From the Guidelines
Amyloid Beta and Tau protein are markers for Alzheimer's disease.
Key Biomarkers
- Amyloid Beta (Aβ): Deposits of Aβ in the brain are a hallmark of Alzheimer's disease, and low levels of Aβ42 in cerebrospinal fluid (CSF) or evidence of Aβ deposition on positron-emission tomography (PET) scans are considered markers of the disease 1.
- Tau protein: Elevated levels of total tau or phosphorylated-tau (p-tau) in CSF are also considered markers of Alzheimer's disease, with p-tau being a strong marker of neuronal injury associated with the disease 1, 2.
Diagnostic Criteria
The presence of both Aβ and tau biomarker positivity is required to establish a diagnosis of Alzheimer's disease, as either biomarker alone may not be specific to the disease 3.
Biomarker Combinations
The combination of low CSF Aβ42 and elevated CSF tau provides a high likelihood of progression to Alzheimer's disease in patients with mild cognitive impairment (MCI) 1.
Blood Biomarkers
Plasma phosphorylated tau (p-tau) assays have been developed as blood biomarkers for Alzheimer's disease, with p-tau181, p-tau217, and p-tau231 being specific to the disease and able to differentiate it from other tauopathies 2.
From the Research
Markers for Alzheimer's Disease
The following are considered markers for Alzheimer's disease:
- Amyloid Beta: implicated in the pathogenesis of Alzheimer's disease and considered a main pathological hallmark 4, 5, 6, 7, 8
- Tau protein: also implicated in the pathogenesis of Alzheimer's disease and considered a main pathological hallmark 4, 5, 6, 7, 8 ### Less Relevant Markers The following are less directly relevant as markers for Alzheimer's disease:
- Ubiquitin: altered ubiquitin signaling has been linked to Alzheimer's disease, but it is not as directly implicated as Amyloid Beta or Tau protein 5, 6
- Notch 3: there is no evidence in the provided studies to suggest that Notch 3 is a marker for Alzheimer's disease ### Key Biomarkers The key biomarkers for Alzheimer's disease are:
- Amyloid-β (Aβ) 8
- Phosphorylated Tau (p-Tau) 7, 8