Patterns of Gastric Injury: Beyond Helicobacter Pylori. Surg Pathol Clin. 2017;10:801-822. [PMID: 29103534 DOI: 10.1016/j.path.2017.07.003]

Clinical Characteristics and Outcomes of Pembrolizumab Induced Gastritis: A Systematic Review of the Literature

BACKGROUND

Pembrolizumab is associated with the development of gastritis, but its clinical features have not been characterized. To explore the clinical features of pembrolizumab induced gastritis and provide reference for the prevention and treatment of gastritis.

METHODS

Case reports and case series related to pembrolizumab induced gastritis were retrospectively analyzed by searching the database from inception to September 30, 2023.

RESULTS

Thirty-nine patients with gastritis entered the study with a median age of 63 years (range 34, 81). The median time to gastritis was 11.1 months (range 0.3, 60) and 7 cycles (range 1, 27) after administration. Epigastric pain (24 cases, 61.5%), nausea (17 cases, 43.6%), and vomiting (16 cases, 41.0%) were the most frequently complained symptoms. Esophagogastroduodenoscopy mainly showed erythematous (16 cases, 41.0%), hemorrhage (14 cases, 35.9%) and erosions (11 cases, 28.2%). Gastric mucosal biopsy shows chronic active gastritis with lymphocytic infiltration. These patients' symptoms and gastric mucosa improved or recovered after receiving systemic steroid and proton pump inhibitor therapy regardless of whether pembrolizumab was discontinued. These patients' symptoms and gastric mucosa improved or recovered after treatment with systemic steroids, proton pump inhibitors, and biological agents.

CONCLUSIONS

Gastritis is an extremely rare adverse effect of pembrolizumab. When patients receiving pembrolizumab complain of abdominal symptoms, endoscopy, tissue biopsy, and immunohistochemical staining should be actively performed for early identification and diagnosis of gastritis.

Pathologie infectieuse du tube digestif : diagnostics à ne pas manquer

Le contexte récent du COVID-19 a renouvelé l’intérêt des pathologistes pour les maladies d’origine infectieuse. Cet intérêt est d’autant plus fort dans le tube digestif où les symptômes sont aspécifiques, souvent frustres avec un aspect endoscopique normal entraînant parfois une errance diagnostique. Dans ce contexte, les biopsies systématiques réalisées par le clinicien sont parfois le seul moyen de parvenir au diagnostic. Néanmoins, le diagnostic précis de ses pathologies nécessite une bonne connaissance à la fois du contexte de survenue de ces pathologies, de l’aspect histopathologique et d’une analyse rigoureuse utilisant des colorations spéciales et/ou des analyses immunohistochimiques. Certaines pathologies infectieuses du tube digestif sont bien connues par les pathologistes qui sont largement sollicités dans leurs diagnostics (gastrite à Helicobacter pylori, œsophagite à Candida albicans ou la colite à CMV), mais d’autres sont plus délicates à diagnostiquer. Dans cet article, nous présenterons, après avoir rappelé les différentes colorations spéciales utiles, des pathologies bactériennes ou parasitaires rares ou de diagnostic difficile « à ne pas manquer » dans le tube digestif.

Expression alteration and dysfunction of ion channels/transporters in the parietal cells induces gastric diffused mucosal injury

Gastric mucosal injuries include focal and diffused injuries, which do and do not change the cell differentiation pattern. Parietal cells loss is related to the occurrence of gastric mucosal diffused injury, with two phenotypes of spasmolytic polypeptide-expressing metaplasia and neuroendocrine cell hyperplasia, which is the basis of gastric cancer and gastric neuroendocrine tumor respectively. Multiple ion channels and transporters are located and expressed in the parietal cells, which is not only regulate the gastric acid-base homeostasis, but also regulate the growth and development of parietal cells. Therefore, alteration and dysregulation of ion channels and transporters in the parietal cells impairs the morphology and physiological functions of stomach, resulted in gastric diffused mucosal damage. In this review, multiple ion channels and transporters in parietal cells, including K⁺ channels, aquaporins, Cl^- channels, Na⁺/H⁺ transporters, and Cl^-/HCO₃^- transporters are described, and their roles in gastric diffused mucosal injury are discussed. We hope to drive researcher's attention to focus on the role of ion channels/transporters loss in the parietal cells induced gastric diffused mucosal injury.

Gastritis: The clinico-pathological spectrum

The inflammatory spectrum of gastric diseases includes different clinico-pathological entities, the etiology of which was recently established in the international Kyoto classification. A diagnosis of gastritis combines the information resulting form the gross examination (endoscopy) and histology (microscopy). It is important to consider the anatomical/functional heterogeneity of the gastric mucosa when obtaining representative mucosal biopsy samples. Gastritis includes self-limiting and non-self-limiting (long-standing) inflammatory diseases, and the latter are epidemiologically, biologically and clinically linked to the onset of gastric cancer (i.e. "inflammation-associated cancer"). Different biological models of inflammation-associated gastric oncogenesis have been proposed. Helicobacter pylori (H. pylori) gastritis is the most prevalent worldwide, and H. pylori is classified as a first-class carcinogen. On these bases, eradicating H. pylori is mandatory for the primary prevention of gastric cancer. Non-self-limiting gastritis may also be triggered by the immune-mediated destruction of gastric parietal cells, resulting in autoimmune gastritis. In both H. pylori-related and autoimmune gastritis, the non-self-limiting inflammation results in atrophy of the gastric mucosa, which is the main factor promoting gastric cancer. Long-term follow-up studies consistently demonstrate the prognostic impact of the histological staging of gastritis in gastric cancer secondary prevention strategies.

Clinicopathological Characteristics and Etiological Factors of Granulomatous Gastritis

AIMS

To examine the clinicopathological characteristics of granulomatous gastritis (GG) among different etiologies, particularly Crohn disease (CD), and determine the contribution of H. pylori and the clinical significance of isolated GG.

METHODS/RESULTS

We identified 269 GG cases overall (0.19% prevalence): 220 had an underlying granulomatous disease (CD, sarcoidosis, tuberculosis) and only 8 of these (3.6%) had H. pylori, fewer than the 10.3% rate among non-GG biopsies (p<.001). Conversely, among 49 GG cases without known cause (foreign body, undetermined, idiopathic), 13 (26.5%) had H. pylori, more than background (p=.001). Most patients (n=185/68.8%) had CD and these were more likely male (p<.001), younger (p<.001), white (p<.001), and had single (p=.010), smaller (p=.005), antral (p=.027) granulomas, amid inflammation (p=.005), compared to non-CD GG cases; younger age was independently associated with CD (p=.003; OR=1.13, 95% CI: 1.04-1.22). Among CD patients, younger age (p=.003; OR=1.04, 95% CI: 1.01-1.07) and upper gastrointestinal (GI) symptoms (p=.017; OR=2.53, 95% CI: 1.18-5.43) were associated with new (vs. established) diagnosis, whereas multiple gastric granulomas (p=.003; OR=4.67, 95% CI: 1.67-13.04) and lack of upper GI symptoms (p<.001; OR=6.75, 95% CI: 2.94-15.49) were associated with lower GI granulomas. Of 86 isolated GG cases (i.e., no prior diagnosis or lower GI granulomas), 51 (59.3%) were eventually diagnosed with CD, and this was independently associated with younger age (p=.014; OR=1.11, 95% CI: 1.02-1.21) and upper GI symptoms (p=.033; OR=19.27, 95% CI: 1.27-293.31). The positive predictive value of finding isolated GG towards a CD diagnosis in patients <30 years-old was 91%, increasing in males (93%), with single (94%), antral (97%) granulomas, or upper GI symptoms (94%).

CONCLUSIONS

GG does not correlate with H. pylori in patients with granulomatous disease, but may be associated with the organism when such diagnosis is lacking. In CD patients with GG, younger age and upper GI symptoms are associated with a new CD diagnosis, whereas multiple gastric granulomas and lack of upper GI symptoms correlate with lower GI granulomas. GG, including in isolated cases with no prior clinical history or granuloma, likely signifies CD, particularly in younger, male patients, or those with single, antral granulomas, or upper GI symptoms.

Multiple Gastric Carcinomas Associated with Epstein-Barr Virus and Helicobacter pylori: A Thought-Provoking Case

BACKGROUND Epstein-Barr virus (EBV) and Helicobacter pylori (HP) infections are associated with gastric carcinoma (GC). We present a thought-provoking case of multiple GCs associated with EBV and HP infections. CASE REPORT HP infection was incidentally detected in an asymptomatic 60-year-old man. Upper endoscopy revealed gastric "kissing" ulcers. The lesions were located in the body of the stomach and measured 25 and 27 mm, respectively. They were diagnosed on pathology as moderately differentiated tubular adenocarcinoma. Imaging revealed no enlarged lymph nodes or distant metastatic lesions. Distal gastrectomy with lymphadenectomy was performed and surgical cure was obtained. The multiple GCs were categorized on pathology as infß ly0 v0 pT1b(SM)UL1N0M0H0P0CY0 pStage IA according to the Japanese classification and as T1bN0M0 Stage IA according to the tumor, node, metastasis classification. Pathological examination revealed remarkable lymphocytic infiltration into the stroma, as shown by in situ hybridization of EBV. These lymphocytic infiltrations were observed only at the sites of GC. In the immunohistochemical examination, in situ hybridization of EBV was positive for EBV-encoded small ribonucleic acid. The patient's postoperative course was uneventful. Hence, an unexpected relationship between EBV infection and multiple GCs was suggested by pathology. Quantitative determination of EBV DNA in peripheral blood was normal postoperatively. Adjuvant chemotherapy was not recommended. HP eradication therapy was successful. The patient remained asymptomatic and developed no recurrence or metastasis for 3 years after surgery. CONCLUSIONS This thought-provoking case suggests that coinfection with EBV and HP increases GC occurrence.

Mucosal lesions of the upper gastrointestinal tract in patients with ulcerative colitis: A review

Ulcerative colitis (UC) is a chronic, nonspecific, relapsing inflammatory bowel disease. The colorectum is considered the chief target organ of UC, whereas upper gastrointestinal (UGI) tract manifestations are infrequent. Recently, emerging evidence has suggested that UC presents complications in esophageal, stomachic, and duodenal mucosal injuries. However, UC-related UGI tract manifestations are varied and frequently silenced or concealed. Moreover, the endoscopic and microscopic characteristics of UGI tract complicated with UC are nonspecific. Therefore, UGI involvement may be ignored by many clinicians. In addition, no standard criteria have been established for patients with UC who should undergo fibrogastroduodenoscopy. Furthermore, specific treatment recommendations may be needed for patients with UC-associated UGI lesions. Herein, we review the esophageal, gastric, and duodenal mucosal lesions of the UC-associated UGI tract, as well as the potential pathogenesis and therapy.

A Deep Learning Convolutional Neural Network Can Differentiate Between Helicobacter Pylori Gastritis and Autoimmune Gastritis With Results Comparable to Gastrointestinal Pathologists

CONTEXT.—

Pathology studies using convolutional neural networks (CNNs) have focused on neoplasms, while studies in inflammatory pathology are rare. We previously demonstrated a CNN differentiates reactive gastropathy, Helicobacter pylori gastritis (HPG), and normal gastric mucosa.

OBJECTIVE.—

To determine whether a CNN can differentiate the following 2 gastric inflammatory patterns: autoimmune gastritis (AG) and HPG.

DESIGN.—

Gold standard diagnoses were blindly established by 2 gastrointestinal (GI) pathologists. One hundred eighty-seven cases were scanned for analysis by HALO-AI. All levels and tissue fragments per slide were included for analysis. The cases were randomized, 112 (60%; 60 HPG, 52 AG) in the training set and 75 (40%; 40 HPG, 35 AG) in the test set. A HALO-AI correct area distribution (AD) cutoff of 50% or more was required to credit the CNN with the correct diagnosis. The test set was blindly reviewed by pathologists with different levels of GI pathology expertise as follows: 2 GI pathologists, 2 general surgical pathologists, and 2 residents. Each pathologist rendered their preferred diagnosis, HPG or AG.

RESULTS.—

At the HALO-AI AD percentage cutoff of 50% or more, the CNN results were 100% concordant with the gold standard diagnoses. On average, autoimmune gastritis cases had 84.7% HALO-AI autoimmune gastritis AD and HP cases had 87.3% HALO-AI HP AD. The GI pathologists, general anatomic pathologists, and residents were on average, 100%, 86%, and 57% concordant with the gold standard diagnoses, respectively.

CONCLUSIONS.—

A CNN can distinguish between cases of HPG and autoimmune gastritis with accuracy equal to GI pathologists.

IL10 hypomethylation is associated with the risk of gastric cancer

Interleukin-10 (IL10), a pleiotropic cytokine secreted by type-2 helper (Th2) T cells, contributes to the oncogenic activation or inactivation of tumor-suppressor genes. The present study investigated whether hypomethylation of IL10 CpG island (CGI) was associated with the risk of developing gastric cancer (GC) and the prognosis of patients with GC. A fragment (hg18, chr1: 206945638-206945774) at the CGI of IL10 was selected for the present methylation assay. Quantitative methylation-specific PCR was used to evaluate the methylation of IL10 CGI in 117 tumor samples from patients with GC. The results demonstrated that IL10 CGI methylation was significantly lower in the tumor tissues compared with that in the paired adjacent non-tumor tissues (median percentage of methylated reference, 29.16 vs. 42.82%, respectively; P=4×10⁻⁸). Furthermore, results from receiver operating characteristic curve analysis identified a significant area under the curve of 0.706, with a sensitivity and a specificity of 77.8 and 58.1%, respectively, between cancer tissues and paired adjacent non-tumor tissues. Furthermore, the methylation of IL10 CGI was significantly associated with patients' age at diagnosis (r=−0.201; P=0.03). Subgroup analyses demonstrated that the association between IL10 CGI hypomethylation and the risk of GC was specific for patients with low differentiation (P=1×10⁻⁷) and Borrmann types III+IV (P=1×10⁻⁷). In addition, IL10 CGI hypomethylation was significantly associated with the risk of GC for patients without smoking history (P=3×10⁻⁷) or a family history of cancer (P=2×10⁻⁷). The results from Kaplan-Meier survival analysis demonstrated that IL10 CGI hypomethylation was associated with a significantly shorter overall survival of patients with GC (P=0.041). Similar results were identified for patients with GC who did not have smoking history (P=0.037) or a family history of cancer (P=0.049). The results from this study demonstrated that IL10 CGI hypomethylation may be considered as a potential biomarker for the diagnosis and prognosis of patients with GC in the Chinese population.

Infectious diseases of the upper gastrointestinal tract

A broad spectrum of pathogens produce gastrointestinal disease. The ongoing spread of human immunodeficiency virus/acquired immune deficiency syndrome, the increased use of immunosuppressive therapy and the persistence of overcrowding and suboptimal sanitation in underdeveloped areas facilitate both disease transmission from environmental and foodborne sources and person-to-person transmission. Clinicians increasingly rely on endoscopic biopsy sample interpretation to diagnose gastrointestinal infections. Thus, pathologists must be aware of diagnostic features of a variety of microbial pathogens. Detection with molecular techniques also allows for correlation between infectious agents and their histopathological features, which has expanded our knowledge of the inflammatory changes produced by infectious agents. This review covers infectious disorders of the upper gastrointestinal tract encountered in surgical pathology. Clinical, endoscopic and pathological features are presented. The review emphasises morphological features of viruses, bacteria, fungi and parasites that may be found in tissue samples, and the inflammatory patterns that they produce. Differential diagnoses and useful ancillary techniques are discussed.

The Gastroprotective Effect of Small Molecule Oligopeptides Isolated from Walnut (Juglans regia L.) against Ethanol-Induced Gastric Mucosal Injury in Rats

The study investigated the protective effect of walnut oligopeptides (WOPs) against ethanol-induced gastric injury using Sprague-Dawley (SD) rats. Rats were randomly divided into seven groups based on body weight (10/group), normal group, ethanol group, whey protein group (220 mg/kg body weight), omeprazole group (20 mg/kg body weight), and three WOPs groups (220, 440, 880 mg/kg body weight). After 30 days of treatment with WOPs, rats were given 5 mL/kg absolute ethanol by gavage to induce gastric mucosal injury. Gastric ulcer index (GUI) were determined and the following measured; gastric content pH, gastric mucin, endogenous pepsinogens (PG), prostaglandin E2 (PGE2), inflammatory cytokines, oxidative stress indicators, and the expression of apoptosis-related proteins were measured to evaluate the gastroprotective effect of WOPs. The results showed that the administration with WOPs markedly mitigated the hemorrhagic gastric lesions caused by ethanol in rats, and decreased the GUI, the gastric content pH, PG1, PG2, and NO levels, enhanced mucin and PGE2. Also, WOPs repressed gastric inflammation through the reduction of TNF-α, IL-6, IL-1β and increase IL-10 levels, and revealed antioxidant properties with the enhancement of superoxide dismutase, glutathione, and catalase activity, while reduction of malondialdehyde. Moreover, WOPs treatment significantly down-regulated Bax, caspase-3 and nuclear factor-κB p65 (NF-κB p65) expression, while up-regulating the expression of Bcl-2 and inhibitor kappa Bα (IκBα) protein. These results indicated that WOPs have protective effects against ethanol-induced gastric mucosal injury in rats through anti-inflammatory, anti-oxidation, and anti-apoptosis mechanisms.

Morphological spectrum of immune check-point inhibitor therapy-associated gastritis

AIMS

Immune check-point inhibitors are frequently used in the treatment of a variety of solid tumours. The mechanism of action of these drugs involves up-regulation of cytotoxic T cells, which can lead to a lack of self-tolerance and immune-related adverse events, including those involving the gastrointestinal tract. This study was performed to characterise the histological features of immune check-point inhibitor therapy-associated gastritis.

METHODS AND RESULTS

Gastric biopsies from patients on immune check-point inhibitor therapy with clinical suspicion of drug-associated gastrointestinal injury were identified. The predominant histological pattern of injury, distribution of injury, degree of tissue eosinophilia and prominence of apoptosis were recorded. Presenting symptoms, treatment and follow-up data were obtained by medical chart review. The 12 patients included in the study group were treated with ipilimumab, nivolumab or pembrolizumab for a variety of tumours. Symptoms at presentation included nausea, vomiting and diarrhoea. Chronic active gastritis with intra-epithelial lymphocytosis and prominent apoptosis was seen in eight of 12 patients, and was the most useful combination for the diagnosis of drug-induced gastritis in these patients. Four patients showed focal enhancing gastritis with a lymphohistiocytic cuff around inflamed glands reminiscent of Crohn's disease. One of those four patients was homozygous for the ATG16L1 Crohn's disease-associated gene variant, but had no history of inflammatory bowel disease. Ten patients responded to medication withdrawal and steroid therapy, while two required treatment with infliximab.

CONCLUSIONS

Awareness of the morphological spectrum of immune check-point inhibitor therapy-associated gastritis is important for the accurate diagnosis and prompt management of these patients.