Is there any relationship between asthma and asthma attack in children and atypical bacterial infections; Chlamydia pneumoniae, Mycoplasma pneumoniae and Helicobacter pylori

Helicobacter pylori infection causes both protective and deleterious effects in human health and disease

Infection with Helicobacter pylori (H. pylori) is necessary but not sufficient for the development of gastric cancer, the third leading cause of cancer death globally. H. pylori infection affects over half of people globally; however, it does not affect populations uniformly. H. pylori infection rates are declining in western industrialized countries but are plateauing in developing and newly industrialized countries where gastric cancer is most prevalent. Despite H. pylori infection being the primary causative agent for gastric cancer, H. pylori infection can also cause other effects, detrimental or beneficial, throughout an individual's life, with the beneficial effects often being seen in childhood and the deleterious effects in adulthood. H. pylori is an ancient bacterium and its likelihood of affecting disease or health is dependent on both human and bacterial genetics that have co-evolved over millennia. In this review, we focus on the impact of infection and its genetic bases in different populations and diseases throughout an individual's lifespan, highlighting the benefits of individualized treatment and argue that universal eradication of H. pylori in its host may cause more harm than good for those infected with H. pylori.

Mycoplasma pneumoniae infection and risk of childhood asthma: A systematic review and meta-analysis

The etiology of childhood asthma is multifactorial, atypical bacterial pathogens, including Mycoplasma pneumoniae, have been proposed as possible risk factors or contributors. This review aims to assess the possible association between M. pneumoniae infection and childhood asthma. We searched major international literature databases (up to January 10, 2021) to identify relevant studies. We used a random-effects meta-analysis (REM) model to generate the pooled odds ratio (OR) and 95% confidence intervals (CIs). Several subgroups analyses were performed concerning the IgG, IgM, and DNA detection of M. pneumoniae infection. We included 22 eligible studies; these studies involved a total of 5064 children. We found that there was a statistically significant association between M. pneumoniae infection, as determined by IgM serology (OR, 3.13; 95% CI, 1.78-5.48), and DNA detection (OR, 1.57; 95% CI, 1.25-1.97) with increased risk of any type of childhood asthma. Moreover, children with acute asthma had significantly higher seropositivity for anti- M. pneumoniae IgM antibodies (OR, 4.43; 95% CI, 2.80-7.02) than children with stable asthma. Although our findings indicate a positive association between M. pneumoniae infection and childhood asthma, well-designed and -controlled studies are need in the future to rigorously test this association and identify the underlying mechanisms.

Chlamydia pneumoniae and chronic asthma: Updated systematic review and meta-analysis of population attributable risk

Background

Chlamydia pneumoniae (Cp) is an obligate intracellular human respiratory pathogen producing persisting lung infection with a plausible link to asthma pathogenesis. The population attributable risk of potentially treatable Cp infection in asthma has not been reported.

Methods

The author searched from 2000 to 2020 inclusive for previously un-reviewed and new cross sectional and prospective controlled studies of Cp biomarkers and chronic asthma in both children and adults. Qualitative descriptive results and quantitative estimates of population attributable risk for selected biomarkers (specific IgG, IgA and IgE) are presented.

Findings

No large, long-term prospective population-based studies of Cp infection and asthma were identified. About half of case-control studies reported one or more significant associations of Cp biomarkers and chronic asthma. Heterogeneity of results by age group (pediatric v adult asthma), severity category (severe/uncontrolled, moderate/partly controlled, mild/controlled) and antibody isotype (specific IgG, IgA, IgE) were suggested by the qualitative results and confirmed by meta-analyses. The population attributable risks for Cp-specific IgG and IgA were nul in children and were 6% (95% confidence interval 2%-10%, p = 0.002) and 13% (9%-18%, p<0.00001) respectively in adults. In contrast to the nul or small population attributable risks for Cp-specific IgG and IgA, the population attributable risk for C. pneumoniae-specific IgE (children and adults combined) was 47% (39%-55%, p<0.00001). In the subset of studies that reported on asthma severity categories, Cp biomarkers were positively and significantly (P<0.00001) associated with asthma severity.

Interpretation

C. pneumoniae-specific IgE is strongly associated with asthma and asthma severity, suggesting a possible mechanism linking chronic Cp infection with asthma in a subset of individuals with asthma. Infection biomarkers should be included in future macrolide treatment trials for severe and uncontrolled asthma.

Association between Helicobacter pylori and risk of childhood asthma: a meta-analysis of 18 observational studies

Objective: The association between Helicobacter pylori (H. pylori) and childhood asthma is unclear. Thus, the aim of this study was to explore the association between H. pylori and childhood asthma.Methods: A literature search, study selection, and data extraction were performed independently and in duplicate. Data were analyzed using STATA software.Results: Eighteen studies enrolling 17,196 children were analyzed. All studies were of moderate-to-high quality. Four studies subcategorized H. pylori infection according to CagA status. Overall, there was a significant negative association between H. pylori and risk for childhood asthma (OR = 0.68; 95% CI, 0.54-0.87; P = 0.002), with no/marginal publication bias identified by the Egger's test and the Begg's test (P = 0.162 and P = 0.198, respectively). The observed inverse association persisted for CagA(+) strains of H. pylori (OR = 0.58; 95% CI, 0.35-0.96; P = 0.034) but not for CagA(-) strains (OR = 0.52; 95% CI, 0.12-2.28; P = 0.387). There was no significant difference between studies with respect to study design, participant age, geographical region, and method of measuring H. pylori.Conclusion: The evidence suggests that H. pylori infection, particularly CagA(+) H. pylori infection, is inversely associated with the risk of childhood asthma. Supplemental data for this article can be accessed at publisher's website.

Vitamin A supplement after neonatal Streptococcus pneumoniae pneumonia inhibits the progression of experimental asthma by altering CD4+T cell subsets

Studies demonstrated that pneumonia can decrease vitamin A productions and vitamin A reduction/deficiency may promote asthma development. Our previous study showed that neonatal Streptococcus pneumoniae (S. pneumoniae) infection promoted asthma development. Whether neonatal S. pneumoniae pneumonia induced asthma was associated with vitamin A levels remains unclear. The aim of this study was to investigate the effects of neonatal S. pneumoniae pneumonia on vitamin A expressions, to explore the effects of vitamin A supplement after neonatal S. pneumoniae pneumonia on adulthood asthma development. Non-lethal S. pneumoniae pneumonia was established by intranasal inoculation of neonatal (1-week-old) female BALB/c mice with D39. S. pneumoniae pneumonia mice were supplemented with or without all-trans retinoic acid 24 hours after infection. Vitamin A concentrations in lung, serum and liver were measured post pneumonia until early adulthood. Four weeks after pneumonia, mice were sensitized and challenged with OVA to induce allergic airway disease (AAD). Twenty-four hours after the final challenge, the lungs and bronchoalveolar lavage fluid (BALF) were collected to assess AAD. We stated that serum vitamin A levels in neonatal S. pneumoniae pneumonia mice were lower than 0.7µmol/L from day 2-7 post infection, while pulmonary vitamin A productions were significantly lower than those in the control mice from day 7-28 post infection. Vitamin A supplement after neonatal S. pneumoniae pneumonia significantly promoted Foxp3⁺Treg and Th1 productions, decreased Th2 and Th17 cells expressions, alleviated airway hyperresponsiveness (AHR) and inflammatory cells infiltration during AAD. Our data suggest that neonatal S. pneumoniae pneumonia induce serum vitamin A deficiency and long-time lung vitamin A reduction, vitamin A supplement after neonatal S. pneumoniae pneumonia inhibit the progression of asthma by altering CD4⁺T cell subsets.

Helicobacter pylori in relation to asthma and allergy modified by abdominal obesity: The HUNT study in Norway

OBJECTIVE

It is unknown whether the decreasing prevalence of H. pylori infections is associated with the increase in obesity and asthma and allergy. In this study, we assessed if obesity plays an intermediate role between H. pylori infections and allergy.

DESIGN

A population-based, nested case-control study of 10,005 participants within the second Nord-Trøndelag Health Study (HUNT2), Norway, was performed in 1995-1997. The presence of H. pylori was tested by an enzyme immunoassay Pyloriset EIA-IgG, and weight, height, and waist circumference were measured. Body mass index (BMI) and waist circumference were used as measures of general and abdominal obesity, respectively. Self-reported asthma and allergic diseases were collected through questionnaires. The odds ratios of H. pylori relative to asthma and allergic diseases were estimated by logistic regression models stratified by waist circumference categories.

RESULTS

H. pylori infection was present in 31%, ever asthma was reported in 10.4% and allergic rhinitis in 16.2%. The mean BMI was 26.4 ​kg/m2 and the mean waist circumference was 86.6 ​cm. H. pylori infection was neither associated with asthma nor allergic diseases. However, when stratified by waist circumference, H. pylori infection was associated with 30-40% reduced odds of asthma and 25% reduced odds of allergic diseases in individuals with abdominal obesity (waist circumference ≥86 ​cm in women and ≥96 ​cm in men).

CONCLUSION

H. pylori infection is associated with reduced risk of asthma and allergy in individuals with abdominal obesity, suggesting a possible causal pathway from reduced H. pylori infections through obesity to increased risk of asthma and allergy.

Accumulated evidence on Helicobacter pylori infection and the risk of asthma: A meta-analysis

BACKGROUND

Helicobacter pylori (H pylori) infection has been suggested to be related to a decreased risk of asthma, but findings in the literature are inconsistent.

OBJECTIVE

To quantitatively summarize the existing evidence on the association between H pylori infection and asthma risk.

METHODS

The PubMed database was searched for observational studies of H pylori infection in relation to the risk of asthma published in English through May 2017. Measurements of association were pooled using a meta-analytic approach and expressed as odds ratios (ORs) with 95% confidence intervals (95% CIs).

RESULTS

Twenty-four studies were identified in this meta-analysis, including 8 case-control studies composed of 1,247 cases and 2,410 controls, and 16 cross-sectional studies composed of 50,290 participants (4,185 cases and 46,105 noncases). The average H pylori infection rates were 40.01% and 48.74% in case-control and cross-sectional studies, respectively. Five studies subcategorized H pylori infection according to CagA status, in which 59.37% of H pylori-infected participants were identified as having CagA positivity. Helicobacter pylori infection was significantly inversely associated with the risk of asthma in case-control studies (OR 0.83, 95% CI 0.71-0.98) but was borderline significant in cross-sectional studies (OR 0.88, 95% CI 0.76-1.02). The observed inverse association persisted for CagA-positive H pylori infection (OR 0.77, 95% CI 0.63-0.93, P for interaction = .03) but not for CagA-negative strains (OR 1.08, 95% CI 0.66-1.78). No significant difference was observed across age or region subgroups.

CONCLUSION

The accumulated evidence supports that H pylori infection, especially CagA-positive H pylori infection, is inversely associated with the risk of asthma.

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.

Helicobacter pylori infection and asthma: Is there a direct or an inverse association? A meta-analysis

AIM: To analyze the consistency of a potential involvement of the bacterium infection in the asthma disease.

METHODS: A systematic literature search of the terms “Helicobacter pylori” (H. pylori) associated to “asthma” using PubMed, Scopus and the Cochrane Library Central was performed. Reference lists from published articles were also employed. Titles of these publications and their abstracts were scanned in order to eliminate duplicates and irrelevant articles. The criteria of inclusion of the studies were: Original studies; the H. pylori diagnostic method has been declared; all ranges of age have been included in our study; a definitive diagnosis of asthma has been reported.

RESULTS: We selected 14 articles in which the association between the two conditions was addressed. In 7 studies the prevalence of H. pylori infection in the asthma population and in the control population was made explicit. There was heterogeneity between the studies (Cohran’s Q = 0.02). The H. pylori infection in the asthma population resulted 33.6% (518 of 1542), while in the control population resulted 37.6% (2746 of 7310) (relative risk of H. pylori infection in the asthma population = 0.87, 95%CI: 0.72-1.05, P = 0.015, random effects model). Instead, considering the more virulent strains, the majority of studies showed an inverse relationship between the prevalence of H. pylori infection and asthma.

CONCLUSION: In our meta-analysis the prevalence of H. pylori infection in the asthma population resulted not statistically significant lower than in control population (P = 0.15). Instead, considering the more virulent strains, the majority of studies showed an inverse relationship between the prevalence of H. pylori infection and asthma.

Helicobacter pylori and allergy: Update of research

Recently a lot of literature has been published about the possible preventive action of Helicobacter pylori (H. pylori) against allergy. The present review summarizes research data about the association between H. pylori and allergic diseases, as well as discusses possible hypotheses about the preventive action of H. pylori against atopy. There is evidence from observational studies to support a weak inverse association between prevalence of H. pylori infection and allergy. However, confounders like some unidentified socioeconomic factors, antibiotic use and others could bias the association. Although data from cohort studies point to a possible association of H. pylori with some of the allergic diseases, no definite proof for causal relationship has been clearly demonstrated yet. A biological mechanism proposed to explain the preventive action of H. pylori to allergy is reduced exposure to a major stimulus for the generation of Treg cells in individuals without H. pylori infection. In addition, H. pylori could be an indicator for changes in gut microbiome, reflecting the complex interaction between microbes and immune system.

Extraintestinal manifestations of Helicobacter pylori: A concise review

Helicobacter pylori (H. pylori) infection has been clearly linked to peptic ulcer disease and some gastrointestinal malignancies. Increasing evidence demonstrates possible associations to disease states in other organ systems, known as the extraintestinal manifestations of H. pylori. Different conditions associated with H. pylori infection include those from hematologic, cardiopulmonary, metabolic, neurologic, and dermatologic systems. The aim of this article is to provide a concise review of the evidence that supports or refutes the associations of H. pylori and its proposed extraintestinal manifestations. Based on data from the literature, PUD, mucosal associated lymphoid tumors lymphoma, and gastric adenocarcinoma has well-established links. Current evidence most supports extraintestinal manifestations with H. pylori in immune thrombocytopenic purpura, iron deficiency anemia, urticaria, Parkinson’s, migraines and rosacea; however, there is still plausible link with other diseases that requires further research.

Helicobacter pylori infection and extragastric disorders in children: a critical update

Helicobacter pylori (H. pylori) is a highly prevalent, serious and chronic infection that has been associated causally with a diverse spectrum of extragastric disorders including iron deficiency anemia, chronic idiopathic thrombocytopenic purpura, growth retardation, and diabetes mellitus. The inverse relation of H. pylori prevalence and the increase in allergies, as reported from epidemiological studies, has stimulated research for elucidating potential underlying pathophysiological mechanisms. Although H. pylori is most frequently acquired during childhood in both developed and developing countries, clinicians are less familiar with the pediatric literature in the field. A better understanding of the H. pylori disease spectrum in childhood should lead to clearer recommendations about testing for and treating H. pylori infection in children who are more likely to develop clinical sequelae. A further clinical challenge is whether the progressive decrease of H. pylori in the last decades, abetted by modern clinical practices, may have other health consequences.

Asthmatic children have increased specific anti-Mycoplasma pneumoniae IgM but not IgG or IgE-values independent of history of respiratory tract infection

BACKGROUND

Bronchial asthma is exacerbated by Mycoplasma pneumoniae-induced upper respiratory tract infections (URTIs) in children. Specific IgM and IgG isotypes are involved in the immune response to M. pneumoniae, but little is known about the role of specific IgE antibodies against M. pneumoniae in asthma.

OBJECTIVE

To investigate the role of IgM-, IgG- and IgE-specific antibody responses to M. pneumoniae in children with persistent asthma in relationship to history of URTI within the past 6 months.

METHODS

Total or specific anti-M. pneumoniae IgM, IgG and IgE antibody responses were studied in stable asthmatic pediatric patients (M. pneumoniae positive and negative) without current exacerbation and nonasthmatic controls (N = 23 and 13, respectively) (UniCAP total IgE Fluoroenzymeimmunoassay, enzyme-linked immunosorbent assay).

RESULTS

Values of specific IgM correlated with specific IgG (Spearman correlation, rho = 0.61, P < 0.0001) but not with specific IgE anti-M. pneumoniae antibodies (AMA) in asthmatic subjects compared with nonasthmatic controls. However, concentrations of specific IgG correlated with specific IgE AMA (rho = 0.49, P = 0.0017). Asthmatic subjects had higher levels of specific IgM AMA levels compared with nonasthmatics (median [interquartile range]: 0.57 [1.00] versus 0.21 [0.19]; Kruskal-Wallis test, P = 0.0008). In addition, IgM positivity was significantly higher in asthmatic compared with nonasthmatic subjects (39.1% versus 0.0%; Fisher's exact test, P = 0.01). These results were independent of URTI history in the past 6 months, which was not associated with higher IgM, IgG or IgE AMA levels compared with no URTI history (P = 0.25-0.64).

CONCLUSIONS

Increased specific IgM anti-M. pneumoniae responses may indicate an important role for M. pneumoniae infection in asthma.

Association between Helicobacter pylori and asthma: a meta-analysis

OBJECTIVE

Helicobacter pylori infection is recognized as a worldwide public health threat. Some studies have suggested that individuals with asthma have a lower rate of H. pylori infection, but the relation remains controversial. This meta-analysis was carried out to quantify the association between H. pylori infection and asthma.

METHODS

Published information on the prevalence of H. pylori in individuals with asthma was collected to assess the potential associations between H. pylori infection and the risk of asthma. Fourteen eligible studies were selected for analysis. Data on the study populations, detection method of H. pylori, and publication year were summarized. Meta-regression models and subgroup analyses were established to screen the factors resulting in heterogeneity.

RESULTS

Of the 106 articles retrieved, 14 fulfilled the inclusion criteria. The 14 studies involved 28 283 patients, with a total H. pylori infection rate of 40.53%. This meta-analysis found a significantly lower rate of H. pylori infection in the asthmatics than in the controls (odds ratio=0.84, 95% confidence interval: 0.73-0.96, P=0.013). Subgroup analysis indicated a similar infection rate of CagA-positive H. pylori infection in the asthmatic group and the control group (odds ratio=0.73, 95% confidence interval: 0.41-1.28, P=0.03).

CONCLUSION

The pooled data suggest that asthmatics have a significantly lower rate of H. pylori infection. Large-scale and multicenter studies should be carried out to further determine the relation between this bacterium and allergic disorders.

The association between asthma and Helicobacter pylori: a meta-analysis

OBJECTIVE

The severity and incidence of asthma have increased drastically in the developed nations of the world over the last decades. Currently, some evidences indicate an inverse association between Helicobacter pylori and asthma, but some studies did not get the same conclusion. To make this question clear, we systematically reviewed the published evidence for an association between H. pylori infection and asthma.

METHODS

Medline and SCI databases up to April 2012 were searched to identify studies that evaluated the association between H. pylori and asthma. Relevant publications were searched using the following keywords or synonyms: asthma or Helicobacter pylori. Methodologic quality was scored by using a standardized list of criteria, and meta-analysis was conducted to calculate crude odds ratios (ORs) with 95% confidence intervals (CIs).

RESULTS

Nineteen studies met our inclusion criteria: nine cross-sectional studies, seven case-control studies, and three prospective cohort studies. The overall methodologic quality score was high. Pooled ORs for the association between asthma and H. pylori infection were 0.84 (95% CI: 0.74-0.96) in nine cross-sectional studies, 0.94 (95% CI: 0.79-1.12) in seven case-control studies, and 0.82 (95% CI: 0.53-1.27) in three cohort studies. The pooled OR for all included studies was 0.81 (95% CI: 0.72-0.91) in children and 0.88 (95% CI: 0.71-1.08) in adults.

CONCLUSIONS

We found a weak evidence for an inverse association between asthma and H. pylori infection both in children and in adults.

Inverse association between Helicobacter pylori and pediatric asthma in a high-prevalence population

BACKGROUND

Helicobacter pylori-associated disease has led to aggressive diagnostic and eradication protocols that are partially responsible for the decrease in prevalence of H. pylori carriage. Recent evidence indicates that in low-prevalence populations, H. pylori may have protective effects on allergic diseases. The aim of this study was to explore the relationship between pediatric asthma and H. pylori infection in a population with high prevalence of H. pylori infection.

MATERIALS AND METHODS

A national referral laboratory was screened for all (13) C urea breath tests performed in children aged 5-18 years between 2007 and 2008, for patient demographics and physician-diagnosed asthma. Data concerning asthma-associated medication usage were extracted from electronic medical records and databases. Data were analyzed using a stepwise logistic regression model.

RESULTS

During the study period, 6959 patients underwent urea breath testing (average age 12.4±3.5years). Of these, 3175/6959 (45.6%) were positive for H. pylori, and 578/6959 (8.3%) had asthma. Rates of asthma in H. pylori-positive and H. pylori-negative children were 7.3 and 9.1%, respectively (odds ratio 0.82; 95% confidence interval (CI) 0.69-0.98; p=.032). We also confirmed that male gender, urban residence, and age are associated with childhood asthma.

CONCLUSIONS

We demonstrate an inverse association between H. pylori and pediatric asthma in a population with a high prevalence of H. pylori.

Is Helicobacter pylori infection associated with asthma risk? A meta-analysis based on 770 cases and 785 controls

OBJECTIVE

Helicobacter pylori (H. pylori) infection has been thought to play a critical role in disorders such as gastric and lung cancer. A number of studies have been devoted to the relationship between H. pylori infection and asthma risk, which have generated inconclusive results. In this study we aimed to derive a more precise estimation of the relationship.

METHODS

Meta-analyses evaluating the association of H. pylori infection and asthma risk were conducted and subgroup analyses on ethnicity and source of controls as well as CagA status were further conducted. Eligible studies were identified for the period up to Jul 2012.

RESULTS

A total of five case-control studies comprising 770 cases and 785 controls were lastly selected for analysis. The overall data failed to indicate a significant association of H. pylori infection and asthma risk (OR=1.01; 95%CI=0.82-1.24). Likewise, in the subgroup analysis regarding ethnicity, source of controls and CagA status, no associations could be observed.

CONCLUSIONS

The pooled data failed to suggest a marked association between H. pylori infection and asthma risk. Future studies are needed to confirm this conclusion.

Viruses and bacteria in acute asthma exacerbations--a GA² LEN-DARE systematic review

To cite this article: Papadopoulos NG, Christodoulou I, Rohde G, Agache I, Almqvist C, Bruno A, Bonini S, Bont L, Bossios A, Bousquet J, Braido F, Brusselle G, Canonica GW, Carlsen KH, Chanez P, Fokkens WJ, Garcia‐Garcia M, Gjomarkaj M, Haahtela T, Holgate ST, Johnston SL, Konstantinou G, Kowalski M, Lewandowska‐Polak A, Lødrup‐Carlsen K, Mäkelä M, Malkusova I, Mullol J, Nieto A, Eller E, Ozdemir C, Panzner P, Popov T, Psarras S, Roumpedaki E, Rukhadze M, Stipic‐Markovic A, Todo Bom A, Toskala E, van Cauwenberge P, van Drunen C, Watelet JB, Xatzipsalti M, Xepapadaki P, Zuberbier T. Viruses and bacteria in acute asthma exacerbations – A GA²LEN‐DARE systematic review. Allergy 2011; 66: 458–468.

Abstract

A major part of the burden of asthma is caused by acute exacerbations. Exacerbations have been strongly and consistently associated with respiratory infections. Respiratory viruses and bacteria are therefore possible treatment targets. To have a reasonable estimate of the burden of disease induced by such infectious agents on asthmatic patients, it is necessary to understand their nature and be able to identify them in clinical samples by employing accurate and sensitive methodologies. This systematic review summarizes current knowledge and developments in infection epidemiology of acute asthma in children and adults, describing the known impact for each individual agent and highlighting knowledge gaps. Among infectious agents, human rhinoviruses are the most prevalent in regard to asthma exacerbations. The newly identified type‐C rhinoviruses may prove to be particularly relevant. Respiratory syncytial virus and metapneumovirus are important in infants, while influenza viruses seem to induce severe exacerbations mostly in adults. Other agents are relatively less or not clearly associated. Mycoplasma and Chlamydophila pneumoniae seem to be involved more with asthma persistence rather than with disease exacerbations. Recent data suggest that common bacteria may also be involved, but this should be confirmed. Although current information is considerable, improvements in detection methodologies, as well as the wide variation in respect to location, time and populations, underline the need for additional studies that should also take into account interacting factors.

Right ventricular function in children with bronchial asthma: a tissue Doppler echocardiographic study

Asthma is the most common cause of respiratory disability among children. Patients with severe bronchial asthma can experience cor pulmonale later in life, but little is known about the function of the right ventricle early in the disease. This study aimed to investigate the right ventricular function in children with bronchial asthma as detected by tissue Doppler echocardiography. This case-control study compared 60 asthmatic children ages 5 to 15 years between attacks (study group) with 60 apparently healthy children (control group). All the children were subjected to full history-taking, complete physical examination, measurement of peak expiratory flow rate (PEFR), chest x-ray, electrocardiography (ECG), echocardiographic examination, and both conventional and tissue Doppler study. The results of the tissue Doppler study examining the right ventricular diastolic function showed that peak E' velocity (10.08 ± 2.8 cm/s), peak A' velocity (5.7 ± 2.5 cm/s), E'/A' ratio (1.77 ± 0.58 m/s), and isovolumetric relaxation time (IVRT) of the lateral tricuspid annulus (138.9 ± 30.7 m/s) among the asthmatic patients differed significantly from those among the control subjects (12.4 ± 2.3, 7.8 ± 2.1 cm/s; 1.58 ± 0.32, and 91.1 ± 32.6 m/s, respectively). In addition, the E' velocity and IVRT of the lateral tricuspid annulus were significantly different among the mild, moderate, and severe cases (P < 0.001). It is concluded that although the clinical and conventional echocardiographic findings of the asthmatic children were apparently normal, the tissue Doppler echocardiographic study showed right ventricular dysfunction that is positively correlated with the severity of asthma. These findings signify the diagnostic value of tissue Doppler echocardiography for the early detection and monitoring of such deleterious effects among asthmatic patients.

A retrospective study of the patients with positive ImmunoCard Mycoplasma test on an outpatient clinic basis

The simplified ImmunoCard Mycoplasma test for rapidly detecting Mycoplasma pneumoniae-specific IgM antibodies has been widely used. We examined the usefulness of this test for outpatient practices as well as for the association with bronchial asthma. Among 196 patients whose ImmunoCard showed positive, we targeted 57 cases in which we were able to perform this test multiple times. We evaluated the degree of inflammatory response in the laboratory findings at the time of the test, the period until negative seroconversion for antibodies, and the course of their pulmonary function findings. The number of days from the onset of pyrexia until the test was a median of 10 (range 2-70) days, wherein the inflammatory response did not have a significant effect on that number of days. In 35 cases in which we observed the seroconversion to negative for antibodies, the period of the positive phase was 180 (21-421) days, wherein it was significantly longer for smokers. We observed exacerbation in the majority of the asthma patients, and some of the non-asthmatic patients showed either asthma or asthma-like clinical conditions. For ImmunoCard-positive individuals, it is desirable to ascertain the history of respiratory infection retrospectively to about half a year, although this test is known to suffer from lack of both of sensitivity and specificity. Additionally, it is necessary for ImmunoCard-positive patients to pay attention to the exacerbation of asthma and the development of asthma thereafter.

Characteristics of asthma attack with long-term management for bronchial asthma

BACKGROUND

There have been no reports on the evaluation of the usefulness of long-term asthma management based on the Japanese Pediatric Guideline for the Treatment and Management of Bronchial Asthma 2005 (JPGL 2005).

METHODS

The purpose of the present study was to retrospectively investigate the records of 350 patients admitted to Yamaguchi University Hospital who had asthma attacks from January 2006 to June 2008. There were 149 patients who were treated for more than 3 months in accordance with the guideline (long-term management group) and 201 who were not (non-long-term management group). The patients were divided into three age groups: 100 infants, 159 toddlers, and 91 schoolchildren.

RESULTS

The onset age of asthma in the long-term management group was earlier than that in the non-long-term management group in toddlers and schoolchildren. The white blood cell counts and C-reactive protein levels were higher in the non-long-term management group in schoolchildren, suggesting the complication of some infections. The severity of asthma in the long-term management group was greater than that in the non-long-term management group among all three age groups. There were no significant differences, however, in the severity of asthma attack at admission between the long-term and non-long-term management groups in the three age groups.

CONCLUSION

Patients who had severe asthma tended to be treated with long-term management, which suggests that long-term asthma management according to JPGL 2005 may reduce the severity of asthma attack at that admission, because the severity of asthma in patients undergoing long-term management correlates with the severity of asthma attack.

The change of asthma-associated immunological parameters in children with Mycoplasma pneumoniae infection

BACKGROUND

Mycoplasma pneumoniae (M. pneumoniae), an atypical pathogen, is increasingly recognized as a common and important pathogen. Previous studies showed that M. pneumoniae infection may play a role in asthmatic mechanisms based on evidence collected from peripheral blood or sputum of patients or animal models. However, evidence reported from the airways of patients has been rare.

OBJECTIVE

To estimate the role of M. pneumoniae infection in asthma by measuring the immunological parameters from peripheral blood and bronchoalveolar lavage fluid (BALF) in pediatric patients with mycoplasma pneumonia.

METHODS

A total of 30 patients with mycoplasma pneumonia and 37 patients without M. pneumoniae infection undergoing fiberoptic bronchoscopy were reviewed. The peripheral blood cell count, immunoglobulins (Ig), BALF cell count, and other clinical and laboratory data were reviewed and analyzed.

RESULTS

There were significantly more patients with raised basophil counts in the M. pneumoniae group than that in the control group (p = 0.033). Serum immunoglobulin (Ig) A, IgM, and IgG levels in the M. pneumoniae group were significantly higher than those in the control group (p = 0.008, p = 0.011, and p = 0.019, respectively). The percentage of eosinophils in BALF cells was in the range 0 to 10% in M. pneumoniae patients, while it ranged between 0 and 4% in the control group with a significant difference (p = 0.043). In the M. pneumoniae group, we found that the percentage of eosinophils in the BALF cells was positively correlated with age, the percentage of peripheral eosinophils, and BALF lymphocytes (r = 0.298, p = 0.030; r = 0.341, p = 0.014; r = 0.387, p = 0.006; respectively) and negatively correlated with total peripheral white blood cell (r = -0.387, p = 0.005).

CONCLUSION

These results suggest that M. pneumonia infection is associated with the asthma mechanism, especially in older children.

Extragastric manifestations of Helicobacter pylori infection: other Helicobacters

The finding that Helicobacter pylori is the main cause of gastritis and peptic ulcer disease has opened a new era in the gastrointestinal world. Today there is evidence that H. pylori may also play a role in different nongastric diseases, opening the new "extragastric manifestations of H. pylori infection" field. Concerning this, several studies have been published in the last year. The most convincing data arise from those investigating idiopathic thrombocytopenic purpura and sideropenic anemia, while there is also an increasing evidence for a possible association with atherosclerotic disease. Furthermore, 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. In particular, several species have been studied for a potential role in different liver and intestinal diseases with interesting findings.