Plasma Neurofilament Light Is Not Elevated In Collegiate Women Soccer Players During A Competitive Season

The blood-based biomarker neurofilament light (NfL) is elevated in contact sports like collegiate American football during a competitive season and is indicative of brain injury. However, it is unknown if similar elevations in NfL are observed in the contact sport of collegiate soccer during a competitive season. PURPOSE: To observe plasma NfL changes in collegiate Division 1-A women soccer players during a competitive season. METHODS: A prospective cohort study design was utilized from a convenience sample of NCAA Division 1-A women soccer players from a single team during the 2022 competitive season. Venous blood samples were collected at four-time points; preseason (July), midseason 1 (Aug), midseason 2 (Sept), and postseason (Oct). Plasma NfL (pg/mL) was measured using the Simoa NF-LIGHT assay and platform (Quanterix, Lexington, MA). Enrolled players were excluded from data analysis if medically unavailable to participate in 80% or more of matches and/or training days or were diagnosed with a concussion. A Wilcoxon signed rank test was utilized as the data did not satisfy normality assumptions, to compare seasonal plasma NfL changes (i.e., mid and postseason) to preseason. RESULTS: See Table. Plasma NfL levels were normal for age (<10 pg/mL). No statistically significant differences between preseason and midseason plasma NfL levels. Postseason NfL was significantly lower than preseason NfL. - N = 13 Student Classification No. Playing Position No. Freshmen 0 Forward 5 Sophomore 5 Midfielder 5 Junior 6 Defender 2 Senior 2 Goalkeeper 1 Games Played 17.3 ± 3.8 Game Minutes 846 ± 544 (8 - 21) (104 - 1596) Preseason Midseason 1 Midseason 2 Postseason Plasma NfL (pg/mL) 5.17 ± 1.27 5.25 ± 1.47 4.73 ± 1.32 4.33 ± 1.63* (3.66 - 7.41) (3.28 - 7.68) (2.87 - 7.10) (1.36 - 8.06) Mean ± SD, Range (min - max). * Significantly different from preseason; p < 0.05. CONCLUSION: Plasma NfL levels are normal and are not elevated in collegiate women soccer players during a competitive season. These results suggest, in the absence of a concussion, competitive participation in the contact sport of soccer among women players does not negatively alter a blood-based biomarker reflective of sports-related brain injury. Supported by the School of Health Professions Research Grant at the University of Kansas Medical Center.