The measurement of total Tau at the CSF is used to investigate Alzheimer's disease, in patients with memory loss, and brain injury investigations.
Tau proteins (the Greek letter T) stabilize the microtubules in cells. They are abundant in neurons of the central nervous system and found at very low levels in astrocytes and oligodendrocytes of the CNS. Pathological conditions of the nervous system, such as Alzheimer's disease, are related to defective Tau proteins that do not stabilize the microtubules properly.
The total Tau protein measurement reflects the axons' destruction and degradation. Tau protein can be phosphorylated to varying degrees (Phospho-Tau). Measurement of total Tau is used as a biomarker for Alzheimer's disease. Still, elevated Tau levels may also be observed in other degenerative diseases of the central nervous system and strokes. Higher Tau levels are observed in Creutzfeldt-Jakob disease with rapid progressive cortical degeneration.
- Alzheimer's disease: moderate to significant increase in total Tau (sensitivity to Alzheimer's disease detection 85%)
- Extensive acute stroke: a sharp increase in total Tau
- Creutzfeldt-Jakob disease (CJD): a sharp rise in total Tau
- Frontal dementia: normal or slightly elevated levels of total Tau
- Lewy body dementia: normal or slightly elevated levels of total Tau
- Vascular dementia: normal or slightly elevated levels of total Tau
- Amyotrophic lateral sclerosis (ALS): normal levels of total Tau
Normal aging, mild cognitive impairment without progression to Alzheimer's disease, depression, Parkinson's disease, and non-acute cerebrovascular disease have normal levels of total Tau.
