Ante-mortem blood samples were obtained from subjects in a Dementia Special Care Unit at the Bedford VA Hospital Geriatric Research Education and Clinical Center (GRECC). Subjects were hospice patients suffering from advanced dementia. AD subjects were diagnosed with sporadic AD based on early-stage cognitive deficits, age of onset, absence of significant family history, and typical neuroimaging and clinical progression (Table 1). Blood was obtained from the subjects as a part of tissue bank repository as approved by the Bedford VA Hospital Institutional Review Board, and written informed consent was obtained from the participants. Blood was collected in Vacutainer cell tubes (CPT, Becton, Dickinson and Company, Franklin Lakes, NJ) and immediately centrifuged at 1500 ×g for 20 min at room temperature. After centrifugation, the plasma was separated and frozen at -80°C. The peripheral blood mononuclear cell (PBMC) layer was transferred to a 15mL Falcon tube with 10mL sterile PBS and centrifuged at 300 ×g for 10 min at room temperature. The supernatant was discarded and the cell pellet was re-suspended in PMBC medium with 10% DMSO (Invitrogen, Carlsbad, CA) for cryostorage.
