What a UK-first pre-hospital biomarker trial could mean for TBI patients and litigation

For fifty years, acute traumatic brain injury (TBI) has been managed with a robust but ageing toolkit: the mechanism of injury, the Glasgow Coma Scale (GCS), and an urgent CT head.

The clinical limitations are stark. A patient can present with a GCS of 15 yet harbour a lethal, expanding haematoma. Conversely, a patient may be obtunded solely from intoxication with no structural brain injury at all. The need for differentiation is critical: to speed up neurosurgical intervention, allocate resources effectively, and avoid unnecessary scans.

Against this backdrop, the BRAIN-FIRST study – led by the East Anglian Air Ambulance (EAAA) in collaboration with Addenbrooke’s Hospital and the University of Cambridge – marks an important inflection point. It is the first UK pre-hospital feasibility trial to use a handheld blood test at the scene of injury to identify intracranial haemorrhage

What is BRAIN-FIRST Testing?

Study aim and setting

BRAIN-FIRST (Biomarker Assessment for Intracranial Haemorrhage: Feasibility of Integrating Pre-hospital Sample Testing) is a prospective feasibility study embedded in EAAA’s Research, Audit, Innovation and Development (RAID) programme.

The core questions are deliberately pragmatic:

1. Feasibility:
   Can helicopter crews safely obtain venous blood, run a point-of-care biomarker panel on scene or in flight, and integrate the result into their workflow without compromising time-critical interventions or delaying transfer?
2. Performance:
   How do those pre-hospital biomarker results correlate with CT findings once the patient reaches hospital? In particular, how well does a negative test exclude CT-detectable intracranial injury?

The trial is focused on adult trauma patients attended by EAAA with suspected head injury. The intent is not to replace clinical assessment, but to add an objective physiological signal at the very start of the care pathway.

The Device: i-STAT Alinity TBI whole-blood test

BRAIN-FIRST uses Abbott’s i-STAT Alinity system with a TBI cartridge that measures two brain-derived proteins, GFAP and UCH-L1, from venous whole blood at the point of care.

A critical feature of this testing is that it uses whole blood (no centrifuge) and yields laboratory-grade results in around 15 minutes.

This is not just a new gadget; it is a philosophy change. We are moving from diagnosing TBI based on symptoms to diagnosing it based on biochemistry.

The Science: GFAP and UCH-11

GFAP and UCH-L1 are not just inflammatory markers; they are structurally and spatially specific to the brain.

• GFAP (Glial Fibrillary Acidic Protein): An astrocyte-specific protein that correlates strongly with CT-visible lesions.
• UCH-L1 (Ubiquitin C-Terminal Hydrolase L1): A neuronal protein that acts as a sensitive “early warning” signal. Crucially, UCH-L1 peaks early and clears rapidly, meaning hospital-based tests often miss the window.

By testing minutes after impact, within the pre-hospital “golden hour”, BRAIN-FIRST captures data that simply isn’t available by the time a patient reaches the Emergency Department.

Established performance of GFAP and UCH-L1

Across multiple ED-based cohorts (including TRACK-TBI-linked work and European validation studies), combined GFAP/UCH-L1 testing has:

• Sensitivity approaching 100% for CT-positive intracranial lesions in mild TBI (GCS 13-15)
• Diagnostic performance that is comparable or superior to widely used clinical rules (e.g. Canadian CT Head Rule, NICE algorithms) for ruling out the need for CT in selected ED populations.

Legal and Clinical Implications

While the UK remains cautious, the direction of travel is clear: the American College of Surgeons’ 2024 guidelines already position GFAP/UCH-L1 as adjuncts to imaging decisions. Beyond diagnosis, day-of-injury levels show prognostic promise for 6-month functional outcomes (GOSE), offering an early quantitative measure of brain insult alongside the GCS.

For the legal sector, a recent narrative review highlighted the forensic potential of these markers to support diagnosis and staging, while rightly warning that premature deployment risks misuse before standardisation is complete.

The End of “Invisible” Injury?

The most contentious cases often involve a specific triad:

• Mild TBI (GCS 13–15)
• Normal CT/MRI
• Persistent cognitive or emotional symptoms

Currently, these disputes rely heavily on retrospective neuropsychological opinion. In future, a positive roadside test provides contemporaneous evidence of neuronal disruption and blood-brain barrier breach, even if the CT is normal.

This shifts the argument materially: away from “was there an organic insult at all?” and towards “how significant was it and what are its sequelae?”.

Causation and Complexity

In complex cases such as a sports concussion followed by a road traffic collision, biomarker kinetics offer theoretical hope for disentangling insults. UCH-L1 peaks and fades rapidly; GFAP declines more slowly.

While current evidence cannot yet support precise legal apportionment, this kinetic difference could eventually help distinguish “old” from “new” injuries

Conclusion

BRAIN-FIRST is not just another air ambulance research project. It is an early test of a radically different philosophy: that TBI should be treated as a measurable biochemical event from the first minutes after impact, rather than a black box that only reveals itself once a patient reaches a CT scanner.

For clinicians, that promises more precise triage, better stewardship of CT and neurosurgical resources and, eventually, a pathway to genuinely early neuroprotective therapies. For lawyers and courts, it signals the arrival of a new type of “biological witness” in the documentation of head injury.

The technology is already here. BRAIN-FIRST will tell us whether it can survive the realities of the roadside and rotor blades. What follows – in guideline committees, trauma networks and courtrooms – is likely to shape neurotrauma care over the next decade.

References

Price, J., et al. (2024). BRAIN-FIRST: Biomarker Assessment for Intracranial Haemorrhage – Feasibility of Integrating Pre-hospital Sample Testing. East Anglian Air Ambulance, RAID Research Portfolio

Abbott Point of Care (2024). i-STAT Alinity TBI test: Whole blood traumatic brain injury assay.

Bazarian, J. J., et al. (2018). Serum GFAP and UCH-L1 for prediction of absence of intracranial injuries on head CT (ALERT-TBI). Lancet Neurology, 17(9).

FDA (2024). 510(k) clearance K240123: i-STAT Alinity TBI whole blood cartridge.

NICE (2023). Head injury: assessment and early management (NG232).

Wilson, L., et al. (2021). The future of biomarkers for traumatic brain injury: A legal and ethical perspective. Journal of Law and the Biosciences.