Immune profiling of Alzheimer patients

Alzheimer's disease (AD) is characterized by extracellular senile plaques in the brain, containing amyloid-beta peptide (A beta). We identify immunological differences between AD patients and age-matched controls greater than those related to age itself. The biggest differences were in the CD4+ rather than the CD8 + T cell compartment resulting in lower proportions of naive cells, more late-differentiated cells and higher percentages of activated CD4 + CD25 + T cells without a Treg phenotype in AD patients. Changes to CD4 + cells might be the result of chronic stimulation by A beta present in the blood. These findings have implications for diagnosis and understanding the aetiology of the disease. (C) 2011 Elsevier B.V. All rights reserved.