CSF biomarkers (Aβ42, p-tau)
DELiquor-Biomarker (Aβ42, p-Tau)
CSF biomarkers for Alzheimer's are proteins measured in your spinal fluid (via a lumbar puncture) that mirror the core brain pathologies. As amyloid gets locked into plaques, Aβ42 (and the Aβ42/40 ratio) drops in the fluid. Meanwhile, phospho-tau (p-tau181 and p-tau217) and total tau rise with tangle pathology and nerve loss. Together they make up the A/T/N framework (amyloid, tau, neurodegeneration), endorsed by the 2024 Alzheimer's Association criteria. That lets doctors diagnose the disease biologically, not just clinically. CSF markers match amyloid and tau PET scans closely. And they can detect Alzheimer's pathology 15 to 20 years before symptoms. Their main downside is the invasiveness of the lumbar puncture. Blood-based versions (especially p-tau217) are maturing fast and nearing CSF-level accuracy.
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Sources
- Blennow K, Dubois B, Fagan AM, Lewczuk P, de Leon MJ, Hampel H. (2015). Clinical utility of cerebrospinal fluid biomarkers in the diagnosis of early Alzheimer's disease. *Alzheimer's & Dementia*doi:10.1016/j.jalz.2014.02.004
- Molinuevo JL, Ayton S, Batrla R, Bednar MM, Bittner T, ..., Hampel H, ..., Blennow K. (2018). Current state of Alzheimer's fluid biomarkers. *Acta Neuropathologica*doi:10.1007/s00401-018-1932-x