Cross-sectional study of respiratory Aspergillus spp. colonization or infection in patients with various stages of chronic obstructive pulmonary disease (COPD) using culture vs non-culture based technique

Abstract

Background COPD patients are now recognized to be at increased risk of colonization by Aspergillus spp. which may progress to invasive pulmonary aspergillosis (IA). Published data on the frequency of Aspergillus detection in COPD are limited. Methods A cross-sectional study was undertaken to determine Aspergillus colonization or infection in COPD patients undergoing bronchoscopy for any indication. Culture as well as galactomannan antigen (GM) and Aspergillus nucleic acid detection (PCR) were performed on bronchoalveolar lavage fluid (BAL). Results One hundred and fifty patients were included (44.7 % female, mean age 68.2 years). 21.3 % were inpatients, 74.7 % outpatients and 4 % were ICU patients. Investigation of lung masses was the most common indication (43.3 %) for bronchoscopy. Most patients (81.3 %) were either GOLD stage 1 or 2 COPD. Cancer was the most frequent co-morbidity (60.48 %). 12 % and 48.7 % were on systemic and inhaled steroids respectively. Lung mass was the most common (28.43 %) CT imaging finding. Seventeen patients (11.3 %) had a positive result for Aspergillus (Culture+Galactomannan+PCR). 76.4 % out of these seventeen were in the early stages (GOLD stage 1 or 2) of COPD. Conclusion Aspergillus sp. was detected in 3.3 % of patients by culture, which increased to 11.3 % if culture was combined with either a positive GM or PCR result. Overall the frequency of Aspergillus detection in this population of COPD patients was low which may reflect the predominance of Gold stages 1 and 2 among the study population.