Procalcitonin as a biomarker in respiratory tract infection

Clin Infect Dis. 2011 May;52 Suppl 4:S346-50. doi: 10.1093/cid/cir050.


Serum procalcitonin (PCT) levels rapidly increase in patients with invasive bacterial disease. PCT levels increase faster than do C-reactive protein levels. Furthermore, a rapid decrease in the PCT level is supporting evidence that the source of the bacterial infection is responding to clinical management. In patients with community-acquired bacterial pneumonia, sequential PCT levels are useful as a guide to shorter courses of antimicrobial therapy. With use of emerging multiplex real-time polymerase chain reaction platforms for the detection of viral and bacterial respiratory pathogens, it should be possible to critically assess whether an elevated serum PCT level is a valid biomarker of invasive bacterial infection.

Publication types

  • Review

MeSH terms

  • Bacterial Infections / diagnosis*
  • Biomarkers / blood*
  • C-Reactive Protein / analysis
  • Calcitonin / blood*
  • Calcitonin Gene-Related Peptide
  • Clinical Laboratory Techniques / methods*
  • Drug Monitoring / methods
  • Humans
  • Protein Precursors / blood*
  • Respiratory Tract Infections / diagnosis*


  • Biomarkers
  • CALCA protein, human
  • Protein Precursors
  • Calcitonin
  • C-Reactive Protein
  • Calcitonin Gene-Related Peptide