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 degrees C) and room temperature (24 degrees 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 degrees C to that in 24 degrees 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.