Cerebrospinal fluid (CSF) biomarkers have been increasingly studied in dementia clinical and differential diagnosis.Methods
We assessed levels of total tau protein (τT), tau phosphorylated at threonine 181 (τP-181), and β-amyloid1-42 (Aβ42) in 34 patients with frontotemporal lobar degeneration (FTLD), 76 Alzheimer disease (AD) cases, and 93 controls (CTRL). Double sandwich enzyme-linked immunosorbent assays (Innogenetics) were used for measurements.Results
Total τ was significantly increased and Aβ42 decreased in FTLD and AD patients as compared with CTRL. CSF τP-181 levels were significantly increased only in AD. The τT/Aβ42 ratio successfully discriminated FTLD from CTRL with a 86.7% specificity and 80.6% sensitivity, whereas the τT alone was more specific (95.7%) but less sensitive (64.75%). For the discrimination of FTLD from AD, τT/Aβ42 ratio was better (90.3% sensitivity and 64.5% specificity) compared with the other biomarkers alone or in combination, whereas τP-181 was less sensitive but more specific (68.4% and 85.7%, respectively). Subtype analysis revealed that the most AD-like profile of biomarkers were observed in FTLD with motor neuron signs, whereas the most non-AD profile were observed in patients with primary progressive aphasia.Conclusions
Combined analysis of CSF biomarkers may be useful for the best possible antemortem discrimination of FTLD from AD.