Helicobacter pylori (HP) is a well-established pathogen responsible for chronic gastritis and peptic ulcer disease. Its presence has been implicated in the development of gastric malignancies such as adenocarcinoma and mucosa-associated lymphoid tissue lymphoma. Chronic H. pylori infection is associated with systemic inflammatory responses and various extra gastric diseases, including cardiovascular, metabolic, and neurological disorders. Furthermore, H. pylori infection contributes to gastrointestinal dysbiosis by interacting with gastrointestinal microbiota, which may be involved in gastric carcinogenesis and other systemic disorders. Growing evidence highlights the role of dysbiosis in chronic respiratory diseases, such as chronic obstructive pulmonary disease (COPD) and asthma. Emerging epidemiological evidence suggests a potential association between H. pylori infection and respiratory diseases, including COPD. Several observational studies and meta-analyses have found that H. pylori infection in patients with COPD may be associated with systemic inflammatory markers and altered pulmonary function parameters. Despite these associations, the causal mechanisms underlying this relationship remain unclear. Furthermore, it is uncertain whether eradication of H. pylori yields measurable benefits on clinical outcomes in COPD patients. So, Our aim to evaluate changes in symptoms, pulmonary function, and inflammatory markers after H. pylori eradication therapy in the H. pylori-positive COPD patients.

an intervention study (quasi experimental), study will be carried out in the inpatient and outpatient clinics of Chest Department, Faculty of Medicine, Zagazig University hospitals.

Patients included in the study:

well controlled COPD patients attending outpatient clinics for a period of 6 months fulfilling inclusion and exclusion criteria will be included in this study.

An interventional study (quasi experimental), this study will be carried out in the inpatient and outpatient clinics of Chest Department, Faculty of Medicine, Zagazig University hospitals.

-Patients included in the study: well controlled COPD patients attending outpatient clinics for a period of 6 months fulfilling inclusion and exclusion criteria will be included in this study.

• Sample size and selection:

All patients diagnosed with COPD attending the study setting during the specified study period (6 months) will be consecutively screened for Helicobacter pylori infection.

All eligible patients who test positive for H. pylori will be included in the intervention phase and will receive eradication therapy.

Therefore, a consecutive sampling technique will be applied, all available cases during the study period will be recruited. Based on the expected patient flow, approximately 108 COPD patients are anticipated over 6 months, with an estimated H. pylori prevalence of around 50% ((Abdelmagied etal., 2019), yielding about 54 cases for the intervention phase.

All patients will be subjected to the following:

1. Recruitment of COPD patients based on clinical diagnosis and spirometry.
2. Collection of baseline demographics, smoking history, comorbidities, exacerbation and hospitalization rate in past year.
3. Assess H. pylori status using Stool antigen test for H. pylori by using rapid antigen test (lateral flow immune chromatographic test with a monoclonal antibody). It has a positive line to indicate a positive reading accompanied by a control line. The test has been reported sensitivity and specificity (94% and 98% respectively.
4. Perform COPD Assessment Test (CAT): The COPD Assessment Test (CAT) is a questionnaire for people with COPD. It is designed to measure the impact of COPD on a person's life, and how this change over time. The CAT is a standard and validated test containing eight items for the evaluation of the impact of COPD on health status.
5. Perform baseline spirometry and laboratory markers.
6. Assess severity of COPD according to GOLD criteria: stage 1 (FEV1 ≥80%), stage 2 (50% ≤FEV1 <80%), stage 3 (30% ≤FEV1 <50%), and stage 4 (FEV1 <30%).
7. For H. pylori-positive COPD patients: administer standard eradication therapy according to current guidelines (e.g., triple or quadruple therapy with proton pump inhibitor and antibiotics). Confirm eradication at least 4-6 weeks after therapy completion via repeat testing.
8. Reassess COPD symptoms, lung function, and biomarkers 3months after successful H. pylori eradication.
9. Follow up H. Pylori-positive COPD patients for 3months by reassessment of COPD symptoms, lung function and biomarkers.

Inclusion Criteria:

• Adults aged ≥40 years.
• Diagnosed with COPD confirmed by spirometry (post-bronchodilator FEV1/FVC < 0.70) and H. pylori positive.
• Willing to participate and provide consent for testing and follow-up.

Exclusion Criteria:

• patients with asthma, known peptic ulcers, acute exacerbation of COPD
• patients who took antibiotics and PPIs within the last month,
• Patients who took histamine-2-receptor antagonists within the last week or antacid within the last 24 hours a
• those having H. pylori eradication treatment within the last 6 months

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