Differentiation of Bacterial Community-Acquired Pneumonia (CAP) from Other Etiologies of Pneumonia (see Pneumonia, Pneumonia)
Rationale: serum procalcitonin is the peptide precursor of calcitonin which is released by parenchymal cells in response to bacterial toxins
Serum Procalcitonin is Elevated in Bacterial Infections
Serum Procalcitonin is Downregulated in Viral Infections
Clinical Efficacy
Systematic Review of the Utility of Serum Procalcitonin in the Diagnosis of Bacterial Pneumonia (Cochrane Database Syst Rev, 2012) [MEDLINE]
Serum Procalcitonin Use to Guide Initiation and Duration of Antibiotic Use Did Not Increase Mortality Rates or Treatment Failures in Any Treatment Setting
Further Research is Required to Determine the Safety of Serum Procalcitonin-Guided Therapy in the ICU Setting
Differentiation of Bacterial Hospital-Acquired Pneumonia (HAP)/Ventilator-Associated Pneumonia (VAP) from Other Etiologies of Pneumonia (see Pneumonia, Pneumonia)
Recommendations (Infectious Diseases Society of America, IDSA/American Thoracic Society, ATS 2016 Clinical Practice Guidelines for the Management of HAP/VAP (Clin Infect Dis, 2016) [MEDLINE]
For Patients with Suspected HAP/VAP, Clinical Criteria Alone Should Be Used, Rather than Clinical Criteria and Serum Procalcitonin (Strong Recommendation, Moderate-Quality Evidence)
Differentiation of Parapneumonic Pleural Effusions from Effusions of Other Etiologies
Clinical Efficacy
Study of Serum Procalcitonin in Differentiating Parapneumonic Effusion from Malignant/Tuberculous Effusion (Clin Biochem, 2013) [MEDLINE]
Serum Procalcitonin >0.18 ng/mL: 83.3% sensitivity/81.0% specificity in determining if a pleural effusion has a bacterial infectious etiology
Serum Procalcitonin Performed Better than Pleural Fluid Procalcitonin
Background
Procalcitonin is a Precursor of Calcitonin that is Constitutively Secreted by C Cells in the Thyroid Gland and K Cells in the Lung
In Healthy Patients, Procalcitonin is Normally Undetectable (<0.01 ng/mL)
When Stimulated by the Presence of Endotoxin, Procalcitonin is Rapidly Produced by Parenchymal Tissues Throughout the Body
Procalcitonin Has Been Observed in a Variety of Bacterial Infections
Less Commonly, Procalcitonin May Increase in Response to Sterile Inflammation or Viral Infection (Lancet, 1993) [MEDLINE]
References
High serum procalcitonin concentrations in patients with sepsis and infection. Lancet 1993; 341:515–8 [MEDLINE]
Procalcitonin to initiate or discontinue antibiotics in acute respiratory tract infections. Cochrane Database Syst Rev. 2012 Sep 12;(9):CD007498. doi: 10.1002/14651858.CD007498.pub2 [MEDLINE]
Procalcitonin as a diagnostic marker in differentiating parapneumonic effusion from tuberculous pleurisy or malignant effusion. Clin Biochem. 2013;46(15):1484 [MEDLINE]
Biomarkers: what is their benefit in the identification of infection, severity assessment, and management of community-acquired pneumonia? Infect Dis Clin North Am. 2013 Mar;27(1):19-31. Epub 2012 Dec 6 [MEDLINE]
Management of Adults With Hospital-acquired and Ventilator-associated Pneumonia: 2016 Clinical Practice Guidelines by the Infectious Diseases Society of America and the American Thoracic Society. Clin Infect Dis. 2016 Sep 1;63(5):e61-e111. doi: 10.1093/cid/ciw353. Epub 2016 Jul 14 [MEDLINE]
