title: [Value of serum procalcitonin in diagnosing bacterial lower respiratory tract infections in people with exacerbation of Chronic Obstructive Pulmonary Disease].
abstract: OBJECTIVE
  To investigate the changes and clinical implications of serum procalcitonin in exacerbation of chronic obstructive pulmonary disease (COPD).
  
  
  METHODS
  We have evaluated PCT measurement in 45 patients with an exacerbation of COPD (group A) and 25 patients with stable COPD (group B), quantitative sputum culture was performed, too. PPMs were only regarded as significant if they reached a growth of > or =10(7) cfu/mL, indicating the presence of bacterial infection.
  
  
  RESULTS
  In patients with an exacerbation, 15 patients, sputum yielded a high (> or =10(7) cfu/mL) bacterial load (group A1), 30 patients, sputum yielded a low (<10(7) cfu/mL) bacterial load or a negative bacterial culture (group A2). The levels of procalcitonin in sera from patients of group A1 were significantly higher than those from group A2 and group B [0.24 (0.17, 0.28) microg/L vs. 0.125 (0.10, 0.18) microg/L vs. 0.12 (0.10, 0.145) microg/L, P= 0.000, 0.000]. The levels of procalcitonin in sera from patients of group A2 were similar to those from group B (P>0.05). Using a cut-off point of 0.155 microg/L for PCT, the sensitivities and specificities for bacterial infection in patients with an exacerbation of COPD were 93.3% and 60% respectively.
  
  
  CONCLUSIONS
  Serum procalcitonin measurements in patients of an exacerbation of chronic obstructive pulmonary disease play a role in the diagnosis of bacterial infection.
authors.affiliation: Department of Respiratory Medicine, Peking University Third Hospital, Beijing 100083, China.
authors.forename: Chun
authors.initials: C
authors.lastname: Chang
authors.forename: Wan-zhen
authors.initials: WZ
authors.lastname: Yao
authors.forename: Ya-hong
authors.initials: YH
authors.lastname: Chen
authors.forename: Zhen-ying
authors.initials: ZY
authors.lastname: Liu
authors.forename: Xiao-wei
authors.initials: XW
authors.lastname: Zhang
mesh_terms: D000368:Aged; D002116:Calcitonin / Q000097:blood*; D015740:Calcitonin Gene-Related Peptide; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D018410:Pneumonia, Bacterial / Q000097:blood / Q000150:complications / Q000175:diagnosis*; D011237:Predictive Value of Tests; D011498:Protein Precursors / Q000097:blood*; D029424:Pulmonary Disease, Chronic Obstructive / Q000150:complications*; D013183:Sputum / Q000382:microbiology
chemical_list: C000606589:CALCA protein, human; D011498:Protein Precursors; D002116:Calcitonin; D015740:Calcitonin Gene-Related Peptide