Tau-protein expression in human blood lymphocytes: a promising marker and suitable sample for life-time diagnosis of Alzheimer’s disease
by Igor M. Kvetnoy, Jose Hernandez-Yago, Tatiana V. Kvetnaia, Vladimir Kh. Khavinson, Vladimir V. Malinin, Alexander A. Yarilin, Nina I. Sharova, Jose R. Blesa, Vladimir N. Anisimov, Lilia V. Lenskaia, Sofia F. Sluchevskaia, Svetlana I. Chekalina, Oleg Yu. Tokarev & Vadim V. Yuzhakov
Alzheimer’s disease, tau-protein, immunocytochemistry, peripheral blood lymphocytes
OBJECTIVES: Taking into account the hypothesis that Alzheimer’s disease (AD) might be a systemic disease that affects several tissues in the body, the aim of this study was to try to detect the expression of tau-protein in human peripheral blood lymphocytes (PBL) in patients with AD.
MATERIAL AND METHODS: Blood samples were obtained from patients with AD (n=16, age 67–98) and from volunteers without psychoneurological pathology (n=10, age 65–78). PBL were isolated on Ficoll-Paque gradient centrifugation. For cell fixation and permeabilization we used a fixative solution (4% formaldehyde and 0.1% glutaraldehyde) and 0.03% Triton X-100. Immunocytochemical detection of tau-protein was carried out by biotin-streptavidin complex method with tau monoclonal antibody (1:100, clone TAU-2, ICN) and universal immunostaining kit IMMU-MARK (ICN).
RESULTS: The expression of tau-protein was shown in PBL in absolute majority of AD patients studied. Only in two healthy volunteers a single lymphocyte from many cells (i.e. a smear) demonstrated a very weak-positive immunostaining to tau-protein
CONCLUSION: This first demonstration of clear difference in localization of tau-protein in blood lymphocytes between healthy and sick people testifies to the fact that tau-protein could be considered as a promising marker and blood lymphocytes as a suitable sample for life-time diagnosis of AD.