Long-term dynamics of gastric biomarkers after eradication of Helicobacter pylori infection

Generation and characterization of nanobodies targeting human pepsinogens

Human pepsinogens (mainly pepsinogen I and pepsinogen II) are the major inactive precursor forms of the digestive enzyme pepsin which play a crucial role in protein digestion. The levels and ratios of human pepsinogens have demonstrated potential as diagnostic biomarkers for gastrointestinal diseases, particularly gastric cancer. Nanobodies are promising tools for the treatment and diagnosis of diseases, owing to their unique recognition properties. In this study, recombinant human pepsinogens proteins were expressed and purified as immunized antigens. We constructed a VHH phage library and identified several nanobodies via phage display bio-panning. We determined the binding potency and cross-reactivity of these nanobodies. Our study provides technical support for developing immunodiagnostic reagents targeting human pepsinogens.

RE.GA.IN.: the Real-world Gastritis Initiative-updating the updates

At the end of the last century, a far-sighted 'working party' held in Sydney, Australia addressed the clinicopathological issues related to gastric inflammatory diseases. A few years later, an international conference held in Houston, Texas, USA critically updated the seminal Sydney classification. In line with these initiatives, Kyoto Global Consensus Report, flanked by the Maastricht-Florence conferences, added new clinical evidence to the gastritis clinicopathological puzzle.The most relevant topics related to the gastric inflammatory diseases have been addressed by the Real-world Gastritis Initiative (RE.GA.IN.), from disease definitions to the clinical diagnosis and prognosis. This paper reports the conclusions of the RE.GA.IN. consensus process, which culminated in Venice in November 2022 after more than 8 months of intense global scientific deliberations. A forum of gastritis scholars from five continents participated in the multidisciplinary RE.GA.IN. consensus. After lively debates on the most controversial aspects of the gastritis spectrum, the RE.GA.IN. Faculty amalgamated complementary knowledge to distil patient-centred, evidence-based statements to assist health professionals in their real-world clinical practice. The sections of this report focus on: the epidemiology of gastritis; Helicobacter pylori as dominant aetiology of environmental gastritis and as the most important determinant of the gastric oncogenetic field; the evolving knowledge on gastric autoimmunity; the clinicopathological relevance of gastric microbiota; the new diagnostic horizons of endoscopy; and the clinical priority of histologically reporting gastritis in terms of staging. The ultimate goal of RE.GA.IN. was and remains the promotion of further improvement in the clinical management of patients with gastritis.

Clinical value of serum pepsinogen in the diagnosis and treatment of gastric diseases

Pepsinogen, secreted from the gastric mucosa, is the precursor of pepsin. It is categorized as pepsinogen 1 and pepsinogen 2 based on its immunogenicity. The pepsinogen content that can enter the blood circulation through the capillaries of the gastric mucosa is approximately 1% and remains stable all the time. The pepsinogen content in serum will change with the pathological changes of gastric mucosa. Therefore, the level of pepsinogen in serum can play a role in serologic biopsy to reflect the function and morphology of different regions of gastric mucosa and serve as an indicator of gastric disease. This study conducts relevant research on serum pepsinogen 1, pepsinogen 2, and the ratio of pepsinogen 1 to pepsinogen 2, and reviews their important value in clinical diagnosis of Helicobacter pylori infection, gastric ulcer, and even gastric carcinoma, providing ideas for other researchers.

Performing the ABC Method Twice for Gastric Cancer Risk Stratification: A Retrospective Study Based on Data from a Large-Scale Screening Facility

The ABC method is a classification method used for stratifying the risk of gastric cancer. However, whether the ABC method should be performed only once or multiple times throughout an individual’s lifetime remains unclear. Therefore, this study aimed to analyze whether performing ABC screening twice in a lifetime is useful. We retrospectively analyzed the data of individuals who participated in health checkups in 2010 and 2015. We collected data on patient characteristics, pepsinogen levels, anti-Helicobacter pylori antibody titers, and the presence of gastric cancer. Overall, 7129 participants without a history of H. pylori eradication were included in this study. The participants’ average age in 2010 was 48.4 ± 8.3 years, and 58.1% were male. In addition, 11 and 20 cases of new H. pylori infection (0.15%) and spontaneous eradication (0.28%), respectively, were recorded. No significant difference was found in the incidence of gastric cancer between participants who underwent the ABC method once and those who underwent it twice (Group A: 0.16% vs. 0.16%; Group B: 0.47% vs. 0.39%; and Group C + D: 1.97% vs. 1.82%). Therefore, performing the ABC method twice, 5 years apart, does not significantly improve gastric cancer risk stratification.

Assessment of Serum Pepsinogens with and without Co-Testing with Gastrin-17 in Gastric Cancer Risk Assessment-Results from the GISTAR Pilot Study

Introduction−−Serum pepsinogen tests for gastric cancer screening have been debated for decades. We assessed the performance of two pepsinogen assays with or without gastrin-17 for the detection of different precancerous lesions alone or as a composite endpoint in a Latvian cohort. Methods−−Within the intervention arm of the GISTAR population-based study, participants with abnormal pepsinogen values by ELISA or latex-agglutination tests, or abnormal gastrin-17 by ELISA and a subset of subjects with all normal biomarker values were referred for upper endoscopy with biopsies. Performance of biomarkers, corrected by verification bias, to detect five composite outcomes based on atrophy, intestinal metaplasia, dysplasia or cancer was explored. Results−−Data from 1045 subjects were analysed, of those 273 with normal biomarker results. Both pepsinogen assays showed high specificity (>93%) but poor sensitivity (range: 18.4−31.1%) that slightly improved when lesions were restricted to corpus location (40.5%) but decreased when dysplasia and prevalent cancer cases were included (23.8%). Adding gastrin-17 detection, sensitivity reached 33−45% while specificity decreased (range: 61.1−62%) and referral rate for upper endoscopy increased to 38.6%. Conclusions−−Low sensitivity of pepsinogen assays is a limiting factor for their use in population-based primary gastric cancer screening, however their high specificity could be useful for triage.

Helicobacter pylori Eradication Induced Constant Decrease in Interleukin- 1B Expression over More Than 5 Years in Patients with Gastric Cancer and Dysplasia

Background/Aims

Helicobacter pylori (Hp) suppresses gastric acid secretion by repressing the expression of the H⁺, K⁺-adenosine triphosphatase (H⁺, K⁺-ATPase) and stimulating interleukin-1 (IL-1β; encoded by IL-1B). This study was aimed at evaluating the expression of the H⁺, K⁺-ATPase and IL-1β after Hp eradication.

Methods

Two hundred twenty-one subjects were categorized as Hp-negative (n=84) or Hp-positive (n=137) according to the results of Hp tests (histology, CLO test, culturing, and serology). The mRNA expression levels of IL-1B and ATP4A (the gene encoding the α-subunit of H⁺, K⁺-ATPase) were measured in biopsy specimens from the gastric corpus using real-time polymerase chain reaction.

Results

The Hp-positive group had significantly higher IL-1B mRNA levels than the whole Hp-negative group and the intestinal metaplasia (IM)-negative subgroup. After Hp eradication, the difference between the Hp-negative and Hp-eradicated groups disappeared, including in the IM-negative subgroup. The IL-1B mRNA level did not significantly change from the baseline level. Within the gastric cancer (GC)/dysplasia subgroup, the IL-1B mRNA levels at 1, 2, 3–4, and ≥5 years after Hp eradication were significantly lower than the baseline level. The difference in ATP4A mRNA levels between the Hp-negative and Hp-positive groups was not significant at baseline, and the changes in the ATP4A mRNA levels after Hp eradication compared to the baseline levels in the whole group and subgroups stratified by the presence of IM and GC/dysplasia were not significant.

Conclusions

Infection with Hp has an effect on the level of IL-1B mRNA in IM-negative subjects. The continuous reduction in the IL-1B mRNA level in patients with GC/dysplasia after Hp eradication contributes to the prevention of metachronous GC after Hp eradication.

ABC Classification Is Less Useful for Older Koreans Born before 1960

Background/Aims

In the ABC classification system, group A consists of seronegative subjects without gastric corpus atrophy. This study aimed to determine the prevalence and characteristics of pseudo group A subjects.

Methods

Group A subjects were identified among consecutive Korean adults who underwent a serum anti-Helicobacter pylori immunoglobulin G (IgG) test and pepsinogen (PG) assay on the day of endoscopy. Past infection was defined as the presence of either eradication history or endoscopic findings suggesting past infection (i.e., gastric xanthoma, metaplastic gastritis, or advanced atrophy >closed-type 1).

Results

Among 2,620 group A subjects, 448 (17.1%) had eradication history, and 133 (5.1%) showed endoscopic findings suggesting past infection. Older age (odds ratio [OR], 1.148; 95% confidence interval [CI], 1.067 to 1.236) and earlier year of birth (OR, 1.086; 95% CI, 1.009 to 1.168) were independent risk factors for classification into pseudo group A, with cutoff points at 50.5 years and birth year of 1959.5, respectively. Positive H. pylori test findings were found in 22 subjects (3.1%) among the 715 subjects who underwent the urea breath test or Giemsa staining on the same day. Current infection was positively correlated with PG I and PG II levels (p<0.001) but not with age, anti-H. pylori IgG titer, or classification into pseudo group A.

Conclusions

Among the group A subjects, 22.2% had past infection. The risk was higher in subjects older than 50 years, especially those born before 1960. Furthermore, current infection was found in 3.1% of the subjects and was correlated with increased gastric secretory ability.

Increased serum gastrin in patients with different clinical forms of Chagas disease coinfected with Helicobacter pylori

Trypanosoma cruzi and Helicobacter pylori (HP) are pathogens that cause chronic diseases and have been associated with hypergastrinemia. The aim of this study was to evaluate the fasting gastrin levels in patients with different clinical forms of Chagas disease (CD), coinfected or not by HP. The enrolled individuals were outpatients attending at the university hospital. HP infection was assessed by serology and 13 C-urea breath test. Fasting serum gastrin concentration was measured by chemiluminescence assay. Gastric endoscopic and histological features were also evaluated. Associations between CD and serum gastrin level were evaluated in a logistical model, adjusting for age, gender and HP status. A total of 113 patients were evaluated (45 with Chagas disease and 68 controls). In the multivariate analysis, increasing serum gastrin levels (OR= 1.02; 95% CI= 1.01-1.12), increasing age (OR= 1.05; 95% CI= 1.02 - 1.09) and HP-positive status (OR = 2.88; 95% CI = 1.10 - 7.51) remained independently associated with CD. The serum gastrin levels were significantly higher in the group of patients with the cardiodigestive form ( P = 0.03) as well as with digestive form ( P = <0.001) of Chagas disease than in the controls. In conclusion, patients with cardiodigestive and digestive clinical forms of CD have increased basal serum gastrin levels in comparison with controls. Moreover, we also demonstrated that H. pylori coinfection contributes to the hypergastrinemia shown in CD.

The corpus-predominant gastritis index can be an early and reversible marker to identify the gastric cancer risk of Helicobacter pylori-infected nonulcer dyspepsia

BACKGROUND

Corpus-predominant gastritis index (CGI) is an early histological marker to identify Helicobacter pylori-infected gastric cancer relatives at risk of cancer. This study validated whether CGI is more prevalent in H. pylori-infected nonulcer dyspepsia (NUD) subjects than in duodenal ulcer (DU) controls and whether it is reversible after H. pylori eradication or is correlated with noninvasive biomarkers.

MATERIALS AND METHODS

In this longitudinal cohort study, 573 H. pylori-infected subjects were enrolled, including 349 NUD and 224 DU. Gastric specimens were provided to assess CGI, spasmolyic polypeptide-expressing metaplasia (SPEM), and Operative Link on Gastric Intestinal Metaplasia assessment (OLGIM). Serum pepsinogen I and II levels were assessed using enzyme-linked immunosorbent assay. CGI subjected were followed up at least 1 year after H. pylori eradication.

RESULTS

NUD subjects had higher prevalence rates of CGI (47.0% vs 29.9%, P<.001) and OLGIM stages III-IV (24.1% vs 15.2%, P=.01) than controls. CGI was highly prevalent in NUD subjects after the age of 40, which was 10 years earlier than atrophic gastritis and intestinal metaplasia. NUD subjects with CGI had higher risk of SPEM (OR 2.86, P<.001) and lower serum pepsinogen I/II ratios (P<.001) than those without CGI. Serum pepsinogen I/II ratios <9 could predict CGI modestly (AUROC 0.69, 95% CI: 0.63-0.74). CGI was regressed after eradication (P<.001).

CONCLUSIONS

CGI was more prevalent in H. pylori-infected NUD subjects than in controls, was correlated with SPEM, and may serve as a marker earlier than OLGIM to indicate risk of gastric cancer. Moreover, CGI could be regressed after eradication.

Pepsinogens to Distinguish Patients With Gastric Intestinal Metaplasia and Helicobacter pylori Infection Among Populations at Risk for Gastric Cancer

OBJECTIVES

The objectives of this study were to investigate the serum pepsinogen test for the prediction of OLGIM (Operative Link on Gastric Intestinal Metaplasia Assessment) stages in first-degree relatives (FDR-GC) of patients with gastric cancer (GC) and autoimmune chronic atrophic gastritis (ACAG).

METHODS

In 67 consecutive patients with ACAG, 82 FDR-GC, and 53 controls (CTRL) without gastric disease (confirmed by biopsy), serum levels of pepsinogen 1 (PG1), pepsinogen 2 (PG2), G17, and the PG1/2 ratio were assessed by enzyme-linked immunosorbent assay kit. All ACAG patients had positive antiparietal cell antibody levels, estimated by indirect immunofluorescence. Biopsies taken in duplicate from the antrum, corpus, and fundus were stained with Giemsa for Helicobacter pylori detection. Endoscopic detection of metaplasia was confirmed by histological diagnosis. Histological classification of OLGIM stages was applied by using the criteria of severity and topography of intestinal metaplasia (IM).

RESULTS

The highest discrimination capacity for distinguishing ACAG from other groups of patients was the gastrin G17 test. The lowest mean for PG1 and PG2 serum levels was found in ACAG. In multivariate analysis by age, PG1 and PG1/PG2 were independent prognostic factors for metaplasia, and PG2 also for the presence of a histological H. pylori infection. The serum PG1 level was significantly lower in individuals with IM at OLGIM stage >2 than in those with IM at OLGIM stage <2, resulting in a useful method for the prediction of OLGIM stage. With the inclusion of patient age at diagnosis in the prediction of ≥2 vs. 0-1 OLGIM stages, the receiver operating characteristic (ROC) curve at 47.9 ng/ml PG1 level reached a significant area under the curve (AUC) value (0.978, P<0.001). We also observed a slight difference in PG2 serum levels between histological H. pylori-positive and H. pylori-negative subjects (ROC AUC: 0.599).

CONCLUSIONS

This study demonstrated an important increase in gastrin G17 serum level in autoimmune gastritis. PG1 serum level corrected by patient age can be used in the management of patients at risk for GC with a high predicted probability of having an OLGIM stage ≥2. Using a cutoff of 47.9 ng/ml, PG1 testing in FDR-GC and ACAG patients had a sensitivity of 95.83% and a specificity of 93.37. Although these results could be validated in a prospective study, the known importance of higher OLGIM stages in increasing the risk of GC development supports the rationale of proposing PG1 algorithm as a diagnostic tool for the selection of high-risk FDR-GC and ACAG patients at high-risk stages for subsequent detailed endoscopic examination to detect dysplasia and asymptomatic GC. In addition, serum PG1 and PG2 levels could stratify patients based on both H. pylori infection and OLGIM risk in consideration of the increased acknowledge regarding the role of H. pylori in the progression of gastritis to GC.