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.