Introduction

Antibiotic resistance in H. pylori (Hp) is becoming a more significant challenge in the management of Hp infection. Resistance surveillance is recommended to guide clinicians in the most appropriate therapy in a given population. Molecular methods offer a more rapid alternative for the detection of Hp resistance to antibiotics than traditional culture-based methods.

Aims & Methods

To evaluate the diagnostic accuracy of molecular-based clarithromycin susceptibility testing in Hp compared to culture and E-test in the Irish healthcare setting.
Following ethical approval and informed consent, adults were recruited prospectively from 2 centres (Tallaght University Hospital and Letterkenny University Hospital, Ireland), regardless of previous Hp treatment history. During routine gastroscopy, subjects had two supplementary biopsies (1 antrum and 1 corpus) taken for Hp culturing and DNA extraction. After successful Hp growth, clarithromycin susceptibility testing was performed by the Etest (Biomerieux) method and resistance was determined according to EUCAST 2023 guidelines. DNA was then extracted from biopsies and underwent PCR using the RIDA®GENE Helicobacter pylori assay (R-Biopharm AG, Germany) for detection of Hp and clarithromycin resistance-associated point mutations (A2146C, A2146G and A2147G).

Results

In all, samples from 191 culture-positive patients (mean age 48.4 ± 15.3 years; 45.0% (N=86) female) were analysed. The rates of clarithromycin resistance detected by culture-based and molecular methods were 49.2% (N=94/191) and 38.7% (N=74/191), respectively (P=0.05; Fisher’s exact test). Results were in agreement between both methods in 84.3% (N=161/191) of cases. The sensitivity and specificity of the Ridagene assay compared to culture for the detection of clarithromycin resistance were 74.2% (95% CI: 64.4-82.6%) and 94.7% (95% CI: 88.0-98.3%), respectively. The positive predictive value was 93.5% (95% CI: 85.5-97.9%) and the negative predictive value was 78.1% (95% CI: 69.4-85.3%).

Conclusion

While the Ridagene assay was easy to use and more rapid than Hp culture, the low sensitivity compared to culture in our cohort may limit its use to cases where culture-based methods are unsuccessful. Further studies are required to characterise the full spectrum of clarithromycin resistance mechanisms present in our population.

Introduction

Recent research from the Netherlands, the United States, and Korea suggests that individuals who receive a positive result on the fecal immunochemical test (FIT) may be at a higher risk of developing gastroesophageal cancer (GEC) within the following 36 months. However, the associations reported in these studies may be biased due to differences in age and sex between the FIT-positive and FIT-negative groups and other confounding factors.

Aims & Methods

We aimed to evaluate the association between FIT results and the risk of GEC in a matched cohort by age and sex. Additionally, we assessed the cost-effectiveness of a one-time Esophago-Gastro-Duodenoscopy (EGD) for individuals with positive FIT results.. We created a matched cohort of individuals aged 50 to 75 who underwent FIT testing at Clalit Health in Israel between June 2016 and June 2019. For each FIT-positive individual, we matched three FIT-negative individuals based on age, sex, and H. pylori status. Adjusted hazard ratios (HRs) with 95% confidence intervals (CIs) were utilized to evaluate the association between a positive FIT result and the risk of GEC within 36 months. We calculated the incremental cost-effectiveness ratio (ICER) for a one-time EGD at $400 in individuals who tested positive for FIT. Screening is considered cost-effective if the ICER is below $50,000.

Results

The primary cohort included 483,710 individuals, while the matched cohort comprised 151,500 individuals (47.6% female, median age 62.5 years). During the follow-up period, 202 cases of GEC occurred: 0.2% (64/38,575) among FIT-positive individuals and 0.1% (138/112,925) among FIT-negative individuals, adjusted HR 1.39 (95% CI 1.03-1.87). Age, male sex, H. pylori exposure, country of birth, proton-pump inhibitor usage, smoking status, and anemia were all significantly associated with an increased risk of gastric cancer. A one-time EGD has been determined to be a cost-effective option in a range of ages and rates of localized disease at the time of EGD.

Conclusion

This matched cohort study suggests that individuals with a positive FIT may have an increased risk of GEC, which occurs at an overall rate of 0.2% within 36 months. A one-time EGD priced at $400 can be cost-effective in many scenarios.

Disclosure

NONE

Introduction

A few studies have suggested the association between Helicobacter pylori (HP) infection and atherosclerosis including coronary heart disease and ischemic stroke. However, the effect of HP eradication on ischemic stroke has not been well evaluated, so far.

Aims & Methods

The objective of this study was twofold: (1) to compare the risks of ischemic stroke and cerebral atherosclerosis as a pre-clinical stage of ischemic stroke according to HP eradication status among HP-infected patients (HP-eradicated vs. HP-non-eradicated), and (2) to compare these risks in HP-eradicated patients to those in HP-naive subjects. We conducted a prospective observational cohort study. HP tests with gastroscopy were performed in Seoul National University Bundang Hospital from May 2003 to February 2023. HP infection was diagnosed through ≥1 findings of histopathology, rapid urease test or culture. Propensity score matching for each group was calculated with relevant covariates, including age, sex, alcohol, smoking, hypertension, diabetes mellitus, dyslipidemia, atrial fibrillation, and aspirin intake. Patients in HP-eradicated group were matched in a 2:1 and 1:1 ratio with patients in HP-non-eradicated and HP-naive groups, respectively. Ischemic stroke and cerebral atherosclerosis were confirmed by brain MRI. The risk of ischemic stroke and cerebral atherosclerosis was analyzed using Cox-proportional hazard regression analysis.

Results

A total of 8,025 patients were included. After 2:1 matching, HP-eradicated group comprised 2,030 patients and HP-non-eradicated group comprised 1,015 patients(Figure). In a Cox-proportional hazard analysis, HP-eradicated group was associated with a significantly lower risk of ischemic stroke and cerebral atherosclerosis (hazard ratio [HR] 0.651, 95% confidence interval [CI] 0.451-0.941, p=0.026) (Table). In a second analysis, we included 2,064 patients with HP-eradicated and 2,064 HP-naive subjects, after PSM at a 1:1 ratio. In a Cox-proportional hazard analysis, the risk of ischemic stroke and cerebral atherosclerosis was not significantly different between the two groups (HR 1.109, 95% CI 0.777-1.584, p=0.569).

Conclusion

This large prospective observational cohort study suggested that HP eradication has preventive effect on the ischemic stroke and cerebral atherosclerosis.