The genetic regulation of the gastric transcriptome is associated with metabolic and obesity-related traits and diseases.

Tissue-specific gene expression and gene regulation lead to a better understanding of tissue-specific physiology and pathophysiology. We analyzed the transcriptome and genetic regulatory profiles of two distinct gastric sites, corpus and antrum, to identify tissue-specific gene expression and its regulation. Gastric corpus and antrum mucosa biopsies were collected during routine gastroscopies from up to 431 healthy individuals. We obtained genotype and transcriptome data and performed transcriptome profiling and expression quantitative trait locus (eQTL) studies. We further used data from genome-wide association studies (GWAS) of various diseases and traits to partition their heritability and to perform transcriptome-wide association studies (TWAS). The transcriptome data from corpus and antral mucosa highlights the heterogeneity of gene expression in the stomach. We identified enriched pathways revealing distinct and common physiological processes in gastric corpus and antrum. Furthermore, we found an enrichment of the single nucleotide polymorphism (SNP)-based heritability of metabolic, obesity-related, and cardiovascular traits and diseases by considering corpus- and antrum-specifically expressed genes. Particularly, we could prioritize gastric-specific candidate genes for multiple metabolic traits, like NQO1 which is involved in glucose metabolism, MUC1 which contributes to purine and protein metabolism or RAB27B being a regulator of weight and body composition. Our findings show that gastric corpus and antrum vary in their transcriptome and genetic regulatory profiles indicating physiological differences which are mostly related to digestion and epithelial protection. Moreover, our findings demonstrate that the genetic regulation of the gastric transcriptome is linked to biological mechanisms associated with metabolic, obesity-related, and cardiovascular traits and diseases. NEW & NOTEWORTHY We analyzed the transcriptomes and genetic regulatory profiles of gastric corpus and for the first time also of antrum mucosa in 431 healthy individuals. Through tissue-specific gene expression and eQTL analyses, we uncovered unique and common physiological processes across both primary gastric sites. Notably, our findings reveal that stomach-specific eQTLs are enriched in loci associated with metabolic traits and diseases, highlighting the pivotal role of gene expression regulation in gastric physiology and potential pathophysiology.

Sporadic adenoma or ulcerative colitis associated neoplasia? The endoscopist's information has an impact on diagnosis and patient management.

BACKGROUND: Diagnosing low grade intraepithelial neoplasia (LGIN) in patients with ulcerative colitis (UC) is difficult. Distinguishing between sporadic adenoma (SA) and UC associated LGIN is even more challenging but has clinical impact. We aimed to examine, if the morphological distinction between both entities is reliably possible, how it influences patient's outcome and the role of the endoscopist in this decision with respect to current endoscopy classification schemes. METHODS: Seven pathologists retrospectively reevaluated 425 cases of LGIN in UC patients, diagnosed between 2009 and 2017 with preceding expert consensus and follow up in two separate readings, based on published morphological differentiation criteria. In the first evaluation, the observers were blinded to any clinical data. In the second evaluation, they knew patients' age as well as endoscopic features. They also rated their subjective diagnostic certainty. RESULTS: Diagnostic correctness improved significantly in the second assessment as did the pathologists' confidence in their diagnoses (p < 0.001 - p = 0.019). Knowledge of clinical and endoscopical data led to a higher percentage of SA (71.8% vs. 85.6%). UC associated LGIN showed significant earlier LGIN relapse as well as more high grade intraepithelial neoplasia and carcinoma during follow up (p < 0.001, p < 0.001, p = 0.005). CONCLUSIONS: Distinction between SA and UC associated LGIN is important as it has an impact on patients' follow up and treatment. Morphological distinction remains difficult with moderate interobserver variability. Adequate clinical information significantly improves pathologists' diagnoses as well as their confidence in their diagnoses.

Validation of a Novel Immunoline Assay for Patient Stratification according to Virulence of the Infecting Helicobacter pylori Strain and Eradication Status.

Helicobacter pylori infection shows a worldwide prevalence of around 50%. However, only a minority of infected individuals develop clinical symptoms or diseases. The presence of H. pylori virulence factors, such as CagA and VacA, has been associated with disease development, but assessment of virulence factor presence requires gastric biopsies. Here, we evaluate the H. pylori recomLine test for risk stratification of infected patients by comparing the test score and immune recognition of type I or type II strains defined by the virulence factors CagA, VacA, GroEL, UreA, HcpC, and gGT with patient's disease status according to histology. Moreover, the immune responses of eradicated individuals from two different populations were analysed. Their immune response frequencies and intensities against all antigens except CagA declined below the detection limit. CagA was particularly long lasting in both independent populations. An isolated CagA band often represents past eradication with a likelihood of 88.7%. In addition, a high recomLine score was significantly associated with high-grade gastritis, atrophy, intestinal metaplasia, and gastric cancer. Thus, the recomLine is a sensitive and specific noninvasive test for detecting serum responses against H. pylori in actively infected and eradicated individuals. Moreover, it allows stratifying patients according to their disease state.

Validation study of the Esohisto consensus guidelines for the recognition of microscopic esophagitis (histoGERD Trial).

In patients with gastroesophageal reflux disease (GERD), histology is generally believed to be a tool of limited diagnostic value. Our study aimed to assess the prevalence of microscopic esophageal lesions as defined by the Esohisto consensus guidelines, which have proven high interobserver agreement in previous studies. In the prospective Central European multicenter histoGERD trial, we recruited 1071 individuals (576 females and 495 males; median age, 53 years; range, 15-93 years) undergoing gastroscopy for nonselected reasons. Biopsy material was systematically sampled from above and below the gastroesophageal junction. Overall, histologic diagnosis of mild and severe esophagitis was made in 423 (39.5%) and 296 (27.6%) individuals, respectively, whereas the squamous mucosa of 352 individuals (32.9%) was normal upon histology or showed only insignificant findings. Proliferative changes of the squamous epithelium, in particular basal cell layer hyperplasia, papillary elongation, and intercellular space dilation, were more common than inflammatory cell infiltration. The presence of microscopic esophagitis was associated with male sex (P = .009), patients' symptoms (P = .003), history of proton pump inhibitor intake (P < .001), and the endoscopic diagnosis of esophagitis (P < .001). Notably, among the 450 patients with no endoscopic signs of esophagitis (Los Angeles Category N), 41.8% and 17.1% were identified with mild and severe (microscopic) esophagitis, respectively, indicating higher sensitivity of histologic diagnosis. In conclusion, our data illustrate the value of histology in the workup of patients with reflux disease. We suggest that biopsies should routinely be obtained when patients undergo upper gastrointestinal endoscopy for evaluation of GERD and may particularly be beneficial in patients with nonerosive reflux disease.

Multilayered epithelium at the gastroesophageal junction is a marker of gastroesophageal reflux disease: data from a prospective Central European multicenter study (histoGERD trial).

Multilayered epithelium is defined as hybrid epithelium with characteristics of both squamous and columnar epithelia. Our aim was to evaluate the clinicopathological significance of the lesion by relating its presence to various histological and clinical and/or endoscopic features indicating gastroesophageal reflux disease (GERD). A total of 1,071 individuals participated in a prospective cross-sectional study (576 females and 495 males; median age 53 years). Biopsy material was systematically sampled from the gastroesophageal junction. The histological diagnosis of esophagitis was made according to the Esohisto consensus guidelines. The endoscopic diagnosis of esophagitis was made according to the modified Los Angeles classification and the diagnosis of Barrett's esophagus according to Prague's C & M criteria, respectively. Multilayered epithelium was identified in 103 (9.6 %) individuals, frequently within or adjacent to the ducts of esophageal glands. Its presence was associated with increasing age (p < 0.001), high BMI (p = 0.026), hiatal hernia (p < 0.001), and the endoscopic diagnoses of esophagitis (p = 0.002) and Barrett's esophagus (p < 0.001). Upon histology, multilayered epithelium was associated with features of the squamous epithelium indicating GERD, particularly intercellular space dilation (p = 0.005), and presence of cardiac mucosa (<0.001). For intestinal metaplasia, a trend was noted (p = 0.094). In conclusion, multilayered epithelium was observed in about every tenth individual undergoing upper gastrointestinal endoscopy. The association with histological and clinical features indicating GERD advocates the lesion as a promising new marker for reflux esophagitis. The association with cardiac mucosa and Barrett's esophagus suggests multilayered epithelium to be an intermediate step in the development of columnar metaplasia and, ultimately, Barrett's esophagus.

Changing prevalence patterns in endoscopic and histological diagnosis of gastritis? Data from a cross-sectional Central European multicentre study.

BACKGROUND AND AIMS: Traditionally, Helicobacter infection is considered to be the most common cause of gastritis. In the cross-sectional Central European histoGERD trial, we assessed the prevalence of different types of gastritis, correlating histological and endoscopic diagnoses. METHODS: A total of 1123 individuals participated in an observational multicentre study. Endoscopists classified individuals as positive or negative for gastritis and rendered the putative cause. Pathologists evaluated biopsy specimens based upon the Updated Sydney System. RESULTS: Histological diagnosis of gastritis was made in 639 (56.9%) participants. In all, 210 (18.7%) individuals were diagnosed with Helicobacter gastritis, 215 (19.1%) with post Helicobacter gastritis, 234 (20.8%) with reactive gastropathy, 26 (2.3%) with autoimmune gastritis, and 6 (0.5%) with focally enhanced gastritis related to Crohn's disease. In 46 out of 639 (7.2%) individuals diagnosed with gastritis, combinations of different histological subtypes were noted the most common being reactive gastropathy and post Helicobacter gastritis. Endoscopic diagnosis of gastritis was made in 534 (47.6%) individuals. CONCLUSIONS: Reactive gastropathy was more common than active Helicobacter gastritis, and the majority of cases attributable to Helicobacter infection were no longer ongoing, i.e. post Helicobacter gastritis. Agreement between histological and endoscopic diagnoses was better in reactive gastropathy than in Helicobacter gastritis.

A novel line immunoassay based on recombinant virulence factors enables highly specific and sensitive serologic diagnosis of Helicobacter pylori infection.

Helicobacter pylori colonizes half of the world's population, and infection can lead to ulcers, gastric cancer, and mucosa-associated lymphoid tissue (MALT) lymphoma. Serology is the only test applicable for large-scale, population-based screening, but current tests are hampered by a lack of sensitivity and/or specificity. Also, no serologic test allows the differentiation of type I and type II strains, which is important for predicting the clinical outcome. H. pylori virulence factors have been associated with disease, but direct assessment of virulence factors requires invasive methods to obtain gastric biopsy specimens. Our work aimed at the development of a highly sensitive and specific, noninvasive serologic test to detect immune responses to important H. pylori virulence factors. This line immunoassay system (recomLine) is based on recombinant proteins. For this assay, six highly immunogenic virulence factors (CagA, VacA, GroEL, gGT, HcpC, and UreA) were expressed in Escherichia coli, purified, and immobilized to nitrocellulose membranes to detect serological immune responses in patient's sera. For the validation of the line assay, a cohort of 500 patients was screened, of which 290 (58.0%) were H. pylori negative and 210 (42.0%) were positive by histology. The assay showed sensitivity and specificity of 97.6% and 96.2%, respectively, compared to histology. In direct comparison to lysate blotting and enzyme-linked immunosorbent assay (ELISA), the recomLine assay had increased discriminatory power. For the assessment of individual risk for gastrointestinal disease, the test must be validated in a larger and defined patient cohort. Taking the data together, the recomLine assay provides a valuable tool for the diagnosis of H. pylori infection.

Pancreatic acinar cells--a normal finding at the gastroesophageal junction? Data from a prospective Central European multicenter study.

Pancreatic acinar cells are a well-recognized finding at the gastroesophageal junction, but their histogenesis and biological significance are unclear. From the prospective Central European multicenter histoGERD trial, we recruited 1,071 individuals undergoing gastroscopy for various non-selected reasons. Biopsy material was systematically sampled from the gastroesophageal junction and from the stomach. The study aimed to assess the prevalence of pancreatic acinar cells and to relate their presence to various histologic and clinical features. Overall, pancreatic acinar cells were observed in 184 (17.2%) participants. Individuals diagnosed with pancreatic acinar cells were slightly younger than those without (median 50 vs. 53 years; p = 0.009). There was no association with patients' symptoms and/or complaints or with an endoscopic diagnosis of esophagitis or Barrett's esophagus. Regarding histology, pancreatic acinar cells were not associated with features of the squamous epithelium indicating reflux disease, such as basal cell hyperplasia, papillary elongation, dilation of intercellular spaces, and inflammatory cell number, but were associated with the presence of cardiac mucosa (p < 0.001), oxyntocardiac mucosa (p < 0.001), and intestinal metaplasia (p = 0.038), respectively. No association with Helicobacter pylori infection or diagnosis of gastritis was noted. In conclusion, pancreatic acinar cells are a common finding at the gastroesophageal junction, and no association with either reflux disease (histologically or endoscopically) or diagnosis of gastritis was observed. These data suggest a congenital rather than an acquired (metaplastic) origin of pancreatic acinar cells at the gastroesophageal junction. This questions the term "pancreatic acinar metaplasia" which is currently widely used for their diagnosis.