Table 2 Number of trials using a specific marker as primary, secondary, or exploratory endpoint per matrix. Unspecified indicates the trial mentioned using Tau or Aβ but not which isoform or species. Rest biomarkers include the biomarkers that are target specific and used less frequently; in CSF: fatty acid levels, microtubule binding region Tau, neurogranin (NRGN), sTREM2, HMGB1, Aβ oligomers, calcineurin, reverse transcriptase activity, apolipoproteins and HDL concentration; in blood: glucose, fatty acid, and ketone levels, receptor mediators of ketone metabolism in plasma exosomes autophagy markers, plasma exosomes, COX/CS activity, 24-hydroxycholesterol, hormone levels, anti-P. gingivalis IgG, apolipoproteins and HDL concentration, Aβ oligomers, NRGN, calcineurin, BACE1 concentration, monocyte CD16 and HLA-DR expression, reverse-transcriptase activity, SASP, CD3, p16INK4A + as senescence markers, SavaDx, eotaxin-1, TSPO phenotype, PRA, sTREM2, gut microbiome, and extracellular vesicles concentrations

From: Utilization of fluid-based biomarkers as endpoints in disease-modifying clinical trials for Alzheimer’s disease: a systematic review