Alzheimer’s Protein Test May Help Diagnose CTE in Living Patients

Detecting CTE in Living Patients Using Alzheimer’s Biomarkers

Chihiro Sato, a neuroscientist at Washington University in St. Louis, stated that while the results require confirmation in a larger dataset, the data suggest a potential path toward diagnosing CTE in living individuals.

John Arena, a neurosurgeon at the University of Pennsylvania who was not involved in the research, noted that diagnosing patients while they are still alive would provide much-needed clarity regarding their well-being and prove invaluable for enrolling them in future clinical trials for CTE treatments. Because postmortem examination is currently required, tracking the true prevalence of the condition has been heavily complicated.

Understanding CTE Pathology and Tau Proteins

CTE is categorized as a tauopathy, meaning the primary molecular driver is a protein called tau. In a healthy brain, tau acts as a structural protein and cellular logistics manager that moves nutrients around brain cells. However, in CTE-affected brains, coroners observe tau tangles, which are warped deposits that damage brain cells and lead to memory problems, mood swings, and suicidal thoughts.

While a 2018 study found CTE-like damage in 1 of 164 donated brains, the condition is significantly more common in individuals exposed to repetitive head impacts. Data published in 2023 by the Boston University CTE Center indicated that CTE pathology was present in over 90 percent of brains within a sample of 376 former NFL players.

Unintended Discoveries in Tau Protein Research

Sato and her Washington University colleague, neuroscientist Kanta Horie, initially set out to develop a new diagnostic tool for Alzheimer’s disease, which also features visible tau dysfunction in different brain regions. Horie is employed by Eisai Inc., a U.S. subsidiary of a Tokyo-based pharmaceutical company developing treatments that target eMTBR-tau243, while working at Washington University. The research team aimed to verify whether eMTBR-tau243 was specific solely to Alzheimer’s disease.

Horie presented cerebrospinal fluid data gathered from 112 patients across seven different brain diseases. Across all tested conditions, elevated levels of eMTBR-tau243 appeared exclusively in patients diagnosed with Alzheimer’s disease or Alzheimer’s combined with another brain condition. However, the team encountered a surprising outlier: a patient with advanced CTE, prompting further investigation into the protein’s utility across neurodegenerative disorders.