February 2, 2026

@michaelokun

Postmortem blood biomarkers and relationship to Alzheimer’s pathology. Postmortem means findings confirmed at brain autopsy. Plasma biomarkers are blood proteins that reflect what is happening in the brain. pTau217 relates to Alzheimer’s tau tangles, GFAP reflects astrocyte activation and NfL signals nerve injury. Kivisäkk and colleagues describe a new paper that just dropped in Neurology how blood biomarkers, measured before death, related to what was found in the brain at autopsy across Alzheimer’s disease and related dementias. Key points: - Plasma pTau217 tracked closely w/ the amount of Alzheimer’s amyloid plaques and tau tangles found in the brain at autopsy. - GFAP rose in Alzheimer’s disease but also increased in other brain diseases, suggesting it reflects broader brain stress rather than Alzheimer’s alone. - NfL increased across many neurodegenerative conditions, highlighting it as a marker of nerve injury rather than disease specific pathology. My take: This study is important because it ties blood tests to the ultimate ground truth: what is in the brain itself. pTau217 continues to stand out as a strong Alzheimer’s signal, while GFAP and NfL appear to tell a wider story about brain health and injury. Here are 5 points that resonated w/ me: 1- Blood based biomarkers are getting closer to reflecting true brain pathology, rather than just clinical symptoms. 2- pTau217 appears to be one of the most specific blood signals for Alzheimer’s related brain changes. 3- GFAP may serve as an early warning sign of brain stress, even before clear symptoms emerge. 4- NfL is useful for tracking neurodegeneration, but needs context because it rises in many brain diseases. 5- The future likely combines multiple blood markers to offer health care providers a more clear and earlier picture of what is happening in the brain across different dementias. https://www.neurology.org/doi/pdf/10.1212/WNL.0000000000214351 #michaelokun #fixelinstitute #parkinson #alzheimer