Understanding endoscopic and clinicopathological features of patients with very early onset inflammatory bowel disease: Results from a decade of study

BACKGROUND

Very early onset inflammatory bowel disease (VEOIBD) is associated with a unique disease course and distinct endoscopic features.

AIMS

This study aims to provide a comprehensive description of the endoscopic and histologic features observed in a large cohort of patients with VEOIBD from a tertiary medical center.

METHODS

A retrospective review of medical records from 2011 to 2021 was conducted to analyze clinical data, including disease phenotypes, endoscopic and histologic findings. Next generation sequencing was performed.

RESULTS

A total of 225 VEOIBD subjects were included in this study. Monogenic defects were identified in 161 patients. Monogenic IBD patients more commonly had CD-like disease. Colonic involvement was more prevalent among those with monogenic IBD (P<0.001). Pseudo-polyps were significantly more common in the monogenic IBD group (P<0.001), while ileal edema and ulcers were significantly more prevalent in non-monogenic IBD cases. IL10RA deficiency were characterized by colonic ulcers and pseudo-polyps without upper gastrointestinal tract lesions, while patients with TNFAIP3 mutations demonstrated both upper and lower gastrointestinal tract involvement. The non-monogenic IBD patients showed a higher incidence of chronic architectural changes of crypt, increased apoptosis and eosinophils infiltration.

CONCLUSIONS

Endoscopic and histologic analysis of children with VEOIBD plays a crucial role in facilitating accurate diagnosis. Various forms of monogenic IBD exhibit distinct endoscopic and pathologic changes.

DNA methylation of the TPMT gene and azathioprine pharmacokinetics in children with very early onset inflammatory bowel disease

BACKGROUND

Thiopurine methyltransferase (TPMT) is a crucial enzyme for azathioprine biotransformation and its activity is higher in very early onset inflammatory bowel disease (VEO-IBD) patients than in adolescents with IBD (aIBD).

AIMS

The aims of this pharmacoepigenetic study were to evaluate differences in peripheral blood DNA methylation of the TPMT gene and in azathioprine pharmacokinetics in patients with VEO-IBD compared to aIBD.

METHODS

The association of age with whole genome DNA methylation profile was evaluated in a pilot group of patients and confirmed by a meta-analysis on 3 cohorts of patients available on the public functional genomics data repository. Effects of candidate CpG sites in the TPMT gene were validated in a larger cohort using pyrosequencing. TPMT activity and azathioprine metabolites (TGN) were measured in patients' erythrocytes by HPLC and associated with patients' age group and TPMT DNA methylation.

RESULTS

Whole genome DNA methylation pilot analysis, combined with the meta-analysis revealed cg22736354, located on TPMT downstream neighboring region, as the only statistically significant CpG whose methylation increases with age, resulting lower in VEO-IBD patients compared to aIBD (median 9.6% vs 12%, p = 0.029). Pyrosequencing confirmed lower cg22736354 methylation in VEO-IBD patients (median 4.0% vs 6.0%, p = 4.6 ×10^-5). No differences in TPMT promoter methylation were found. Reduced cg22736354 methylation was associated with lower TGN concentrations (rho = 0.31, p = 0.01) in patients with VEO-IBD and aIBD.

CONCLUSION

Methylation of cg22736354 in TPMT gene neighborhood is lower in patients with VEO-IBD and is associated with reduced azathioprine inactivation and increased TGN concentrations.

Clinical Phenotypes and Outcomes in Monogenic Versus Non-monogenic Very Early Onset Inflammatory Bowel Disease

BACKGROUND AND AIMS

Over 80 monogenic causes of very early onset inflammatory bowel disease [VEOIBD] have been identified. Prior reports of the natural history of VEOIBD have not considered monogenic disease status. The objective of this study is to describe clinical phenotypes and outcomes in a large single-centre cohort of patients with VEOIBD and universal access to whole exome sequencing [WES].

METHODS

Patients receiving IBD care at a single centre were prospectively enrolled in a longitudinal data repository starting in 2012. WES was offered with enrollment. Enrolled patients were filtered by age of diagnosis <6 years to comprise a VEOIBD cohort. Monogenic disease was identified by filtering proband variants for rare, loss-of-function, or missense variants in known VEOIBD genes inherited according to standard Mendelian inheritance patterns.

RESULTS

This analysis included 216 VEOIBD patients, followed for a median of 5.8 years. Seventeen patients [7.9%] had monogenic disease. Patients with monogenic IBD were younger at diagnosis and were more likely to have Crohn's disease phenotype with higher rates of stricturing and penetrating disease and extraintestinal manifestations. Patients with monogenic disease were also more likely to experience outcomes of intensive care unit [ICU] hospitalisation, gastrostomy tube, total parenteral nutrition use, stunting at 3-year follow-up, haematopoietic stem cell transplant, and death. A total of 41 patients [19.0%] had infantile-onset disease. After controlling for monogenic disease, patients with infantile-onset IBD did not have increased risk for most severity outcomes.

CONCLUSIONS

Monogenic disease is an important driver of disease severity in VEOIBD. WES is a valuable tool in prognostication and management of VEOIBD.

Characterization of novel and large fragment deletions in exon 1 of the IL10RA gene in Chinese children with very early onset inflammatory bowel diseases

BACKGROUND

Defects in interleukin 10 (IL10) and its receptors are particularly involved in very early onset inflammatory bowel disease (VEOIBD). However, large fragment deletions of IL10 receptor A (IL10RA) are rare.

METHODS

VEOIBD patients with confirmed mutations in the IL10RA gene were enrolled from January 1, 2019 to June 30, 2020. The clinical features and endoscopic-radiological findings of the patients with large fragment deletions of the IL10RA gene were determined and followed up.

RESULTS

Thirty-five patients with IL10RA gene mutations, namely, 28 compound heterozygous mutations and 7 homozygote mutations, were enrolled in this study. Six patients carried the reported point mutation c.301C > T (p. R101RW) or c.537 G > A (p. T179T) in one locus and a large fragment deletion in exon 1 in another locus, which were novel mutations in this gene. A 333-bp deletion of exon 1 (117857034-11857366 del) was the main mutation in this locus in 85.7% of the patients with large fragment deletions. The time of disease onset ranged from birth to 4 years, and diarrhea was the main initial symptom. In total, 6/7 patients had perianal complications, including perianal abscess, fistula and skin tags. Six patients accepted thalidomide treatment, 5/7 accepted mesalamine, 3/7 accepted hematopoietic stem cell transplantation (HSCT), and 3/7 were waiting for HSCT.

CONCLUSIONS

We identified a novel large deletion of exon 1 involving the IL10RA gene for the first time and showed the characteristics of VEOIBD patients. This study expands the spectrum of Chinese VEOIBD patients with IL0RA gene mutations.

Complications of enterostomy and related risk factor analysis of very early onset inflammatory bowel disease with interleukin-10 signalling deficiency: a single-centre retrospective analysis

Background

Interleukin-10 (IL10) signalling pathway deficiency results in severe very early onset inflammatory bowel disease (VEOIBD), and enterostomy is often inevitable. However, studies in these surgical populations are lacking. This study aims to determine the enterostomy characteristics, postoperative complications and related risk factors in enterostomy patients.

Methods

From March 1, 2015, to December 31, 2018, patients with IL10R-mutation who underwent enterostomy were recruited for analysis. We collected data on the patients’ clinical characteristics, enterostomy characteristics, postoperative complications and related risk factors.

Results

Twelve patients required emergency enterostomy, and 10 patients underwent elective enterostomy. Twelve patients experienced postoperative complications, including wound infection (27.3%), wound dehiscence (18.2%), reoperation (18.2%), etc. Compared with the pre-enterostomy values, there was a decrease in C-reactive protein (CRP) (P = 0.001), an increase in albumin (P = 0.001) and an improvement in the weight-for-age (P = 0.029) and body mass index (BMI) Z-scores (P = 0.004) after enterostomy. There was a significant difference between the pre-operation and postoperation medicine expenses (P = 0.002). Univariate binary logistic regression analysis revealed a statistically significant influence of CRP (OR: 1.43, 95% CI: 1.07–1.91, P = 0.016) and a tendency towards a significant influence of intestinal perforation, albumin level, BMI Z-score and weighted paediatric Crohn’s disease activity index (wPCDAI). Multivariate logistic regression analysis showed that CRP (OR: 1.40), wPCDAI (OR: 2.88) and perforation (OR: 1.72) showed a tendency to behave as independent risk factors for postoperative complications, but the results were not significant (all P > 0.05).

Conclusions

Surgery and enterostomy showed benefits for VEOIBD with IL-10 signalling deficiency. The timing of intervention, potential postoperative complications, economic burden and other related problems should be considered.

Genetics on early onset inflammatory bowel disease: An update

Inflammatory bowel disease (IBD) is more common in adults than in children. Onset of IBD before 17 years of age is referred as pediatric onset IBD and is further categorized as very early onset IBD (VEO-IBD) for children who are diagnosed before 6 years of age, infantile IBD who had the disease before 2 years of age and neonatal onset IBD for children less than 28 days of life. Children presenting with early onset disease may have a monogenic basis. Knowledge and awareness of the clinical manifestations facilitates early evaluation and diagnosis. Next generation sequencing is helpful in making the genetic diagnosis. Treatment of childhood IBD is difficult; targeted therapies and hematopoietic stem cell transplantation form the mainstay. In this review we aim to summarize the genetic defects associated with IBD phenotype. We describe genetic location and functions of various genetic defect associated with VEO-IBD with their key clinical manifestations. We also provide clinical clues to suspect these conditions and approaches to the diagnosis of these disorders and suitable treatment options.

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

BACKGROUND & AIM

Comparing to adult inflammatory bowel disease (IBD), those with early onset manifestations have different features in terms of the underlying molecular pathology, the course of disease and the response to therapy. We investigated the IL-10 signaling pathway previously reported as an important cause of infantile (Very Early Onset) IBD to find any possible variants.

METHOD

With the next generation sequencing technique we screened IL-10, IL-10RA and IL10RB genes of 15 children affected by very early onset-GI (gastrointestinal) disorders. Additionally, we analyzed them based on Thermo Fisher immune deficiency panel for genes either having a known role in IBD pathogenesis or cause the disorders with overlapping manifestations. We performed multiple functional analyses only for the cases showing variants in IL-10- related genes.

RESULT

In 3 out of 15 patients we identified variants including a homozygous and heterozygote mutations in IL-10RA and a novel homozygous mutation in IL-12RB1. Our functional studies reveal that in contrast to the IL-10RA heterozygote mutation that does not have deleterious effects, the homozygous mutation abrogates the IL-10 signaling pathway.

CONCLUSION

Our study suggests we need to modify the classical diagnostic approach from functional assays followed by candidate- gene or genes sequencing to the firstly parallel genomic screening followed by functional studies.

An Overview of Inflammatory Bowel Disease: General Consideration and Genetic Screening Approach in Diagnosis of Early Onset Subsets

Inflammatory bowel disease (IBD) is the consequence of an aberrant hemostasis of the immune cells at the gut mucosal border. Based on clinical manifestation, laboratory tests, radiological studies, endoscopic and histological features, this disease is divided into three main types including Crohn's disease (CD), Ulcerative colitis (UC), and IBDunclassified (IBD-U). IBD is frequently presented in adults, but about 20% of IBD cases are diagnosed during childhood called pediatric IBD (PIBD). Some patients in the latter group emerge the first symptoms during infancy or under 5 years of age named infantile and very early onset IBD (VEO-IBD), respectively. These subtypes make a small fraction of PIBD, but they have exclusive phenotypic and genetic characteristics such that they are accompanied by severe disease course and resistance to conventional therapy. In this context, understanding the underlying molecular pathology opens a promising field for individualized and effective treatment. Here, we describe current hypotheses on IBD pathophysiology then explain the new idea about genetic screening technology as a good potential approach to identify the causal variants early in the disease manifestation, which is especially important for the fast and accurate treatment of VEO-IBD.