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Procalcitonin Levels in the Management of COPD Exacerbations

Procalcitonin Levels in the Management of COPD Exacerbations

The use of procalcitonin-based protocols to guide the decision to administer antibiotics has been evaluated in infections of different origins and settings. A well-conducted systematic review supported the effectiveness of procalcitonin-guided protocols in lower respiratory tract infections, based on evidence of moderate quality from GRADE (Grading of Recommendations, Assessment, Development and Evaluation). However, these results do not necessary imply that such protocols would be effective in patients presenting with acute exacerbation of chronic obstructive pulmonary disease (AECOPD), since the chronically elevated baseline inflammatory status and the chronic bacterial colonization of the airways of patients with COPD could affect the serum procalcitonin levels—and its utilization to help guide antibiotic therapy in a patient with AECOPD is controversial. However, a substantial fraction of acute COPD exacerbations are caused by viruses, and some experts use procalcitonin to help guide antibiotic discontinuation in patients with non-severe AECOPD.

Procalcitonin synthesis pathways vary in different inflammatory states. In the absence of systemic inflammation, procalcitonin synthesis is restricted to thyroid neuroendocrine cells, and the protein is not released into the blood until it is split into its mature form, calcitonin. Thus, serum procalcitonin is typically undetectable in healthy persons when standard assays are used. Not all bacterial infections cause procalcitonin to rise, or rise to the same degree. Typical bacteria, such as Streptococcus pneumoniae or Hemophilus influenzae, tend to cause greater rises in procalcitonin than atypical bacteria.

The reference value of procalcitonin in adults and children older than 72 hours is 0.15 ng/mL or less (reference values have not been established in infants younger than 72 hours). In healthy adults, the reference range of procalcitonin is below the level of detection. The half-life of procalcitonin is 25 to 30 hours.

While procalcitonin use in patients hospitalized with AECOPD has been shown to reduce antibiotic exposure without increasing adverse events in several trials, this benefit has not been consistently demonstrated in all trials and treatment settings. Additional data in varying clinical settings are needed before broad use can be recommended.

References
  • De Jong E, van Oers JA, Beishuizen A, et al. Efficacy and safety of procalcitonin guidance in reducing the duration of antibiotic treatment in critically ill patients: a randomised, controlled, open-label trial. Lancet Infect Dis. 2016;16:819-827.
  • Christ-Crain M, Müller B. Procalcitonin in bacterial infections--hype, hope, more or less? Swiss Med Wkly. 2005;135:451.
  • Gilbert DN. Use of plasma procalcitonin levels as an adjunct to clinical microbiology. J Clin Microbiol. 2010;48:2325.
  • Maruna P, Nedelníková K, Gürlich R. Physiology and genetics of procalcitonin. Physiol Res. 2000;49(Suppl 1):S57.
  • Schuetz P, Müller B, Christ-Crain M, et al. Procalcitonin to initiate or discontinue antibiotics in acute respiratory tract infections. Evid Based Child Health. 2013;8:1297-1371.
  • Schuetz P, Muller B, Christ-Crain M, et al. Procalcitonin to initiate or discontinue antibiotics in acute respiratory tract infections. Cochrane Database Syst Rev. 2012;9:CD007498.
  • Van der Does Y, Rood PP, Haagsma JA, et al. Procalcitonin-guided therapy for the initiation of antibiotics in the ED: a systematic review. Am J Emerg Med. 2016;34:1286-1293.
  • Verduri A, Luppi F, D'Amico R, et al. Antibiotic treatment of severe exacerbations of chronic obstructive pulmonary disease with procalcitonin: a randomized noninferiority trial. PloS One. 2015;10:e0118241.

Filed under: Infectious Diseases, Pulmonary Medicine

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