Are CSF Tau And Phospho Tau Levels Really Biomarkers Of Amyotrophic Lateral Sclerosis? (P6.003)

OBJECTIVE: To evaluate the role of CSF tau and ptau181 proteins in Amyotrophic Lateral Sclerosis(ALS). BACKGROUND: Tau protein belongs to the Microtubule-Associated Proteins(MAP) family and it’s released in CSF following axonal damage. Conversely, hyperphosphorylated tau is over produced in some neurodegenerative diseases, so-called “Tauopathies”. ALS is the most common motor neuron disease, characterized by progressive degeneration of both upper and lower motor neurons. Great interest has been directed toward the study of CSF Tau and pTau181 profile in ALS, as candidate diagnostic tool. DESIGN/METHODS: Tau and p-tau181 were assayed in CSF of 43 ALS patients according to El Escorial criteria, 95 suspected Alzheimer Disease (sAD), 13 Fronto-temporal Dementia (FTD), 20 viral encephalitis (VE) and 17 with other non-degenerative neurological diseases (OND). ALSFRS-r at the time of rachicentesis, progression rate[PR], time to generalization[TG] and onset-diagnosis interval[ODI] were correlated with tau, p-tau181 and ptau181/tau ratio. RESULTS: In ALS patients CSF tau levels were lower than in sAD (p<0.0001) and VE (p<0.01) but higher than in OND (p=0.04), no differences were found with FTD. pTau181 levels were lower in ALS patients than in sAD (p<0.0001) and FTD (p=0.01) but didn’t differ from OND and VE. p-tau181/tau ratio was higher in ALS patients than in VE (p=0.008), no differences was found with other groups. Finally, ptau181 levels correlated with ALSFRS-r score (rs=0.422; p=0.01) but not with other clinical parameters. CONCLUSIONS: Our study confirms recent literature’s data. CSF levels of tau and ptau181 we found in ALS suggest that the neurodegenerative process in ALS is less wide than in AD, FTD and VE; moreover, pTau181’s levels in ALS correlate with clinical disability. Nowadays, the presumed diagnostic role of these biomarkers in ALS seems to be still limited and we speculate that other studies in a broader number of cases are needed. Disclosure: Dr. Scarafino has nothing to disclose. Dr. Leante has nothing to disclose. Dr. Introna has nothing to disclose. Dr. Cortese has nothing to disclose. Dr. Distaso has nothing to disclose. Dr. D9Errico has nothing to disclose. Dr. Simone has received personal compensation for activities with Sanofi-Aventis Pharmaceuticals, Inc., and Biogen Idec.