Subject-Specific Increases in Serum S-100B Distinguish Sports-Related Concussion from Sports-Related Exertion

• Published in: PloS one Vol. 9; no. 1; p. e84977
• Main Authors: Kiechle, Karin, Bazarian, Jeffrey J., Merchant-Borna, Kian, Stoecklein, Veit, Rozen, Eric, Blyth, Brian, Huang, Jason H., Dayawansa, Samantha, Kanz, Karl, Biberthaler, Peter
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 08.01.2014; Public Library of Science (PLoS)
• Subjects: Adult; Athletes; Biomarkers - blood; Brain; Brain Concussion - blood; Brain Concussion - diagnosis; Brain Concussion - genetics; Brain injury; Brain research; Cohort analysis; Concussion; Diagnosis; Discriminators; Electrochemiluminescence; Emergency medical care; Female; Gene Expression; Head injuries; High school basketball; High school football; Humans; Ice hockey; Injuries; Injury analysis; Longitudinal Studies; Male; Medical imaging; Medicine; Neurosurgery; Physical Exertion - genetics; Proteins; S100 Calcium Binding Protein beta Subunit - blood; S100 Calcium Binding Protein beta Subunit - genetics; S100b protein; Soccer; Sports; Sports injuries; Sports medicine; Src protein; Student athletes; Surgery; Time Factors; Trauma; Traumatic brain injury; United States > US; Germany
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0084977

The on-field diagnosis of sports-related concussion (SRC) is complicated by the lack of an accurate and objective marker of brain injury. To compare subject-specific changes in the astroglial protein, S100B, before and after SRC among collegiate and semi-professional contact sport athletes, and compare these changes to differences in S100B before and after non-contact exertion. Longitudinal cohort study. From 2009-2011, we performed a prospective study of athletes from Munich, Germany, and Rochester, New York, USA. Serum S100B was measured in all SRC athletes at pre-season baseline, within 3 hours of injury, and at days 2, 3 and 7 post-SRC. Among a subset of athletes, S100B was measured after non-contact exertion but before injury. All samples were collected identically and analyzed using an automated electrochemiluminescent assay to quantify serum S100B levels. Forty-six athletes (30 Munich, 16 Rochester) underwent baseline testing. Thirty underwent additional post-exertion S100B testing. Twenty-two athletes (16 Rochester, 6 Munich) sustained a SRC, and 17 had S100B testing within 3 hours post-injury. The mean 3-hour post-SRC S100B was significantly higher than pre-season baseline (0.099±0.008 µg/L vs. 0.058±0.006 µg/L, p = 0.0002). Mean post-exertion S100B was not significantly different than the preseason baseline. S100B levels at post-injury days 2, 3 and 7 were significantly lower than the 3-hour level, and not different than baseline. Both the absolute change and proportional increase in S100B 3-hour post-injury were accurate discriminators of SRC from non-contact exertion without SRC (AUC 0.772 and 0.904, respectively). A 3-hour post-concussion S100B >0.122 µg/L and a proportional S100B increase of >45.9% over baseline were both 96.7% specific for SRC. Relative and absolute increases in serum S100B can accurately distinguish SRC from sports-related exertion, and may be a useful adjunct to the diagnosis of SRC.