Comparison of sample materials for S100b analysis.

Area of Science:

• Emergency Medicine
• Clinical Chemistry
• Biomarker Analysis

Background:

• Head injuries are common in emergency departments, necessitating rapid and accurate diagnostic tools.
• S100B protein levels are utilized to rule out the need for head CT scans in low-risk mild head injury patients.
• Current diagnostic methods using standard serum tubes have lengthy turn-around times, impacting patient flow.

Purpose of the Study:

• To evaluate the performance of two alternative blood collection tubes, a rapid serum tube (RST) and a hirudin tube (HIR), for S100B analysis.
• To compare the diagnostic accuracy and efficiency of RST and HIR against standard serum clotting tubes.
• To determine if alternative tubes can reduce laboratory turn-around time for S100B measurements.

Main Methods:

• Paired blood samples from 221 subjects were analyzed for S100B using standard serum tubes, RST, and HIR on a Roche Cobas 602 analyser.
• Method comparison, repeatability, and agreement analyses were performed between the standard tubes and the alternative tubes.
• Key performance metrics included bias, repeatability, and predictive values.

Main Results:

• Both RST and HIR showed minor positive bias compared to standard tubes.
• RST demonstrated excellent repeatability (2%) and 100% negative predictive value, comparable to the standard tube's 4% repeatability.
• HIR showed higher positive predictive value (73%) than RST (62%) but had lower repeatability (10%).

Conclusions:

• The rapid serum tube (RST) is a feasible alternative for S100B analysis, significantly reducing laboratory turn-around time.
• RST offers a practical solution to improve emergency department workflow for mild head injury evaluations.
• Further validation may be needed, but RST shows promise in expediting S100B diagnostics.