Does Chlamydia pneumoniae Infection Trigger to Development of Asthma in Wheezy Infants?

The role of Chlamydia pneumonia (CP) infection in infantile asthma remains obscure. CP infection was serologically determined (Immunoglobulin M antibody titer of index (ID) ≥ 2.00) in wheezing infants who were then re-examined at 3 years of age to determine whether asthma is associated with CP infection. Wheezing infants with CP infection progressed to asthma more frequently than those who were not infected. These findings may suggest that CP infection triggers the development of asthma in wheezy infants.     

The development of asthma in wheezing infants with Chlamydia pneumoniae infection.

Chlamydia pneumoniae infection might play a role in the pathology of asthma, but its role in infantile asthma remains obscure. The presence of Chlamydia pneumoniae was serologically determined in wheezing infants who were then re-examined 1-year later to determine whether or not asthma is associated with this type of infection. Wheezing infants progressed to asthma more frequently after infection with Chlamydia pneumoniae than those who were not infected. These findings suggested that Chlamydia pneumoniae infection triggers asthma in wheezy infants.     

Chlamydia species and Mycoplasma pneumoniae

Chlamydia psittaci, Chlamydia pneumoniae, and Mycoplasma pneumoniae are a group of respiratory pathogens that have similar pulmonary and extrapulmonary manifestations. Recent studies suggest that C. pneumoniae and M. pneumoniae may play a role in the pathogenesis of asthma, but further studies are needed to delineate the importance of these organisms in this disease. The diagnosis of C. pneumoniae infection is hindered by the lack of a gold standard: Asymptomatic carriage of C. pneumoniae lowers the specificity of culture and polymerase chain reaction, and the current use of single high titers to identify infection also has specificity problems. Newer antibiotics simplify the management of infection with C. psittaci, C. pneumoniae, and M. pneumoniae and offer the potential for prophylaxis.     

Update on Infection and Antibiotics in Asthma

Asthma pathogenesis seems to be a result of a complex mixture of genetic and environmental influences. There is evidence that Mycoplasma pneumoniae and Chlamydophila pneumoniae (formerly known as Chlamydia pneumoniae) play a role in promoting airway inflammation that could contribute to the onset and clinical course of asthma. Evidence also indicates that when antimicrobial therapy can eradicate or suppress these organisms, it may be possible to alter the course of the disease. Certain macrolide antibiotics have been shown to improve control of asthma symptoms and lung function in patients diagnosed with acute C. pneumoniae or M. pneumoniae infection. Positive polymerase chain reaction studies for C. pneumoniae or M. pneumoniae are needed to select asthma patients for chronic treatment. Macrolide antibiotics may also have independent anti-inflammatory activity that may be useful in the management of asthma and other inflammatory diseases.     

Atypical Bacterial Pneumonia and Asthma Risk

The role of respiratory infections in asthma is poorly understood. Atypical bacteria Mycoplasma pneumoniae and Chlamydia pneumoniae are present in the lower airways of approximately 50% of asthmatics. This study tested the hypothesis that early life community‐acquired pneumonia caused by Mycoplasma pneumoniae or Chlamydia pneumoniae is associated with increased asthma prevalence. Thirty‐five subjects with a history of community‐acquired pneumonia (22 due to atypical bacteria, 13 due to nonatypical pathogens) were evaluated by questionnaire 7–9 years after the episode of pneumonia. Subjects with a history of either typical or atypical pneumonia demonstrated increased asthma prevalence. Current or past asthma prevalence was 55% in subjects with atypical bacterial pneumonia and 61.5% in subjects with nonatypical bacterial pneumonia. Significant between‐group differences were not demonstrated with regard to asthma prevalence (risk ratio = 0.89; 95% confidence interval = 0.49–1.61), current bronchodilator use [1.18 (0.44–3.17)], and family history of atopy [1.18 (0.73–1.91)], or asthma [1.63 (0.68–3.88)]. These data suggest that atypical bacterial pneumonia confers a risk of asthma similar to that seen with nonatypical bacterial pneumonia. Prospective studies are warranted to more fully evaluate the importance of atypical bacterial pneumonia as an asthma risk factor.     

High Rate of Seropositivity of Chlamydia pneumoniae IgA in Male Patients with Nonalcoholic Steatohepatitis

The aim of this study was to investigate if there was any relationship between nonalcoholic steatohepatitis and the rate of Chlamydia pneumoniae seropositivity in a male population. Fifteen men with nonalcoholic steatohepatitis and 20 healthy men were enrolled in the study. The seropositivity rate of Chlamydia pneumoniae immunoglobulin A in the nonalcoholic steatohepatitis and control groups was 53.3 and 5%, respectively. The rate of Chlamydia pneumoniae immunoglobulin A positivity was significantly higher in the nonalcoholic steatohepatitis group than the controls (P = 0.002), while such a difference did not occur for Chlamydia pneumoniae immunoglobulin G positivity (P > 0.05). There is an association between nonalcoholic steatohepatitis and persistent Chlamydia pneumoniae infection as a probable causative or triggering agent. These findings suggest that further studies are necessary to clarify this association.     

Virus and Mycoplasma pneumoniae prevalence in a selected pediatric population with acute asthma exacerbation

Objective: To determine the prevalence of viral and atypical bacteria Mycoplasma pneumoniae infection in children experiencing asthma exacerbation and compare positive and negative subjects with regard to exacerbation severity, need for hospitalization, and treatment. Methods: One hundred sixty-nine asthmatic children aged 2–15 years old who were admitted to emergency rooms in Bogota, Colombia for acute asthma exacerbation were interviewed. Nasopharyngeal aspirates were taken for DNA and RNA extraction. M. pneumoniae and virus were detected by PCR using specific primers. Results: The prevalence of M. pneumoniae and viral infection in the study population was 12.4% and 83.7%, respectively. All subjects positive for M. pneumoniae were also positive for viral infection. Rhinovirus was the most frequently detected viral agent. No significant differences in severity of asthma exacerbations or in need for hospitalization between the virus or M. pneumoniae positive and negative groups were observed. A significantly lower percentage of M. pneumoniae positive subjects had used inhaled steroids over the six months prior to asthma exacerbation compared to M. pneumoniae negative subjects (38.1% vs. 68.2%), suggesting that inhaled corticosteroids may have a protective effect against M. pneumoniae infections. Conclusions: The M. pneumoniae and virus prevalence found in this study were similar to those described in the literature. The 100% co-infection rate observed suggests that viral infection can predispose patients to M. pneumoniae infection, and that this interaction may trigger asthmatic exacerbation. Further studies should be done to confirm the protective effect of inhaled corticosteroids on M. pneumoniae infection in patients with asthma exacerbations.     

<Emphasis Type="Italic">Chlamydia pneumoniae</Emphasis> Infections in Asthma

Chlamydia pneumoniae is an intracellular pathogen that has been suggested to play a role in the pathology of asthma. However, so far none of the studies have provided clear evidence for a causative role of C. pneumoniae infections in asthma, although there is little doubt that chronic C. pneumoniae infection does aggravate asthma and should be treated.The diagnosis of C. pneumoniae infection is still a matter of concern for it is dependent on trained skilled personnel and can vary significantly between different diagnostic laboratories. This fact is also one of the major problems encountered when comparing epidemiological studies investigating the possible role of C. pneumoniae infections and their impact on the pathogenesis of other diseases.With regard to therapy, long-term treatment with macrolides is the best available method to eradicate C. pneumoniae. Successful therapy for C. pneumoniae, however, can also be complicated by the high possibility of de novo infection as epidemiological studies have shown that the prevalence of antibodies to C. pneumoniae increases with age in all populations studied. In the northern hemisphere the prevalence of C. pneumoniae is also affected by seasonal conditions. It is too early to draw any conclusions from the equatorial belt countries. The available data on C. pneumoniae in tropical countries indicate a much faster infection rate during early adulthood with 100% serological prevalence at an age greater than 25 years. This data, if confirmed, would argue against C. pneumoniae causing asthma since the asthma prevalence in those countries does not increase in a parallel pattern.An alternative interpretation of most studies could be that the increased rate of C. pneumoniae infections in patients with asthma results from a modified susceptibility towards the microorganism, due to yet unknown changes of the host cell’s physiology. It should be kept in mind that increased prevalence of C. pneumoniae infection is not restricted to asthma.Further studies are needed to understand the role of C. pneumoniae, especially of chronic infection, in the pathogenesis of inflammatory diseases with a specific focus on the effect that the microorganism triggers in the infected host cell. Only when we understand what C. pneumoniae does to its host cell will we be able to judge its impact on the overall status of an affected patient, and this knowledge will help us to develop a successful therapy.     

Respiratory symptoms,asthma, atopy and Chlamydia pneumoniae IgG antibodies in a general population sample of young adults

Background: This study was designed to test the association of Chlamydia pneumoniae infection with respiratory symptoms and atopy. Methods: A general population sample of 369 young adults (aged 20-44 years) completed a questionnaire on respiratory symptoms and underwent skin prick testing. C pneumoniae IgG and IgM serum titers were measured by micro-immunofluorescence. Prior infection was defined by titers of IgG ≥ 1:32, acute infection by titers of IgG ≥ :512 and/or IgM ≥ 1:16. Results: The prevalence of cough and phlegm was higher in subjects with (19.0%) than in those without (11.4%) prior C. pneumoniae infection (p = 0.01). A similar difference was found for wheezing (14.3% vs 8.0%; p = 0.05), whereas the percentage of asthmatics was equally distributed between seropositive and seronegative subjects. IgG titers ≥ 1:128 were found more frequently in atopic subjects (p = 0.04). After adjusting for any confounding factors, cough and phlegm (but not wheezing) were found significantly associated with C. pneumoniae positivity, both for 1 : 32 (OR 1.80; 95% CI: 1.01-3.36; p = 0.05) and for 1 : 128 titers (OR 2.31; 95% CI: 1.20-4.42; p = 0.01). A significant association was also found for atopy, for titers ≥ 1 : 128 (OR 1.73; 95% CI: 1.01-3.20, p = 0.05). Acute infection was not associated with respiratory symptoms or asthma. Conclusion: We conclude that C. pneumoniae infection is associated with cough and phlegm and may have a role in the pathogenesis of chronic respiratory diseases. Moreover, our results indicate a relationship between atopy and C. pneumoniae infection. Received: October 9, 2001 · Revision accepted: March 3, 2002     

The role of Chlamydia in upper respiratory tract infections

Although Chlamydia pneumoniae and Chlamydia psittaci are well-established causes of community-acquired pneumonia, little is known about the role of Chlamydia species in upper respiratory tract infections. C. pneumoniae may play a role in the pathogenesis of acute otitis media. Although C. pneumoniae has been isolated from the middle-ear fluid of children with otitis, children in whom the organism was isolated from middle-ear fluid improved despite being treated with antibiotics that are not active against C. pneumoniae. Although many patients with community-acquired pneumonia caused by C. pneumoniae have symptoms suggestive of sinusitis, there is only one report of isolation of the organism from the maxillary sinus of a patient with sinusitis. Studies of the association with pharyngitis are all based on serology, which often has a poor correlation with isolation of the organism by culture.     

Antibiotics in asthma

Asthma pathogenesis appears to be a result of a complex mixture of genetic and environmental influences. There is evidence that Mycoplasma pneumoniae and Chlamydia pneumoniae play a role in promoting airway inflammation that could contribute to the onset and clinical course of asthma. If antimicrobial therapy can eradicate these organisms, it might be possible to alter the course of the disease. Although antibiotics have no role in the routine management of acute exacerbations of asthma, certain macrolide antibiotics have been shown to have anti-inflammatory activity. Part of this effect is due to their known inhibition of steroid and theophylline metabolism, but through a myriad of mechanisms that are incompletely understood, macrolide antibiotics have additional broad anti-inflammatory properties that might prove useful in the management of asthma and other inflammatory diseases.     

Chlamydia pneumoniae,and mycoplasma pneumoniae: Are they related to severe asthma in childhood?

Background: Mycoplasma pneumoniae and Chlamydia pneumoniae are frequent agents of acute respiratory diseases and they have been recognized as infectious triggers of asthma. Objective: To determine the frequency of these triggers and their relationship to severe asthma. Methods: 82 patients were enrolled in a prospective cross-sectional study from January 2007 to March 2013 and they were divided into three study groups: Group 1: 27 children with severe asthma, Group 2: 29 children with stable asthma and Group 3: 26 children which was the control group. Serological tests included IgG and IgM for both C. pneumoniae and M. pneumoniae. Results: Average age ± SD was 10.9 ± 2.5 for Group 1; 10.1 ± 2.9 for Group 2 and 9.9± 1.9 for Group 3 (p = 0.4). M. pneumoniae IgM was observed in 6/27 (22.2%) in Group 1, 2/29 (6.9%) in Group 2 and 0/26 in the Control Group (p = 0,01). C.pneumoniae IgM was present in 7/26 (26.9%) in Group 1, 2/29 (6.9%) in Group 2 and 0/26 in Group 3 (p = 0.005). No significant difference was observed between Group 2 and Group 3. M. pneumoniae IgG was observed in 7/27 (25.9%) in Group 1, 4/29 (13.7%) in Group 2 and 0/26 in the Control Group (p < 0,05). C.pneumoniae IgG was present in 8/26 (30.7%) in Group 1, 5/29 (17.2%) in Group 2 and 0/26 in Group 3 (p < 0,05). Conclusions: M. pneumoniae and C. pneumoniae may play a role in the development of severe asthma.     

Rapamycin can Inhibit the Development of <Emphasis Type="Italic">Chlamydia pneumoniae</Emphasis>, which Might Partly Contribute to the Prevention of In-stent Restenosis

Background  

Rapamycin, an immunosuppressive and antiproliferative drug, is used to prevent neointima formation to reduce the risk of in-stent restenosis with rapamycin eluting-stents. Chronic infection of Chlamydia pneumoniae has been associated with cardiovascular diseases, and could play an important role in the mechanism of restenosis. We examined the effect of rapamycin on the growth of C. pneumoniae in cell cultures.     

Chlamydia pneumoniae DNA in the Arterial Wall of Patients with Peripheral Vascular Disease

Background: Chlamydia pneumoniae is a human respiratory pathogen that has recently been related to the genesis of symptomatic atherosclerosis. C. pneumoniae has been studied more widely in relation to coronary atherosclerosis than to peripheral arterial occlusive disease (PAOD). The present study aimed to retrospectively analyze the presence of C. pneumoniae DNA in patients with PAOD. Materials and Methods: A seminested PCR method was applied on 85 samples from 71 patients with PAOD secondary to surgical treatment. The control group comprised 50 patients with chronic superficial venous insufficiency who required varicose resection surgery. Results: The number of patients, number of samples studied and percentage of patients found to be positive in the PCR study were 17, 18 and 59%, respectively, for arteries of the lower extremities: 15, 16 and 60% for aneurysm of the abdominal aorta; 22, 23 and 73% for carotid stenosis and 17, 18 and 65% for aortic stenosis. C. pneumoniae DNA was found in six external pudendal arteries (12%) of the control group, significantly lower than the incidence in the patient group (p < 0.0001). Conclusion: A causal relationship between chronic C. pneumoniae infection and PAOD cannot be ruled out. On the contrary, the high incidence of C. pneumoniae DNA detected in our patients suggest that C. pneumoniae infection may play some role in the pathogenesis of peripheral vascular disease. Received: December 3, 2000 · Revision accepted: May 16, 2001     

Mycoplasma pneumoniae et infections respiratoires aiguës

Mycoplasma pneumoniae infection can be entirely asymptomatic but it can also lead to bronchitis or pneumonis. M. pneumoniae is the first cause of community-acquired pneumonia in children older than five years of age. Clinical symptoms are often mild but treatment is required because of the risk of sequelae, mainly a decrease of gas diffusion. In children at risk for asthma, M. pneumoniae infection can cause acute attacks. In a study performed on children with an attack of severe asthma with hypoxemia hospitalized at the St-Vincent-de-Paul hospital, 26% of those having an exacerbation of their pre-existing asthma had a mycoplasma infection. Furthermore, when hospitalized for their first asthma attack, 50% of those children who were at risk for asthma had a mycoplasma infection.     

Antibiotic Therapy in Coronary Heart Disease—Where Do We Currently Stand?

A casual association between Chlamydia pneumoniae infection and atherosclerosis remains unresolved but plausible. Evidence comes from sero-epidemiological data, pathological specimen examinations, animal models and in vitro experiments. A number of prospective antibiotic intervention trials targeted against C pneumoniae infection in patients with coronary heart disease are now underway. We remain wary that C pneumoniae infection can persist in cell lines (associated with atherosclerosis) despite antibiotic therapy and also that reactivation of infection can occur. Issues such as delineating the patient group that could be targeted for treatment, choice of optimal antibiotic regimens, duration of therapy and effective methods of monitoring treatment response remain controversial and, as yet, unresolved. The relevance of persistence of C pneumoniae infection and potential antimicrobial resistance will require equal consideration.     

Detection of Chlamydia pneumoniae on cytospin preparations from bronchoalveolar lavage in COPD patients and in lung tissue from advanced emphysema

Chronic obstructive pulmonary disease (COPD) is associated with smoking but other etiological factors contribute. Chlamydia pneumoniae is an obligate intracellular bacterium causing both acute and chronic respiratory tract infections. Studies have revealed an association between chronic C. pneumoniae infection and COPD, asthma and lung cancer but there have been difficulties detecting C. pneumoniae in the bronchial tree. Cytospin slides prepared from bronchoalveolar lavage (BAL) fluid from 14 patients with COPD, 10 healthy smokers (S) and 7 non smokers (NS) were analyzed with a fluorescein isothiocyanate labeled monoclonal antibody to C. pneumoniae. Lung tissue from 24 patients with advanced emphysema who had undergone lung volume reduction surgery (LVRS) was examined with immunohistochemistry for C. pneumoniae. Archived serum samples for detection of specific C. pneumoniae antibodies by microimmunofluorescence were available for 30 of the BAL subjects and 11 of LVRS patients. C. pneumoniae elementary body like structures were found in 29% of cytospin specimens from COPD patients, 14% of NS and 10% of HS. C. pneumoniae was detected in lung tissue in 8%. COPD patients had higher titres of IgG and IgA than NS and S. There was no association between occurrence of C. pneumoniae in BAL fluid and antibody titres. In conclusion, the assays used for detection of C. pneumoniae in lung tissue are feasible, and could be adapted in adequately powered studies to further confirm an association between C. pneumoniae infection and COPD.     

Is Asthma an Infectious Disease? New Evidence

The pathogenetic mechanisms leading to asthma are likely to be diverse, influenced by multiple genetic polymorphisms as well as elements of the environment. Recent data on the microbiome of the airway have revealed intriguing differences between the number and diversity of microbial populations in healthy persons and asthmatics. There is convincing evidence that early viral infections, particularly with human rhinovirus and respiratory syncytial virus, are often associated with the development of chronic asthma and with exacerbations. Recent studies suggest that two unrelated types of atypical bacteria, Mycoplasma pneumoniae (Mpn) and Chlamydia pneumoniae, are present in the airways of a substantial proportion of the population, bringing up the possibility that the persistent presence of the organism may contribute to the asthmatic phenotype in a subset of patients. This review will examine the current data regarding a possible role for infection in chronic asthma with a particular focus on atypical bacterial infections.     

Azithromycin: Single 1.5g dose in the treatment of patients with atypical pneumonia syndrome—A randomized study

Summary An open comparative study was undertaken in order to assess the efficacy and safety of a single dose of azithromycin in the treatment of community-acquired atypical pneumonia. A total of 100 adult patients with atypical penumonia syndrome were randomized to receive 1.5 g of azithromycin as a single dose, or 500 mg once daily for 3 days. The presence ofMycoplasma pneumoniae, Chlamydia pneumoniae, Chlamydia psittaci, Coxiella burnetii, andLegionella pneumophila infection was diagnosed by serological tests. Control clinical examinations were performed 72h, 10–12 days and 4 weeks after treatment initiation. Among 96 patients (48 in each group) who were evaluable for clinical efficacyM. pneumoniae infection was confirmed in 24,C. pneumoniae in nine,C. psittaci in five,C. burnetii in six, andL. pneumophila in five. Forty-seven patients (97.9%) in each group were cured. Side effects were observed in two patients in the single-dose group, and one patient in the 3-day group. In conclusion, a single 1.5 g dose of azithromycin may be an alternative to the standard 3-day azithromycin regimen in the treatment of outpatients with atypical pneumonia syndrome.