Advancing the Need to Reduce Unnecessary Antibiotic Treatment by Using the Biomarker Procalcitonin

Authors: Raymond Beyda, MD; Jackie Shibata, MD; Lee Grodin, MD; and Theodore Segarra, MD
Editors: Kelly Maurelus, MD FAAEM and Michael C. Bond, MD FAAEM
Originally Published: Common Sense January/February 2017

ED physicians frequently treat and admit patients for infectious diseases. Judicious use of antimicrobial therapy is important in order to avoiding the development of antimicrobial resistance and adverse drug effects. Procalcitonin (PCT) is one of several bbiomarkers which may be useful in decreasing unnecessary antibiotic therapy. Specifically, PCT levels should be low for viral, as opposed to bacterial, infections. Procalcitonin has been studied as both a diagnostic and prognostic marker in various types of systemic and organ-specific infections. The potential for PCT to reduce unnecessary antimicrobial therapy has been shown in several observational and randomized controlled trials performed in outpatient, inpatient, and ICU environments. The most robust evidence is in sepsis and pulmonary infections. Here we review some of the evidence behind the use of PCT in acute infectious disease management.

Clinical Pearl: Procalcitonin and Lower Respiratory Tract Infections

Image Credit: Flickr

Author: Jordan Kaylor, MD PGY4
Northwestern/McGaw Medical Center

Procalcitonin (PCT) is a serum biomarker that, when paired with clinical judgment, may help guide management of lower respiratory tract infections (LRTIs) in the emergency department (ED). Procalcitonin levels can help clinicians distinguish between bacterial and viral infections and might subsequently guide decisions to initiate or discontinue antibiotics. Procalcitonin is a prohormone of calcitonin. It is an acute-phase reactant synthesized in many tissues and released in response to cytokines such as interleukin (IL)-1, IL-6, and tumor necrosis factor (TNF)-α.1 Normal serum concentrations are <0.05ng/mL, but in bacterial infections, PCT increases to detectable levels within three to four hours (earlier than ESR or CRP).[1] Elevations are not seen in noninfectious inflammatory conditions or viral infections, but are possible in Addisonian crises, malaria, severe fungal infections and medullary thyroid carcinoma.[1] In viral infections, interferon (INF)-ɣ probably decreases PCT release, leading to lower or undetectable serum levels.[2]