Ramos, Guilherme P

ABSTRACT Enteroendocrine cells (EECs) are specialized sensors of the gastrointestinal (GI) epithelium that regulate gut function and systemic metabolism through hormone secretion. The molecular pathways directing intestinal stem cell (ISC) differentiation into EECs are incompletely understood due, in part, to their rarity. We sought to identify novel regulators of human EEC differentiation using a high-throughput screen of FDA-approved drugs and human duodenal organoids. Two epidermal growth factor receptor inhibitors (EGFRi) commonly used in cancer therapy and known to cause GI side effects, erlotinib and lapatinib, emerged as strong inducers of EEC differentiation, dramatically increasing chromogranin A (CHGA) expression compared to controls, while maintaining ISC function and organoid growth. EGFRi-treated organoids revealed robust and broad upregulation of EEC hormones, including serotonin (5HT), motilin (MLN), and somatostatin (SST), among others. In agreement with these findings, analysis of a patient cohort with lung cancer revealed an association with erlotinib use and increased circulating levels of the above EEC hormones compared to matched controls. Supporting a direct effect of EGFRi on EEC differentiation, mice treated with erlotinib demonstrated increased EEC numbers and hormones and showed EGFRi-associated diarrhea (EAD), a limiting side effect of these medications. Mechanistically, EGFRi induced upregulation of interferon (IFN) signaling targets during early ISC-to-EEC differentiation. Consistent with this, inhibition of Signal Transducer and Activator of Transcription 1 (STAT1) attenuated EGFRi-induced EEC differentiation. These findings provide important insight into EEC differentiation that could inform treatment strategies for EAD, metabolic diseases, and GI diseases. Brief Summary Inhibition of EGFR signaling promotes human ISC-to-EEC differentiation through activation of STAT1 signaling.

Abstract Background Microscopic colitis (MC) is suspected to result from increased immune activity in gut mucosa. Immune checkpoint inhibitors (ICIs) treat cancer by activating the immune system, and further investigation is needed regarding their role in the development of MC. Methods A retrospective case series investigated cases of endoscopically and histologically confirmed MC developing after administration of ICIs. Clinical notes and medication administration records were reviewed for demographics, symptom duration, and treatment response. Results Nineteen cases of de novo MC were identified, with 95% of cases requiring steroid treatment, 53% presenting with hospitalization, and colitis-related mortality in 1 individual. Symptom onset occurred a median of 160 days after initiation of ICI therapy and 53 days after their most recent dose of therapy. Patients had a median of 125 days of symptoms, and ICI therapy was held in 70% of individuals due for treatment. Conclusions MC can develop after ICI administration, and presents with severe symptoms, often requiring hospitalization and steroid treatment. In certain individuals this can require a prolonged treatment course of steroid therapy or immunomodulators. Individuals developing diarrhea after ICI therapy warrant thorough workup including endoscopy and rapid treatment initiation given the disease severity observed in this series.

LINKED CONTENT This article is linked to Meserve et al paper. To view this article, visit https://doi.org/10.1111/apt.16217

AbstractSeveral environmental factors have been implicated in the pathogenesis of inflammatory bowel diseases (IBD); however, the evidence for alcohol is sparse, as is its implications on disease activity and overall management. Here, we examine the available evidence for the effect of alcohol on IBD, including its association with the development of IBD, role in exacerbations, and potential medication interactions. Several mechanisms have been demonstrated to mediate the effects of ethanol in the gastrointestinal tract. Alcohol has been shown to alter the gut microbiome, disrupt intestinal barrier, and increase intestinal permeability, directly and indirectly promoting immune activation. Conversely, specific alcoholic beverages, notably red wine, may have anti-inflammatory properties capable of assisting in disease control and affecting disease monitoring. Nonetheless, most alcohol-mediated effects seem to facilitate intestinal inflammation and consequently impact disease onset, recurrence, and symptom control. Furthermore, alcohol use interferes with the metabolism of several medications leading to increased side effect profiles or even loss of effect. Notably, mesalamine, azathioprine, methotrexate, and biologic medications can all be affected by concomitant alcohol intake via a variety of mechanisms.

Abstract Background Certolizumab pegol (CZP) has been successfully used for the treatment of Crohn disease (CD); however, real-world data regarding the utility of CZP trough levels (CTLs) are lacking. We aimed to correlate CTL with CD outcomes and to determine frequency of CZP antibodies. Methods Retrospective evaluation of all CD patients on maintenance CZP with CTL obtained between 2016 and 2019. Outcomes included: median CTL, presence of anti-CZP antibodies, biochemical response (BR), clinical response (CR), radiologic response (RR), radiologic healing (RH), and mucosal healing (MH). Results Seventy-seven CD patients were included. Median CTL was 18.9 µg/mL (interquartile range, 7.6–35.4). Twenty-three patients (27.3%) had positive antibody levels, with lower median CTL compared to patients with no antibodies (0.0 vs 29.8; P < 0.0001). Median CTL levels were higher in patients with vs without CR (30.4 vs 10.3 µg/mL; P = 0.0015) and RR (29.6 vs 5.8 µg/mL; P = 0.006). CZP dosing at least every 2 weeks was associated with higher odds of achieving MH (odds ratio, 3.2; 95% confidence interval, 1.03–9.97). CTL resulted in change in clinical management in 62.7% of cases and presence of CMZ antibodies was associated with an odds ratio of 5.83 (95% confidence interval, 1.57–21.73) of change in management. Receiver operating characteristic curve and quartile analysis suggested that CTL >19 µg/mL is associated with increased rates of CR and RR. Conclusions Higher CTL was significantly associated with CR and RR. The rate of CZP antibodies was 27.3%. Our data suggest maintenance CTL of ≥19 µg/mL should be achieved in order to optimize outcomes in clinical practice.

Abstract Background There are limited data on how vedolizumab (VDZ) impacts extraintestinal manifestations (EIMs) in inflammatory bowel disease (IBD). The aim of this study was to determine the clinical outcomes of EIMs after initiation of VDZ for patients with IBD. Methods A multicenter retrospective study of patients with IBD who received at least 1 dose of VDZ between January 1, 2014 and August 1, 2019 was conducted. The primary outcome was the rate of worsening EIMs after VDZ. Secondary outcomes were factors associated with worsening EIMs and peripheral arthritis (PA) specifically after VDZ. Results A total of 201 patients with IBD (72.6% with Crohn disease; median age 38.4 years (interquartile range, 29-52.4 years); 62.2% female) with EIMs before VDZ treatment were included. The most common type of EIM before VDZ was peripheral arthritis (PA) (68.2%). Worsening of EIMs after VDZ occurred in 34.8% of patients. There were no statistically significant differences between the worsened EIM (n = 70) and the stable EIM (n = 131) groups in term of age, IBD subtype, or previous and current medical therapy. We found that PA was significantly more common in the worsening EIM group (84.3% vs 59.6%; P < 0.01). Worsening of EIMs was associated with a higher rate of discontinuation of VDZ during study follow-up when compared with the stable EIM group (61.4% vs 44%; P = 0.02). Treatment using VDZ was discontinued specifically because of EIMs in 9.5% of patients. Conclusions Almost one-third of patients had worsening EIMs after VDZ, which resulted in VDZ discontinuation in approximately 10% of patients. Previous biologic use or concurrent immunosuppressant or corticosteroid therapy did not predict EIM course after VDZ.

AbstractBackgroundAn association between inflammatory bowel disease (IBD) and obesity has been observed. Little is known about the effect of weight loss on IBD course. Our aim was to determine the impact of bariatric surgery on long-term clinical course of obese patients with IBD, either Crohn's disease (CD) or ulcerative colitis (UC).MethodsPatients with IBD who underwent bariatric surgery subsequent to IBD diagnosis were identified from 2 tertiary IBD centers. Complications after bariatric surgery were recorded. Patients were matched 1:1 for age, sex, IBD subtype, phenotype, and location to patients with IBD who did not undergo bariatric surgery. Controls started follow-up at a time point in their disease similar to the disease duration in the matched case at the time of bariatric surgery. Inflammatory bowel disease medication usage and disease-related complications (need for corticosteroids, hospitalizations, and surgeries) among cases and controls were compared.ResultsForty-seven patients met inclusion criteria. Appropriate matches were found for 25 cases. Median follow-up among cases (after bariatric surgery) and controls was 7.69 and 7.89 years, respectively. Median decrease in body mass index after bariatric surgery was 12.2. Rescue corticosteroid usage and IBD-related surgeries were numerically less common in cases than controls (24% vs 52%; odds ratio [OR], 0.36; 95% confidence interval [CI], 0.08–1.23; 12% vs 28%; OR, 0.2; 95% CI, 0.004–1.79). Two cases and 1 control were able to discontinue biologics during follow-up.ConclusionsInflammatory bowel disease patients with weight loss after bariatric surgery had fewer IBD-related complications compared with matched controls. This observation requires validation in a prospective study design.

Abstract Background The aetiology of Crohn’s disease [CD] involves immune dysregulation in a genetically susceptible individual. Genome-wide association studies [GWAS] have identified 200 loci associated with CD, ulcerative colitis, or both, most of which fall within non-coding DNA regions. Long non-coding RNAs [lncRNAs] regulate gene expression by diverse mechanisms and have been associated with disease activity in inflammatory bowel disease. However, disease-associated lncRNAs have not been characterised in pathogenic immune cell populations. Methods Terminal ileal samples were obtained from 22 CD patients and 13 controls. RNA from lamina propria CD4+ T cells was sequenced and long intergenic non-coding RNAs [lincRNAs] were detected. Overall expression patterns, differential expression [DE], and pathway and gene enrichment analyses were performed. Knockdown of novel lincRNAs XLOC_000261 and XLOC_000014 was performed. Expression of Th1 or Th17-associated transcription factors, T-bet and RORγt, respectively, was assessed by flow cytometry. Results A total of 6402 lincRNAs were expressed, 960 of which were novel. Unsupervised clustering and principal component analysis showed that the lincRNA expression discriminated patients from controls. A total of 1792 lincRNAs were DE, and 295 [79 novel; 216 known] mapped to 267 of 5727 DE protein-coding genes. The novel lincRNAs were enriched in inflammatory and Notch signalling pathways [p <0.05]. Furthermore, DE lincRNAs in CD patients were more frequently found in DNA regions with known inflammatory bowel disease [IBD]-associated loci. The novel lincRNA XLOC_000261 negatively regulated RORγt expression in Th17 cells. Conclusions We describe a novel set of DE lincRNAs in CD-associated CD4+ cells and demonstrate that novel lincRNA XLOC_000261 appears to negatively regulate RORγt protein expression in Th17 cells.