Innate lymphoid cells (ILCs) are a group of innate immune cells that have garnered considerable attention due to their critical roles in regulating immunity and tissue homeostasis. They are particularly abundant in the gastrointestinal tract, where they have been shown to interact with commensal bacteria, pathogens, and other components of the local microenvironment to influence host immune responses to infection and oncogenesis. Their tissue-residency properties enable gastric ILCs a localized and rapid response to alert and stress, which indicates their key potential in regulating immunosurveillance. In this review, we discuss the current understanding of the role of ILCs in the gastric mucosa, with a focus on their interactions with the gastric microbiota and Helicobacter pylori and their contributions to tissue homeostasis and inflammation. We also highlight recent findings on the involvement of ILCs in the pathogenesis of gastric cancer and the implications of targeting ILCs as a therapeutic approach. Overall, this review provides an overview of the diverse functions of ILCs in gastric mucosa and highlights their potential as targets for future therapies for gastric cancer.

Background Aerosol-generating procedures such as oesophagogastroduodenoscopy (OGD) result in infectious particles being exhaled by patients. This substantially increases the medical staff’s risk of occupational exposure to pathogenic particles via airway inhalation and facial mucosal deposition. Infectious particles are regarded as a key route of transmission of SARS-CoV-2 and, thus, represents a major risk factor for medical staff during the ongoing COVID-19 pandemic. There is a need for quantitative evidence on medical staff’s risk of multiroute exposure to infectious particles exhaled by patients during OGD to enable the development of practical, feasible and economical methods of risk-reduction for use in OGD and related procedures. This randomised controlled trial (RCT)—Personal protective EquiPment intervention TrIal for oesophagogastroDuodEnoscopy (PEPTIDE)—aims to establish a state-of-the-art protocol for quantifying the multiroute exposure of medical staff to infectious particles exhaled by patients during real OGD procedures. Method and analysis PEPTIDE will be a prospective, two-arm, RCT using quantitative methods and will be conducted at a tertiary hospital in China. It will enrol 130 participants (65 per group) aged over 18. The intervention will be an anthropomorphic model with realistic respiratory-related morphology and respiratory function that simulates a medical staff member. This model will be used either without or with a surgical mask, depending on the group allocation of a participant, and will be placed beside the participants as they undergo an OGD procedure. The primary outcome will be the anthropomorphic model’s airway dosage of the participants’ exhaled infectious particles with or without a surgical mask, and the secondary outcome will be the anthropomorphic model’s non-surgical mask-covered facial mucosa dosage of the participants’ exhaled infectious particles. Analyses will be performed in accordance with the type of data collected (categorical or quantitative data) using SPSS (V.26.0) and RStudio (V.1.3.959). Ethics and dissemination Ethical approval for this RCT was obtained from the Ethics Committee of Peking Union Medical College Hospital (ZS-3377). All of the potential participants who agree to participate will provide their written informed consent before they are enrolled. The results will be disseminated through presentations at national and international conferences and publications in peer-reviewed journals. Trial registration number NCT05321056.

Background/Objectives: Duodenal lymphomas (DLs) are a rare subset of gastrointestinal lymphomas with incompletely characterized clinicopathological features due to low incidence and diagnostic challenges. This study assessed DL survival outcomes, characterized clinical/endoscopic features, and identified prognostic factors. Methods: This was a retrospective observational study of patients undergoing endoscopic examinations between 1 November 2002 and 1 November 2022 at Peking Union Medical College Hospital, with a subsequent histopathological diagnosis of DL. The primary outcome was overall survival (OS), and Cox proportional hazards modeling was used for survival analyses. Results: Sixteen patients (32%) had indolent B-cell lymphoma, 20 (40%) had aggressive B-cell lymphoma, and 14 (28%) had T-cell lymphoma. Diarrhea and weight loss were more common in patients with T-cell lymphoma. The most common endoscopic appearance was mucosal granularity, and 40% of patients had mass lesions. The median OS was 24.1 (95% CI: 13.3–117) months, with 1- and 5-year survival rates of 68.0% (95% CI: 56.2–82.2%) and 33.8% (95% CI: 22.3–51.44%), respectively. In multivariable analysis, a granular appearance (HR: 0.33, 95% CI: 0.11–0.99, and p = 0.049) and taking chemotherapy (HR: 0.22, 95% CI: 0.07–0.69, and p = 0.01) were associated with better OS, while T-cell lymphoma (HR: 9.19, 95% CI: 2.12–32.83, and p = 0.003) and stage IV lymphoma (HR: 12.76, 95% CI: 1.70–95.66, and p = 0.013) were associated with worse OS. Conclusions: This first integrated study provides new information on the clinical, endoscopic, and prognostic features of DL. While no specific clinical or endoscopic feature is diagnostic of DL, DL must remain in the differential diagnosis of any patient presenting with nonspecific gastrointestinal symptoms.