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Procalcitonin: Diagnosing Sepsis with PCT

PCT Improves Accuracy of Clinical Sepsis Diagnosis

Moreover, PCT was shown to be the only laboratory parameter that made a significant contribution to the clinical diagnosis of sepsis (Figure 1).4

Information obtained from IL-6, IL-8 and CRP had no impact on the clinical diagnosis of sepsis on admission.

FIGURE 1 - Accuracy of sepsis diagnosis based on a clinical model with and without PCT.4

PCT - Useful Parameter for Early Sepsis Diagnosis

Among several laboratory parameters, PCT has been shown to be the most useful. 4,5,6,7
PCT showed the best performance for differentiating patients with sepsis from those with a systemic inflammatory reaction not related to an infectious cause (Figure 2a,b)

Figure 2:
Comparison of diagnostic performances of various markers for diagnosis of bacterial infection/sepsis

PCT versus CRP 6
PCT: Better differentiation of bacterial infection from non-infectious causes of inflammation.

Summary receiver operating characteristic (SROC) curves comparing serum procalcitonin (PCT; •) and C-reactive protein (CRP; •) markers for detection of bacterial infections versus non-infective causes of inflammation. Each point contributing to the SROC curve represents 1 study (total number of studies: 10; total number of patients: 905).


PCT versus IL-6 and IL-8 4
PCT: More accurate diagnosis of sepsis than IL-6 and IL-8.
Receiver operating characteristic (ROC) curves comparing serum procalcitonin (PCT), interleukin 6 (IL-6) and interleukin 8 (IL-8) for detection of sepsis on day of admission to ICU.


Increased PCT Values - Indicator for the Severity of Infection and Organ Failure

PCT development accurately reflects the progression of the disease with greater reliability than other parameters (Figure 3a-d).


FIGURE 3a, b
Differentiation between SIRS*, sepsis, severe sepsis and septic shock by PCT and IL-6.4 * Systemic Inflammatory Response Syndrome

Assessment of severity of disease (increasing organ dysfunction) by PCT and CRP.8

Increased PCT values - indicator of mortality risk for patients in ICU

A high maximum procalcitonin level and a procalcitonin increase for 1 day are early independant predictors of all-cause mortality in a 90 day follow-up period after intensive care unit admission.9 Mortality risk increases for every day that procalcitonin increases.

Levels or increases of CRP and white blood cell count do not seem to predict

FIGURE 4 - PCT increase and 90-day mortality in the ICU.



4. Harbarth S, Holeckova K, Froidevaux C, Pittet D, Ricou B, Grau GE, Vadas L, Pugin J; Geneva Sepsis Network.
Diagnostic value of procalcitonin, interleukin-6, and interleukin-8 in critically ill patients admitted with
suspected sepsis. Am J Respir Crit Care Med. 2001;164:396-402.
5. Muller B, Becker KL, Schachinger H, Rickenbacher PR, Huber PR, Zimmerli W, Ritz R. Crit Care Med.
2000;28:977-83. Calcitonin precursors are reliable markers of sepsis in a medical intensive care unit.
6. Simon L, Gauvin F, Amre DK, Saint-Louis P, Lacroix J. Serum procalcitonin and C-reactive protein levels as
markers of bacterial infection: a systematic review and meta-analysis. Clin Infect Dis. 2004;39:206-17.
7. van Rossum AM, Wulkan RW, Oudesluys-Murphy AM. Procalcitonin as an early marker of infection in
neonates and children. Lancet Infect Dis. 2004;4:620-30.
8. Meisner M, Tschaikowsky K, Palmaers T, Schmidt J. Comparison of procalcitonin (PCT) and C-reactive
protein (CRP) plasma concentrations at different SOFA scores during the course of sepsis and MODS. Crit
Care. 1999;3:45-50.
9. Jensen JU, Heslet L, Jensen TH, Espersen K, Steffensen P, Tvede M. Procalcitonin increase in early
identification of critically ill patients at high risk of mortality. Crit Care Med. 2006;34:2596-602.


Watch the inspiring video of sepsis survivor Patricia Cragen and her family as they experience a once in a lifetime event at Strike Out Sepsis Day with the St. Louis Cardinals on August 31, 2015. Watch Video >

See highlights from the Second National Forum on Sepsis, held September 16, 2015 in Washington, DC, and learn more about the Rory Staunton Foundation’s initiatives to raise awareness and knowledge about sepsis. Watch Video >


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