Use of a footstool improves rectal balloon expulsion in some patients with defecatory disorders.

BACKGROUND: Whether patients with defecatory disorders (DDs) with favorable response to a footstool have distinctive anorectal pressure characteristics is unknown. We aimed to identify the clinical phenotype and anorectal pressure profile of patients with DDs who benefit from a footstool. METHODS: This is a retrospective review of patients with high resolution anorectal manometry (HR-ARM) and balloon expulsion test (BET) from a tertiary referral center. BET was repeated with a 7-inch-high footstool in those who failed it after 120 s. Data were compared among groups with respect to BET results. KEY RESULTS: Of the 667 patients with DDs, a total of 251 (38%) had failed BET. A footstool corrected BET in 41 (16%) of those with failed BET. Gender-specific differences were noted in anorectal pressures, among patients with and without normal BET, revealing gender-based nuances in pathophysiology of DDs. Comparing patients who passed BET with footstool with those who did not, the presence of optimal stool consistency, with reduced instances of loose stools and decreased reliance on laxatives were significant. Additionally, in women who benefited from a footstool, lower anal pressures at rest and simulated defecation were observed. Independent factors associated with a successful BET with a footstool in women included age <50, Bristol 3 or 4 stool consistency, lower anal resting pressure and higher rectoanal pressure gradient. CONCLUSION & INFERENCES: Identification of distinctive clinical and anorectal phenotype of patients who benefited from a footstool could provide insight into the factors influencing the efficacy of footstool utilization and allow for an individualized treatment approach in patients with DDs.

The association between vitamin-D deficiency and fecal incontinence.

BACKGROUND: Vitamin-D is essential for musculoskeletal health. We aimed to determine whether patients with fecal incontinence (FI): (1) are more likely to have vitamin-D deficiency and, (2) have higher rates of comorbid medical conditions. METHODS: We examined 18- to 90-year-old subjects who had 25-hydroxy vitamin-D levels, and no vitamin-D supplementation within 3 months of testing, in a large, single-institutional electronic health records dataset, between 2017 and 2022. Cox proportional hazards survival analysis was used to assess association of vitamin-D deficiency on FI. KEY RESULTS: Of 100,111 unique individuals tested for serum 25-hydroxy vitamin-D, 1205 (1.2%) had an established diagnosis of FI. Most patients with FI were female (75.9% vs. 68.7%, p = 0.0255), Caucasian (66.3% vs. 52%, p = 0.0001), and older (64.2 vs. 53.8, p < 0.0001). Smoking (6.56% vs. 2.64%, p = 0.0001) and GI comorbidities, including constipation (44.9% vs. 9.17%, p = 0.0001), irritable bowel syndrome (20.91% vs. 3.72%, p = 0.0001), and diarrhea (28.55% vs. 5.2%, p = 0.0001) were more common among FI patients. Charlson Comorbidity Index score was significantly higher in patients with FI (5.5 vs. 2.7, p < 0.0001). Significantly higher proportions of patients with FI had vitamin-D deficiency (7.14% vs. 4.45%, p < 0.0001). Moreover, after propensity-score matching, rate of new FI diagnosis was higher in patients with vitamin-D deficiency; HR 1.9 (95% CI [1.14-3.15]), p = 0.0131. CONCLUSION & INFERENCES: Patients with FI had higher rates of vitamin-D deficiency along with increased overall morbidity. Future research is needed to determine whether increased rate of FI in patients with vitamin-D deficiency is related to frailty associated with increased medical morbidities.

Development and Validation of a Machine Learning System to Identify Reflux Events in Esophageal 24-Hour pH/Impedance Studies.

INTRODUCTION: Esophageal 24-hour pH/impedance testing is routinely performed to diagnose gastroesophageal reflux disease. Interpretation of these studies is time-intensive for expert physicians and has high inter-reader variability. There are no commercially available machine learning tools to assist with automated identification of reflux events in these studies. METHODS: A machine learning system to identify reflux events in 24-hour pH/impedance studies was developed, which included an initial signal processing step and a machine learning model. Gold-standard reflux events were defined by a group of expert physicians. Performance metrics were computed to compare the machine learning system, current automated detection software (Reflux Reader v6.1), and an expert physician reader. RESULTS: The study cohort included 45 patients (20/5/20 patients in the training/validation/test sets, respectively). The mean age was 51 (standard deviation 14.5) years, 47% of patients were male, and 78% of studies were performed off proton-pump inhibitor. Comparing the machine learning system vs current automated software vs expert physician reader, area under the curve was 0.87 (95% confidence interval [CI] 0.85-0.89) vs 0.40 (95% CI 0.37-0.42) vs 0.83 (95% CI 0.81-0.86), respectively; sensitivity was 68.7% vs 61.1% vs 79.4%, respectively; and specificity was 80.8% vs 18.6% vs 87.3%, respectively. DISCUSSION: We trained and validated a novel machine learning system to successfully identify reflux events in 24-hour pH/impedance studies. Our model performance was superior to that of existing software and comparable to that of a human reader. Machine learning tools could significantly improve automated interpretation of pH/impedance studies.

The integrated relaxation pressure may not be an appropriate gold standard for deglutitive relaxation due to reliance on a single intragastric reference sensor.

BACKGROUND: Integrated relaxation pressure (IRP) calculation depends on the selection of a single gastric reference sensor. Variable gastric pressure readings due to sensor selection can lead to diagnostic uncertainty. This study aimed to examine the effect of gastric reference sensor selection on IRP measurement and diagnosis. METHODS: We identified high-resolution manometry (HRM) conducted between January and November 2017 with at least six intragastric reference sensors. IRP measurements and Chicago Classification 3.0 (CCv3) diagnoses were obtained for each of six gastric reference sensors. Studies were categorized as "stable" (no change in diagnosis) or "variable" (change in diagnosis with gastric reference selection). Variable diagnoses were further divided into "variable normal/dysmotility" (≥1 normal IRP measurement and ≥1 CCv3 diagnosis), or "variable dysmotility" (≥1 CCv3 diagnosis, only elevated IRP measurements). Bland-Altman plots were used to compare IRP measurements within HRM studies. KEY RESULTS: The analysis included 100 HRM studies, among which 18% had variable normal/dysmotility, and 10% had variable dysmotility. The average IRP difference between reference sensors was 6.7 mmHg for variable normal/dysmotility and 5.9 mmHg for variable dysmotility. The average difference between the proximal-most and distal-most sensors was -1.52 mmHg (lower limit of agreement -10.03 mmHg, upper limit of agreement 7.00 mmHg). CONCLUSIONS & INFERENCES: IRP values can vary greatly depending on the reference sensor used, leading to inconsistent diagnoses in 28% of HRM studies. Choosing the correct gastric reference sensor is crucial for accurate test results and avoiding misdiagnosis. Standardization of reference sensor selection or supportive testing for uncertain results should be considered.

The Impact of Intermittent Fasting on Patients With Suspected Gastroesophageal Reflux Disease.

GOAL: The aim was to investigate the short-term impact of time restricted feeding on patients with suspected gastroesophageal reflux disease (GERD). BACKGROUND: Lifestyle modifications are often suggested, but the role of diet in GERD is unclear. Intermittent fasting is popular in the media and has demonstrated potential benefits with weight loss and inflammatory conditions as well as alterations in gastrointestinal hormones. STUDY: Patients who were referred for 96-hour ambulatory wireless pH monitoring off proton pump inhibitor to investigate GERD symptoms were screened for eligibility. Patients were instructed to maintain their baseline diet for the first 2 days of pH monitoring and switch to an intermittent fasting regimen (16 consecutive hour fast and 8 h eating window) for the second 2 days. Objective measures of reflux and GERD symptom severity were collected and analyzed. RESULTS: A total of 25 participants were analyzed. 9/25 (36%) fully adhered to the intermittent fasting regimen, with 21/25 (84%) demonstrating at least partial compliance. Mean acid exposure time on fasting days was 3.5% versus 4.3% on nonfasting days. Intermittent fasting was associated with a 0.64 reduction in acid exposure time (95% CI: -2.32, 1.05). There was a reduction in GERD symptom scores of heartburn and regurgitation during periods of intermittent fasting (14.3 vs. 9.9; difference of -4.46, 95% CI: -7.6,-1.32). CONCLUSIONS: Initial adherence to time restricted eating may be difficult for patients. There is weak statistical evidence to suggest that intermittent fasting mildly reduces acid exposure. Our data show that short-term intermittent fasting improves symptoms of both regurgitation and heartburn.

Quality Indicators for the Diagnosis and Management of Eosinophilic Esophagitis.

INTRODUCTION: Despite best practice recommendations for managing eosinophilic esophagitis (EoE), variation in care exists. METHODS: We used established methodology for quality indicator development to identify metrics to define quality for the treatment of EoE. RESULTS: Among 29 proposed quality indicator statements, 9 (31%) were adopted as highly valid across all categories. Two (22%) of these statements were identified as having existing or suspected quality gaps. DISCUSSION: We identified highly valid EoE quality indicators for adult gastroenterologists, which can be used for quality improvement with resulting benefits for patient outcomes.

KIR+CD8+ T cells suppress pathogenic T cells and are active in autoimmune diseases and COVID-19.

In this work, we find that CD8+ T cells expressing inhibitory killer cell immunoglobulin-like receptors (KIRs) are the human equivalent of Ly49+CD8+ regulatory T cells in mice and are increased in the blood and inflamed tissues of patients with a variety of autoimmune diseases. Moreover, these CD8+ T cells efficiently eliminated pathogenic gliadin-specific CD4+ T cells from the leukocytes of celiac disease patients in vitro. We also find elevated levels of KIR+CD8+ T cells, but not CD4+ regulatory T cells, in COVID-19 patients, correlating with disease severity and vasculitis. Selective ablation of Ly49+CD8+ T cells in virus-infected mice led to autoimmunity after infection. Our results indicate that in both species, these regulatory CD8+ T cells act specifically to suppress pathogenic T cells in autoimmune and infectious diseases.

An efficient urine peptidomics workflow identifies chemically defined dietary gluten peptides from patients with celiac disease.

Celiac disease (CeD) is an autoimmune disorder induced by consuming gluten proteins from wheat, barley, and rye. Glutens resist gastrointestinal proteolysis, resulting in peptides that elicit inflammation in patients with CeD. Despite well-established connections between glutens and CeD, chemically defined, bioavailable peptides produced from dietary proteins have never been identified from humans in an unbiased manner. This is largely attributable to technical challenges, impeding our knowledge of potentially diverse peptide species that encounter the immune system. Here, we develop a liquid chromatographic-mass spectrometric workflow for untargeted sequence analysis of the urinary peptidome. We detect over 600 distinct dietary peptides, of which ~35% have a CeD-relevant T cell epitope and ~5% are known to stimulate innate immune responses. Remarkably, gluten peptides from patients with CeD qualitatively and quantitatively differ from controls. Our results provide a new foundation for understanding gluten immunogenicity, improving CeD management, and characterizing the dietary and urinary peptidomes.

Eosinophilic Esophagitis: Incidence, Diagnosis, Management, and Future Directions.

Eosinophilic esophagitis (EoE) is an antigen-mediated esophageal disease defined by the presence of esophageal eosinophilia and symptoms of esophageal dysfunction. The pathophysiology involves an allergen-driven Th2 T cell response that triggers infiltration of eosinophils into the esophagus leading to inflammation, remodeling, and fibrosis. This results in disruption of esophageal function and accompanying symptoms - most notably dysphagia. Effective therapies target inflammation or fibrostenotic complications and include proton pump inhibitors, swallowed topical steroids, dietary exclusion, and dilation. Clinical trials testing promising biologic therapies are ongoing.

Gastric Mucosal Immune Profiling and Dysregulation in Idiopathic Gastroparesis.

INTRODUCTION: It is unclear how immune perturbations may influence the pathogenesis of idiopathic gastroparesis, a prevalent functional disorder of the stomach which lacks animal models. Several studies have noted altered immune characteristics in the deep gastric muscle layer associated with gastroparesis, but data are lacking for the mucosal layer, which is endoscopically accessible. We hypothesized that immune dysregulation is present in the gastroduodenal mucosa in idiopathic gastroparesis and that specific immune profiles are associated with gastroparesis clinical parameters. METHODS: In this cross-sectional prospective case-control study, routine endoscopic biopsies were used for comprehensive immune profiling by flow cytometry, multicytokine array, and gene expression in 3 segments of the stomach and the duodenal bulb. Associations of immune endpoints with clinical parameters of gastroparesis were also explored. RESULTS: The gastric mucosa displayed large regional variation of distinct immune profiles. Furthermore, several-fold increases in innate and adaptive immune cells were found in gastroparesis. Various immune cell types showed positive correlations with duration of disease, proton pump inhibitor dosing, and delayed gastric emptying. DISCUSSION: This initial observational study showed immune compartmentalization of the human stomach mucosa and significant immune dysregulation at the level of leukocyte infiltration in idiopathic gastroparesis patients that extends to the duodenum. Select immune cells, such as macrophages, may correlate with clinicopathological traits of gastroparesis. This work supports further mucosal studies to advance our understanding of gastroparesis pathophysiology.

Human KIR + CD8 + T cells target pathogenic T cells in Celiac disease and are active in autoimmune diseases and COVID-19.

Previous reports show that Ly49 + CD8 + T cells can suppress autoimmunity in mouse models of autoimmune diseases. Here we find a markedly increased frequency of CD8 + T cells expressing inhibitory Killer cell Immunoglobulin like Receptors (KIR), the human equivalent of the Ly49 family, in the blood and inflamed tissues of various autoimmune diseases. Moreover, KIR + CD8 + T cells can efficiently eliminate pathogenic gliadin-specific CD4 + T cells from Celiac disease (CeD) patients' leukocytes in vitro . Furthermore, we observe elevated levels of KIR + CD8 + T cells, but not CD4 + regulatory T cells, in COVID-19 and influenza-infected patients, and this correlates with disease severity and vasculitis in COVID-19. Expanded KIR + CD8 + T cells from these different diseases display shared phenotypes and similar T cell receptor sequences. These results characterize a regulatory CD8 + T cell subset in humans, broadly active in both autoimmune and infectious diseases, which we hypothesize functions to control self-reactive or otherwise pathogenic T cells. ONE-SENTENCE SUMMARY: Here we identified KIR + CD8 + T cells as a regulatory CD8 + T cell subset in humans that suppresses self-reactive or otherwise pathogenic CD4 + T cells.

Gastrointestinal Eosinophil Responses in a Longitudinal, Randomized Trial of Peanut Oral Immunotherapy.

BACKGROUND & AIMS: Gastrointestinal side effects are common during oral immunotherapy (OIT) and eosinophilic esophagitis (EoE) is a potential complication. We aimed to characterize eosinophilic gastrointestinal responses to peanut OIT, in which peanut protein is given orally, with incremental increases in dose over time. METHODS: Twenty adults with IgE-mediated peanut allergy were randomly assigned to groups given peanut OIT (n = 15) or placebo (n = 5); 1 additional subject withdrew before randomization. Serial gastrointestinal biopsies were collected at baseline (n = 21, 0 weeks), following dose escalation (n = 10, 52 weeks), and during the maintenance phase (n = 11, 104 weeks). Endoscopic findings were characterized using the EoE endoscopic reference score. Biopsies were assessed for eosinophils per high-power field (eos/hpf) and other pathology features using EoE histologic scoring system scores. We performed immunohistochemical analyses of eosinophil peroxidase deposition, quantified using automated image analysis. RESULTS: At baseline, no subjects reported current gastrointestinal symptoms. However, 3 of the 21 subjects (14%) had esophageal peak eosinophil counts ≥15 eos/hpf and all subjects had dilated intercellular spaces (DIS). OIT induced or exacerbated esophageal eosinophilia (EE) at 52 weeks in most subjects (peak eosinophil counts >5 eos/hpf in 6 of 7 patients [86%]; peak eosinophil counts ≥15 eos/hpf in 4 of 7 patients [57%]). One subject met clinicopathologic criteria for EoE and withdrew; no significant changes in esophageal peak eosinophil counts were observed in the placebo group. EE in the OIT group corresponded with significant increases in EoE histologic scoring system scores and deposition of eosinophil peroxidase. In 4 of 6 participants (67%), OIT-induced EE and gastrointestinal eosinophilia resolved by the end of the maintenance phase. Gastrointestinal symptoms were not clearly associated with EE or gastrointestinal eosinophilia. CONCLUSIONS: In this pilot study, we found that peanut OIT-induced EE and gastrointestinal eosinophilia are usually transient and are not always associated with gastrointestinal symptoms. Clinicaltrials.gov no: NCT02103270.

Baseline impedance via manometry and ambulatory reflux testing are not equivalent when utilized in the evaluation of potential extra-esophageal gastroesophageal reflux disease.

BACKGROUND: Esophageal baseline impedance (BI) shows promise for the diagnosis of gastroesophageal reflux disease (GERD), but means of acquisition and relevance to extra-esophageal manifestations of GERD (EE-GERD) remain unclear. In this study we aim to (I) evaluate concordance between BI as measured by 24-hour pH-impedance (pH-MII) and high-resolution impedance manometry (HRIM), and (II) assess relationship to potential EE-GERD symptoms. METHODS: In this prospective open cohort study, patients presenting for outpatient HRIM and pH-MII studies were prospectively enrolled. All patients completed the GERD-HRQL, NOSE, and respiratory symptom index questionnaire (RSI), plus questions regarding wheezing and dental procedures. HRIM and pH-MII were evaluated with calculation of BI. Correlations were assessed using either Pearson's correlation or Spearman's rank coefficients. RESULTS: 70 HRIM patients were enrolled, 35 of whom underwent pH-MII. There was no correlation between BI measurements as assessed by HRIM and pH-MII proximally, but there was moderate-weak correlation distally (r=0.34 to 0.5). Distal acid exposure time correlated with distal BI only for measurements by pH-MII (rho= -0.5 to -0.65), and not by HRIM. There was no relationship between proximal acid exposure time and proximal BI. There were no correlations when comparing proximal or distal BI measurements, acid exposure times, and impedance events to symptoms. CONCLUSIONS: Concordance between BI as measured by HRIM and pH-MII is poor, especially proximally, suggesting that these two methods are not interchangeable. There is no correlation between BI both distally/proximally and symptoms of either GERD/EE-GERD, suggesting that many symptoms are unrelated to acid or that BI is not an adequate marker to assess EE-GERD symptoms.

Achalasia: physiology and diagnosis.

Achalasia is a rare motility disorder with incomplete relaxation of the lower esophageal sphincter and ineffective contractions of the esophageal body. It has been hypothesized that achalasia does not result from only one pathway but rather involves a combination of infectious, autoimmune, and familial etiological components. On the basis of other observations, a novel hypothesis suggests that a muscular form of eosinophilic esophagitis is involved in the pathophysiology of achalasia in some patients. This appears to progressively diminish the myenteric plexus at stage III, gradually destroy it at stage II, and finally eliminate it at stage I, the most advanced and final stage of achalasia. Although high-resolution manometry has identified these three different types of achalasia, another subset of patients with a normal-appearing sphincter relaxation has been proposed. Provocative maneuvers, such as the rapid drinking challenge, have recently been demonstrated to improve diagnosis in certain borderline patients, but have to be studied in more detail. However, whether the different types of achalasia will have a long-term impact on tailored therapies is still a matter of debate. Additionally, novel aspects of the standard timed barium swallow appear to be an important adjunct of diagnosis, as it has been shown to have a diagnostic as well as a predictive value.

Gastric antral vascular ectasia in systemic sclerosis: Association with anti-RNA polymerase III and negative anti-nuclear antibodies.

OBJECTIVE: Gastric antral vascular ectasia (GAVE) is a vascular manifestation of systemic sclerosis (SSc) that can lead to iron deficiency anemia or acute gastrointestinal (GI) bleeding. We aimed to identify clinical features associated with GAVE. METHODS: We performed a cohort study of SSc patients who were seen at Stanford between 2004 and 2018 and had undergone esophagogastroduodenoscopy (EGD). We compared the clinical features of those with and without GAVE, and multivariable logistic regression was performed to identify clinical correlates with GAVE. RESULTS: A total of 225 patients with SSc who underwent EGD were included in this study and 19 (8.4%) had GAVE. Those with GAVE were more likely to have scleroderma renal crisis (SRC) (21% vs 3%; p < 0.01), positive anti-RNA polymerase III antibody (71% vs 19%; p < 0.01), nucleolar pattern of anti-nuclear antibody (ANA) (33% vs 11%; p=0.04), and negative ANA (<1:80 by immunofluorescence) (33% vs 11%; p=0.02). On multivariate analysis with multiple imputation, anti-RNA polymerase III positivity (OR 4.57; 95% CI (1.57 - 13.23), p < 0.01) and ANA negativity (OR 3.75; 95% CI (1.21 - 11.62), p=0.02) remained significantly associated with GAVE. CONCLUSION: Positive anti-RNA polymerase III antibody and ANA negativity were significantly associated with GAVE. Further studies are necessary to determine whether patients with these autoantibody profiles should undergo screening endoscopies for GAVE.

Eosinophilic esophagitis: updates on key unanswered questions.

Eosinophilic esophagitis (EoE) is a clinicopathologic disease characterized by symptoms of esophageal dysfunction and esophageal eosinophilia. In the last decade, there has been a dramatic increase in its prevalence for reasons that are not completely understood. The underlying pathophysiology involves an antigen-mediated TH 2 immune response that draws eosinophils to the esophagus, causing mucosal inflammation, esophageal remodeling, and fibrosis. This ultimately leads to esophageal dysfunction that most commonly manifests as dysphagia. In this review, we will discuss updates on key questions regarding the diagnosis and treatment of EoE.

The functional lumen imaging probe in gastrointestinal disorders: the past, present, and future.

The functional lumen imaging probe (FLIP) is a diagnostic tool that utilizes impedance planimetry to allow the assessment of luminal diameter and distensibility. It has been used primarily in esophageal diseases, in particular, in the assessment of achalasia, esophagogastric junction outflow obstruction, and eosinophilic esophagitis (EoE). The usage and publications have increased over the past decade and it is now an essential tool in the armamentarium of the esophagologist. Indications are emerging outside of the esophagus, in particular with regard to gastroparesis. Our paper will review the history of FLIP, optimal current usage, data for key esophageal disorders (including achalasia, reflux, and EoE), data for nonesophageal disorders, and our sense as to whether FLIP is ready for prime time, as well as gaps in evidence and suggestions for future research.