The use of blood stem cell-mobilizing agents (such as filastrim) for treatment of neurologic diseases is being applied for the first time to patients with AD. Administration of filgastrim to mouse models of AD resulted a dramatic improvement in cogntive function and marked decrease in amyloid plaque deposition. Filgastrim is already clinically approved for other indications (to increase blood stem cell production in leukemia) and in normal donors of blood stem cells. This clinical study will be the first to determine whether filgastrim administration will be effective and safe as a pro-cognitive and disease-modifying agent in patients with AD.