The expression and the clinical significance of eosinophils, PCT and CRP in patients with acute exacerbation of chronic obstructive pulmonary disease complicated with pulmonary infection.

objectiveTo investigate the expression and clinical significance of eosinophil (EOS), procalcitonin (PCT) and C-reactive protein (CRP) in patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD) complicated with pulmonary infection.

methodsAll of the 167 AECOPD patients treated in our hospital were included as the research subjects for this retrospective study. The patients were divided into an infected group (n=41) and a non-infected group (n=126) according to the presence or absence of pulmonary infection. Etiological analysis and antimicrobial susceptibility test were performed on patients in the infection group, and the levels of serum PCT, CRP and EOS were compared between the two groups. According to the forced expiratory volume in one second (FEV1), the pulmonary function of the infection group was divided into 1-3 grades, and the levels of CRP, PCT and EOS in different grades were compared. The correlation between the levels of CRP, PCT, EOS and the ratio of FEV1/FVC (forced vital capacity) in infection group was analyzed. The ROC curve was used to analyze the clinical value of CRP, PCT and EOS levels in the diagnosis of AECOPD complicated with lung infection.

resultsA total of 59 strains of pathogenic bacteria were isolated from 41 patients, including 41 strains of Gram-negative bacteria (69.49%), 16 strains of Gram-positive bacteria (27.12%) and 2 strains of fungi (3.39%). Among the Gram-negative bacteria, Klebsiella Pneumoniae and Pseudomonas Aeruginosa were highly resistant to Cefuroxime, Levofloxacin and Ampicillin. And among the Gram-positive bacteria, Staphylococcus Aureus and Streptococcus Pneumoniae were highly resistant to Penicillin, Gentamicin and Erythromycin. The levels of CRP, PCT and EOS in infected group were significantly higher than those in non-infected group (P<0.05); with the increase of pulmonary function grade, the levels of CRP, PCT and EOS were significant increased (P<0.05); and the levels of CRP, PCT and EOS were negatively correlated with the FEV1/FVC ratio (P<0.05). ROC curve results show that the levels of CRP, PCT and EOS have high clinical value in the diagnosis in patients of AECOPD complicated with pulmonary infection (all AUC>0.7).

conclusionGram-negative bacteria are the main bacteria in AECOPD complicated with pulmonary infection, and drugs should be used rationally according to the results of antimicrobial susceptibility test. The levels of CRP, PCT and EOS increased significantly and were closely related to pulmonary function, and thus have obvious clinical value in the diagnosis of AECOPD complicated with pulmonary infection.