Lobar distribution in non-cystic fibrosis bronchiectasis predicts bacteriologic pathogen treatment

Non-cystic fibrosis bronchiectasis (NCFBr) is a major cause of morbidity due to frequent infectious exacerbations. We analyzed the influence of patient age and bronchiectasis location on the bacterial profile of patients with NCFBr. This retrospective cohort study included 339 subjects diagnosed with an infectious exacerbation of NCFBr during the 9-year period between January 2006 and December 2014. Bronchoalveolar lavage (BAL) cultures and high-resolution computed tomography scans (HRCT) were utilized to characterize the location of the bronchiectasis and bacteriologic pathogenic profile. In univariate logistic regression, the frequency of Haemophilus influenzae was higher in patients aged ≤64 years (OR = 0.969, p < 0.0001, 95 % CI 0.954-0.983), whereas the frequency of Pseudomonas aeruginosa (OR = 1.027, p = 0.008, 95 % CI 1.007-1.048) and Enterobacteriaceae (OR = 1.039, p = 0.01, 95 % CI 1.009-1.069) were significantly higher in patients aged >64 years. The lobar distribution of bronchiectasis in the subjects was 25.9 % in the right middle lobe (RML), 20.7 % in the right lower lobe (RLL), 20.4 % in the left lower lobe (LLL), 13.8 % in the lingula, 13 % in the right upper lobe (RUL), and 6.2 % in the left upper lobe (LUL). In the lower lobes, H. influenzae was the dominant species isolated, whereas in the RUL it was P. aeruginosa and in the LUL it was non- tuberculous mycobacterium (NTM). H. influenzae was more prevalent in younger patients, whereas P. aeruginosa, Enterobacteriaceae and NTM predominated in older patients. Different pathogens were associated with different lobar distributions. The RML, RLL and LLL showed a greater tendency to develop bronchiectasis than other lobes.