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

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 pylori is associated with weakened pulmonary function and reduced incidence of allergic conditions in patients with chronic cough

The present study aimed to investigate the potential association between Helicobacter pylori (a H. pylori) positive state and chronic cough. A clinical observational study with systematic analysis was performed, including 278 patients with complaints of chronic cough and 148 healthy controls. a H. pylori positive state was present in 61.2% of the patients in the chronic cough group and 68.9% in the chronic refractory cough group, as opposed to 43.9% in the control group. There was a significant improvement in 65.5% of the patients with chronic refractory cough following successful a H. pylori eradication therapy. In addition, patients with chronic cough exposed to a H. pylori exhibited decreased pulmonary function with a decrease in forced expiratory volume in 1 sec by 84 ml, a decrease in the forced vital capacity by 53 ml and a decrease in maximal vital capacity by 46 ml. The difference was even more obvious in the chronic refractory cough group. The allergy status differed significantly according to age between a H. pylori-positive and -negative cases in the cough variant asthma and allergic cough groups. Among patients aged <40 years, a H. pylori-positive cases had a lower prevalence of atopy and lower total serum immunoglobin E levels compared with a H. pylori-negative cases. However, there was no significant association between a H. pylori status and C-reactive protein levels, erythrocyte sedimentation rate or eosinophil count in the peripheral blood. In conclusion, the present study demonstrated that a H. pylori infection may be a factor associated with chronic cough and it may be associated with a decline in pulmonary function and reduced incidence of allergic conditions. Thus, a H. pylori may represent a target for the treatment of chronic cough.

Does Helicobacter pylori play a role in the pathogenesis of non-cystic fibrosis bronchiectasis?

BACKGROUND

The aim of this study was to investigate whether Helicobacter pylori plays a role in the pathogenesis and severity of non-cystic fibrosis bronchiectasis, and its relationship with gastroesophageal reflux (GER).

METHODS

Forty-one patients and 16 controls between 5 and 18 years of age were enrolled. H. pylori was investigated on polymerase chain reaction and culture in gastric juice (GJ) and bronchoalveolar lavage fluid (BALF). Urea breath test (UBT) was also used for defining H. pylori infection. GER was detected on 24 h pH monitoring or scintigraphy. Computed tomography (CT) scoring was used to quantify the severity and extent of bronchiectasis.

RESULTS

Nine patients (22%) in the bronchiectasis group (BG) and three patients (18.8%) in the control group (CG) had H. pylori-positive BALF. Sixteen BG patients (39%) and seven CG patients (43.8%) had H. pylori-positive GJ. UBT was positive in 11 BG patients (26.8%) and in three CG patients (18.8%). H. pylori positivity in BALF, GJ and UBT was not significantly different between the two groups (P > 0.05). Six patients with GER and five patients without GER in BG had H. pylori-positive BALF and GJ (P = 0.827). No association was found between BALF H. pylori positivity and forced expiratory volume in 1 s (FEV1 ) in BG. CT score was significantly higher in BG patients with H. pylori-positive compared with H. pylori-negative BALF (P < 0.05).

CONCLUSIONS

Helicobacter pylori is not associated with the pathogenesis of bronchiectasis but it may be responsible for the severity of the disease.

Screening for Helicobacter pylori in Idiopathic Pulmonary Fibrosis Lung Biopsies

BACKGROUND

Increasing evidence suggests a role of gastro-oesophageal reflux (GER) in idiopathic pulmonary fibrosis (IPF) pathogenesis. Recently, an association between serum Helicobacter pylori (HP) antibody positivity and more severe disease was described, but HP has not been directly analysed in lung tissue so far.

OBJECTIVE

To investigate the presence of HP in the lung tissue of IPF patients.

METHODS

Two tertiary interstitial lung disease care centre databases were screened for available lung biopsy material from IPF patients. Clinical and radiological data, including presence of GER and antiacid medication, were evaluated. HP-specific PCR was carried out on the IPF lung biopsy specimens.

RESULTS

A total of 39 IPF patients were included, of whom 85% were male. The patients' median age was 66 years, their vital capacity was 79% predicted, and their diffusing capacity for carbon monoxide was 53% predicted. In all, 82% of the lung biopsies were surgical and 18% transbronchial. Comorbidities were GER disease in 23% (n = 9), sleep apnoea in 13% (n = 5) and hiatal hernia in 38% of the cases (n = 15). Proton pump inhibitors were prescribed at the time of biopsy in 21% of the cases (n = 9). After a median follow-up of 25 months (range 6-69), there were 1 death, 1 lung transplantation and 8 acute exacerbations without relevant differences between the GER and non-GER subgroups. HP DNA was not detected in any of the lung tissue samples.

CONCLUSION

The fact that no HP DNA was detected in the lung tissues calls into question the proposed relevance of HP to the direct pathogenesis of IPF.

[Preparation, identification and application of monoclonal antibody against urease subuint B of Helicobacter pylori]

OBJECTIVE

To prepare and characterize the monoclonal antibody (mAb) against Helicobacter pylori (Hp) and establish a competitive ELISA used for detection of Hp antibodies in the sera of Hp-infected patients.

METHODS

BALB/c mice were immunized with inactivated Hp to generate Hp mAb using the hybridoma technology. Hp mixed proteins including cytotoxin-associated gene A (CagA), vacuolating cytotoxin A (VacA) and urease, as well as inactivated Hp were applied to screen positive hybridoma. Selected Hp mAb was analyzed and characterized with ELISA and Western blotting, and then labeled with horseradish peroxidase (HRP) for establishing a competitive ELISA to detect Hp antibodies in the sera of Hp-infected patients.

RESULTS

One Hp mAb named as C3 was selected after screening large amount of hybridoma, and the C3 Hp mAb was special for IgG2a subtype with the affinity titer of 1×10(7). Western blotting, ELISA and mass spectrum analysis indicated that the C3 Hp mAb could recognize Hp urease subunit B specifically. Using the C3 Hp mAb, we developed a competitive ELISA which could be used to detect Hp antibodies in the sera of Hp-infected patients.

CONCLUSION

We successfully obtained one mAb that could specifically recognize Hp urease subunit B and developed a competitive ELISA using the Hp mAb.

Detection of helicobacter pylori in bronchoalveolar lavage of patients with chronic obstructive pulmonary disease by real time polymerase chain reaction

Background:

Chronic obstructive pulmonary disease (COPD) is one of the most important causes of disability and mortality in the world. Although cigarette smoking and environmental pollutants have been recognized as the major causes of COPD, the role of infection in the pathogenesis and progression of COPD has also been reported.

Objectives:

The aim of the present study was to find the relationship between Helicobacter Pylori infection and COPD through anti H. pylori IgG serology, real time PCR of bronchoalveolar lavage and trans bronchial biopsy urease tests.

Patients and Methods:

This descriptive cross-sectional study was carried out on 60 adults with COPD. After obtaining the patient’s history, physical examination, spirometry and confirmation of COPD diagnosis by pulmonologist, subjects were selected through convenience sampling. In order to determine the severity and prognosis of disease, the global initiative for chronic obstructive lung disease (GOLD) criteria and BODE index were used. Subjects underwent bronchoscopy for obtaining bronchoalveolar lavage (BAL) samples and biopsy was performed. Biopsy and BAL samples were investigated respectively by urease test and real time PCR. Moreover, patients’ serum samples were serologically studied for detection of anti H. pylori IgG.

Results:

Mean age of the participants was 60.65 ± 9.15 years, and 25% were female and 75% were male. The prevalence rate of H. pylori in COPD patients was 10% according to real time PCR, 88.3% according to the serology test and 0% based on the urease test. According to the results of PCR and considering the severity of disease based on the GOLD criteria, from those with a positive PCR, one patient (16.6%) had very severe obstruction, three (50%) had severe obstruction and two patients (33.3%) had moderate obstruction. The relationship between H. pylori presence (based on PCR) and disease severity and prognosis was not statistically significant.

Conclusions:

These findings can justify the hypothesis of direct injury and chronic inflammation via inhalation and aspiration resulting in H. pylori colonization. In fact, it is thought that H. Pylori infection, beside the host genetic vulnerability and other environmental risk factors might make the patient susceptible to COPD or lead to COPD worsening. Although we found H. pylori infection in some patients with COPD, the results of this study, could not explain the pathogenic mechanisms of COPD.

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.

Extragastric manifestations of Helicobacter pylori infection -- other Helicobacters

Today there is evidence that Helicobacter pylori has a critical role in different extragastric diseases. The discovery of a number of other novel Helicobacter species has stimulated the research in different extragastric diseases, in which an infectious hypothesis is plausible. Enterohepatic Helicobacter species have been hypothesized to play a role in different disorders, including hepatocellular carcinoma, gallstones formation and cholangiocellular carcinoma, as well as enteric diseases and inflammatory bowel diseases. Concerning the extragastric manifestations of H. pylori infection, idiopathic thrombocytopenic purpura, and sideropenic anemia represent, based on the current data, the diseases in which the pathogenic link appears to be strongest. There is also an increasing evidence for a possible association of H. pylori with cardiovascular disease.