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Procalcitonin: A promising tool or just another overhyped test?

Over the last few decades, there is an ongoing quest for the ideal biomarker in sepsis. Procalcitonin (PCT), when used alone or alongside additional clinical information, has shown to be a promising tool to aid in the diagnosis and management of patients with sepsis. In February 2017, the Food and Drug Administration (FDA) approved the use of PCT to guide antibiotic treatment in lower respiratory tract infections and sepsis. Despite a good negative predictive value for bacterial infection, the utility of PCT-guided antibiotic initiation is conflicting at best. On the other hand, the use of PCT-guided antibiotic discontinuation has shown to reduce the duration of antibiotic use, the associated…

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Articles of Interest

Clinical Utility and Measurement of Procalcitonin

PCT, the precursor of the hormone calcitonin, has been used as a biomarker to aid in diagnosis of bacterial infection or sepsis, as well as in differentiating bacterial pneumonia from viral pneumonia and chronic obstructive pulmonary disease (COPD). Diagnosis of sepsis is especially challenging as the clinical criteria for its diagnosis overlap with non-infective causes of systemic inflammation.

Diagnostics: Inflammatory Markers

Etiology: PCT was first discovered in 1984. However, it was not until a 1993 study that its significance was realized. In a small study involving 79 hospitalized children, PCT was found to be elevated in bacterial infections, with a decrease after appropriate antibiotic therapy, and decreased in viral infections. While PCT may be more specific for bacterial infections, it is flawed by still being rather non-specific and is not validated as a stand-alone diagnostic criteria for infection in the setting of the emergency department. Like the other two inflammatory markers, it still may be used to help shape pretest/posttest probability for infection.

Procalcitonin

Meta-analysis data is conflicting; some studies suggest procalcitonin is superior to CRP while other have concluded it is a weak biomarker in critical illness.

Procalcitonin (PCT) Tests Are So Functional

Procalcitonin (PCT) is a hormonally inactive glycoprotein containing 116 amino acids. Produced by thyroid-C cells under physiological conditions, it is barely detectable in serum or cerebrospinal fluid of healthy people. Its sensitivity and specificity are much higher than the traditional detection of C-reactive protein and peripheral blood white blood cell count, so PCT testing reagent has important clinical diagnosis and differential diagnosis value.

Procalcitonin As a Biomarker and Mediator of Sepsis: Implications for Critical Care

Sepsis represents the most common cause of death in noncardiac intensive care units (ICU). Procalcitonin (PCT), a peptide overexpressed ubiquitously during systemic inflammation, is considered the most sensitive and specific biomarker for bacterial sepsis.

Procalcitonin as a biomarker of infectious diseases

Traditional biomarkers, including C-reactive protein, leukocytes, erythrocyte sedimentation rate, and clinical signs and symptoms, are not sufficiently sensitive or specific enough to guide treatment decisions in infectious febrile diseases. Procalcitonin (PCT) is synthesized by a large number of tissues and organs in response to invasion by pathogenic bacteria, fungi, and some parasites. A growing body of evidence supports the use of PCT as a marker to improve the diagnosis of bacterial infections and to guide antibiotic therapy.

Procalcitonin Frequently Asked Questions

Procalcitonin is a biomarker produced by the body that is elevated in times of systemic inflammation, particularly when due to bacterial infection. In clinical practice, it can be used to help determine the likelihood of the presence of bacterial infection and guide cessation of antibiotic therapy.

Procalcitonin versus C-reactive protein: Usefulness as biomarker of sepsis in ICU patient

PCT is found to be superior to CRP in terms of accuracy in identification and to assess the severity of sepsis even though both markers cannot be used in differentiating infectious from noninfectious clinical syndrome.

The Prognostic Role of Procalcitonin in Critically Ill Patients Admitted in a Medical Stepdown Unit: A Retrospective Cohort Study

Procalcitonin (PCT) is a a marker of bacterial infection. Its prognostic role in the critically-ill patient, however, is still object of debate.

Using Procalcitonin to Guide Antibiotic Therapy

Procalcitonin levels rise in response to systemic inflammation, especially of bacterial origin. Multiple randomized controlled trials have demonstrated that procalcitonin-based algorithms can safely reduce antibiotic use in 2 clinical scenarios. First, in stable, low-risk patients with respiratory infections, procalcitonin levels of <0.25 µg/L can guide the decision to withhold antibiotics or stop therapy early. Second, in critically ill patients with suspected sepsis...

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StatPearls

In current clinical practice, procalcitonin (PCT) has developed into a promising new biomarker for the early detection of systemic bacterial infections. PCT is a 116-amino acid residue first explained by Le Moullec et al. in 1984; its diagnostic significance was not recognized until 1993.