Blood Biomarkers for Return to Play after Concussion in Professional Rugby Players.

We prospectively evaluated a panel of seven blood biomarkers (S100 calcium-binding protein B [S100B], neuron specific enolase [NSE], spectrin breakdown products [SBDP], ubiquitin C-terminal hydrolase L1 [UCHL1], glial fibrillary acidic protein [GFAP], neurofilament light chain [NFL], and tubulin-associated unit [Tau]) for sport-related concussion (SRC) in a large multi-centric cohort of 496 professional rugby players from 14 French elite teams. Players were sampled twice during the season (beginning and end) away from any sport practice. From these two baseline samples, we evaluated the intra-individual variability to establish the effect of rugby on blood biomarkers over a season. Only S100B and GFAP remained stable over the course of a season. During the period of the study, a total of 45 SRC cases was reported for 42 players. In 45 SRCs, the head injury assessment (HIA) process was performed and blood collection was realized 36 h after the concussion (HIA-3 stage). For each biomarker, raw concentrations measured 36 h after SRC were not significantly different between players with a non-resolutive SRC (n = 28) and those with a resolutive SRC (n = 17; p between 0.06 and 0.92). In a second step, blood concentrations measured 36 h after SRC were expressed according to the basal concentrations as an individual percentage change (PCH36[%]), calculated as follows: PCH36 = 100 × (([Biomarker]36h - [Biomarker]basal)/[Biomarker]basal). S100B and NFL concentrations expressed as PCH36[%] were significantly different between non-resolutive and resolutive SRCs (p = 0.006 and 0.01 respectively), with a positive delta found in non-resolutive SRCs. Among the two biomarkers, it is important to note that only the S100B protein was stable during the season. In the context of our study, during HIA-3 assessment, S100B seems to perform better than NSE, SBDP, UCHL1, GFAP, NFL, and Tau as biomarker for SRC. From a clinical standpoint, the S100B modification over baseline may be valuable, at 36 h after concussion to distinguish non-resolutive SRC from resolutive SRC.

Utility of S100B Serum Level for the Determination of Concussion in Male Rugby Players.

BACKGROUND: The incidence of concussion in professional direct-contact sports, particularly in rugby, has increased in recent years. To date, cognitive assessment is the most common means of determining whether a concussed player can return to the game. Serum S100B assay, an objective blood test known to be useful in brain injury management, may offer a novel additional approach to the management of concussed male rugby players. OBJECTIVE: The aim of this study was to investigate the S100B utility for the determination of concussion in a professional 15-players-a-side rugby team. METHODS: Thirty-nine male rugby players were included in a prospective study during the 2014-2015 French championship season. Serum sampling was carried out several times at baseline and after a match and/or a concussion, at set times (2, 36 h). Serum S100B concentrations were determined using chemiluminescence immunoassay on a Roche Diagnostics® instrument. RESULTS: The players' basal serum S100B was stable during the season and was not correlated with anthropometric data, body composition, or creatine kinase concentration. A significant increase in S100B concentration within 2 h after a game (without concussion) was observed. This increase was correlated with the number of body collisions during a match. Seventy-seven assays were performed 36 h after a game, including the follow-up of five concussed players. Thirty-six hours after a match, an increase of a minimum of 20 % compared with individual basal concentrations identified concussion with 100 % sensitivity and 81 % specificity. CONCLUSION: S100B measured 36 h after a match is thus a discriminating test to identify concussion in a male rugby player, with a 100 % negative predictive value.