Helicobacter pylori seroprevalence in patients with chronic obstructive pulmonary disease and its relation to pulmonary function tests

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.

A Bidirectional Label Propagation Based Computational Model for Potential Microbe-Disease Association Prediction

A growing number of clinical observations have indicated that microbes are involved in a variety of important human diseases. It is obvious that in-depth investigation of correlations between microbes and diseases will benefit the prevention, early diagnosis, and prognosis of diseases greatly. Hence, in this paper, based on known microbe-disease associations, a prediction model called NBLPIHMDA was proposed to infer potential microbe-disease associations. Specifically, two kinds of networks including the disease similarity network and the microbe similarity network were first constructed based on the Gaussian interaction profile kernel similarity. The bidirectional label propagation was then applied on these two kinds of networks to predict potential microbe-disease associations. We applied NBLPIHMDA on Human Microbe-Disease Association database (HMDAD), and compared it with 3 other recent published methods including LRLSHMDA, BiRWMP, and KATZHMDA based on the leave-one-out cross validation and 5-fold cross validation, respectively. As a result, the area under the receiver operating characteristic curves (AUCs) achieved by NBLPIHMDA were 0.8777 and 0.8958 ± 0.0027, respectively, outperforming the compared methods. In addition, in case studies of asthma, colorectal carcinoma, and Chronic obstructive pulmonary disease, simulation results illustrated that there are 10, 10, and 8 out of the top 10 predicted microbes having been confirmed by published documentary evidences, which further demonstrated that NBLPIHMDA is promising in predicting novel associations between diseases and microbes as well.

The Diagnostic Tests for Detection of Helicobacter pylori Infection

Helicobacter pylori causes one of the most common infections in human populations. The role of this bacterium in chronic gastritis, gastric ulcer, gastric cancer, as well as extra-digestive diseases such as ischemic heart disease and chronic obstructive pulmonary diseases, is well known. Prevention and control of these diseases can occur by early diagnosis and eradication of H. pylori infection. At present, different methods have been established to detect H. pylori infection. The biopsy-based tests, which are known as invasive methods, such as rapid urease test and histology, have the highest specificity among the others. Similarly, culture of biopsy samples is used for diagnosis of H. pylori infection. It has a high specificity value, and also allows us to perform antibiotic sensitivity testing. On the contrary, polymerase chain reaction and other molecular methods have good sensitivity and specificity, and can be used for detection of H. pylori infection, its virulence factors, and eradication success after treatment. While serological tests are more appropriate for epidemiological studies, their main weakness for clinical use is low specificity. Overall, specificity and sensitivity, cost, usefulness, and limitation of tests should be considered for selection of detection methods of H. pylori in each country.

LRLSHMDA: Laplacian Regularized Least Squares for Human Microbe-Disease Association prediction

An increasing number of evidences indicate microbes are implicated in human physiological mechanisms, including complicated disease pathology. Some microbes have been demonstrated to be associated with diverse important human diseases or disorders. Through investigating these disease-related microbes, we can obtain a better understanding of human disease mechanisms for advancing medical scientific progress in terms of disease diagnosis, treatment, prevention, prognosis and drug discovery. Based on the known microbe-disease association network, we developed a semi-supervised computational model of Laplacian Regularized Least Squares for Human Microbe-Disease Association (LRLSHMDA) by introducing Gaussian interaction profile kernel similarity calculation and Laplacian regularized least squares classifier. LRLSHMDA reached the reliable AUCs of 0.8909 and 0.7657 based on the global and local leave-one-out cross validations, respectively. In the framework of 5-fold cross validation, average AUC value of 0.8794 +/-0.0029 further demonstrated its promising prediction ability. In case studies, 9, 9 and 8 of top-10 predicted microbes have been manually certified to be associated with asthma, colorectal carcinoma and chronic obstructive pulmonary disease by published literature evidence. Our proposed model achieves better prediction performance relative to the previous model. We expect that LRLSHMDA could offer insights into identifying more promising human microbe-disease associations in the future.

Increased Exhaled 8-Isoprostane and Interleukin-6 in Patients with Helicobacter pylori Infection

BACKGROUND

Helicobacter pylori (H. pylori) infection triggers both local inflammation, usually in gastric mucosa, and chronic systemic inflammation. It is assumed that this local and systemic inflammation is caused by extracellular products excreted by H. pylori. The aim of this study was to investigate the possible association between H. pylori infection and a local inflammatory response in the airway by using exhaled breath condensate technique.

MATERIALS AND METHODS

This study includes 41 H. pylori seropositive patients who have gastric symptoms and 27 healthy control subjects. Pulmonary function tests (PFT), chest X ray, and physical examination were performed in all patients and interleukin-6 (IL-6), 8-isoprostane and nitrotyrosine levels were measured in exhaled breath condensate.

RESULTS

Levels of IL-6 and 8-isoprostane in exhaled breath condensate (EBC) were significantly higher in H. pylori positive patients than control subjects (p < 0.05). Nitrotyrosine levels were also higher in H. pylori positive patients but the difference was not statistically significant. Both groups had similar leukocyte counts, C-reactive protein (CRP) levels and PFT parameters.

CONCLUSION

H. pylori infection causes an asymptomatic airway inflammation which can be detected by exhaled breath condensate. The clinical importance of this inflammation remains unclear.

Association between Helicobacter pylori seropositivity and mild to moderate COPD: clinical implications in an Asian country with a high prevalence of H. pylori

Background

Helicobacter pylori infection is a major cause of gastric diseases. The clinical implications of H. pylori infection in various diseases outside the gastrointestinal system have also been reported, including in some respiratory disorders. In this study, we investigated the seroprevalence of H. pylori in patients with mild to moderate COPD in an Asian country with a high prevalence of H. pylori infection. Also, we aimed to elucidate the association between the seroprevalence of H. pylori and the decline of lung function in patients with COPD.

Methods

Participants who underwent a medical checkup for H. pylori at a referral hospital in Korea were recruited for this study. All participants were tested for H. pylori infection using an immunoassay of the H. pylori-specific immunoglobulin G (IgG) concentration and a rapid urease test at the time of endoscopy with a gastric mucosal specimen. We assessed the decline in lung function using the spirometric data of those who underwent spirometry more than three times.

Results

In total, 603 participants (201 patients with COPD and 402 controls) were analyzed. The seroprevalence of H. pylori IgG in the patients and controls was 45.8% and 52.2%, respectively (P=0.134). The H. pylori IgG level in patients with COPD was not significantly different from that of the controls (114.8 and 109.6 units/mL, respectively; P=0.549). In addition, there were no significant differences in the annual forced expiratory volume in 1 second or forced vital capacity between the participants with H. pylori seropositivity and seronegativity.

Conclusion

This study showed no relationship between H. pylori infection and COPD in a country with a high burden of H. pylori infection. Furthermore, H. pylori infection did not affect the rate of lung function decline in this study population.

Helicobacter pylori Infection Increase the Risk of Myocardial Infarction: A Meta-Analysis of 26 Studies Involving more than 20,000 Participants

BACKGROUND

Myocardial infarction is a fatal cardiovascular disease and one of the most common death causes all around the world. The aim of the meta-analysis was to quantify the risk of myocardial infarction associated with Helicobacter pylori infection.

METHODS

A literature search was performed to identify studies published before 14 July, 2014, for relevant risk estimates. Fixed and random effect meta-analytical techniques were conducted for myocardial infarction.

RESULTS

Twenty-six case-control studies involving 5829 myocardial infarction patients and more than 16,000 controls were included. Helicobacter pylori infection was associated with an increased risk of myocardial infarction (OR: 2.10, 95%CI: 1.75-2.53, p = .06). We also discovered a significant association between the bacteria and risk of myocardial infarction in young people (OR: 1.93, 95% CI: 1.41-2.66, p = .07), in elder people (OR: 2.02, 95% CI: 1.60-2.54, p = .29), in Caucasians (OR: 2.29, 95% CI: 1.99-2.63, p = .12), and in Asians (OR: 1.75, 95% CI: 1.12-2.73, p = .08).

CONCLUSION

Our meta-analyses suggested a possible indication of relationship between Helicobacter pylori infection and the risk of myocardial infarction. The pathogenicity might not be affected by age and race. More researches should be conducted to explore the mechanisms involved.

The relationship between Helicobacter pylori seropositivity and COPD

RATIONALE

Chronic systemic infections such as those with Helicobacter pylori (H. pylori) may contribute to the evolution and progression of chronic obstructive pulmonary disease (COPD). Using data from the Lung Health Study (LHS), we determined the relationship of H. pylori infection with the severity and progression of COPD.

METHODS

Using an immunoassay, we measured H. pylori immunoglobulin G (IgG) antibody titres in serum samples of 4765 patients with mild-to-moderate COPD. We then determined their relationship with the individual's FEV1 and the rate of decline in FEV1 and mortality over 11 years using multiple regression analysis.

RESULTS

Approximately 18% of the patients were seropositive to H. pylori and these individuals demonstrated lower FEV1 (L) values at every study visit compared with individuals who were seronegative for H. pylori (p value=0.00012). However, patients with seropositivity to H. pylori were on average 0.012 m shorter than those with seronegativity (p value=0.0015). The significant relationship between FEV1 and H. pylori seropositivity disappeared when FEV1 per cent predicted (FEV1pp) was used (p value=0.45). H. pylori seropositive individuals had greater circulating C reactive protein (CRP) levels compared with H. pylori seronegative individuals (p value=0.012), and had increased risk of cardiovascular mortality (relative risk 1.61, p=0.05).

CONCLUSIONS

H. pylori infection was associated with reduced lung function that is most likely due to the effect of the bacterium on lung growth earlier in life. It is also associated with systemic inflammation and increased risk of cardiovascular mortality in patients with COPD.

TRIAL REGISTRATION NUMBERS

NCT00000568 and NCT00000569.

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 infections in chronic obstructive pulmonary disease

OBJECTIVE

We aimed to investigate the prevalence of Helicobacter pylori (H. pylori) in patients with chronic obstructive pulmonary disease (COPD) using the C-14 urea-breath test (C14UBT) and to determine whether there is an association between H. pylori infection and the severity of COPD. This is the first report in the literature of the use of C14UBT to investigate the prevalence of H. pylori in patients with COPD.

MATERIALS AND METHODS

Fifty subjects with COPD (38 males and 12 females, aged 61±10 years) and 20 control subjects (10 males and 10 females, aged 55±11 years) were evaluated. C14UBT was used to determine H. pylori infection.

RESULTS

The prevalences of H. pylori infection in subjects with COPD and in controls were 72% and 65%, respectively (p=0.56). Forced expiratory volume in one second (FEV1) and forced vital capacity (FVC) values were significantly higher in the H. pylori-infected subjects with COPD than in the uninfected subjects (p=0.008 and p=0.006, respectively).

CONCLUSION

The presence of H. pylori infection in COPD patients affects pulmonary functions, but the effects of H. pylori infection on the respiratory system and COPD are not clear.

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.

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.

Factors affecting first-line triple therapy of Helicobacter pylori including CYP2C19 genotype and antibiotic resistance

BACKGROUND

Emerging evidence shows that the eradication rate of proton pump inhibitor (PPI)-based triple therapy for the first-line treatment of Helicobacter pylori (H. pylori) has decreased.

AIMS

To clarify the trend of eradication rate of PPI-based triple therapy and to assess the related factors in Korea during the past decade.

METHODS

We prospectively prescribed the triple regimen for seven days (PPI + amoxicillin 1.0 g + clarithromycin 500 mg, twice a day) from March 2003 to May 2013 in 2,202 H. pylori-positive patients. Antibiotic susceptibility tests were performed by the agar dilution method, and the CYP2C19 genotype was determined by the PCR method.

RESULTS

In the past decade, the annual eradication rate showed a decreasing trend in intention-to-treat and per-protocol analyses (P = 0.001, both). The antibiotic resistance was increased to amoxicillin (7.2-17.2%, P = 0.003) and clarithromycin (23.2-37.3%, P = 0.010) during the study period. The poor metabolizer genotype of CYP2C19 showed a high eradication rate compared to the extensive metabolizer (86.8 vs. 78.2%, P = 0.035). In addition, age ≥ 50 years, female gender, BMI < 25 kg/m(2), amoxicillin and/or clarithromycin resistance were associated with treatment failure on univariate analysis. However, on multivariate analysis, clarithromycin resistance was the only significant factor for treatment failure (OR, 12.76; 95% CI, 5.58-29.18; P < 0.001).

CONCLUSIONS

An increase in clarithromycin resistance has led to decreased eradication rate of first-line triple therapy, and; hence, a new strategy is needed to improve the eradication rate of H. pylori.

Can Helicobacter pylori infection influence human reproduction?

Helicobacter pylori (H. pylori) infection could be associated with extra-digestive diseases. Here, we report the evidences concerning the decrease in reproductive potential occurring in individuals infected by H. pylori, especially by strains expressing CagA. This infection is more prevalent in individuals with fertility disorders. Infected women have anti-H. pylori antibodies in cervical mucus and follicular fluid that may decrease sperm motility and cross react immunologically with spermatozoa, conceivably hampering the oocyte/sperm fusion. Infection by CagA positive organisms enhances the risk of preeclampsia, which is a main cause of foetus death. These findings are supported by the results of experimental infections of pregnant mice, which may cause reabsorption of a high number of foetuses and alter the balance between Th1 and Th2 cell response. Infected men have decreased sperm motility, viability and numbers of normally shaped sperm and augmented systemic levels of inflammatory cytokines, such as tumor necrosis factor-α, which may damage spermatozoa. In countries where parasitic infestation is endemic, detrimental effects of infection upon spermatozoa may not occur, because the immune response to parasites could determine a switch from a predominant Th1 type to Th2 type lymphocytes, with production of anti-inflammatory cytokines. In conclusion, the evidences gathered until now should be taken into consideration for future studies aiming to explore the possible role of H. pylori infection on human reproduction.

Urease and Helicobacter spp. antigens in pulmonary granuloma

Pulmonary sarcoidosis, a human disease of unknown cause, has no animal model. Sarcoidosis patients have serum antibodies specific for Helicobacter pylori and its surface enzyme urease. H. pylori do not survive in the high-oxygen pulmonary atmosphere, but urease may access the lung by oesophageal reflux. A model was established in rats to study gastro-oesophageal reflux of urease into the airways. Pathology in tissues from human sarcoidosis patients was compared with that in the rat model. Changes observed in the rat model included prominent peribronchial lymphocytic infiltration, which is seen occasionally in human sarcoidosis. Granulomas, pathognomonic for human sarcoidosis, occurred occasionally in the lungs of rats given urease protein intratracheally, but were widespread when urease was coupled to microbeads and administered intravenously. Biomarkers associated with human sarcoidosis (interleukin1-β and platelet-activating factor) were up-regulated acutely in the rat model. Further investigations with this model may provide significant insights into the origin and pathogenesis of pulmonary diseases in man and other species that carry gastric Helicobacter spp. and its associated enzyme.

[The trend of eradication rate of Helicobacter pylori infection and clinical factors that affect the eradication of first-line therapy]

BACKGROUND/AIMS

Although triple combination therapy containing a proton pump inhibitor (PPI) and two antibiotics is considered as a standard regimen for the first-line anti-Helicobacter pylori treatment, the recent trend of eradication rates following this therapy has been declined in the last few years. The purpose of this study was to investigate the trend of H. pylori eradication rates over the last 9 years and to evaluate are clinical factors affecting eradication rates.

METHODS

From January 2001 to June 2009, H. pylori eradication rates in 709 patients with documented H. pylori infection who received triple combination therapy for 7 days were retrospectively evaluated according to years and various clinical factors. H. pylori status was evaluated by 13C urea breath test 4-6 weeks after completion of treatment. results: The overall H. pylori eradication rate was 77.0%. The annual eradication rates from year 2001 to 2009 were 78.9%, 72.5%, 81.0%, 75.0%, 79.1%, 77.1%, 77.8%, 77.8%, and 75.0% by per-protocol analysis. There was no decreasing tendency of the eradiation rate over 9 years (p=0.974). There was no statistical difference in the eradication rates according to age, sex, smoking, alcohol, NSAIDs, underlying diseases, endoscopic diagnosis, and PPI. However, the eradication rate was lower in patients who took aspirin (OR=0.509, 95% CI=0.292-0.887, p=0.001) and antibiotics within 6 months (OR=0.347, 95% CI=0.183-0.658, p=0.001).

CONCLUSIONS

The H. pylori eradication rate has not changed at Gwangju-Chonnam province in Korea for recent 9 years. Lower eradication rate in aspirin and antibiotics users warrants further attention.

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.

Helicobacter pylori and extragastric diseases

Since the discovery of Helicobacter pylori, several studies have investigated the hypothetical role of this bacterium in various extragastric diseases, e.g. ischemic heart disease, idiopathic thrombocytopenic purpura, iron-deficiency anaemia, and other disorders. The majority of these studies are epidemiological or eradication trials, but there are also case reports and in-vitro studies. Idiopathic thromobocytopenic purpura is the disease that shows the strongest link with H. pylori infection. There is also evidence of a role of CagA-positive H. pylori infection in iron-deficiency anaemia and ischemic heart disease. The association between H. pylori infection and other extragastric diseases remains controversial, being mostly supported by 'case reports', small pilot studies, or just in-vitro data. Further studies are needed to identify whether there is any pathological implication for H. pylori infection in these diseases.