- Cunningham AF,
- Johnston SL,
- Julious SA,
- Lampe FC,
- Ward ME
Purpose of the Study
To investigate the reported association between Chlamydia pneumoniae and Mycoplasma pneumoniae infection and the expression of asthmatic symptoms in susceptible patients.
One hundred eight children with a history of asthma-related symptoms were followed longitudinally for 13 months. Subjects kept a daily diary of symptoms and peak flow rates, and when asthma-related symptoms occurred an investigator was contacted for collection of nasal aspirates. A total of 292 samples were collected during symptomatic episodes and a total of 65 children provided a sample when asymptomatic. Polymerase chain reaction (PCR) was used to identify the presence of C pneumoniae and M pneumoniae. The presence of secretory immunoglobulin A (IgA) specific to C pneumoniae was also detected.
In asymptomatic patients and patients experiencing an acute asthma episode, the rate of C pneumoniae detection was similar (28 vs 23%, respectively). Patients who reported multiple episodes tended to remain PCR-positive, which suggested a chronic infection. Subjects who reported four or more exacerbations had secretory-IgA levels more than seven times higher than those patients who had only one symptomatic episode. Throughout the study, PCR detected M pneumoniae in just 2 of the 292 symptomatic episodes, and in 2 if the 65 asymptomatic patients.
Chronic infection with this very common respiratory pathogen, C pneumoniae, as evidenced by persistent positive PCR and elevated secretory-IgA, was associated with recurrent asthma symptoms. This study did not show any connection between M pneumoniae and chronic asthma symptoms.
The standard evaluation of patients with chronic asthma can be a lengthy and costly process often without revealing a definitive cause. PCR analysis for C pneumoniae is not a routine evaluation in most cases, but this study certainly suggests that this organism could be considered a cause of chronic asthma symptoms in some patients. Further study, including antibiotic therapy in infected patients, is warranted.