Blast exposure results in tau and neurofilament light chain changes in peripheral blood

ABSTRACT

Objectives

To evaluate how blast exposure impacts peripheral biomarkers

in military personnel enrolled in 10-day blast training.

Methods

On day 7, 21 military personnel experienced peak overpressure <2 pounds per square inch (psi); while 29 military personnel experienced peak overpressure ≥5 psi. Blood samples were collected each day to measure changes in amyloid beta (Aβ), neurofilament light chain (NFL), and tau concentrations.

Results

Within 24 hours following exposure ≥5 psi, the ≥5 psi group had lower Aβ42 (p = .004) and NFL (p < .001) compared to the <2 psi group and lower Aβ42 (9.35%) and NFL (22.01%) compared to baseline. Twenty-four hours after ≥5 psi exposure, the ≥5 psi group had lower tau (p < .001) and NFL (p < .001) compared to the <2 psi group and baseline. Seventy-two hours after exposure ≥5 psi, tau increased in the ≥5 psi group compared to the <2 psi group (p = .02) and baseline. The tau:Aβ42 ratio 24 hours after blast (p = .012), and the Aβ40:Aβ42 ratio 48 hours after blast (p = .04) differed in the ≥5 psi group compared to the <2 psi group.

Conclusions

These findings provide an initial report of acute alterations in biomarker concentrations following blast exposure.

KEYWORDS:

• Blast exposure
• tau
• peripheral biomarkers
• military
• neurofilament light chain (NFL)

Acknowledgments

Thank you to the leadership from the US Army Special Operations Command and US Army Engineer School for their support. We also thank the military personnel for their service to our nation and their participation in this study.

Disclosure of interest

The authors report no declarations of conflicts of interest. The opinions and assertions in this manuscript are those of the authors and are not to be construed as official as reflecting true views of the Department of Navy, Department of the Army, Department of Defense, the Uniformed Services University of the Health Sciences, U.S. Government, the Center for Neuroscience and Regenerative Medicine or any other agency of the U.S. government. This study was funded by the National Institutes of Health, Intramural Department of Research, and the US Army Medical Research and Material Command and the US Navy Bureau of Medicine (WUN 603115HP.2380.001.A1304.). The study protocol was approved by the Walter Reed Army Institute of Research/Naval Medical Research Center Institutional Review Boards in compliance with AR 70-25 and all applicable Federal regulations governing the protection of human subjects. Some of the authors are military service members or employees of the U.S. Government. This work was prepared as part of their official duties. Title 17 U.S.C. §105 provides that ‘Copyright protection under this title is not available for any work of the United States Government.’ Title 17 U.S.C. §101 defines a U.S. Government work as a work prepared by a military service member or employee of the U.S. Government as part of that person’s official duties. Material has been reviewed by the Walter Reed Army Institute of Research. There is no objection to its presentation and/or publication.

Additional information

Funding

This work was supported by the National Institute of Nursing Research Intramural Program, the US Army Medical Research and Materiel Command, the US Navy Bureau of Medicine (WUN 603115HP.2380.001.A1304.), and by the U.S. Defense Health Program Joint Project Committee (JPC) 5.