Immunohistochemical staining for Chlamydia pneumoniae is increased in lungtissue from subjects with chronic obstructive pulmonary disease

The seroprevalence of Chlamydia pneumoniae is increased in chronic obstruct ive pulmonary disease (COPD), and subjects with COPD are more likely to hav e a positive polymerase chain reaction for C. pneumoniae in their sputum. I t has been suggested that C. pneumoniae may have a role in the pathogenesis of COPD. We undertook immunohistochemistical staining for C. pneumoniae in archival tissue from subjects who had undergone lobectomy for bronchial ca rcinoma. There were 16 subjects with COPD (FEV1 = 64 +/- 8% [mean I SD] pre dicted) and 21 subjects with normal lung function (FEV1 = 95 +/- 11% predic ted). There was no difference between the two groups in age or smoking hist ory. Tissues from all of the subjects stained positively for C. pneumoniae, but in the subjects with COPD there were 14.5 positive cells per field (ma gnification x400), as compared with 9.3 cells per field in the control subj ects (p = 0.02). Fifty-four percent of the macrophages from the subjects wi th COPD stained positively for C. pneumoniae, as compared with 29% from the control subjects (p < 0.001). A second control group consisted of 18 young er individuals (mean age: 32 yr) who died accidentally. Only 44% of these s ubjects had positive staining for C. pneumoniae, and the mean number of cel ls per field was 0.4. These findings suggest that persistent infection with C. pneumoniae is common, and that there is increased immunostaining for C. pneumoniae in COPD. Further studies are necessary to determine whether chr onic infection with C. pneumoniae is important in the pathogenesis of COPD.