An Adolescent with Undiagnosed Ulcerative Colitis Presenting with Toxic Megacolon and Cavitary Pulmonary Nodules

Toxic megacolon and pulmonary nodules are not seen frequently on diagnosis in pediatric ulcerative colitis patients. This report emphasizes the importance of carefully evaluating and managing complications in pediatric ulcerative colitis cases, especially in the presence of pulmonary nodules.

Multi-omics analysis reveals the influence of genetic and environmental risk factors on developing gut microbiota in infants at risk of celiac disease

BACKGROUND

Celiac disease (CD) is an autoimmune digestive disorder that occurs in genetically susceptible individuals in response to ingesting gluten, a protein found in wheat, rye, and barley. Research shows that genetic predisposition and exposure to gluten are necessary but not sufficient to trigger the development of CD. This suggests that exposure to other environmental stimuli early in life, e.g., cesarean section delivery and exposure to antibiotics or formula feeding, may also play a key role in CD pathogenesis through yet unknown mechanisms. Here, we use multi-omics analysis to investigate how genetic and early environmental risk factors alter the development of the gut microbiota in infants at risk of CD.

RESULTS

Toward this end, we selected 31 infants from a large-scale prospective birth cohort study of infants with a first-degree relative with CD. We then performed rigorous multivariate association, cross-sectional, and longitudinal analyses using metagenomic and metabolomic data collected at birth, 3 months and 6 months of age to explore the impact of genetic predisposition and environmental risk factors on the gut microbiota composition, function, and metabolome prior to the introduction of trigger (gluten). These analyses revealed several microbial species, functional pathways, and metabolites that are associated with each genetic and environmental risk factor or that are differentially abundant between environmentally exposed and non-exposed infants or between time points. Among our significant findings, we found that cesarean section delivery is associated with a decreased abundance of Bacteroides vulgatus and Bacteroides dorei and of folate biosynthesis pathway and with an increased abundance of hydroxyphenylacetic acid, alterations that are implicated in immune system dysfunction and inflammatory conditions. Additionally, longitudinal analysis revealed that, in infants not exposed to any environmental risk factor, the abundances of Bacteroides uniformis and of metabolite 3-3-hydroxyphenylproprionic acid increase over time, while those for lipoic acid and methane metabolism pathways decrease, patterns that are linked to beneficial immunomodulatory and anti-inflammatory effects.

CONCLUSIONS

Overall, our study provides unprecedented insights into major taxonomic and functional shifts in the developing gut microbiota of infants at risk of CD linking genetic and environmental risk factors to detrimental immunomodulatory and inflammatory effects. Video Abstract.

RNA sequencing of intestinal mucosa reveals novel pathways functionally linked to celiac disease pathogenesis

BACKGROUND & AIMS

The early steps in the pathophysiology of celiac disease (CD) leading to loss of tolerance to gluten are poorly described. Our aim was to use RNA sequencing of duodenal biopsies in patients with active CD, CD in remission, and non-CD controls to gain insight into CD pathophysiology, identify additional genetic signatures linked to CD, and possibly uncover targets for future therapeutic agents.

METHODS

We performed whole transcriptome shotgun sequencing of intestinal biopsies in subjects with active and remission CD and non-CD controls. We also performed functional pathway analysis of differentially expressed genes to identify statistically significant pathways that are up or down regulated in subjects with active CD compared to remission CD.

RESULTS

We identified the upregulation of novel genes including IL12R, ITGAM and IGSF4 involved in the immune response machinery and cell adhesion process in the mucosa of subjects with active CD compared to those in remission. We identified a unique signature of genes, related to innate immunity, perturbed exclusively in CD irrespective of disease status. Finally, we highlight novel pathways of interest that may contribute to the early steps of CD pathogenesis and its comorbidities such as the spliceosome, pathways related to the innate immune response, and pathways related to autoimmunity.

CONCLUSIONS

Our study confirmed previous findings based on GWAS and immunological studies pertinent to CD pathogenesis and describes novel genes and pathways that with further validation may be found to contribute to the early steps in the pathogenesis of CD, ongoing inflammation, and comorbidities associated with CD.

Targeted genotyping for the prediction of celiac disease autoimmunity development in patients with type 1 diabetes and their family members

BACKGROUND

Patients with type 1 diabetes (T1D) and their first-degree relatives (FDRs) have an increased risk of developing celiac disease (CD) compared to the general population. This is largely explained by the shared association with major histocompatibility class II human leukocyte antigen (HLA) DQ2 and/or DQ8 between the two disease states.

AIM

To describe the frequency of CD autoimmunity (CDA) and the distribution of HLA and haptoglobin genotypes in patients with T1D and their FDRs. Additionally, we aimed at identifying predictors associated with an increased risk of developing CDA in patients with T1D and their family members.

METHODS

We obtained clinical information and blood samples from 1027 participants (302 with T1D and 725 FDRs) over a five-year period. Samples were tested for autoantibodies associated with CD, HLA-DQ alleles, and haptoglobin genotype. We fit univariate and multiple logistic regression models for CDA separately for subjects with T1D and for FDRs of subjects with T1D.

RESULTS

Implementation of a screening program increased the frequency of CDA by 2-fold in participants with T1D and 2.8-fold in their FDRs. Multivariate analysis found that, in participants with T1D, having both DR7-DQ2 and DR4-DQ8 was associated with an increased frequency of CDA. In FDRs of T1D patients, reported CD in the family was associated with an increased frequency of CDA during screening. Haptoglobin 2 genotype was not associated with developing CDA in the multivariate analysis.

CONCLUSION

Patients with T1D and their FDRs have a high frequency of CDA. Carrying both DR7-DQ2 and DR4-DQ8 was associated with development of CDA in patients with T1D.

Proinflammatory cytokine interferon-γ and microbiome-derived metabolites dictate epigenetic switch between forkhead box protein 3 isoforms in coeliac disease

Coeliac disease (CD) is an autoimmune enteropathy triggered by gluten and characterized by a strong T helper type 1 (Th1)/Th17 immune response in the small intestine. Regulatory T cells (T_reg ) are CD4⁺ CD25⁺⁺ forkhead box protein 3 (FoxP3⁺ ) cells that regulate the immune response. Conversely to its counterpart, FoxP3 full length (FL), the alternatively spliced isoform FoxP3 Δ2, cannot properly down-regulate the Th17-driven immune response. As the active state of CD has been associated with impairments in T_reg cell function, we aimed at determining whether imbalances between FoxP3 isoforms may be associated with the disease. Intestinal biopsies from patients with active CD showed increased expression of FOXP3 Δ2 isoform over FL, while both isoforms were expressed similarly in non-coeliac control subjects (HC). Conversely to what we saw in the intestine, peripheral blood mononuclear cells (PBMC) from HC subjects did not show the same balance between isoforms. We therefore hypothesized that the intestinal microenvironment may play a role in modulating alternative splicing. The proinflammatory intestinal microenvironment of active patients has been reported to be enriched in butyrate-producing bacteria, while high concentrations of lactate have been shown to characterize the preclinical stage of the disease. We show that the combination of interferon (IFN)-γ and butyrate triggers the balance between FoxP3 isoforms in HC subjects, while the same does not occur in CD patients. Furthermore, we report that lactate increases both isoforms in CD patients. Collectively, these findings highlight the importance of the ratio between FoxP3 isoforms in CD and, for the first time, associate the alternative splicing process mechanistically with microbial-derived metabolites.

[Design of a genomic, environmental, microbial and metabolomic study on celiac disease: an approach to the future of personalized prevention of celiac disease]

Over recent years we have seen rising many clinical and scientific innovations about celiac disease (CE), however the most important innovation that will contribute to change the future of the research and clinic in this field is the natural history of the disease. For many years it has been though that a genetic predisposition and the exposure to gluten were necessary and sufficient to develop CE. Recent studies, however, suggest that the loss of tolerance to gluten may occur in any moment of life upon certain conditions. Furthermore, several environmental factors known to play a role in shaping the intestinal microflora have also been considered related to the development of CE. Delivery mode, the infant diet and the use of antibiotics are included among these factors. To this day no large scale studies have determined if and how the microbiome composition and its metabolomic profile may influence the loss of tolerance to gluten and the consequent development of CE. In this paper we describe a prospective, multi-centric and longitudinal study on infants at risk for CE that will use different techniques to better understand the role of the microbome during the first steps in the development of the autoimmune disease.

Celiac Disease Genomic, Environmental, Microbiome, and Metabolomic (CDGEMM) Study Design: Approach to the Future of Personalized Prevention of Celiac Disease

In the past it was believed that genetic predisposition and exposure to gluten were necessary and sufficient to develop celiac disease (CD). Recent studies however suggest that loss of gluten tolerance can occur at any time in life as a consequence of other environmental stimuli. Many environmental factors known to influence the composition of the intestinal microbiota are also suggested to play a role in the development of CD. These include birthing delivery mode, infant feeding, and antibiotic use. To date no large-scale longitudinal studies have defined if and how gut microbiota composition and metabolomic profiles may influence the loss of gluten tolerance and subsequent onset of CD in genetically-susceptible individuals. Here we describe a prospective, multicenter, longitudinal study of infants at risk for CD which will employ a blend of basic and applied studies to yield fundamental insights into the role of the gut microbiome as an additional factor that may play a key role in early steps involved in the onset of autoimmune disease.

Effect of transcutaneous auricular vagus nerve stimulation on impaired glucose tolerance: a pilot randomized study

Background

Impaired glucose tolerance (IGT) is a pre-diabetic state of hyperglycemia that is associated with insulin resistance, increased risk of type II diabetes, and cardiovascular pathology. Recently, investigators hypothesized that decreased vagus nerve activity may be the underlying mechanism of metabolic syndrome including obesity, elevated glucose levels, and high blood pressure.

Methods

In this pilot randomized clinical trial, we compared the efficacy of transcutaneous auricular vagus nerve stimulation (taVNS) and sham taVNS on patients with IGT. 72 participants with IGT were single-blinded and were randomly allocated by computer-generated envelope to either taVNS or sham taVNS treatment groups. In addition, 30 IGT adults were recruited as a control population and not assigned treatment so as to monitor the natural fluctuation of glucose tolerance in IGT patients. All treatments were self-administered by the patients at home after training at the hospital. Patients were instructed to fill in a patient diary booklet each day to describe any side effects after each treatment. The treatment period was 12 weeks in duration. Baseline comparison between treatment and control group showed no difference in weight, BMI, or measures of systolic blood pressure, diastolic blood pressure, fasting plasma glucose (FPG), 2-hour plasma glucose (2hPG), or glycosylated hemoglobin (HbAlc).

Results

100 participants completed the study and were included in data analysis. Two female patients (one in the taVNS group, one in the sham taVNS group) dropped out of the study due to stimulation-evoked dizziness. The symptoms were relieved after stopping treatment. Compared with sham taVNS, taVNS significantly reduced the two-hour glucose tolerance (F(2) = 5.79, p = 0.004). In addition, we found that taVNS significantly decreased (F(1) = 4.21, p = 0.044) systolic blood pressure over time compared with sham taVNS. Compared with the no-treatment control group, patients receiving taVNS significantly differed in measures of FPG (F(2) = 10.62, p < 0.001), 2hPG F(2) = 25.18, p < 0.001) and HbAlc (F(1) = 12.79, p = 0.001) over the course of the 12 week treatment period.

Conclusions

Our study suggests that taVNS is a promising, simple, and cost-effective treatment for IGT/ pre-diabetes with only slight risk of mild side-effects.

Relationships among changes in C-reactive protein and cardiovascular disease risk factors with lifestyle interventions

BACKGROUND AND AIMS

Inflammation plays a role in the development of cardiovascular disease (CVD). Elevated levels of the inflammatory marker, C-reactive protein (CRP), are cross-sectionally associated with traditional CVD risk factors and are being considered as an emerging CVD risk factor. In a secondary data analysis, we examined changes in CRP and several CVD risk factors after one-year diet and physical activity interventions to assess whether CRP changed concurrently with other risk factors, or was independent of the traditional risk factors.

METHODS AND RESULTS

Data were analyzed from 143 men and 133 women with dyslipidemia who were randomized to one-year interventions of low-fat diet only, physical activity only, diet plus physical activity, or control. Plasma high-sensitivity CRP, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, triglycerides (TG), fasting and 2-hr blood glucose and insulin, blood pressure (BP), and waist circumference were obtained at baseline and follow-up. Multiple linear regression models were used to predict CRP change based on other risk factor changes, controlling for age, race, alcohol intake, and hormone replacement therapy. Treatment groups were combined for analysis. Baseline mean (SD) CRP levels were 1.3 ± 1.3 (men) and 1.9 ± 1.8 mg/L (women), with mean changes of -0.11 ± 1.3 and -0.17 ± 1.5 mg/L, respectively. Plasma CRP change was negatively associated with TG change in men (p = 0.003) and women (p = 0.05), positively associated with change in systolic BP in men (p = 0.01), but was not associated with changes in the other risk factors.

CONCLUSION

Dietary and/or physical activity induced changes in CRP may be largely independent of traditional CVD risk factors in persons with dyslipidemia.

Identification of a second region upstream of the mouse heme oxygenase-1 gene that functions as a basal level and inducer-dependent transcription enhancer

A 161-base pair fragment (AB1) approximately 10 kilobase pairs upstream of the transcription start site of the mouse heme oxygenase-1 gene functions as a basal level and inducer-dependent enhancer. AB1/chloramphenicol acetyltransferase fusion genes stably transfected into mouse hepatoma (Hepa) cells or L929 fibroblasts were activated 7-8- or 17-22-fold, respectively, after treatment of the cells with either CdCl2 or heme. The AB1 fragment is composed largely of three tandem repeats containing two conserved core elements, A and B. Part of core element A (TCCGGAGCTGTG) resembles the consensus-binding site for transcription factor AP-4, whereas core element B (GCTGAGTCANGG) includes the consensus-binding site (TGAGTCA) for the AP-1 family of transcription factors. Nuclear proteins from Hepa cells did not bind to any of the core A elements, but bound to all three copies of the core B element. AB1 derivatives with one or two mutant AP-1-binding elements exhibited reduced but measurable inducer-dependent enhancer activity, but mutation of all three AP-1-binding sites abolished activation by CdCl2 and heme and also by mercury chloride, zinc chloride, H2O2, sodium arsenate, and 12-O-tetradecanoylphorbol-13-acetate. Pretreatment of stably transfected L929 cells with protein kinase C inhibitors, but not with tyrosine kinase inhibitors or N-acetylcysteine, abrogated 12-O-tetradecanoylphorbol-13-acetate-dependent activation of the AB1/chloramphenicol acetyltransferase fusion gene. Induction by H2O2 was unaffected by the kinase inhibitors, but completely abolished by N-acetylcysteine. Heme-dependent induction was not significantly affected by any of these chemicals.