Pseudomonas aeruginosa isolation in patients with non-cystic fibrosis bronchiectasis: a retrospective study

Abstract

Objectives: Pseudomonas aeruginosa (P. aeruginosa) occupies an important niche in the pathogenic microbiome of bronchiectasis. The objective of this study is to evaluate the clinical characteristics and prognostic value of P. aeruginosa in Chinese adult patients with bronchiectasis.

Methods: This retrospective and follow-up study enrolled 1188 patients diagnosed with bronchiectasis at Shanghai Pulmonary Hospital between January 2011 and December 2012. The patients' clinical data including anthropometry, clinical symptoms, serum biomarkers, radiographic manifestations and lung function indices were reviewed. The median follow-up duration (IQR) was 44 (40-54) months, during which 289 patients were lost to follow-up. Data from 899 patients were collected and analysed for the outcomes of mortality, annual exacerbation frequency and health-related quality of life.

Results: P. aeruginosa was isolated from 232 patients, alongside other pathogens such as Aspergillus (n=75) and Candida albicans (n=72). There were 74 deaths (12% of patients with P. aeruginosa, 7.3% of those without) over the course of the follow-up. The isolation of P. aeruginosa was a risk factor for all-cause mortality (HR, 3.07; 95% CI 1.32 to 7.15) and was associated with high rates of exacerbations (ie, ≥3 exacerbations per year of follow-up) (HR, 2.40; 95% CI 1.20 to 4.79). Patients with P. aeruginosa also had worse scores on the Hospital Anxiety and Depression Scale (anxiety, p=0.005; depression, p<0.001), the Leicester Cough Questionnaire (p=0.033) and the modified Medical Research Council scale (p=0.001) compared with those without P. aeruginosa.

Conclusions: Isolation of P. aeruginosa in patients with bronchiectasis is a significant prognostic indicator and should be a major factor in the clinical management of the disease.

Keywords: bronchiectaiss; exacerbation; mortality; pseudomonas aeruginosa.

Figure 1

Flow diagram depicting patient selection and analysis. HRCT, high-resolution CT.

Figure 2

Kaplan-Meier plot illustrating the survival of all patients with bronchiectasis. There are statistically significant differences in (A) and (B). (p(a)=0.045; p(b1)=0.017; p(b2)=0.414; p(b3)=0.125. P(a) means the difference between PA and non-PA groups; p(b1) means the difference between PA and negative groups; p(b2) means the difference between PA and others groups; p(b3) means the difference between others and negative groups).

Figure 3

Variables associated with high rates of exacerbations in a logistic regression model: (A) among all the patients, (B) among the patients in the PA or others group and (C) among patients in the PA or negative group.) BMI, body mass index; FEV₁, forced expiratory volume in 1s; PA, Pseudomonas aeruginosa.