Diagnostic Value of CSF Biomarker Profile in Frontotemporal Lobar Degeneration
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.