Impact of chronic infection by Pseudomonas aeruginosa in systemic inflammation and on the quality of life of patients with bronchiectasis

Abstract

Bronchiectasis are dilatations of the airways resulting from recurrent infections and chronic inflammation. Dilated and structurally altered airways are conducive to the permanence of bacteria, which leads to more chronic inflammation and the progression of structural damage. Chronic infection by Pseudomonas aeruginosa is associated with more severe disease, worse lung function and worse quality of life. The inflammatory response to P aeruginosa persistence involves the release of inflammatory mediators, potential biomarkers of bronchiectasis severity and progression. Serological tests can be used in conjunction with the culture of secretions for the early detection of P aeruginosa infection; however, its importance in patients with bronchiectasis not associated with cystic fibrosis (NFCB) is not known. The present study aims to evaluate systemic inflammation and quality of life in patients with NFCB, according to the situation of chronic P aeruginosa infection and the serological response to P aeruginosa. This is a cross-sectional study with patients followed up at the chronic insufficiency outpatient clinic of Hospital das Clínicas (HC) at Unicamp. Patients over 18 years of age and diagnosed with NFCB by chest tomography will be included. After inclusion, patients will answer a quality-of-life questionnaire (SF-36) and a socioeconomic and educational level; will be collected a blood sample (dosage of C-reactive protein, total leukocytes, immunoglobulins, serology for P aeruginosa, interleukins) and sputum (microbiological culture). Clinical (frequency of exacerbations, degree of dyspnea), functional (spirometry) and tomographic data will be evaluated. Patients will be classified according to the state of chronic infection by P aeruginosa, and according to the serological response; groups will be compared for quality-of-life data, inflammatory markers, clinical and functional data. It will also be investigated whether there is an association between systemic inflammatory markers with quality of life and pulmonary function tests. It is hoped that this study will contribute to the understanding of the clinical relevance, as well as quality of life, of patients with NFCB.