Systemic inflammation and the effects of short-term antibiotic treatment for PPM positive patients with stable COPD

Abstract

Objective

To evaluate patients with stable COPD for the presence of potentially pathogenic microorganisms (PPM), systemic inflammation and the effects of short-term antibiotic therapy in PPM positive patients.

Methods

From January 2016 to June 2017, we enrolled 96 stable COPD patients. Bacterial cultures from sputum collections were quantitated, along with markers for systemic inflammation including serum C-reactive protein (CRP), interleukin-8 (IL-8) and plasma fibrinogen (FIB) in all patients. All enrolled patients were followed for 12 months. Forty patients were identified as PPM positive and were randomly divided into an antibiotic group and a control group. The antibiotic group was treated with moxifloxacin orally for 6 days. Lung function and markers for systemic inflammation were repeatedly measured at 30 days and 6 months in PPM positive subjects.

Results

Binary logistic regression analysis showed that risk factors for PPM positive are bronchiectasis (OR 4.18, 95% CI 1.20–14.59; P=0.025), COPD assessment test (CAT) ≥20 (OR 17.55, 95% CI 2.82–109.18; P=0.002), spontaneous sputum (OR 15.09, 95% CI 1.36–168.02; P=0.027) and sputum purulence (OR 38.43, 95% CI 5.39–274.21; P=0.000). CRP and IL-8 were higher in PPM positive group than those in PPM negative group (P=0.001, P=0.007, respectively), but there were no differences of FIB between the two groups (P=0.086). Compared to the PPM negative group, the rate of acute exacerbation of COPD was higher (P=0.029) and time to next acute exacerbation was shorter (P=0.030) in PPM positive group. There were no differences in lung function and systemic inflammatory markers either in the control group or the antibiotic group at different time points of follow-up.

Conclusion

PPM exists in stable COPD patients and can cause systemic inflammation and is associated with acute exacerbation of COPD. Short-term antibiotic therapy had no effect on systemic inflammation nor on acute exacerbation of COPD.

China Clinical Trials Registry: ChiCTR-IOR-15006769

Keywords:

• COPD
• potentially pathogenic microorganisms
• systemic inflammation
• antibiotics
• C-reactive protein
• interleukin-8

Data sharing statement

Authors allow sharing personal identification participant data and specific data related to the paper. Furthermore, data related to the paper can be accessed freely from the date of publication at the Clinical Trial Management Public Platform: http://www.medresman.org/uc/sindex.aspx.

Disclosure

Jin-Xiang Wang and Hui-Qiao Li are co-first authors for this study. The authors report no conflicts of interest in this work.