SPUTUM MICROBIOME IN AGED PATIENTS WITH DIFFERENT CLINICAL PHENOTYPES OF CHRONIC OBSTRUCTIVE PULMONARY DISEASE

Abstract

Objective: To analyze the sputum microbiome and air flow limitation during an exacerbation in aged patients with different clinical phenotypes of COPD. Methods: Patients over 60 years old hospitalized for exacerbation of COPD were enrolled in retrospective study. Everyone has had a history of COPD for at least 5 years. According to the clinical phenotype 2 groups were formed: rare exacerbators (RE, n = 56) versus frequent exacerbators (FE, n = 30). Spirometry was performed in every case, and one sample of sputum for bacteriological examination from every patient also was taken. Two tailed Fisher’s exact test and others methods were performed for comparisons. Results: The average age was 80,4 ± 5,8 years in RE versus 77,9 ± 8,2 years in FE. RE had 18 persons out of 56 with FEV1 more than 60 % whereas among FE there were only 3 of them out of 30 (p < 0,05). A simultaneous decrease in FEV1 ( < 50 %) and FVC ( < 50 %) was more often observed in the FE (15 cases out of 30) than in RE (13 cases out of 56, p < 0,05). Various microorganisms of firmicutes (44,3 % [95 % CI, 37.1 % - 51.5 %]), proteobacteria (25,9 % [95 % CI, 19.6 % - 32.2 %]), actinobacteria (2,7 % [95 % CI, 0.9 % - 5.5 %]) and candida (27 % [95 % CI, 20.6 % - 33.4 %]) were identified totally 185 times in 83 sputum samples. Three more were sterile. Potentially dangerous microorganisms predominated in the 26 cases from both groups. Klebsiella pneumoniae, Pseudomonas aeruginosa, Staphylococcus aureus, Moraxella, Acinetobacter and Enterobacter were detected. Pneumococcus and Haemophilus influenzae have never been found. Genera Moraxella and Acinetobacter belonging to the same family Moraxellaceae were revealed 6 times out of 64 (9.4 % [95 % CI, 5.6 % - 21.7 %]) in FE versus 2 times out of 121 in RE (1.7 % [95 % CI, 0.2 % - 4.8 %] p < 0,05). Conclusions: 1) Frequent exacerbators have showed more severe air flow limitation then rare exacerbators; 2) firmicutes, proteobacteria, actinobacteria and candida consist the sputum microbiome in both phenotypes; 3) the detection rates of family of Moraxellaceae was a little higher in frequent exacerbators, and their contribution pushed the ratio proteobacteria/furmicutes up in this group.