Streptococcus pneumoniae urinary antigen test and acute exacerbations of chronic obstructive pulmonary disease.

BACKGROUND Streptococcus pneumoniae is one of the most common bacteria identified in sputum obtained from subjects with acute exacerbations of chronic obstructive pulmonary disease (AECOPD). PURPOSE To examine the urinary pneumococcal antigen test in subjects admitted with AECOPD and subjects with COPD, and to evaluate its relationship with AECOPD. METHODS Urine samples from 82 subjects with AECOPD involved in 122 consecutive hospitalizations were tested. Additionally, 196 consecutive subjects with stable COPD were tested a total of 607 times at intervals greater than 6 months. RESULTS Pneumococcal antigen was positive in 14 (17.1%) out of all 82 subjects first hospitalized with AECOPD. It was positive in 7 (20.6%) out of the 34 subjects with pneumonic exacerbations of COPD, and in 7 (14.6%) out of the 48 subjects with non-pneumonic exacerbations of COPD. Two subjects with non-pneumonic S. pneumoniae-related AECOPD were identified, and they both tested positive. A total of 607 urinary antigen tests were performed on stable COPD subjects, and 16 (2.6%) specimens were positive. Colonization by S. pneumoniae was found in the sputum of only 25% of the COPD subjects with positive urinary pneumococcal antigen test results. CONCLUSION The results of the pneumococcal urinary antigen test were similar for AECOPD subjects with and without pneumonia. This test may be a useful method for preventing the under-diagnosis of S. pneumoniae-related exacerbations of COPD. The detection of pneumococcal antigen in the urine is not related to the persistent colonization of the respiratory mucosa by S. pneumoniae.