The Bronchial Lavage of Pediatric Patients With Asthma Contains Infectious Chlamydia

Abstract

Purpose of the Study. To examine the frequency of Chlamydia pneumoniae infections in pediatric patients with asthma. Study Population. Seventy pediatric patients undergoing flexible fiber-optic bronchoscopy as a part of their ongoing clinical care. Methods. Bronchoaveolar lavage (BAL) fluid and blood were examined for the presence of C pneumoniae by smear examination and culture. The BAL and blood samples were cultured on human or mouse macrophages to determine infectivity. Polymerase chain reaction (PCR) amplification of BAL samples was performed to confirm specificity of the culture technique. Blood was examined for total immunoglobulin E (IgE). Blood samples from 70 matched, nonrespiratory control patients were cultured for Chlamydia. Results. Forty-two patients undergoing bronchoscopy had asthma and 28 had various other respiratory diseases. Thirty-eight (54%) BAL samples were positive for Chlamydia by PCR and 22 (31%) samples were positive for Chlamydia by culture. Of the positive BAL samples, 28 (74%) of 38 PCR-positive and 14 (64%) of 22 culture-positive samples were from children with asthma. Culture-positive blood samples were found in 24 (34%) of 70 respiratory patients and 8 (11%) of 70 nonrespiratory controls. In the blood culture–positive respiratory group, 17 (71%) of 24 were from children with asthma. Elevated total serum IgE was associated with BAL culture–positive results, and this relationship was stronger than total IgE and asthma diagnosis. Conclusions. Viable C pneumoniae organisms are frequently present in the lung lavage in a cohort of predominately asthmatic pediatric patients. Reviewer Comments. Results from this study suggest that infectious C pneumoniae may be common in BAL fluid of children with asthma. Historically, C pneumoniae has been associated with exacerbation and increased incidence of respiratory conditions in adults, but studies to examine similar associations in children have not been performed. This is the first investigation to report viable and infectious C pneumoniae in the BAL fluid of children with asthma. These findings are intriguing and should encourage investigators to examine the clinical implications of Chlamydia infection among pediatric patients with asthma.