title: Inflammatory response in mixed viral-bacterial community-acquired pneumonia.
abstract: BACKGROUND
  The role of mixed pneumonia (virus+bacteria) in community-acquired pneumonia (CAP) has been described in recent years. However, it is not known whether the systemic inflammatory profile is different compared to monomicrobial CAP. We wanted to investigate this profile of mixed viral-bacterial infection and to compare it to monomicrobial bacterial or viral CAP.
  
  
  METHODS
  We measured baseline serum procalcitonin (PCT), C reactive protein (CRP), and white blood cell (WBC) count in 171 patients with CAP with definite etiology admitted to a tertiary hospital: 59 (34.5%) bacterial, 66 (39.%) viral and 46 (27%) mixed (viral-bacterial).
  
  
  RESULTS
  Serum PCT levels were higher in mixed and bacterial CAP compared to viral CAP. CRP levels were higher in mixed CAP compared to the other groups. CRP was independently associated with mixed CAP. CRP levels below 26 mg/dL were indicative of an etiology other than mixed in 83% of cases, but the positive predictive value was 45%. PCT levels over 2.10 ng/mL had a positive predictive value for bacterial-involved CAP versus viral CAP of 78%, but the negative predictive value was 48%.
  
  
  CONCLUSIONS
  Mixed CAP has a different inflammatory pattern compared to bacterial or viral CAP. High CRP levels may be useful for clinicians to suspect mixed CAP.
authors: Servicio de Neumologia, Hospital Universitario Miguel Servet, Paseo Isabel La Católica, 1-3, 50009 Zaragoza, Spain. sbello@salud.aragon.es.
authors: Salvador
authors: S
authors: Bello
authors: Elisa
authors: E
authors: Mincholé
authors: Sergio
authors: S
authors: Fandos
authors: Ana B
authors: AB
authors: Lasierra
authors: María A
authors: MA
authors: Ruiz
authors: Ana L
authors: AL
authors: Simon
authors: Carolina
authors: C
authors: Panadero
authors: Carlos
authors: C
authors: Lapresta
authors: Rosario
authors: R
authors: Menendez
authors: Antoni
authors: A
authors: Torres
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D002097:C-Reactive Protein / Q000378:metabolism; D002116:Calcitonin / Q000097:blood; D015740:Calcitonin Gene-Related Peptide; D060085:Coinfection / Q000097:blood* / Q000175:diagnosis / Q000382:microbiology*; D017714:Community-Acquired Infections / Q000097:blood / Q000175:diagnosis / Q000382:microbiology; D005260:Female; D006801:Humans; D007958:Leukocyte Count; D008297:Male; D008875:Middle Aged; D018410:Pneumonia, Bacterial / Q000097:blood* / Q000150:complications / Q000175:diagnosis; D011024:Pneumonia, Viral / Q000097:blood* / Q000150:complications / Q000175:diagnosis; D011237:Predictive Value of Tests; D011498:Protein Precursors / Q000097:blood; D012372:ROC Curve; D012720:Severity of Illness Index
chemical_list: D015415:Biomarkers; C000606589:CALCA protein, human; D011498:Protein Precursors; D002116:Calcitonin; D002097:C-Reactive Protein; D015740:Calcitonin Gene-Related Peptide