Effective September 5, 2017, Clinical Pathology Laboratories will offer in-house testing for Procalcitonin (PCT). Procalcitonin (PCT) is a(n):

  • Prohormone of the hormone calcitonin and is produced in several cell types and organs in response to inflammatory stimuli, in particular, bacterial products.1
  • Biomarker associated with the inflammatory response to bacterial infection.
  • Aid in the risk assessment of critically ill patients for progression to severe sepsis.

In healthy individuals, plasma PCT concentrations are found to be below 0.10 ng/mL. Depending on the clinical context, a PCT concentration above 0.10 ng/mL may indicate clinically relevant bacterial infection requiring antibiotic treatment. PCT levels rise rapidly (within 6 to 12 hours) after a bacterial infectious insult with systemic consequences. The magnitude of the increase in PCT concentration correlates with severity of the bacterial infection.

0.10 – 0.49 ng/mL: Low risk for progression to severe systemic infection (severe sepsis). Local bacterial infection is possible.*
0.50 – 1.99 ng/mL: Moderate risk for progression to severe systemic infection (severe sepsis). Consider close monitoring and repeat assay in 6 to 24 hours.**
2.00 – 9.99 ng/mL: High risk for progression to severe sepsis.
>=10.00 ng/mL: High likelihood of severe sepsis or septic shock.
Procalcitonin Result Clinical Interpretation 

*PCT levels below 0.5 ng/mL do not exclude an infection. Localized infections without systemic signs may be associated with such low levels. If the PCT measurement is performed very early after a bacterial challenge (usually <6 hours), these values may still be low. In this case, PCT should be reassessed 6 to 24 hours later.

Percent change of PCT over time aids in assessing cumulative 28-day risk of all-cause mortality for patients diagnosed with severe sepsis or septic shock.

For convenience, one can use the Change in Procalcitonin Calculator to determine ΔPCT results from the absolute PCT concentrations of a patient obtained on the day severe sepsis or septic shock was first diagnosed (or 24 hours later) and on Day 4. Go to www.BRAHMS-PCT-Calculator.com.