Plasma Protein S100-B Useful Screening Tool in Head Trauma
(HealthDay News) – Measuring plasma levels of the protein S100-B has a high negative predictive value compared with computed tomography (CT) scans for patients with minor head injuries, according to research published in the March issue of the Annals of Emergency Medicine.
To evaluate the negative predictive value of using the S100-B test as a screening tool for minor head injury, Drissa Zongo, MD, MPH, of the University of Bordeaux in France, and colleagues conducted a prospective observational study involving 1,560 patients with minor head injury who had both CT scans and plasma S100-B protein levels measured.
The researchers found that CT scans identified intracranial lesions in 7 percent of patients, and their median S100-B level was 0.46µg/L compared with 0.22µg/L in the other patients. A cut-off value of 0.12µg/L was established, and using this threshold, traumatic brain injuries on CT were identified with 99.1% sensitivity and 99.7% negative predictive value.
"We report here the largest study ever conducted, to our knowledge, on a consecutive sample of 1,560 patients with minor head injury, comparing initial blood levels of S100-B protein with head trauma-relevant CT scan findings. Our results show that blood S100-B measurement within six hours of minor head injury compared with CT scan has a high negative predictive value," the authors write.