American Journal of Gastroenterology

Background: Gastric cancer surveillance in CDH1 pathogenic variant carriers is challenging, as predictors of localized (stage T1a) and advanced (stage >T1a) signet ring cell carcinoma (SRCC) are not well defined. We established the Group of investigAtors STriving toward Research In CDH1 (GASTRIC) consortium to identify clinicopathological factors associated with localized and advanced SRCC. Methods: A retrospective observational study (1998-2025) of CDH1 carriers across twelve academic centers was performed. Clinical, endoscopic, and pathological data were compared between carriers with and without SRCC on endoscopy, and between those with advanced versus localized or no cancer on gastrectomy specimens. Results: Overall, 390 CDH1 carriers from 235 families were included. Presence of SRCCs on endoscopy was significantly associated with thickened folds, nodularity, masses, and intestinal metaplasia, while gastritis was negatively associated. Of 196 carriers (52.4%) undergoing gastrectomy, 11 (5.6%) had advanced cancers, 10(90.9%) of which showed endoscopic abnormalities. Identification of SRCC on baseline endoscopy was the most sensitive feature for advanced disease (0.81) but had moderate specificity (0.74), whereas masses and thickened folds were highly specific (0.99 and 0.96, respectively) but less sensitive. Negative predictive values were high (0.94-1.0), while positive predictive values were modest (0.13-0.66). On multivariate analysis, masses and SRCC foci on baseline endoscopy were independent predictors of advanced disease. Conclusion: Among CDH1 carriers, absence of endoscopic findings was reassuring, whereas significance of detected endoscopic and pathological abnormalities was less certain. Advanced cancer occurred in a small number of carriers, with endoscopic abnormalities in nearly all cases. Endoscopic surveillance might be an alternative to surgery in carriers without worrisome mucosal findings.

Background: Jejunal diverticulitis is an uncommon but increasingly recognized cause of acute abdomen. It can present with a range of CT findings, including peridiverticular inflammation, bowel wall thickening, and fecalized small bowel content, with perforation or abscess occurring as complications in roughly 6% of cases. Case reports note varied presentations with jejunal and ileal involvement, treatment ranging from nonoperative management with antibiotics to urgent surgical intervention. Though rare, small bowel diverticulitis, particularly involving the jejunum, can result in significant morbidity, including peritonitis and sepsis, requiring heightened clinical suspicion in elderly or immunocompromised patients. Methods: We conducted a single center retrospective review of patients diagnosed with jejunal diverticulitis in a single academic center's Emergency General Surgery registry between December 2017 and December 2024. Of 42 patients initially identified, 34 had confirmed diagnoses on chart review. Data abstracted included age, sex, imaging modality, presence of perforation, serial physical exams, lab values (CBC, lactate), ICU admission, length of stay (LOS), antibiotic duration, operative status and timing, distance of residence from our institution, disposition after index admission, and readmission within one year. Results: Of the 34 confirmed cases, 24 (71%) were perforated: 2 presented with small bowel obstruction, 16 with abscesses and/or contained perforations, and 1 with both. 19 of the 24 perforated patients required operative intervention: 9 proceeded directly to the OR, 3 on hospital day one, and 2 as late as hospital day six. Among non-operative patients treated with antibiotics alone, the average LOS was 6 days (range: 2-23). Two patients were readmitted within one year: neither had undergone surgery during their index admission and neither were related to their index admission. Overall, three patients died: two during the index admission (both perforated and operated on) and one on readmission. Conclusion: Compared to the 6% complication rate reported in prior literature, our series demonstrates a notably higher rate of perforation (71%) among patients diagnosed with jejunal diverticulitis. Operative intervention was common, though a subset of patients was successfully managed non-operatively with antibiotics. Mortality was limited to patients with significant comorbidities and complex presentations. These findings underscore the heterogeneity in presentation and outcomes and highlight the need for a standardized approach. Development of practice guidelines incorporating clinical, radiographic, and laboratory parameters may improve diagnostic accuracy and guide timely, evidence-based management of this rare but serious condition.

Background & Aims: Per- and polyfluoroalkyl substances (PFAS) are persistent endocrine-disrupting chemicals associated with metabolic dysfunction, including metabolic dysfunction-associated steatotic liver disease (MASLD). While PFAS perturb lipid and bile acid (BA) metabolism in a sex-specific manner, the underlying mechanisms remain unclear. We tested whether steroid hormones mediate PFAS-associated metabolic alterations. Methods: In 104 patients with biopsy-characterized MASLD, we performed sex-stratified analyses applied liquid chromatography coupled to mass spectrometry (LC-MS) for chemical analysis, integrating circulating steroids, PFAS exposure, hepatic lipidomics and BA profiles. Results: Steroid hormones were associated with MASLD severity in a sexually-dimorphic manner. Dihydrotestosterone showed consistent inverse associations with steatosis, fibrosis, necroinflammation and insulin resistance, particularly in females. PFAS exposure was associated with altered steroid profiles, predominantly indicating suppressed steroidogenesis in females. These PFAS-associated hormonal changes were linked to downstream alterations in hepatic lipids and BAs. Mediation analysis supported indirect effects of PFAS on metabolic pathways via steroids, including testosterone/epi-testosterone-mediated effects on ether phospholipids and estradiol-mediated effects on lithocholic acid. Females exhibited stronger PFAS-steroid-BA associations, whereas males showed weaker, lipid-centric effects. Conclusions: PFAS exposure is associated with sex-specific disruption of steroid hormone pathways that may link environmental exposure to lipid and BA dysregulation in MASLD. These findings identify steroid hormones as potential key mediators of PFAS-associated metabolic dysfunction and highlight sex as a critical determinant in environmental liver disease.

Hypermobile Ehlers-Danlos Syndrome (hEDS) is a genetic connective tissue disorder characterized by hypermobile joints, chronic pain, fatigue, brain fog, orthostatic intolerance, and GI symptoms and dysmotility. Its heterogeneous presentation contributes to poor quality of life, inappropriate interventions, and prolonged diagnostic delays, often up to 10 years. This study primarily aimed to determine if physiological signals captured by a medical-grade wrist wearable could characterize autonomic patterns in hEDS and relate them to symptoms. Individuals with hEDS (n=30) and healthy controls (n=28) wore a medical grade smartwatch for 30 days, collecting continuous heart rate variability, activity, oxygen saturation, and blood pressure, alongside initial baseline symptom and quality-of-life surveys. Individuals with hEDS showed greater instability and variability in both systolic and diastolic blood pressure as well as the HRV metric LF/HF ratio, in comparison to healthy controls (p-values: 0.04, 0.02, 0.02). During sleep, metrics of parasympathetic activity (HRV measures: HF power, pNN50, RMSSD) trended lower in hEDS than healthy in comparison. As expected, survey domains assessing physiologic symptoms and quality-of-life were significantly worse in the hEDS cohort (p-values < 0.05). Notably, autonomic metrics correlated with GI symptoms in the hEDS cohort (Spearman's {rho} range: 0.38-0.60), and psychological symptoms in the healthy cohort (Spearman's {rho} range: -0.47-0.41). Principal component analysis (PCA) of physiologic and symptom features clearly separated groups, supporting distinct physiologic profiles. Combination of GI symptom index and wearable monitoring show promise as a hybrid screening approach that could substantially shorten the time to diagnosis in this population.

Background and Aims: Alterations in immunoglobulin G (IgG) N-glycosylation are implicated in inflammatory bowel disease (IBD); however, the robustness of IgG glycan signatures across IBD cohorts with diverse demographics and geographic origins remains underexplored. We aimed to determine whether compositional data analysis (CoDA) and machine learning (ML) can identify IBD-related IgG N-glycan signatures and whether these signatures capture disease-associated acceleration of biological aging. Methods: We analyzed the IgG glycome profiles of 1,367 plasma samples collected from healthy controls (HC), symptomatic controls (SC), and people with newly diagnosed Crohn's (CD), and ulcerative colitis (UC) across four cohorts (UK, Italy, United States, and Netherlands). IgG glycosylation was analyzed by ultra-high-performance liquid chromatography, yielding 24 total-area-normalized glycan peaks (GPs). Analyses were performed using cross-sectional data obtained at baseline. CoDA-powered association analyses were used to identify disease-related effects on GPs while controlling for demographic covariates. ML models were trained and evaluated to assess generalizability to unseen cohorts and demographic subgroups, with a focus on discrimination and reliability. Results: Across all cohorts, people with IBD demonstrated accelerated biological aging as quantified by the GlycanAge index. This was accompanied by consistent reductions in IgG galactosylation, with effects partially modulated by age. Classification models trained on glycomics and demographics achieved robust discrimination (AUROC~0.80) between non-IBD (HC+SC) and IBD across cohorts. Conclusion: These findings reveal accelerated biological aging in people with IBD and support the translational potential of IgG glycans as biomarkers and a novel route toward clinically interpretable personalized risk estimates.

BackgroundDespite extensive characterization of key oncogenic drivers, pancreatic ductal adenocarcinoma (PDAC) continues to exhibit profound molecular heterogeneity and inconsistent responses to standard therapies, including gemcitabine. The role of pathway-level alterations, particularly in the context of age at onset and therapeutic exposure, remains insufficiently defined. MethodsIn this study, we leveraged a conversational artificial intelligence framework (AI-HOPE-TP53 and AI-HOPE-PI3K) to enable precision oncology, driven interrogation of clinical and genomic data from 184 PDAC tumors, stratified by age at diagnosis and gemcitabine exposure. Using AI-enabled cohort construction and pathway-centric analyses, we evaluated alterations in TP53 and PI3K signaling networks, with findings validated through conventional statistical methods. ResultsTP53 pathway analysis revealed a significantly higher frequency of TP53 mutations in early-onset compared to late-onset PDAC among gemcitabine-treated patients (86.7% vs. 57.1%, p = 0.04), with a similar trend observed between treated and untreated early-onset cases (86.7% vs. 40%, p = 0.07). Notably, in late-onset PDAC patients not treated with gemcitabine, absence of TP53 pathway alterations was associated with improved overall survival (p = 0.011). Complementary analyses of the PI3K pathway demonstrated a higher prevalence of pathway alterations in late-onset gemcitabine-treated tumors compared to untreated counterparts (13.2% vs. 2.7%, p = 0.02). Importantly, among late-onset patients not receiving gemcitabine, those without PI3K pathway alterations exhibited significantly improved overall survival (p < 0.0001). ConclusionTogether, these findings identify distinct TP53 and PI3K pathway dependencies that are modulated by both age-of-onset and treatment exposure in PDAC. This work highlights the utility of conversational artificial intelligence in enabling rapid, integrative, and hypothesis-generating analyses within a precision oncology framework, supporting the identification of clinically relevant molecular stratification strategies for this aggressive disease.

Background: Lateral lymph node metastasis (LLNM) is associated with poor prognosis in patients with rectal cancer and may influence the indication for lateral lymph node dissection. Accurate preoperative identification of LLNM remains challenging. This study aimed to develop and internally validate a clinicoradiological model for preoperative prediction of LLNM in rectal cancer. Methods A retrospective cohort of 64 patients undergoing lateral lymph node dissection (LLND) for rectal cancer was analysed; 21 (32.8%) had pathological lateral lymph node metastasis (LLNM). A prespecified preoperative clinicoradiological model was fitted using penalised logistic regression with L2 regularisation (ridge), incorporating MRI-measured lateral lymph node short-axis diameter (LLN-SAD), dichotomised clinical T stage (T3-4 vs T1-2), dichotomised clinical N stage (N+ vs N0), and log(CA19-9+1). Model performance was evaluated using the area under the receiver operating characteristic curve (AUC), calibration analysis, and bootstrap internal validation. Results The model showed good discrimination (AUC 0.914), with an optimism-corrected AUC of 0.887 on bootstrap validation. Calibration remained acceptable after optimism correction (calibration intercept -0.127; slope 1.045). Decision curve analysis suggested net benefit across clinically relevant threshold probabilities, particularly between 0.10 and 0.30. The model was implemented as a web-based calculator to facilitate clinical use. Conclusion This clinicoradiological model showed good discrimination, acceptable calibration, and potential clinical utility for preoperative assessment of LLNM risk in rectal cancer. It may assist individualized risk stratification and treatment planning, although external validation is required before routine clinical implementation.

Background: Long COVID presents with one or multiple symptoms or diagnosable conditions after SARS-CoV-2 infection. To study whether use of the antiviral remdesivir in persons hospitalized with acute COVID-19 is associated with reduced Long COVID, we created a computational phenotype for Long COVID. Methods: In electronic health records (EHR) from a multistate healthcare system (US), hospital admissions from 5/1/20 - 9/30/22 were reviewed. The study group was hospitalized with acute COVID-19 and the control group was hospitalized for other reasons without prior SARS-CoV-2 infection. The populations were balanced with overlap weights based on a high-dimensional propensity score of pre-specified variables and the top 100 comorbidities differing between the groups. Hazard ratios (HR) were calculated for the combined primary outcome: U09.9 (Post-Covid Conditions) or any incident secondary outcome from 90 to 365 days after admission. Secondary outcomes included 27 individual incident diagnoses, corrected for multiplicity with Holm-Bonferroni. Results: Admissions included 45,540 with, and 409,186 without COVID-19 during the study period, evaluable for the primary outcome. After weighting, standardized difference was < 0.01 for all measured confounders including demographic and clinical features. In the COVID+ and non-COVID groups 38.0% and 29.3% met the combined primary outcome, respectively. Weighted HR (95%CI) for the primary outcome was 1.37 (1.35, 1.40), p < 0.0001. All secondary outcomes were associated with the COVID+ group, when adjusted for multiplicity. Incident diagnoses with strong associations (HR > 2) included thromboembolism, hair loss, diabetes mellitus, obesity, and hypoxia. Anosmia/dysgeusia was associated with COVID, but wide confidence intervals reflected few charted diagnoses. Conclusions: Manifestations of Long COVID at population scale are detectable as part of routine symptoms and clinical diagnoses in the EHR after admissions for COVID-19, compared with all other hospital admissions. This a prior computational phenotype for Long COVID will be used to assess whether remdesivir use is associated with decreased Long COVID.

Background: Creatine monohydrate (typically 5 to 20 g/day) has a well-established safety profile across diverse populations. Creatine hydrochloride (CR-HCl) is a highly soluble creatine formulation that may allow effective supplementation at substantially lower doses (750 mg to 3 g/day); however, controlled human safety data specific to CRHCl remain limited. Objective: To evaluate the short-term laboratory safety and tolerability of low dose CRHCl supplementation administered for 28 days in healthy adults. Methods: This single center, single arm, singl blind pilot safety study enrolled 11 healthy adults (10 females, 1 male; mean age 44.6 plus/minus 7.2 years). Participants consumed 750 mg/day CRHCl for 28 consecutive days while maintaining their usual diet and physical activity patterns. Fasting blood and urine samples were collected at baseline and Day 28. Laboratory assessments included hematological, lipid, and clinical chemistry biomarkers. Pre and post changes were evaluated using paired parametric and nonparametric tests, baseline-adjusted regression models, bootstrap confidence intervals, and false discovery rate (FDR) correction. Results: All participants completed the intervention. No clinically meaningful changes were observed in lipid parameters, hematologic indices, renal markers, or most chemistry analytes after adjustment for multiple comparisons. Fasting glucose increased modestly (8.1 mg/dL) prior to multiplicity adjustment but was not statistically significant after FDR correction and remained within reference ranges. Serum bicarbonate decreased slightly (2.4 mmol/L); although statistically detectable in parametric analysis, values remained within physiological limits and were not consistently supported by nonparametric testing.

ObjectiveTo establish a fetal lamb model of complex gastroschisis and characterize the impact on the intestines over time. Summary Background DataGastroschisis is a congenital abdominal wall defect and in its complex form is associated with serious morbidity. Robust large-animal models may help understanding are lacking. MethodsAt gestational day 75, gastroschisis was induced by creating a 1-cm abdominal wall defect reinforced by a silicone ring. Fetuses were assessed either at term or at mid-gestation (13-21 days post-induction). The primary outcome was complex gastroschisis occurrence, defined by bowel stenosis, atresia, volvulus, perforation or necrosis; otherwise classified as simple. At mid-gestation, occurrence was compared between early (13-16 days) and late (17-21 days) intervals. Secondary outcomes included prenatal ultrasound findings, in vivo bowel motility and morphology, ex-vivo bowel contractility, amniotic fluid composition, and histology across complex, simple, and normal groups. ResultsGastroschisis was induced in 32 fetuses. At term (n=14), all survivors (7/14; 50%) had complex gastroschisis, with impaired bowel motility, altered enteric neural contractile responses and smooth muscle remodeling. At mid-gestation (n=18), complex gastroschisis occurred more frequently in the late than in the early group (71% vs. 11%; p=0.035). Mid-gestation gastroschisis fetuses showed greater intra-abdominal bowel dilatation on ultrasound and higher amniotic fluid digestive enzyme levels compared with non-operated littermates, with the greatest dilation observed in complex gastroschisis. ConclusionsThis model consistently reproduces complex gastroschisis in term survivors. After induction, complex gastroschisis occurrence increases with disease duration and is accompanied by structural and functional bowel changes.

Irritable Bowel Syndrome (IBS) affects a substantial proportion of university students, yet its factors remain incompletely characterised in South Asian populations. We reanalysed a publicly available dataset of 550 Bangladeshi students from Hasan et al. (2025), conducting a data audit that identified implausible records, including males reporting menstrual symptoms, and reduced the analytic sample to 506 observations. Using Explainable Boosting Machines (EBMs), which capture non-linear effects and pairwise interactions without sacrificing interpretability, we found that psychological distress, elevated BMI and academic dissatisfaction were the strongest predictors of IBS (mean AUC = 0.852 across 100 stratified train-test splits). Critically, several findings diverged from the original logistic regression analysis. Physical activity showed a non-linear risk pattern only at high intensity, the association with gender was substantially weaker when we accounted for metabolic and psychological factors as well and malnourishment does not have a strong an impact as in the original study. These divergences likely arise because the machine-learning model captures non-linear effects and interactions that were not represented in the original regression specification. Our findings underscore the value of reanalysing existing datasets with methods suited to capturing complexity and highlight data quality verification as a necessary step in the secondary analysis.

BackgroundThis study aims to examine the independent relationships between individual components of metabolic syndrome (MetS) and two key clinical outcomes in patients with Crohns disease (CD): disease activity, as quantified by the Crohns Disease Activity Index (CDAI), and the occurrence of complications. MethodsThis retrospective cross-sectional study included 376 adults with newly diagnosed Crohns disease. Multiple linear regression was used to examine associations between metabolic parameters and CDAI scores, while multivariate logistic regression assessed links to complications. Analyses were also based on clinical CDAI cut-offs. Predictive nomograms were developed and internally validated via bootstrap resampling. ResultsMultiple linear regression indicated that higher CDAI scores were independently associated with lower BMI (B = -5.866, P < 0.001), lower HDL-C levels (B = -81.770, P < 0.001), higher triglycerides (B = 15.618, P = 0.001), and lower ESR (B = -0.375, P = 0.03). Multivariate logistic regression established low HDL-C (OR = 0.042, P < 0.001), low BMI (OR = 0.915, P = 0.034), and high triglycerides (OR = 1.792, P = 0.007) as significant independent risk factors for complications. The developed nomograms demonstrated strong predictive performance, with an adjusted R2 of 0.207 for the CDAI model and an AUC of 0.765 for the complication model. For both predictive tasks, the model incorporating separate TG and HDL-C measurements significantly outperformed the TG/HDL-C ratio model. ConclusionMetabolic disturbances demonstrate a significant association with increased disease severity and a higher risk of complication development in Crohns disease. Core tipO_LIDual-outcome study reveals HDL-C and TG differentially link to CD inflammation and complications, pointing to distinct mechanisms. C_LIO_LILow HDL-C is the strongest independent predictor for CD complications, underscoring its protective role beyond cholesterol transport. C_LIO_LIIndividual TG and HDL-C metrics outperform their ratio in prediction, challenging its use and suggesting independent pathways in CD. C_LIO_LILow BMI independently associates with both adverse outcomes, refining the "obesity paradox" and highlighting malnutritions key role. C_LIO_LIA practical, validated nomogram (AUC=0.765) integrates HDL-C, TG, and BMI to stratify complication risk, aiding clinical decision-making. C_LI

BackgroundLynch syndrome (LS) is a cancer susceptibility syndrome caused by germline pathogenic variants in DNA mismatch repair (MMR) genes. Due to increased risk of colorectal cancer (CRC), enhanced colonoscopic surveillance is recommended for heterozygote MMR-carriers. ObjectiveUsing a registry of English LS patients linked to digital National Health Service records, we aimed to assess adherence of MMR-carriers to national surveillance guidelines, and to determine the impact of surveillance on CRC incidence and mortality. DesignWe described the frequency of colonoscopies in 4,732 MMR-carriers and used logistic regression to determine predictors of surveillance adherence. For MMR-carriers with a record of surveillance and those without, we: estimated age-specific annual CRC incidence rates (AS-AIRs) and cumulative lifetime risks, assessed for stage-shift by comparing CRC stage distributions and stage-specific AS-AIRs, and estimated risks of death from CRC and any cause using Kaplan-Meier methods and Cox Proportional Hazards regression. ResultsSurveillance at a mean interval of [&le;] 3 years (n=3028) was associated with a decrease in CRC-specific and all-cause mortality, without an associated change in total CRC incidence, even after multivariate adjustment. No strong evidence of stage-shift was observed. Colonoscopic surveillance at a mean interval of [&le;] 2 years (n=1569) was associated with an increase in total CRC incidence. Incidence of early-stage cancers was also higher, with no corresponding decrease in late-stage cancers, which may reflect the short follow-up period or the impact of overdiagnosis. ConclusionThe observed reduction in all-cause mortality amongst regularly-surveilled MMR-carriers may indicate an impact of surveillance on CRC-specific mortality, though in the context of a non-randomised study likely reflects the influence of selection bias. KEY MESSAGES OF ARTICLEO_ST_ABSWhat is already known on this topicC_ST_ABSRegular surveillance colonoscopy is recommended in Lynch syndrome, though evidence to support this remains mixed. We searched PubMed for articles published from inception to 01/05/2024 using the terms "Lynch syndrome", "HNPCC", "colonoscopy", "sigmoidoscopy", "surveillance", and "screening". We found one controlled trial and several small analytical studies dating from the early 2000s which compared surveilled and non-surveilled populations and found surveillance to be associated with reduced colorectal cancer (CRC) incidence and improved survival. More recent longitudinal observational studies, most without comparator groups, found a high incidence of CRC in LS populations despite being resident in countries where surveillance was recommended. A small number of studies directly assessed time since last colonoscopy against CRC incidence and stage with mixed findings. Finally, cross-sectional comparisons between countries of CRC incidence rates and surveillance interval recommendations found no relationship between the two1,2. What this study addsHere, we conduct an observational cohort study on a large national cohort of MMR germline pathogenic variant (GPV) carriers (MMR-carriers) in England (n=4,732), comparing CRC incidence and mortality in individuals with a record of regular surveillance to those without. Through linkage of the English National Lynch Syndrome Registry to Hospital Episodes Statistics data, we are uniquely able to study a comprehensive national population of MMR-carriers and identify the dates on which colonoscopies were undertaken over time, allowing assessment of adherence to national surveillance guidelines and the impact this has on CRC outcomes. Notably, receipt of regular colonoscopy was strongly associated with deprivation as well as ethnicity. The results show that regular surveillance at an average interval of 3 years (or less) is not associated with a reduction in CRC incidence when compared to less frequent surveillance, but an apparent decrease in both CRC-specific and overall mortality is observed, even after adjustment for confounding variables. Conversely, regular surveillance at an average interval of 2 years (or less) is associated with an increase in CRC incidence when compared to less frequent surveillance, which may suggest increased diagnosis of early-stage cancers or, due to the absence of a reduction in late-stage cancers, overdiagnosis. The observed impact of surveillance on overall mortality may demonstrate the impact of surveillance on CRC-specific mortality, or, in the context of an observational (non-randomised) study, indicate that the results are subject to selection bias. How this study might affect research, practice, or policyEvidence for the benefit of surveillance colonoscopy remains mixed. Whilst polypectomy would be anticipated to prevent CRC development (thus reducing CRC incidence), several studies have observed increased frequency of CRCs in MMR-carriers undergoing frequent surveillance colonoscopy, which may reflect overdiagnosis. The selection bias inherent to observational studies of surveillance renders mortality outcomes challenging to interpret. Randomised controlled trials of colonoscopic surveillance in MMR-carriers are required for effectiveness of this intervention to be accurately assessed. Given ethical and feasibility challenges, randomised controlled trials might be complemented by quasi-experimental designs using advanced observational methods for assessing effectiveness.

BackgroundGastroesophageal reflux disease (GERD) is highly prevalent in systemic sclerosis (SSc) and frequently persists despite proton pump inhibitor (PPI) therapy. However, the mechanisms underlying PPI-refractory GERD in SSc remain incompletely understood. MethodsWe conducted a singlel7lcentre, retrospective study of adults with SSc who underwent ambulatory pH-multichannel intraluminal impedance (pH/MII) monitoring while receiving twicel7ldaily PPI therapy (2021-2025). Esophageal motility (highl7lresolution manometry, HREM) and gastric emptying scintigraphy were integrated to examine associations between gastro-esophageal dysmotility and reflux phenotypes. ResultsThirty patients were included, of whom 67% had PPI-refractory reflux symptoms and 33% were undergoing pre-lung transplantation evaluation. Refractory GERD was present in 29/30 patients (97%) based on Lyon 2.0 classification, with conclusive evidence in 53% and borderline evidence in 43%. Esophageal dysmotility was identified in 80%, most commonly absent contractility (67%), and was associated with impaired reflux clearance, reflected by longer acid clearance times (2.20 [1.15-3.75] vs 1.15 [0.43-1.90] min) and prolonged reflux episode duration (16.60 [4.38-40.63] vs 1.95 [0.53-20.43] min). Gastric dysmotility was identified in 60.7% and was associated with an increased reflux episode burden (51.00 [30.00-81.50] vs 25.00 [21.00-54.00] episodes/24h). ConclusionsPPIl7lrefractory GERD is nearly universal in this SSc cohort and reflects heterogeneous, quantifiable abnormalities across the foregut, including impaired esophageal clearance and increased reflux burden related to gastric retention. These findings support integrated physiologic evaluation to define reflux mechanisms, inform risk stratification (including lung transplantation), and guide targeted, mechanism-based therapies beyond acid suppression.

Purpose: Aicardi-Goutieres syndrome (AGS) is a type I interferonopathy presently associated with nine genes. PTPN1 is a negative regulator of the interferon pathway previously associated with chronic inflammation and recently type 1 IFN autoinflammation. Methods: Genomic data from undiagnosed individuals with suspected AGS were interrogated for PTPN1 variants, and predicted loss-of-function (pLOF) and damaging missense variants in PTPN1 were sought in two additional academic databases as well as the All of Us database. Results: We identified 13 cases with ultra-rare heterozygous pLOF or highly damaging missense variants in PTPN1. Nine cases were identified in a cohort of 53 individuals (~ 17%) with clinical, imaging and persistent biochemical features of AGS. Median age of onset is 1.75 years (IQR 0.67), significantly later (p< 0.0001) than other AGS genotypes. Four additional cases were identified in academic datasets with variable clinical features suggestive of autoinflammation. Additionally, 49 individuals with ultra-rare, damaging PTPN1 variants were identified in the All of Us database, none had features suggestive of AGS, but autoimmunity was highly prevalent (~21.6%). Conclusion: Our data implicate PTPN1 as a cause of later-onset presentations of AGS within a broader spectrum of autoinflammatory phenotypes. Segregation and biobank data demonstrate reduced penetrance, with carriers being enriched for autoimmune disorders.

Colorectal cancer (CRC) is a leading cause of cancer-related death, with incidence rising substantially among individuals under 50 years of age. Polygenic risk scores (PRS) hold promise for identifying high-risk individuals; when combined with lifestyle factors, they substantially improve prediction accuracy compared with models based on lifestyle factors alone. However, few clinical tools currently exist that facilitate this integrated, PRS-enhanced risk assessment. To bridge this gap, we developed MyGeneRisk Colon, a publicly accessible web portal that delivers individualized CRC risk prediction by incorporating genetic, demographic, family history, and lifestyle factors. This paper details the development of the underlying risk prediction model, the portal's architecture and data security, our reporting framework, and engagement with a community advisory panel. Designed as a user-friendly platform, MyGeneRisk Colon aims to effectively communicate personalized CRC risk profiles and educate users and healthcare providers about prevention strategies.

Patients with myasthenia gravis (MG) may produce autoantibodies neutralizing type I interferons (AAN-I-IFN), which have been shown to underlie severe viral diseases, including critical COVID-19 pneumonia, in patients without MG. We studied an international cohort of 85 unvaccinated SARS-CoV-2-infected MG patients with no antiviral treatment. Hypoxemic pneumonia occurred in 48 of these patients, including 22 (45.8%) with AAN-I-IFN, which neutralized both IFN-2 and IFN-{omega} in 14 (29.2%) patients. Six (16.2%) of the remaining 37 patients had AAN-I-IFN, which neutralized both IFN-2 and IFN-{omega} in three patients. The risk of hypoxemic pneumonia was greater in MG patients with AAN-I-IFN neutralizing 10 ng/mL of both IFN-2 and IFN-{omega} (odds ratio and 95% confidence interval (OR [95% CI]): 12.7 [2.1-78.9], p=0. 0010) or IFN-2 at any dose (4.7 [1.5-15.0], p=0.0054) than in those without such autoantibodies. The risk of AAN-I-IFN production was much higher in MG patients than in the general population (28.9 [10.8-77.7], p=4.9x10-27). Fourteen patients had thymoma, which increased the risk of AAN-I-IFN (64% versus 27%, (OR [95% CI]: 5.6 [1.6-19.4], p=0.0050) and hypoxemic pneumonia (9.2 [1.9-44.2]; p=0.0019). Thymoma is, thus, associated with a higher risk of producing AAN-I-IFN, and these autoantibodies are associated with a higher risk of developing life-threatening COVID-19 pneumonia in patients with MG.

ObjectiveLevetiracetam is commonly prescribed for seizure prophylaxis after acute ischemic stroke (AIS) and often continued beyond discharge. While its short-term effectiveness for preventing post-stroke seizures is established, it is unclear whether prolonged use improves survival, particularly in older adults. We estimated the effect of continued levetiracetam use on 90-day mortality among Medicare beneficiaries after AIS. MethodsUsing Traditional Medicare claims data (2008-2021), we identified beneficiaries aged [&ge;]66 years hospitalized for AIS who initiated outpatient levetiracetam within 90 days of discharge. After one month of continued post-stroke use of levetiracetam (start of follow-up), we compared 90-day mortality between patients with a new levetiracetam dispensation within a 14-day grace period post-follow up and those without one. We performed cloning, censoring and weighting to address immortal time bias and estimated standardized mortality risks, risk differences, and 95% confidence intervals (CI). ResultsAmong 3,212 eligible beneficiaries, 1,779 (55.4%) received a new levetiracetam dispensation within the 14-day grace period. Median age was 76 years (IQR 70-83); 57.8% were female. After adjustment for demographics, hospitalization characteristics, timing of initiation, and comorbidities, continued use was associated with lower 90-day mortality than discontinuation (53 vs 62 deaths per 1,000; risk difference -9 per 1,000; 95% CI: (-12,-5)). The reduction was observed primarily among patients aged [&ge;]75 years. SignificanceAmong older Medicare beneficiaries who initiated levetiracetam after AIS, continued outpatient use was associated with modestly lower 90-day mortality, particularly in those aged [&ge;]75 years. These findings suggest potential benefits of levetiracetam continuation beyond the immediate post-stroke period.

Objectives. To compare the efficacy and safety of invasive sacral neuromodulation (SNM) and noninvasive enteral neuromodulation (ENM) in children with refractory gastrointestinal motility disorders (GMD). Materials and Methods. This prospective interventional trial enrolled pediatric patients with GMD between 2019 and 2024 at a single tertiary referral center. Children with inflammatory bowel disease or mechanical causes of GMD were excluded. Participants received either SNM via an implanted device or ENM via surface electrodes. Stimulation was delivered at 14 Hz, 210 s pulse width, with individualized intensity (median 1.0 mA for SNM; 6.0 mA for ENM). Primary outcomes were abdominal pain, fecal incontinence, defecation frequency, and stool consistency. Treatment success was defined as clinically significant improvement in at least two of these four domains. Quality of life was assessed at baseline and 12 weeks. Safety outcomes were monitored over a 12-month follow-up. Results. Of 70 eligible patients, 48 completed the study (18 SNM; 30 ENM). Diagnoses included Hirschsprung disease, functional constipation, and congenital neuronal malformations. Severe comorbidities were more frequent in the SNM group (45%) than the ENM group (3%; P = .0018). Treatment success was observed in 80% of ENM and 83% of SNM patients (P = 1.00). No significant differences were found between groups for individual outcomes. No major complications occurred. Minor adverse events were comparable (ENM 27% vs SNM 17%; P = .50). Conclusions. Both SNM and ENM are effective and safe options for treating pediatric GMD and may be considered within a multimodal therapeutic approach.

Gastrointestinal (GI) dysmotility is a highly prevalent and clinically significant feature of Rett syndrome (RTT), yet its underlying mechanisms remain poorly defined. Here, we investigated these mechanisms of GI dysmotility in a Mecp2-null mouse model of RTT. First, we observed that MeCP2 was expressed in murine myenteric ganglia, including in enteric neurons and that Mecp2-null males developed maturation-associated functional regression in their GI motility. In dysmotile mice, longitudinal muscle-myenteric plexus tissue showed marked reductions in enteric Bdnf isoforms IV, VI, and II, whereas expression of the BDNF receptor isoforms TrkB.FL and TrkB.T1 was not significantly altered, consistent with reduced enteric BDNF-TrkB signaling. Despite impaired GI motility, Mecp2-null mice showed no significant changes in total enteric neuronal density, nitrergic neuronal abundance, or expression of Nos1, Chat, and Uchl1. In contrast, Vip expression was significantly reduced, while expression of VIP receptor genes: Vipr1 and Vipr2 was increased, indicating disrupted VIPergic signaling. Integration with publicly available enteric single-cell/nucleus datasets and targeted qRT-PCR further suggested altered inhibitory neuronal subtype composition, with reduced Vip+ Cartpt+ signatures and increased Nfia expression, suggesting that MeCP2 loss differentially affects distinct inhibitory neuronal subpopulations. Finally, conditional loss of TrkB.FL in neural crest-derived cells reduced Vip expression without recapitulating the full Mecp2-null VIPergic phenotype, indicating that impaired BDNF-TrkB signaling contributes to, but does not completely explain, the GI dysmotility in this model of RTT. Together, these findings identify enteric BDNF-TrkB and VIPergic dysfunction as key mechanisms underlying GI dysmotility in RTT.