Blood Marker Offers Hope for Diagnosing CTE in Living Patients

WHO:

ABC News Health - The study concerns football players and other people who have suffered repeated blows to the head.

The Guardian - Researchers at Washington University School of Medicine in St Louis identified the blood biomarker eMTBR-tau243.

The Guardian - Kanta Horie was a co-senior author of the study published in JAMA Neurology.

The Guardian - Neuroscientist Chihiro Sato co-authored the study with Horie.

The Guardian - People whose brains showed CTE after death include NFL players Mike Webster, Junior Seau and Frank Gifford; boxer Ricky Hatton also received a mild CTE diagnosis after his death.

The Guardian - Steve Thompson, an England Rugby World Cup winner, is among living former rugby union and league players diagnosed with Traumatic Encephalopathy Syndrome (TES) who are involved in continuing legal action.

WHAT:

ABC News Health - A preliminary study found a clue that measuring a toxic protein associated with Alzheimer’s disease might eventually help diagnose another brain disease in people with repeated head impacts.

The Guardian - CTE is a degenerative brain condition associated with repeated head trauma; it can currently be diagnosed only after death by examining brain tissue.

The Guardian - Blood levels of eMTBR-tau243 were higher in 11 people whose CTE was confirmed at autopsy than in healthy people, and increased with disease severity.

The Guardian - The test distinguished people with advanced CTE from healthy people with high accuracy but could not reliably identify early-stage CTE. It has not been validated for diagnosing CTE.

The Guardian - A study of nearly 400 NFL players whose brains were donated after death found evidence of CTE in 93.5%.

The Guardian - More than 350 NFL players have been diagnosed with CTE after death.

The Guardian - The Professional Footballers’ Association recommended that professional players head a ball no more than 10 times a week in training and that children under 12 not head balls at all.

WHERE:

The Guardian - Researchers conducted the work at Washington University School of Medicine in St Louis.

The Guardian - CTE is a concern in collision and contact sports including American football, rugby and football.

WHY:

The Guardian - Researchers said that, if larger studies confirm the findings, a blood test could help monitor people at risk of CTE and enable trials of drugs to treat the condition.

The Guardian - Chihiro Sato said the biomarker could be relevant when someone has repeated head injuries, tests negative for Alzheimer’s disease and has elevated eMTBR-tau243; Sato cautioned that it would not be a standalone biomarker.

HOW:

The Guardian - The researchers measured eMTBR-tau243, a protein fragment in blood that is elevated in Alzheimer’s disease and other brain diseases involving similar toxic protein buildup, including CTE.

The Guardian - Kanta Horie said: “We are potentially opening a new door for diagnosing and treating CTE in living patients.”

The Guardian - Chihiro Sato said: “Our study shows that an Alzheimer’s disease biomarker can be applied to other tauopathies, including CTE.”

(UPDATED November 14, 2026 06:58 UTC)

Researchers found a blood marker linked to CTE, a brain disease caused by repeated head impacts. The marker was higher with confirmed CTE, but cannot reliably detect early disease. If larger studies confirm results, testing could help monitor at-risk people and guide treatment trials.