Studies of neuroimmune markers in Alzheimer's disease.

Based on a suspected role of the immune system in the pathophysiology of Alzheimer's disease (AD) and the new discoveries of neuroimmune networks, the investigation of certain neuroimmune markers was performed in AD patients, healthy controls, and disease controls. In agreement with our previous immunological research on AD, the assessment of additional immune parameters revealed abnormalities of both cellular and humoral immunity in several AD patients. These include: 1. Enhanced production of cytokines, such as interleukin-1 (IL-1), interleukin-2 (IL-2), and interleukin-6 (IL-6); 2. Increase plasma level of CD8-positive lymphocyte derived soluble CD8 (sCD8) antigen; and 3. Increased incidence of autoantibodies to brain myelin basic protein (MBP) and thymic cells. As analyzed by flow cytometry and enzyme immunoassay, the peripheral blood immunocytes from AD patients showed a significant increase in the expression of the brain-derived S-100 protein. In the cell proliferation assay, the blood immunocytes from healthy subjects responded to stimulation with beta-amyloid protein (beta AP), but this response was absent in AD patients. The initial results of our research suggest that the studies of specific markers of the neuroimmune axis may be potentially important for the new development of diagnostic and therapeutic strategies for AD.