Plasma extracellular vesicle tau and TDP-43 as diagnostic biomarkers in FTD and ALS

Minimally invasive biomarkers are urgently needed to detect molecular pathology in frontotemporal dementia (FTD) and amyotrophic lateral sclerosis (ALS). Here, we show that plasma extracellular vesicles (EVs) contain quantifiable amounts of TDP-43 and full-length tau, which allow the quantification of 3-repeat (3R) and 4-repeat (4R) tau isoforms. Plasma EV TDP-43 levels and EV 3R/4R tau ratios were determined in a cohort of 704 patients, including 37 genetically and 31 neuropathologically proven cases. Diagnostic groups comprised patients with TDP-43 proteinopathy ALS, 4R tauopathy progressive supranuclear palsy, behavior variant FTD (bvFTD) as a group with either tau or TDP-43 pathology, and healthy controls. EV tau ratios were low in progressive supranuclear palsy and high in bvFTD with tau pathology. EV TDP-43 levels were high in ALS and in bvFTD with TDP-43 pathology. Both markers discriminated between the diagnostic groups with area under the curve values >0.9, and between TDP-43 and tau pathology in bvFTD. Both markers strongly correlated with neurodegeneration, and clinical and neuropsychological markers of disease severity. Findings were replicated in an independent validation cohort of 292 patients including 34 genetically confirmed cases. Taken together, the combination of EV TDP-43 levels and EV 3R/4R tau ratios may aid the molecular diagnosis of FTD, FTD spectrum disorders and ALS, providing a potential biomarker to monitor disease progression and target engagement in clinical trials.

Madhurima Chatterjee, Selcuk Özdemir, Christian Fritz, Wiebke Möbius, Luca Kleineidam, Eckhard Mandelkow, Jacek Biernat, Cem Doğdu, Oliver Peters, Nicoleta Carmen Cosma, Xiao Wang, Luisa-Sophia Schneider, Josef Priller, Eike Spruth, Andrea A. Kühn, Patricia Krause, Thomas Klockgether, Ina R. Vogt, Okka Kimmich, Annika Spottke, Daniel C. Hoffmann, Klaus Fliessbach, Carolin Miklitz, Cornelia McCormick, Patrick Weydt, Björn Falkenburger, Moritz Brandt, René Guenther, Elisabeth Dinter, Jens Wiltfang, Niels Hansen, Mathias Bähr, Inga Zerr, Agnes Flöel, Peter J. Nestor, Emrah Düzel, Wenzel Glanz, Enise Incesoy, Katharina Bürger, Daniel Janowitz, Robert Perneczky, Boris S. Rauchmann, Franziska Hopfner, Olivia Wagemann, Thomas Gasser, Kathrin Brockmann, David Mengel, Milan Zimmermann, Matthis Synofzik, Carlo Wilke, Sara Rubio-Guerra, Juan Fortea, Janina Turon-Sans, Miguel Angel Santos-Santos, Daniel Alcolea, Judit Selma-González, Álvaro Carbayo, Alberto Lleó, Ricardo Rojas-García, Ignacio Illán-Gala, Michael Wagner, Ingo Frommann, Sandra Roeske, Lucas Bertram, Michael T. Heneka, Frederic Brosseron, Alfredo Ramirez, Matthias Schmid, Rudi Beschorner, Annett Halle, Jochen Herms, Manuela Neumann, Nicolas R. Barthélemy, Randall J. Bateman, Patrizia Rizzu, Peter Heutink, Oriol Dols-Icardo, Günter Höglinger, Andreas Hermann, Anja Schneider