Evidence for Chlamydia pneumoniae infection in steroid-dependent asthma

Background: Chlamydia pneumoniae is an obligate intracellular respiratory pathogen capable of persistent infection. Seroepidemiologic studies and the results of open-label antimicrobial treatment of patients with non-steroid-dependent asthma have suggested a potential role for C. pneumoniae in asthma. Objective: To evaluate the results of antimicrobial treatment in patients with uncontrolled steroid-dependent asthma and serologic evidence suggesting C. pneumoniae infection. Methods: Three nonsmoking asthmatic patients (aged 13 to 65 years) whose symptoms remained poorly controlled despite daily administration of inhaled and oral steroid (10 to 40 mg/d). All met serologic criteria for current or recent C. pneumoniae infection. Results: After prolonged treatment (6 to 16 weeks) with clarithromycin or azithromycin all three patients were able to discontinue oral steroids. All three patients have remained well controlled with inhaled antiasthma therapy only during 3 to 24 months of postantibiotic therapy observation. Conclusions: In adolescent and adult asthmatic patients, Chlamydia pneumoniae infection may contribute to symptoms of asthma that are poorly controlled by steroids. Serologic evidence for C. pneumoniae infection should be sought in such patients. A trial of appropriate antibiotic therapy may be helpful in those patients with high titers of anti-C. pneumoniae IgG antibodies.