Procalcitonin Assay Harmonization Remains Incomplete Despite Growing Clinical Adoption
This comprehensive analysis of published comparison studies and 137 external quality assessment surveys reveals significant inter-assay variability in procalcitonin measurement, though the clinical impact on decision-making appears moderate at standard cut-offs. EQA schemes provide highly discrepant estimates of interlaboratory CV, largely due to unknown commutability of EQA materials. The study calls for development of commutable reference materials and standardized calibration to ensure PCT results are truly interchangeable across platforms as clinical adoption accelerates.
The original study
Harmonization status of procalcitonin measurements: what do comparison studies and EQA schemes tell us?
- Authors
- Huynh HH, Bœuf A, Pfannkuche J, Schuetz P, Thelen M, Nordin G, et al.
- Journal
- Clinical chemistry and laboratory medicine
- Type
- Journal Article, Research Support, Non-U.S. Gov't, Review
- PMID
- 34147043
Original abstract
Sepsis represents a global health priority because of its high mortality and morbidity. The key to improving prognosis remains an early diagnosis to initiate appropriate antibiotic treatment. Procalcitonin (PCT) is a recognized biomarker for the early indication of bacterial infections and a valuable tool to guide and individualize antibiotic treatment. To meet the increasing demand for PCT testing, numerous PCT immunoassays have been developed and commercialized, but results have been questioned. Many comparison studies have been carried out to evaluate analytical performance and comparability of results provided by the different commercially available immunoassays for PCT, but results are conflicting. External Quality Assessment Schemes (EQAS) for PCT constitute another way to evaluate results comparability. However, when making this comparison, it must be taken into account that the variety of EQA materials consist of different matrices, the commutability of which has not yet been investigated. The present study gathers results from all published comparison studies and results from 137 EQAS surveys to describe the current state-of-the-art harmonization of PCT results. Comparison studies globally highlight a significant variability of measurement results that nonetheless seem to have a moderate impact on medical decision-making. For their part, EQAS for PCT provides highly discrepant estimates of the interlaboratory CV. Due to differences in commutability of the EQA materials, the results from different peer groups could not be compared. To improve the informative value of the EQA data, the existing limitations such as non-harmonized conditions and suboptimal and/or unknown commutability of the EQA materials have to be overcome. The study highlights the need for commutable reference materials that could be used to properly evaluate result comparability and possibly standardize calibration, if necessary. Such an initiative would further improve the safe use of PCT in clinical routine.