Role of Bacterial Colonization in Severe Persistent Asthma

Abstract

PURPOSE: To determinate the prevalence of bacterial colonization in severe persistent bronchial asthma and variables related airway inflammation, systemic, pulmonary function and clinical behavior METHODS: 28 patients with severe persistent asthma who are medically indicated bronchoscopy in a stable situation were recruited. We obtained health resource utilization, ACT, according MRC dyspnea, quality of life (AQLQ-Sydney), and pulmonary function laboratory data. Telescoping catheter (CTT) and bronchoalveolar lavage (BAL) cell count were performed. RESULTS: Of 28 patients, 7 were men. No smoker and only one ex-smoker. Mean age: 57 years, mean FEV1%: 56%. Mean ACT: 17. In 8 of 28 patients (28.6%) had positive culture CTT, 6 for Haemophilus influenzae and 2 for Pseudomonas aeruginosa. The sample was divided in two groups depending on colonization. We observed that the colonized group had significantly higher serum CRP (7,4 VS 2,6 mg/dl; p:0.04), fibrinogen (457vs386; p=0.030) and segmented leucocytes % of the BAL (31.4vs7.8; p=0.003). They also had lower serum albumin(40vs43 mg/dl; p=0.004) and Hb (12.7 vs 14; p=0.049). The values of FEV1 (53.4 vs 64.4%) and FEV1/FVC (57.6 vs 62.8%) were lower, but not significant. The 23 patients with FEV1/FVC%<70% had a higher % of colonization (34.7%). Of the 5 non-obstructive no one was colonized CONCLUSIONS: Bronchial colonization is common in patients with severe persistent asthma: 28.6%; and higher in patients with bronchial obstruction: 34.7%. No relation was established with health resource utilization, symptoms or quality of life. It was related to systemic and airway inflammatory parameters. The colonized patients had lower levels of Hb and albumin and worse lung function.