Oliver Jonathan M, Anzalone Anthony J, Stone Jason D, Turner Stephanie M, Blueitt Damond, Garrison J Craig, Askow Andrew T, Luedke Joel A, Jagim Andrew R
1Sports Concussion Research Group, Department of Kinesiology, Texas Christian University.
2Texas Health Sports Medicine Concussion Center; and.
J Neurosurg. 2018 May 29;130(5):1655-1662. doi: 10.3171/2017.12.JNS172035. Print 2019 May 1.
Repetitive subconcussive head trauma is a consequence of participation in contact sports and may be linked to neurodegenerative diseases. The degree of neurological injury caused by subconcussive head trauma is not easily detectible, and this injury does not induce readily identifiable clinical signs or symptoms. Recent advancements in immunoassays make possible the detection and quantification of blood biomarkers linked to head trauma. Identification of a blood biomarker that can identify the extent of neurological injury associated with subconcussive head trauma may provide an objective measure for informed decisions concerning cumulative exposure to subconcussive head trauma. The purpose of the current study was to examine changes in the blood biomarkers of subconcussive head trauma over the course of an American football season.
Thirty-five National Collegiate Athletic Association (NCAA) American football athletes underwent blood sampling throughout the course of a football season. Serial samples were obtained throughout the 2016 season, during which the number and magnitude of head impacts changed. Blood samples were analyzed for plasma concentrations of tau and serum concentrations of neurofilament light polypeptide (NF-L). Athletes were grouped based on their starter status, because athletes identified as starters are known to sustain a greater number of impacts. Between-group differences and time-course differences were assessed.
In nonstarters, plasma concentrations of tau decreased over the course of the season, with lower values observed in starters; this resulted in a lower area under the curve (AUC) (starters: 416.78 ± 129.17 pg/ml/day; nonstarters: 520.84 ± 163.19 pg/ml/day; p = 0.050). Plasma concentrations of tau could not be used to discern between starters and nonstarters. In contrast, serum concentrations of NF-L increased throughout the season as head impacts accumulated, specifically in those athletes categorized as starters. The higher serum concentrations of NF-L observed in starters resulted in a larger AUC (starters: 1605.03 ± 655.09 pg/ml/day; nonstarters: 1067.29 ± 272.33 pg/ml/day; p = 0.007). The AUC of the receiver operating characteristic curve analyses displayed fair to modest accuracy to identify athletes who were starters with the use of serum NF-L following periods of repetitive impacts.
The different patterns observed in serum NF-L and plasma tau concentrations provide preliminary evidence for the use of blood biomarkers to detect the neurological injury associated with repetitive subconcussive head trauma. Although further investigation is necessary, such findings might lay the foundation for the further development of an objective measure for the detection of neurological injury caused by subconcussive head trauma.
重复性轻度脑震荡性头部创伤是参与接触性运动的后果，可能与神经退行性疾病有关。轻度脑震荡性头部创伤所导致的神经损伤程度不易察觉，且这种损伤不会引发易于识别的临床体征或症状。免疫测定技术的最新进展使得检测和量化与头部创伤相关的血液生物标志物成为可能。识别一种能够确定与轻度脑震荡性头部创伤相关的神经损伤程度的血液生物标志物，可能为就累积暴露于轻度脑震荡性头部创伤做出明智决策提供一种客观指标。本研究的目的是考察美式橄榄球赛季期间轻度脑震荡性头部创伤的血液生物标志物的变化情况。
35名美国大学体育协会（NCAA）美式橄榄球运动员在整个橄榄球赛季接受了血液采样。在2016赛季期间获取了系列样本，在此期间头部撞击的次数和强度发生了变化。对血液样本进行分析，以测定血浆中tau蛋白的浓度以及血清中神经丝轻链多肽（NF-L）的浓度。根据运动员的首发状态进行分组，因为已知被认定为首发球员的运动员会承受更多的撞击。评估组间差异和时间进程差异。
在非首发球员中，血浆tau蛋白浓度在赛季过程中下降，首发球员中观察到的值更低；这导致曲线下面积（AUC）更低（首发球员：416.78±129.17 pg/ml/天；非首发球员：520.84±163.19 pg/ml/天；p = 0.050）。血浆tau蛋白浓度无法用于区分首发球员和非首发球员。相比之下，随着头部撞击的累积，血清NF-L浓度在整个赛季中升高，特别是在那些被归类为首发球员的运动员中。首发球员中观察到的更高血清NF-L浓度导致更大的AUC（首发球员：1605.03±655.09 pg/ml/天；非首发球员：1067.29±272.33 pg/ml/天；p = 0.007）。在重复性撞击后的时期，利用血清NF-L识别首发球员的受试者工作特征曲线分析的AUC显示出中等至较好的准确性。
在血清NF-L和血浆tau蛋白浓度中观察到的不同模式为使用血液生物标志物检测与重复性轻度脑震荡性头部创伤相关的神经损伤提供了初步证据。尽管有必要进行进一步研究，但这些发现可能为进一步开发用于检测轻度脑震荡性头部创伤所致神经损伤的客观指标奠定基础。
