P1‐154: QUANTITATIVE EEG (QEEG) AS A DIAGNOSTIC TOOL FOR ALZHEIMER'S DEMENTIA IN PATIENTS WITH DOWN SYNDROME

coupled to a hybrid quadropole orbitrap mass analyzer. Functionality and specificity of the immunoprecipitation was validated using Western blotting. Using isotope labeled peptides a selected reaction monitoring (SRM) method was developed to monitor and quantitate their identified endogenous equivalents in CSF. Results: We have detected seven proteotypic LAMP2 peptides, however not isoform specific, in CSF using mass spectrometry. By the combination of mass spectrometry and immunoprecipitationwe have confirmed the presence of a LAMP2 fragment consisting of at least amino acid 46-351. Furthermore we have developed an SRM method with the ability to quantitate the level of LAMP2 in CSF. Conclusions: For the first time we have detected LAMP2 in CSF using mass spectrometry and further developed an SRM method to quantitate the level of LAMP2. The protein is presently being explored as a potential CSF biomarker for AD in a number of case-control cohorts.