Very early onset inflammatory bowel disease: Investigation of the IL-10 signaling pathway in Iranian children

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.

Treatment of IL-10RA deficiency of pediatric patients with very early onset inflammatory bowel disease by allogeneic haematopoietic stem cell transplantation

Very early onset inflammatory bowel disease (VEO-IBD) with interleukin-10 receptor-A (IL-10RA) defects is characterised by severe and unmanageable intestinal inflammation, perianal lesions, and a high mortality rate, with the onset of the disease occurring at a very early age. Currently, allogeneic hematopoietic stem cell transplantation (allo-HSCT) is one of the most effective treatments for VEO-IBD patients with IL-10 signaling deficiency. The objective of this study was to evaluate the clinical effectiveness of allo-HSCT in the treatment of children with VEO-IBD and IL-10RA deficiency, and to provide further clinical insights. A retrospective analysis and summary of the clinical data of seven patients with VEO-IBD and IL-10RA deficiency from January 2021 to December 2023 was performed. These patients subsequently underwent allo-HSCT after receiving a reduced-intensity conditioning regimen followed by a cyclosporine-based regimen for the prevention of graft versus host disease (GVHD). Hematopoietic reconstruction was performed on seven children with VEO-IBD combined with IL-10RA deficiency. Four patients developed grade I-II GVHD, while three patients developed grade III-IV GVHD after undergoing allo-HSCT. At a median follow-up of 518 days after allo-HSCT (range: 210-1072 days), six patients were alive, while one patient died 16 months after the procedure because of chronic GVHD and severe infections. The 3-year cumulative overall survival (OS) probability rate was 80.0% (95% CI: 44.7-100.0). All VEO-IBD patients demonstrated weight gain following HSCT, with substantial improvements observed in severe malnutrition and growth retardation associated with IL-10RA deficiency post-transplantation. Allo-HSCT is thus identified as the optimal curative therapy for VEO-IBD patients with IL10-RA deficiency. The importance of early multidisciplinary intervention and co-management of VEO-IBD is paramount in improving HSCT outcomes.

The treatment of inflammatory bowel disease with monoclonal antibodies in Asia

Crohn's disease (CD) and ulcerative colitis (UC), the two main forms of inflammatory bowel disease (IBD), are chronic, systemic autoimmune diseases. As the incidence of IBD rapidly increases in Asia, increasing attention has been paid to developing additional treatment strategies. Presently, the end point of therapy is achieving clinical and endoscopic remission through the blockade of inflammatory cascades. Recent studies have shown that monoclonal antibodies (mAbs) use for precise molecular targeting of inflammatory pathways has a promising effect on IBD, especially moderate-to-severe CD and UC. Since the 1997 report on the use of infliximab (a monoclonal antibody against tumor necrosis factor alpha [TNF-α]) in patients with CD, mAbs have expanded therapeutic options and have also complicated initial management options and subsequent treatment. This review comprehensively summarizes the clinical reports and studies related to the use of mAbs for the treatment of IBD in Asian countries and regions in recent years thus demonstrating the current status of mAbs use in Asia. In addition, the differences in the use of mAbs for the treatment of IBD between the Asia and the West are expounded. Ultimately, it is hoped that this review will provide new insights and a scientific basis for the clinical application of mAbs.

The regulatory role of alternative splicing in inflammatory bowel disease

Inflammatory bowel disease (IBD) mainly includes Crohn's disease and ulcerative colitis. These diseases have a progressive course of chronic relapse and remission and affect a large number of children and adults worldwide. The burden of IBD is rising worldwide, with levels and trends varying greatly in countries and regions. Like most chronic diseases, the costs associated with IBD are high, including hospitalizations, outpatient and emergency visits, surgeries, and pharmacotherapies. However, there is no radical cure for it yet, and its therapeutic targets still need further study. Currently, the pathogenesis of IBD remains unclear. It is generally assumed that the occurrence and development of IBD are related to the environmental factors, gut microbiota, immune imbalance, and genetic susceptibility. Alternative splicing contributes to a various diseases, such as spinal muscular atrophy, liver diseases, and cancers. In the past, it has been reported that alternative splicing events, splicing factors, and splicing mutations were associated with IBD, but there were no reports on the practical application for clinical diagnosis and treatment of IBD using splicing-related methods. Therefore, this article reviews research progress on alternative splicing events, splicing factors, and splicing mutations associated with IBD.

The clinical, molecular, and therapeutic features of patients with IL10/IL10R deficiency: a systematic review

Interleukin10 (IL10) and IL10 receptor (IL10R) deficiencies are monogenic inborn errors of immunity (IEI) causing early-onset inflammatory bowel diseases (IBD). In this report, we systematically reviewed articles that included related keywords using PubMed, Web of Science, and Scopus databases. The articles were screened for eligibility criteria before data extraction. We assessed 286 patients (44.5% female) with IL10 and/or IL10R deficiencies who were predominantly from China (40.7%), Italy (13.9%), and South Korea (8.5%). The median age of onset was 1.0 (0.3-4.0) months with a median age of genetic diagnosis at 16.0 (7.4-81.0) months. Consanguinity was reported in all evaluable patients with IL10 deficiency and in 38.2% of patients with IL10R deficiency (22.9% of patients with IL10RA, and 79.4% of patients with IL10RB deficiency). The most prevalent mutations in IL10RA were c.301C>T (p.R101W) and c.537G>A (p.T179T), those in IL10RB were c.139A>G (p.K47E) and c.611G>A (p.W204X). Auto-inflammation and enteropathy were present in all cases. The first presentation of both groups was protracted diarrhea (45.7%), bloody diarrhea (17.8%), and colitis (15.5%). Patients with IL10R deficiency had a high frequency of dermatologic manifestations (50.5%) and failure to thrive (60.5%), while IL10-deficient patients lacked those complications. In the majority of patients, the basic immunologic parameters were in normal ranges. Of the entire publications, 30.7% underwent hemopoietic stem cell transplantation, 57.5% surgery, and 86.6% immunosuppressive treatment. The 10-year survival rate was higher in patients with IL10 deficiency than in patients with IL10R deficiency. In conclusion, IL10/IL10R deficiency predominantly presents with treatment-resistant, early-onset IBD within the first months of life. We detected no clear correlation between the phenotype of patients carrying the same variant. The high prevalence of distinct clinical manifestations reported in IL10RA- and IL10RB-deficient patients might be attributable to the interactions between the target tissue and cytokines other than IL10 capable of binding to IL10RB. These results gain translational significance by contributing to earlier diagnosis, adequate therapy, and avoiding delay in the diagnosis and unfavorable outcomes.

Very early-onset inflammatory bowel disease: an integrated approach

PURPOSE OF REVIEW

Immune dysregulation disorders are among the most rapidly growing set of inborn errors of immunity. One particular subset is the category where early-onset inflammatory bowel disease (IBD) is the most common manifestation. These disorders are being increasingly appreciated although there has been minimal effort to articulate a unified approach to their diagnosis and management. This review will cover current thinking and strategies related to diagnosis and management of very early-onset IBD.

RECENT FINDINGS

There is an expanding set of monogenic causes of early-onset IBD. In many cases, the precise genetic cause dictates management. Lessons learned from the management of these monogenic conditions can sometimes be extrapolated to other refractory cases of IBD.

SUMMARY

An integrated approach to diagnosis, risk analysis, and management can include diagnostic approaches not often utilized for traditional IBD such as whole exome sequencing. Management can also include nontraditional approaches such as targeted biologics or hematopoietic cell transplantation.

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.

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.