Comparison of the temperature influence on the activity of currently available Procalcitonin reagents

Background: Procalcitonin (PCT) is a stable biomarker for bacterial infections; however, limited data is available on new trivalent reagents. We evaluated temperature influence on the activity of PCT reagents. Methods: Using both conventional and trivalent reagents, we measured PCT levels of 30 clinical samples, stored residuum at refrigerator (4°C) and room temperature (24°C), and reexamined it after 24 hours. We defined a reduction rate as a percentage of PCT level at 24 hours compared to that after defrost and evaluated a ratio of reduction rate in 4°C to that in 24°C. Results: The reduction rate at room temperature decreased significantly compared to that in the refrigerated condition for all the reagents examined (p < 0.001). In addition, the ratio of reduction rate between the conventional and trivalent reagents showed a significant difference (p < 0.001) Conclusions: The serum PCT levels significantly decrease at room temperature, particularly when using newer trivalent reagents.