Chlamydia pneumoniae infection in patients with diffuse panbronchiolitis and COPD.

Study Objectives: To determine the possible association of Chlamydia pneumoniae infection with diffuse panbronchiolitis (DPB) and with COPD.

Design: Prospective case-control study.

Setting: Division of Respiratory Diseases, Kawasaki Medical School Hospital.

Participants: Fifteen DPB and 77 COPD patients who had acute exacerbations of respiratory conditions and 35 and 120 control subjects, respectively, matched for age, sex, and smoking status.

Measurements And Results: Nasopharyngeal swabs and paired serum samples were obtained from all patients and control subjects for isolation and antibody testing of C pneumoniae. C pneumoniae was isolated from one DPB patient and from no COPD patients or control subjects. Serologic evidence of acute C pneumoniae infection was observed in one DPB patient (6.7%) and six COPD patients (7.8%). The prevalence and mean titer of C pneumoniae IgG and IgA antibodies were significantly higher in COPD patients than in control subjects (p<0.001). However, no such differences were observed between DPB patients and control subjects.

Conclusions: This study showed that C pneumoniae infection may be associated with acute exacerbations of COPD and that chronic C pneumoniae infection is common in COPD but not in DPB.