Correlation Study Of Lower Airway Bacterial Colonization In Stable PHase Chronic Obstructive Pulmonary Disease Patient And Airway Inflammation.

Objective To test the hypothesis that lower airway bacterial colonization (LABC)existed in stable pHase of Chronic Obstructive Pulmonary Disease (COPD) and toinvestigate the relationship between LABC and airway inflammation,quality oflife,frequency of exacerbation. Materials and Methods A total of 30 patients withmoderate or severe COPD but stable at baseline were included in this study. Theinduced sputum were collected at the first visit as baseline and at second visit at theexacerbation period. The samples were analyzed for their bactefial loads based on thesemi-quantitate bacterial culture, meanwhile the levels of interleukin (IL)-8 and the St.George's respiratory questionnaire (SGRQ) were measured. As contradistinction,30healthy controls were included in this study too. Results Among 30 subjects, 26.7%and 46.7% showed LABC or LRI(lower respiratory infection) the bacterial loads≥+++ in sputum at visit 1 and 2 respectively. At visit 1, pathogenic bacterias includingStreptococcus pneumoniae, HemopHilus influenza, HemopHilus parainfluenzae,Pseudomonas aeruginosa were found,at visit 2, there were Pseudomonas aeruginosa,Baumanii, Klebsiella pneumonia, HemopHilus influenza, Streptococcus pneumoniae.5 (16.67%) subjects had the same pathogenic both in visitl&2. The detection rate ofpathogenic bacterias at visit 2 was higher than it at visit 1(P＜0.05). IL-8 in patientswith LABC were significantly higher than those without LABC(P＜0.05). Thepresence of LABC had a positive correlation with elevated IL-8,the index number ofsmoking, SGRQ total and symptom score at visit 1(P＜0.05). IL-8 had a negativeconelation with FEV₁(% predicted),FVC(% predicted),FEV₁/FVC, but a positive correlation with SGRQ total, symptoms, mobility and impacts score.ConclusionLABC were present in a good portion of stable COPD patients. Smoking may be arisk factor of LABC.LABC may be stimulator which induce airway inflammatory andlead to degrading of lung function.So,those patients with LABC had poor quality oflife than those patients without LABC. LABC may be responsible for COPDexacerbation by increasing bacteria colonization and/or promoting the airwayinflammatory responses.