin-10 receptor-A deficiency were significantly improved post-transplantation.

CONCLUSIONS

We recommend umbilical cord blood transplantation as a potential treatment for very early-onset inflammatory bowel disease with a defined monogenic immunodeficiency, and we suggest that reduced-intensity conditioning chemotherapy is more suitable than myeloablative conditioning for patients with severe malnutrition and bowel disease. We have demonstrated success with reduced-intensity conditioning for interleukin-10 receptor-A deficiency in pediatric patients with severe clinical conditions. 10.1093/ibd/izy028_video1izy028.video15786489183001.

Common genetic variation in the autoimmune regulator (AIRE) locus is associated with autoimmune Addison's disease in Sweden

Autoimmune Addison's disease (AAD) is the predominating cause of primary adrenal failure. Despite its high heritability, the rarity of disease has long made candidate-gene studies the only feasible methodology for genetic studies. Here we conducted a comprehensive reinvestigation of suggested AAD risk loci and more than 1800 candidate genes with associated regulatory elements in 479 patients with AAD and 2394 controls. Our analysis enabled us to replicate many risk variants, but several other previously suggested risk variants failed confirmation. By exploring the full set of 1800 candidate genes, we further identified common variation in the autoimmune regulator (AIRE) as a novel risk locus associated to sporadic AAD in our study. Our findings not only confirm that multiple loci are associated with disease risk, but also show to what extent the multiple risk loci jointly associate to AAD. In total, risk loci discovered to date only explain about 7% of variance in liability to AAD in our study population.

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.

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.

Early Diagnosis and Hematopoietic Stem Cell Transplantation for IL10R Deficiency Leading to Very Early-Onset Inflammatory Bowel Disease Are Essential in Familial Cases

Alterations of immune homeostasis in the gut may result in development of inflammatory bowel disease. A five-month-old girl was referred for recurrent respiratory and genitourinary tract infections, sepsis in neonatal period, chronic diarrhea, perianal abscess, rectovaginal fistula, and hyperemic skin lesions. She was born to second-degree consanguineous, healthy parents. Her elder siblings were lost at 4 months of age due to sepsis and 1 year of age due to inflammatory bowel disease, respectively. Absolute neutrophil and lymphocyte counts, immunoglobulin levels, and lymphocyte subsets were normal ruling out severe congenital neutropenia and classic severe combined immunodeficiencies. Quantitative determination of oxidative burst was normal, excluding chronic granulomatous disease. Colonoscopy revealed granulation, ulceration, and pseudopolyps, compatible with colitis. Very early-onset colitis and perianal disease leading to fistula formation suggested probability of inherited deficiencies of IL-10 or IL-10 receptor. A mutation at position c.G477A in exon of the IL10RB gene, resulting in a stop codon at position p.W159X, was identified. The patient underwent myeloablative hematopoietic stem cell transplantation from full matched father at 11 months of age. Perianal lesions, chronic diarrhea, and recurrent infections resolved after transplantation. IL-10/IL-10R deficiencies must be considered in patients with early-onset enterocolitis.

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.

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.

Genetics of inflammatory bowel disease from multifactorial to monogenic forms

Inflammatory bowel disease (IBD) is a group of chronic multifactorial disorders. According to a recent study, the number of IBD association loci is increased to 201, of which 37 and 27 loci contribute specifically to the development of Crohn’s disease and ulcerative colitis respectively. Some IBD associated genes are involved in innate immunity, in the autophagy and in the inflammatory response such as NOD2, ATG16L1 and IL23R, while other are implicated in immune mediated disease (STAT3) and in susceptibility to mycobacterium infection (IL12B). In case of early onset of IBD (VEO-IBD) within the 6^th year of age, the disease may be caused by mutations in genes responsible for severe monogenic disorders such as the primary immunodeficiency diseases. In this review we discuss how these monogenic disorders through different immune mechanisms can similarly be responsible of VEO-IBD phenotype. Moreover we would highlight how the identification of pathogenic genes by Next Generation Sequencing technologies can allow to obtain a rapid diagnosis and to apply specific therapies.

IL-10 Potentiates Differentiation of Human Induced Regulatory T Cells via STAT3 and Foxo1

Foxp3(+) regulatory T cells (Tregs) play essential roles in maintaining the immune balance. Although the majority of Tregs are formed in the thymus, increasing evidence suggests that induced Tregs (iTregs) may be generated in the periphery from naive cells. However, unlike in the murine system, significant controversy exists regarding the suppressive capacity of these iTregs in humans, especially those generated in vitro in the presence of TGF-β. Although it is well known that IL-10 is an important mediator of Treg suppression, the action of IL-10 on Tregs themselves is less well characterized. In this article, we show that the presence of IL-10, in addition to TGF-β, leads to increased expansion of Foxp3(+) iTregs with enhanced CTLA-4 expression and suppressive capability, comparable to that of natural Tregs. This process is dependent on IL-10R-mediated STAT3 signaling, as supported by the lack of an IL-10 effect in patients with IL-10R deficiency and dominant-negative STAT3 mutation. Additionally, IL-10-induced inhibition of Akt phosphorylation and subsequent preservation of Foxo1 function are critical. These results highlight a previously unrecognized function of IL-10 in human iTreg generation, with potential therapeutic implications for the treatment of immune diseases, such as autoimmunity and allergy.

Heritability in inflammatory bowel disease: from the first twin study to genome-wide association studies

Since Tysk et al's pioneering analysis of the Swedish twin registry, twin and family studies continue to support a strong genetic basis of the inflammatory bowel diseases. The coefficient of heritability for siblings of inflammatory bowel disease probands is 25 to 42 for Crohn's disease and 4 to 15 for ulcerative colitis. Heritability estimates for Crohn's disease and ulcerative colitis from pooled twin studies are 0.75 and 0.67, respectively. However, this is at odds with the much lower heritability estimates from Genome-Wide Association Studies (GWAS). This "missing heritability" is likely due to shortfalls in both family studies and GWAS. The coefficient of heritability fails to account for familial shared environment. Heritability calculations from twin data are based on Falconer's method, with premises that are increasingly understood to be flawed. GWAS based heritability estimates may underestimate heritability due to incomplete linkage disequilibrium, and because some single nucleotide polypeptides (SNPs) do not reach a level of significance to allow detection. SNPs missed by GWAS include common SNPs with low penetrance and rare SNPs with high penetrance. All methods of heritability estimation regard genetic and environmental variance as separate entities, although it is now understood that there is a complex multidirectional interplay between genetic are environmental factors mediated by the microbiota, the epigenome, and the innate and acquired immune systems. Due to the limitations of heritability estimates, it is unlikely that a true value for heritability will be reached. Further work aimed at quantifying the variance explained across GWAS, epigenome-wide, and microbiota-wide association studies will help to define factors leading to inflammatory bowel disease.