P2–152: Novel diagnostic biomarkers of Alzheimer's disease in human CSF

gate the relationships between episodic memory, ApoE genotype and CSF biomarker levels (total-tau, t-tau; hyperphosphorylated tau, p-tau; b-amyloid, Ab42), and also to examine these variables as predictors of cognitive decline during a 3-year follow-up. Methods: This retrospective study included 149 memory clinic patients who were examined with neuropsychological tests in close conjunction with a lumbar puncture. Analyses of t-tau, p-tau and Ab42 in CSF and ApoE genotype were performed. Memory was assessed at baseline using Rey Auditory Verbal Learning Test (RAVLT); 47 cases were severely impaired (SIM), 58 were moderately impaired (MIM) and 44 patients had normal memory (NIM). Cognitive decline during 3 years was investigated in 124 patients. Results: Apoe4 carriers, but not none4 -carriers in patients with severe memory impairment (SIM) showed decreased Ab42 levels and increased t-tauand p-tau levels when compared to the other groups. However, both SIMe4 carriers and none4-carriers declined cognitively during 3 years and converted to dementia at an equal rate. MIMe4 carriers showed decreased Ab42 levels and normal tau levels; this group tended to decline in memory. Apoe4 positive and negative subjects with normal memory (NIM) showed normal levels of the CSF biomarkers. Conclusions: The Apoe4 allele is associated with pathological CSF markers in patients with severe memory impairment. Patients without the e4 allele and with severe memory impairment had normal t-tau, p-tau and Ab42. However, both the e4-carriers and the non-carriers with severe memory impairment declined cognitively over time.