Mitochondrial depletion in CD4⁺ and CD19⁺ peripheral lymphocytes in early stage Alzheimer's disease

Alzheimer's disease (AD) may be associated with mitochondrial defects. The aim of the present study was to investigate changes in mitochondrial abundance in peripheral lymphocytes of early and late stage AD patients. We analysed levels of mitochondrial DNA (mtDNA) and mean fluorescence intensity (MFI) of the mitochondria-specific antibody 113-1 in CD4⁺, CD8⁺, CD19⁺ and CD56⁺ peripheral lymphocytes of early and late stage AD by quantitative real-time PCR and flow cytometry, respectively. In early stage AD, the levels of mtDNA were significantly decreased in CD4⁺, CD19⁺ and CD56⁺ peripheral lymphocytes while the MFI of 113-1 staining was significantly decreased in CD4⁺ and CD19⁺ cells. Thus, CD4⁺ and CD19⁺ peripheral lymphocytes of early stage AD patients exhibit mitochondrial depletion, as seen both at the level of DNA and protein.