Procalcitonin and C-reactive protein cannot differentiate bacterial or viral infection in COPD exacerbation requiring emergency department visits.
BACKGROUND
Viral and bacterial infections are the most common causes of chronic obstructive pulmonary disease (COPD) exacerbations. Whether serum inflammatory markers can differentiate bacterial from virus infection in patients with COPD exacerbation requiring emergency department (ED) visits remains controversial.


METHODS
Viral culture and polymerase chain reaction (PCR) were used to identify the viruses in the oropharynx of patients with COPD exacerbations. The bacteria were identified by the semiquantitative culture of the expectorated sputum. The peripheral blood white blood cell (WBC) counts, serum C-reactive protein (CRP), procalcitonin (PCT), and clinical symptoms were compared among patients with different types of infections.


RESULTS
Viruses were isolated from 16 (22.2%) of the 72 patients enrolled. The most commonly identified viruses were parainfluenza type 3, influenza A, and rhinovirus. A total of 30 (41.7%) patients had positive bacterial cultures, with the most commonly found bacteria being Haemophilus influenzae and Haemophilus parainfluenzae. Five patients (6.9%) had both positive sputum cultures and virus identification. The WBC, CRP, and PCT levels of the bacteria-positive and bacteria-negative groups were not statistically different. Multivariate analysis showed that patients with increased sputum volumes during the COPD exacerbations had higher risks of recurrent exacerbations in the 1-year period following the first exacerbation.


CONCLUSIONS
WBC, CRP, or PCT could not differentiate between bacterial and viral infections in patients with COPD exacerbation requiring ED visits. Those with increased sputum during a COPD exacerbation had higher risks for recurrent exacerbations.
Department of Pulmonary and Critical Care Medicine, Linkou Chang-Gung Memorial Hospital, Chang-Gung Medical Foundation, Chang-Gung University College of Medicine, Taoyuan, Taiwan.
Chih-Hao
CH
Chang
Department of Laboratory Medicine, Linkou Chang-Gung Memorial Hospital, Chang-Gung Medical Foundation, Taoyuan, Taiwan ; Department of Medical Biotechnology and Laboratory Science, Chang Gung University, Taoyuan, Taiwan.
Kuo-Chien
KC
Tsao
Department of Pulmonary and Critical Care Medicine, Linkou Chang-Gung Memorial Hospital, Chang-Gung Medical Foundation, Chang-Gung University College of Medicine, Taoyuan, Taiwan ; Department of Respiratory Therapy, Chang-Gung University, Taoyuan, Taiwan.
Han-Chung
HC
Hu
Department of Pulmonary and Critical Care Medicine, Linkou Chang-Gung Memorial Hospital, Chang-Gung Medical Foundation, Chang-Gung University College of Medicine, Taoyuan, Taiwan ; Department of Respiratory Therapy, Chang-Gung University, Taoyuan, Taiwan.
Chung-Chi
CC
Huang
Department of Pulmonary and Critical Care Medicine, Linkou Chang-Gung Memorial Hospital, Chang-Gung Medical Foundation, Chang-Gung University College of Medicine, Taoyuan, Taiwan ; Department of Respiratory Therapy, Chang-Gung University, Taoyuan, Taiwan.
Kuo-Chin
KC
Kao
Department of Pulmonary and Critical Care Medicine, Linkou Chang-Gung Memorial Hospital, Chang-Gung Medical Foundation, Chang-Gung University College of Medicine, Taoyuan, Taiwan ; Department of Respiratory Therapy, Chang-Gung University, Taoyuan, Taiwan.
Ning-Hung
NH
Chen
Department of Pulmonary and Critical Care Medicine, Linkou Chang-Gung Memorial Hospital, Chang-Gung Medical Foundation, Chang-Gung University College of Medicine, Taoyuan, Taiwan ; Department of Respiratory Therapy, Chang-Gung University, Taoyuan, Taiwan.
Cheng-Ta
CT
Yang
Department of Respiratory Therapy, Chang-Gung University, Taoyuan, Taiwan ; Department of Pulmonary and Critical Care Medicine, Chiayi Chang-Gung Memorial Hospital, Chang-Gung Medical Foundation, Puzi City, Taiwan.
Ying-Huang
YH
Tsai
Department of Respiratory Therapy, Chang-Gung University, Taoyuan, Taiwan ; Department of Pulmonary and Critical Care Medicine, Chiayi Chang-Gung Memorial Hospital, Chang-Gung Medical Foundation, Puzi City, Taiwan.
Meng-Jer
MJ
Hsieh
D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D002097:C-Reactive Protein / Q000032:analysis*; D002116:Calcitonin / Q000097:blood*; D015740:Calcitonin Gene-Related Peptide; D016009:Chi-Square Distribution; D003937:Diagnosis, Differential; D018450:Disease Progression; D004636:Emergency Service, Hospital; D005260:Female; D006801:Humans; D018836:Inflammation Mediators / Q000097:blood*; D053208:Kaplan-Meier Estimate; D007958:Leukocyte Count; D008297:Male; D015999:Multivariate Analysis; D009960:Oropharynx / Q000821:virology; D011237:Predictive Value of Tests; D011379:Prognosis; D011498:Protein Precursors / Q000097:blood*; D029424:Pulmonary Disease, Chronic Obstructive / Q000097:blood / Q000175:diagnosis* / Q000382:microbiology / Q000821:virology; D012141:Respiratory Tract Infections / Q000097:blood / Q000175:diagnosis* / Q000382:microbiology / Q000821:virology; D012307:Risk Factors; D013183:Sputum / Q000382:microbiology; D013997:Time Factors
D015415:Biomarkers; C000606589:CALCA protein, human; D018836:Inflammation Mediators; D011498:Protein Precursors; D002116:Calcitonin; D002097:C-Reactive Protein; D015740:Calcitonin Gene-Related Peptide
CRP; bacterial infection; chronic obstructive pulmonary disease; virus