Helicobacter pylori antibody responses in association with eradication outcome and recurrence: a population-based intervention trial with 7.3-year follow-up in China

A noninvasive multianalytical approach establishment for risk assessment and gastric cancer screening

Effective screening and early detection are critical to improve the prognosis of gastric cancer (GC). Our study aims to explore noninvasive multianalytical biomarkers and construct integrative models for preliminary risk assessment and GC detection. Whole genomewide methylation marker discovery was conducted with CpG tandems target amplification (CTTA) in cfDNA from large asymptomatic screening participants in a high-risk area of GC. The methylation and mutation candidates were validated simultaneously using one plasma from patients at various gastric lesion stages by multiplex profiling with Mutation Capsule Plus (MCP). Helicobacter pylori specific antibodies were detected with a recomLine assay. Integrated models were constructed and validated by the combination of multianalytical biomarkers. A total of 146 and 120 novel methylation markers were found in CpG islands and promoter regions across the genome with CTTA. The methylation markers together with the candidate mutations were validated with MCP and used to establish a 133-methylation-marker panel for risk assessment of suspicious precancerous lesions and GC cases and a 49-methylation-marker panel as well as a 144-amplicon-mutation panel for GC detection. An integrated model comprising both methylation and specific antibody panels performed better for risk assessment than a traditional model (AUC, 0.83 and 0.63, P < .001). A second model for GC detection integrating methylation and mutation panels also outperformed the traditional model (AUC, 0.82 and 0.68, P = .005). Our study established methylation, mutation and H. pylori-specific antibody panels and constructed two integrated models for risk assessment and GC screening. Our findings provide new insights for a more precise GC screening strategy in the future.

Long-term Response of Helicobacter pylori Antibody Titer After Eradication Treatment in Middle-aged Japanese: JPHC-NEXT Study

BACKGROUND

Helicobacter pylori (H. pylori) is an established causative factor of gastric cancer. Although the expansion of insurance coverage has led to an increase in the number of patients treated for H. pylori, the population impact of eradication treatment for H. pylori has been scarcely investigated. This study aimed to clarify the long-term responses of H. pylori antibody titer after eradication treatment using large scale cross-sectional data from the Japan Public Health Center-based Prospective Study for the Next Generation (JPHC-NEXT Study).

METHODS

A total of 55,282 Japanese participants aged 40 to 74 years residing in 16 areas provided blood samples from 2011 through 2016. From these, treated (n = 6,276) and untreated subjects who were seropositive for H. pylori or had serological atrophy (n = 22,420) formed the study population (n = 28,696). Seropositivity was defined as an anti-H. pylori IgG titer of ≥10 U/mL. Antibody level was compared among subjects according to self-reported treatment history as untreated, and treated for less than 1 year (<1Y), 1 through 5 years (1-5Y), and 6 or more years ago (6Y+).

RESULTS

Median serum antibody titer was 34.0 U/mL, 7.9 U/mL, 4.0 U/mL, and 2.9 U/mL for the untreated, <1Y, 1-5Y, and 6Y+ groups, respectively. While those treated for H. pylori within the previous year had a 76.8% lower antibody titer compared to untreated subjects, approximately 41% of subjects were still seropositive.

CONCLUSION

A significant reduction in H. pylori antibody titer occurs within 1 year after eradication treatment, but that a long period is needed to achieve complete negative conversion.

Gastric cancer: Epidemiology, risk factors and prevention strategies

Gastric cancer (GC) is a global health problem, with more than 1 million people newly diagnosed with GC worldwide each year. GC is more prevalent in less developed countries than in more developed countries. About half of all GC cases worldwide occur in East Asia, notably China. Globally, overall incidence rates of GC are declining, which is potentially attributed to a decrease in Helicobacter pylori (H. pylori) infection and the use of refrigeration to preserve foods rather than salt. GC is a multifactorial disease, and its occurrence and development were impacted by environmental and genetic factors. H. pylori infection is the primary risk factor for GC, especially for non-cardia. The prognosis of GC is poor due to stages at the first diagnosis. The 5-year survival rate is less than 10% when patients are diagnosed at an advanced stage, but the rate is as high as 85% if patients are detected at an earlier stage. Endoscopic screening can potentially prevent GC by early diagnosis and early treatment and has been widely adopted in screening programs in East Asian countries, such as Japan and Korea. This review summarizes updated epidemiological aspects, risk factors, and prevention strategies of GC in recent years to help researchers determine the most effective intervention strategies for reducing risk of GC.

<em>Helicobacter pylori</em> infection and the risk of upper gastrointestinal bleeding in low dose aspirin users: systematic review and meta-analysis

OBJECTIVE

To determine whether the risk of upper gastrointestinal bleeding in patients taking low dose aspirin (≤ 325 mg/day) is increased in people with Helicobacter pylori infections.

STUDY DESIGN

A systematic search for all publications since 1989 (when H. pylori was named) using search term equivalents for "upper gastrointestinal haemorrhage" and "aspirin". Articles were assessed individually for inclusion of data on H. pylori infection, as not all relevant papers were indexed with this term. Data that could be pooled were then subjected to meta-analysis, using a random effects model.

DATA SOURCES

MEDLINE, Embase, Scopus, the Cochrane Library.

DATA SYNTHESIS

Of 7599 retrieved publications, reports for seven case-control studies contained data suitable for meta-analysis; four were deemed high quality on the Newcastle-Ottawa scale. Upper gastrointestinal haemorrhage was more frequent in aspirin users infected with H. pylori than in those who were not (odds ratio [OR], 2.32; 95% CI, 1.25-4.33; P = 0.008). The heterogeneity of the studies was significant (Q = 19.3, P = 0.004; I² = 68.9%, 95% CI, 31.5-85.9%), but the pooled odds ratio was similar after removing the two studies that contributed most to heterogeneity (OR, 2.34; 95% CI, 1.56-3.53; P < 0.001). The number needed to treat to prevent one bleeding event annually was estimated to be between 100 and more than 1000.

CONCLUSIONS

The odds of upper gastrointestinal bleeding in patients taking low dose aspirin is about twice as great in those infected with H. pylori. Testing for and treating the infection should be considered in such patients, especially if their underlying risk of peptic ulcer bleeding is already high.

Serologic Response to Helicobacter pylori Proteins Associated With Risk of Colorectal Cancer Among Diverse Populations in the United States

BACKGROUND & AIMS

Previous studies reported an association of the bacteria Helicobacter pylori, the primary cause of gastric cancer, and risk of colorectal cancer (CRC). However, these findings have been inconsistent, appear to vary with population characteristics, and may be specific for virulence factor VacA. To more thoroughly evaluate the potential association of H pylori antibodies with CRC risk, we assembled a large consortium of cohorts representing diverse populations in the United States.

METHODS

We used H pylori multiplex serologic assays to analyze serum samples from 4063 incident cases of CRC, collected before diagnosis, and 4063 matched individuals without CRC (controls) from 10 prospective cohorts for antibody responses to 13 H pylori proteins, including virulence factors VacA and CagA. The association of seropositivity to H pylori proteins, as well as protein-specific antibody level, with odds of CRC was determined by conditional logistic regression.

RESULTS

Overall, 40% of controls and 41% of cases were H pylori-seropositive (odds ratio [OR], 1.09; 95% CI, 0.99-1.20). H pylori VacA-specific seropositivity was associated with an 11% increased odds of CRC (OR, 1.11; 95% CI, 1.01-1.22), and this association was particularly strong among African Americans (OR, 1.45; 95% CI, 1.08-1.95). Additionally, odds of CRC increased with level of VacA antibody in the overall cohort (P = .008) and specifically among African Americans (P = .007).

CONCLUSIONS

In an analysis of a large consortium of cohorts representing diverse populations, we found serologic responses to H pylori VacA to associate with increased risk of CRC risk, particularly for African Americans. Future studies should seek to understand whether this marker is related to virulent H pylori strains carried in these populations.