Abstract
BackgroundRecent studies have confirmed the presence of viable Chlamydia in the bronchoalveolar lavage (BAL) fluid of pediatric patients with airway hyperresponsiveness. While specific IgG and IgM responses to C. pneumoniae are well described, the response and potential contribution of Ag-specific IgE are not known. The current study sought to determine if infection with Chlamydia triggers the production of pathogen-specific IgE in children with chronic respiratory diseases which might contribute to inflammation and pathology.MethodsWe obtained BAL fluid and serum from pediatric respiratory disease patients who were generally unresponsive to corticosteroid treatment as well as sera from age-matched control patients who saw their doctor for wellness checkups. Chlamydia-specific IgE was isolated from BAL and serum samples and their specificity determined by Western blot techniques. The presence of Chlamydia was confirmed by species-specific PCR and BAL culture assays.ResultsChlamydial DNA was detected in the BAL fluid of 134/197 (68%) patients. Total IgE increased with age until 15 years old and then decreased. Chlamydia-specific IgE was detected in the serum and/or BAL of 107/197 (54%) patients suffering from chronic respiratory disease, but in none of the 35 healthy control sera (p < 0.0001). Of the 74 BAL culture-positive patients, 68 (91.9%, p = 0.0001) tested positive for Chlamydia-specific IgE. Asthmatic patients had significantly higher IgE levels compared to non-asthmatics (p = 0.0001). Patients who were positive for Chlamydia DNA or culture had significantly higher levels of serum IgE compared to negative patients (p = 0.0071 and p = 0.0001 respectively). Only 6 chlamydial antigens induced Chlamydia-specific IgE and patients with C. pneumoniae-specific IgE had significantly greater levels of total IgE compared to C. pneumoniae-specific IgE negative ones (p = 0.0001).ConclusionsIgE antibodies play a central role in allergic inflammation; therefore production of Chlamydia-specific IgE may prove significant in the exacerbation of chronic, allergic airway diseases, thus highlighting a direct role for Chlamydia in asthma pathogenesis.
Highlights
Inflammation of the airways is the most common finding in all asthma patients and today, most asthma experts consider airway inflammation a central feature of asthma pathogenesis [1,2]
In the current study we examined the bronchoalveolar lavage (BAL) fluid and serum of a large cohort of children with chronic respiratory disease for the presence of Chlamydia-specific IgE antibodies
Prevalence of Chlamydia in patient cohort Polymerase chain reaction (PCR) was utilized to determine if C. trachomatis and/or C. pneumoniae organisms were present in patient BAL samples
Summary
Inflammation of the airways is the most common finding in all asthma patients and today, most asthma experts consider airway inflammation a central feature of asthma pathogenesis [1,2]. Published evidence strongly suggests a relationship between microbes and asthma [4]. Recent studies confirm that bacterial respiratory infections are frequently associated with increased airway obstruction in patients with bronchial asthma [3]. While the hygiene hypothesis predicts that infections in early life by non-pathogenic microbes should protect against asthma and atopy [5], there is increasing evidence that certain chronic pathogenic infections might promote airway hyperresponsiveness and asthma development or exacerbation [6,7,8]. Recent studies have confirmed the presence of viable Chlamydia in the bronchoalveolar lavage (BAL) fluid of pediatric patients with airway hyperresponsiveness. The current study sought to determine if infection with Chlamydia triggers the production of pathogen-specific IgE in children with chronic respiratory diseases which might contribute to inflammation and pathology
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
