NEW YORK — The American Association for Clinical Chemistry on Thursday released guidelines for the clinical testing of procalcitonin (PCT), a blood-based marker of bacterial infection and sepsis. The group said the guidance will provide lab professionals with clarity on how best to use PCT tests.
While PCT tests have long been used in Europe, they only became available in the US in 2017, when the US Food and Drug Administration cleared BioMérieux's automated Vidas Brahms PCT Assay to aid clinical decisions about the optimal use of antibiotics in patients with lower respiratory tract infections or sepsis. Since then, a number of other PCT tests have been cleared by the FDA.
Because of the newness of these tests in the US, there is confusion about when to use them, the AACC said, noting that they are often ordered in situations that are not clinically appropriate. As such, the group has released guidance that it said provides a "rigorous examination of the research evaluating procalcitonin along with an analysis of its limitations, with the goal of facilitating better testing and treatment."
The AACC said that the guidelines specifically address PCT testing in adult, pediatric, and newborn patients with suspected sepsis and/or bacterial infections, reviewing data around the use of the tests to guide antimicrobial treatment and predict patient outcomes.
For instance, the guidance document states, among other points, that PCT testing should be incorporated into broad antimicrobial stewardship efforts that draw on the expertise of multidisciplinary teams.
The document also warns about the use of PCT levels to determine when antibiotics should be discontinued in newborn and pediatric patients with suspected sepsis who show signs of improvement as current data are not robust enough to determine standard levels that can be applied across these populations. Therefore it is necessary to establish pediatric reference intervals or define interpretive criteria, it says.
The AACC also notes in its guidance that PCT tests should not be routinely used to predict 28-day mortality risk in sepsis patients, despite their clearance from the FDA for this purpose. It says there is a lack of consistent PCT cutoffs and clearance parameters as well as insufficient evidence demonstrating a benefit to estimating 28-day mortality risk in patients with sepsis and lower respiratory tract infections.
"Improved outcomes from PCT implementation are more likely to be realized when the test is used in conjunction with antimicrobial stewardship programs, institutional interpretive algorithms, and clinical decision support tools," the authors of the guidelines write. "Successful implementation of clinical PCT requires a multidisciplinary effort among laboratorians, pharmacists, and infectious disease providers."
The full AACC guidance document can be found here.