Overpressure Exposure From .50-Caliber Rifle Training Is Associated With Increased Amyloid Beta Peptides in Serum.

Area of Science:

• Neurology
• Military Medicine
• Biomarker Discovery

Background:

• Military personnel face repeated low-level overpressure (OP) exposure from weapon systems.
• OP exposure may increase risks for neurological and psychological disorders.
• Early detection of OP-mediated brain effects is crucial for timely intervention.

Purpose of the Study:

• To investigate the acute temporal profile of traumatic brain injury (TBI)-associated serum biomarkers after repeated OP exposure.
• To correlate biomarker changes with neurocognitive decrements and self-reported symptoms.
• To evaluate the utility of biomarkers in detecting subconcussive OP effects.

Main Methods:

• Pilot study involving military personnel undergoing .50-caliber sniper rifle training.
• Daily OP exposure (peak pressure 3.8-4.5 psi) for three consecutive days.
• Measurement of serum biomarkers (GFAP, UCH-L1, Nf-L, tau, Aβ-40, Aβ-42) and neurocognitive testing pre- and post-exposure.

Main Results:

• Serum GFAP decreased on days 1 and 3; Nf-L was suppressed on day 3.
• Amyloid beta-40 (Aβ-40) elevated on day 2; Aβ-42 elevated daily post-exposure.
• GFAP suppression and Aβ-42 elevation correlated with OP impulse levels.

Conclusions:

• Acute measurement of Aβ-peptides may serve as biomarkers for subconcussive OP from rifle fire.
• Fluctuations in GFAP, Nf-L, and Aβ peptides indicate systemic response to subconcussive OP.
• These biomarkers may detect OP effects even without overt clinical deficits.