High seroprevalence of Helicobacter pylori in chronic bronchitis among Chinese population

Helicobacter pylori and Respiratory Diseases: 2021 Update

Helicobacter pylori (H. pylori) is a Gram-negative bacterium involved in the development of gastritis, peptic ulcer disease, gastric adenocarcinoma, and gastric mucosa-associated lymphoid tissue. Unexplained iron deficiency anemia, idiopathic thrombocytopenic purpura and vitamin B12 deficiency have also been related to H. pylori infection, whereas for other extra-gastric diseases, the debate is still open. In this review, we evaluate and discuss the potential involvement of H. pylori infection in the pathogenesis of several respiratory diseases. A MEDLINE search of all studies published in English from 1965 to 2021 was carried out. Controversial findings have been reported in patients with bronchial asthma, chronic obstructive pulmonary disease, bronchiectasis, lung cancer, tuberculosis, cystic fibrosis, and sarcoidosis. Most of the available literature is concerned with case-control studies based on seroprevalence, with a small sample size and low consideration of confounders, which represents a potential issue. So far, there is no clear evidence of a causal association between H. pylori infection and respiratory diseases, and larger studies with appropriate epidemiological design are required.

Helicobacter, Hygiene, Atopy, and Asthma

The hygiene hypothesis links environmental and microbial exposures in early life to the prevalence of atopy, allergy, and asthma. Helicobacter pylori infection is typically acquired in childhood and acquisition of the infection is associated with poor household hygiene. Some population surveys have shown an inverse association between H. pylori infection and atopy, allergy, and asthma leading to the suggestion that H. pylori infection may be protective against disease; others consider it simply a biomarker for poor household hygiene. We review the relevant surveys, cohort studies, meta-analyses, and studies testing the protective hypothesis. Overall, the results of surveys and cohort studies are inconsistent, whereas meta-analyses show a significant but weak inverse correlation. In contrast, studies directly testing the protection hypothesis in relation to asthma in populations with poor hygiene and low H. pylori prevalence failed to confirm a protective effect. H. pylori is a major cause of human disease including chronic gastritis, peptic ulcer, and gastric malignancies. H. pylori infections most likely serve as a biomarker for poor hygienic conditions in childhood. We conclude that while synergistic interactions between environmental factors in childhood are important determinants of the pathogenesis of atopy, allergy, and asthma; H. pylori is inversely related to good hygiene and thus it's presence serves as a biomarker rather than for a specific prevention role for H. pylori or H. pylori antigens.

Increased risk of chronic obstructive pulmonary disease among patients with Helicobacter pylori infection: a population-based cohort study

BACKGROUND

Increasing evidence suggests that Helicobacter pylori infection (HPI) may have extragastric manifestations, including the respiratory system. This study investigated the role of HPI in increasing the subsequent risk of chronic obstructive pulmonary disease (COPD) in a nationwide population.

METHODS

We conducted this retrospective cohort study using data from the Longitudinal Health Insurance Database, which is derived from the Taiwanese National Health Insurance Research Database. A total of 5941 adults who were newly diagnosed with HPI between 2005 and 2006 were selected. Healthy patients without HPI were selected from the general population and frequency matched as a ratio of 4:1, according to age, sex, and index years. Both cohorts were followed up from the index date to the end of 2011 to measure the incidence of COPD. Cox proportional hazard regression analysis was used to assess the hazard ratio (HR) of COPD between the HPI cohort and non-HPI cohorts.

RESULTS

The overall HR of COPD was 1.84 (95% confidence intervals = 1.57-2.17) for the HPI cohort, compared with the non-HPI cohort, after adjusting for age, sex, and comorbidities. Although the incidence of COPD was substantially higher in the elderly participants (age, ≥ 65 years) than that in younger participants, the highest HR (4.05, 95% confidence intervals = 1.39-11.8) of COPD was observed in the youngest (age, 20-49 years) participants.

CONCLUSION

In this study, the patients with HPI exhibited a significantly higher risk of COPD than those without HPI did.

Association of Helicobacter pylori infection with chronic obstructive pulmonary disease and chronic bronchitis: a meta-analysis of 16 studies

BACKGROUND

Chronic obstructive pulmonary disease (COPD) and chronic bronchitis (CB) are common respiratory diseases globally. The aim of this meta-analysis was to quantify the risk of these two diseases being associated with Helicobacter pylori infection.

METHODS

A literature search was performed to identify studies published before 5 June 2014 for relevant risk estimates. Fixed and random effect meta-analytical techniques were conducted for COPD and CB.

RESULTS

Sixteen observational studies involving 1390 patients with COPD, 734 with CB and more than 13 000 controls were included. Helicobacter pylori infection was associated with an increased risk of COPD and CB [odds ratio (OR) 2.07, 95% confidence interval (CI) 1.81-2.36, p for heterogeneity = 0.05; and OR 1.57, 95% CI 1.33-1.86, p for heterogeneity = 0.08]. We discovered a significant association between CagA-positive strains and risk for COPD (OR 3.46, 95% CI 2.29-5.25, p for heterogeneity = 0.20).

CONCLUSIONS

Our meta-analysis suggested a potential relationship between H. pylori infection and the development of COPD and CB.

Helicobacter pylori infection and atopic diseases: Is there a relationship? A systematic review and meta-analysis

AIM: To review and conduct a meta-analysis of the existing literature on the relationship between Helicobacter pylori (H. pylori), atopy and allergic diseases.

METHODS: Studies published in English assessing the prevalence of atopy and/or allergic diseases in patients with H. pylori infection and the prevalence of H. pylori infection in patients with atopy and/or allergic diseases were identified through a MEDLINE search (1950-2014). Random-effect model was used for the meta-analysis.

RESULTS: Pooled results of case-control studies showed a significant inverse association of H. pylori infection with atopy/allergic disease or with exclusively atopy, but not with allergic disease, whereas pooled results of cross-sectional studies showed only a significant association between allergic disease and H. pylori infection.

CONCLUSION: There is some evidence of an inverse association between atopy/allergic diseases and H. pylori infection, although further studied are needed.

Association Between Chronic Respiratory Diseases and Helicobacter pylori: A Meta-Analysis

BACKGROUND

The prevalence of chronic respiratory diseases (CRDs), including chronic bronchitis and chronic obstructive pulmonary disease (COPD), has increased significantly over the past decades. Several studies suggest that Helicobacter pylori infection may be related to the development of CRDs, but the results were not consistent. We carried out a meta-analysis to evaluate the potential association of H.pylori infection with CRDs.

METHODS

We conducted a systematic literature search in PubMed, Embase, Ovid, Google Scholar and CNKI from inception to October 31, 2013. The following search terms were used: "chronic respiratory disease," "chronic bronchitis," "chronic obstructive pulmonary disease" or "COPD" in combination with "Helicobacter pylori" or "Campylobacter pylori." According to established inclusion criteria, we selected all eligible published papers and then extracted essential data. To evaluate the association of H.pylori with chronic bronchitis and COPD, an overall analysis and subgroup analyses were conducted.

RESULTS

A total of 9 case-control studies comprising 782 cases and 815 controls were included in the study. Pooled ORs were 2.30 (95%CI: 1.85-2.85) in the overall analysis, 2.90 (95%CI: 2.04-4.13) in the chronic bronchitis subgroup, and 2.11 (95%CI: 1.35-3.29) in the COPD subgroup.

CONCLUSIONS

The results of the overall analysis and subgroup analyzed suggest a significant association between H.pylori and CRDs. Further studies are needed to clarify the pathogenetic mechanisms involved.

Helicobacter pylori infection and lung cancer: a review of an emerging hypothesis

Helicobacter pylori (Hp) is one of the most common bacteria infecting humans. Recently, certain extragastric manifestations, linked to Hp infection, have been widely investigated, suggesting that Hp infection might be a 'systemic' disease. Accumulating, yet limited, evidence points to a potential association between Hp infection and lung cancer risk. Epidemiologic studies have shown that odds ratios (estimated relative risks) of lung cancer with Hp infection range from 1.24 to 17.78 compared with the controls, suggesting an increased lung cancer risk in the population exposed to Hp infection although far from supporting a causal relationship between Hp and lung cancer. Many studies have demonstrated the existence of Hp in the mucosa of the upper respiratory tract with no direct evidence of Hp-localization in lung tissue in the published literatures, rendering the possible functional mechanism underlying the association an open question. We followed the classic hypothesis-generating path, where we have thoroughly reviewed the publications on lung cancer and Hp infection from serological association to possible mechanisms as: (i) p130cas activated by Src kinase following Hp-host communication and p130cas-related carcinogenesis as in various malignancies; and (ii) gastroesophageal reflux and inhalation of urease or gastrin, which are Hp-related carcinogenic factors and present in lung tissues. We propose rigorous investigations regarding the Hp-lung cancer association and, if confirmed, the mechanisms of Hp infection leading to lung cancer development and progression. Clarification on Hp-lung cancer association is important for the understanding of lung cancer beyond tobacco-smoking-related carcinogenesis.

Association between Helicobacter pylori and liver-to-spleen ratio: a randomized-controlled single-blind study

BACKGROUND AND AIM

Helicobacter pylori infection is reported to be associated with some extragastrointestinal manifestations, such as hematological diseases (thrombocytopenia, anemia), obesity, and fatty liver disease. The length or the volume ratio of liver to spleen was suggested to be changed in some hematological and hepatobiliary disorders. We hypothesized that the liver-to-spleen ratio may be affected in H. pylori-positive patients. In this respect, we aimed to evaluate the effect of H. pylori infection on the liver-to-spleen ratio and platelet indices.

METHOD

A total of 174 patients with functional dyspepsia were included in the study. Patients were divided into group 1 (H. pylori-positive gastritis) (n=95) and group 2 (H. pylori negative, control group) (n=79). Liver, spleen length measurement, and liver steatosis scores were performed by ultrasonography by the same physicians who were blinded to the H. pylori results. Blood count values including the platelet count and the mean platelet volume (MPV) were compared between the two groups. BMI was also evaluated as a potential confounding factor for fatty liver.

RESULTS

The liver-to-spleen ratio, platelet-to-spleen ratio, MPV-to-spleen ratio, and the MPV-to-liver ratio were significantly lower in the H. pylori-positive group compared with the H. pylori-negative group (P<0.001, <0.001, <0.001, and 0.038, respectively). Fatty liver was significantly more frequent in H. pylori-positive patients.

CONCLUSION

Liver-to-spleen ratio and the MPV-to-spleen ratio are important indices in the pathogenesis of H. pylori-linked liver and spleen manifestations, and thrombocytopenia.

Gastroesophageal Reflux Disease and Helicobacter pylori: What May Be the Relationship?

Relationship between Helicobacter pylori (H. pylori) and gastroesophageal reflux disease (GERD) is controversial. We aimed to review the possible relationship between H. pylori infection and GERD. Epidemiological data indicate an inverse relationship between frequency of H. pylori infection and prevalence of GERD and its complications like Barrett's esophagus and esophageal adenocarcinoma. H. pylori eradication in patients with peptic ulcer disease may be associated with increased risk of development of GERD compared with untreated patients. Infection with cagA bearing strains of H. pylori was associated with less severe GERD including endoscopic esophagitis, possibly due to pangastritis leading to hypochlorhydria. Recent studies on inflammatory markers (IL-1β and IL-1RN) suggest pro-inflammatory genotypes to be protective against development of severe GERD, especially in patients with H. pylori infection. Identification of candidate genes playing an important role in gastric acid secretion and visceral hypersensitivity to the esophageal epithelium might help in early detection of individuals susceptible to develop GERD. Interplay between H. pylori and host factors play an important role in the pathogenesis of GERD.

Advances in understanding the association of Helicobacter pylori infection with extragastric diseases

Helicobacter pylori (H. pylori) infection is one of the most common human infections worldwide. It is associated with the development of a number of important upper gastrointestinal (GI) diseases such as chronic gastritis, peptic ulcer and gastric malignancy. At present, there is evidence that H. pylori infection probably plays a critical role in the development of some extragastric diseases. However, there is still controversy over such association. In this article, we will give an overview of the recent advances in understanding the association of H. pylori infection with extragastric diseases.

[Comparison of clinical characteristics and outcomes between geriatric and non-geriatric patients in peptic ulcer bleeding]

BACKGROUND/AIMS

In geriatric patients with peptic ulcer, the use of NSAID and prevalence of chronic illness have been increased, but the Helicobacter pylori (H. pylori) infected portion decreased. The aim of this study was to evaluate the clinical characteristics and outcomes of geriatric patients (aged 65 or older) with peptic ulcer bleeding and compare with non-geriatric patients (less than 65 years old).

METHODS

We conducted a retrospective study of 88 patients with peptic ulcer bleeding treated with therapeutic endoscopy from January 2006 to December 2006. We compared the clinical characteristics and outcomes of geriatric patients (n=34, 38.6%) with those of non-geriatric patients (n=54, 61.4%).

RESULTS

Hypertension (52.9% vs. 24.1%), cardiovascular disease (35.3% vs. 13.0%), and chronic obstructive pulmonary disease (20.6% vs. 3.7%) were more prevalent in the geriatric group, compared with the non-geriatric group (p<0.05). The geriatric group had taken more ulcerogenic drugs than the non-geriatric group (64.7% vs. 33.3%, p<0.05); aspirin plus clopidogrel (23.6% vs. 13.0%) and aspirin (20.6% vs. 11.0%). Sixteen (21.1%) of the 76 cases had H. pylori-negative ulcer. Between the two groups, there was no difference in the prevalence of H. pylori-negative ulcer (25.9% vs. 18.4%, p>0.05). The amount of transfusion length of ICU stay, rebleeding rate, operation rate and mortality were not different between the two groups. The length of hospital stay in the geriatric patients was significantly longer than the non-geriatric group (12.3+/-10.6 vs. 7.2+/-5.9 days, p<0.05). In multiple regression analysis, old age was a significant risk factor for longer hospital stay (p<0.05).

CONCLUSIONS

The geriatric patients with bleeding peptic ulcer had longer hospital stay than the non-geriatric patients in our study. The important emerging etiologies such as ulcerogenic drug and associated chronic illness should be checked and treated in these patients.

Helicobacter pylori in Bronchiectasis: A Polymerase Chain Reaction Assay in Bronchoalveolar Lavage Fluid and Bronchiectatic Lung Tissue

BACKGROUND

A number of studies have implicated an association between H. pylori and diverse extra-gastroduodenal pathologies. Chronic inflammation and increased immune response have been observed in bronchiectasis, likely gastroduodenal inflammatory diseases. H. pylori has been found in the trachea-bronchial aspirates of mechanically ventilated patients. Furthermore, the seroprevalence of H. pylori was found to be significantly higher in patients with bronchiectasis than in the control group. The present study was performed to investigate the possible role of H. pylori in the pathogenesis of bronchiectasis.

METHODS

Prospectively, bronchoalveolar lavage fluid (BALF) was obtained from patients with bronchiectasis (n=26) and control (n=20). BALF was subjected to polymerase chain reaction (PCR) to determine the presence of H. pylori and serum IgG against H. pylori was determined with micro-ELISA kit. In addition, PCR was performed to determine H. pylori in surgically removed lung tissues from patients with bronchiectasis (n=97).

RESULTS

H. pylori DNA was not detected in the BALF or in lung tissue samples. In addition, anti-H. pylori IgG level in patients with bronchiectasis did not show statistically significant difference from that of the control.

CONCLUSIONS

Our study provided evidence that there might be no direct association between H. pylori and bronchiectasis; however, the indirect role of soluble products of H. pylori could not be excluded.