General information [10-16]
Procalcitonin (PCT), the precursor of the hormone calcitonin, is a 116 amino acid protein with a molecular weight of 13 kDa. In healthy individuals PCT is primarily expressed in thyroid C cells and is enzymatically cleaved to calcitonin, a calcium-regulating peptide. Upon stimulation by bacterial toxins and inflammatory cytokines PCT is expressed in the tissue of all organs. Thus, in patients with systemic bacterial infections, PCT concentrations rise from <0.1 ng/mL up to 1000 ng/mL within a few hours.
Benefits of PCT [18-21]
In comparison to other sepsis biomarkers, PCT shows several advantages:
- Fast in sepsis diagnosis and monitoring
- Good specificity and sensitivity for sepsis
- Beneficial kinetic in comparison to other parameters:
Early onset (3 - 6h) and short half-life (~12 - 24h) - Sensitive to bacterial origin
However, in order to correctly interpret PCT results, they should be placed into clinical context. Clinical findings, evaluation of severity of illness and of patient’s characteristics should be taken into account. Thus, decisions should not be based solely on PCT serum levels.
Available methods for measuring PCT
Until recently only fluorescence and luminescence immunoassays were available.
Due to advances in particle-enhanced turbidimetric immunoassay (PETIA) technology, PCT is now available for photometric analyzers, thus showing several benefits in comparison to other methods in the market:
- Cost-efficient
- Faster time to result
- High throughput
- Applicable on various clinical chemistry analyzers
- Available for any laboratory