Abstract: The present application relates to methods and compositions that can be used to diagnose Alzheimer's disease in mammals, most notably humans. Ti describes most notably peripheral blood biomarkers Alzheimer's disease and uses said biomarkers in diagnostic methods. It also relates to tools and/or kits that can be used to implement said methods (reagents, probes, primers, antibodies, arrays or chips, cells, etc.), as well as the preparation and use thereof. The invention can further be used to detect the presence or the advance of Alzheimer's disease in mammals, including during the disease's early phase, as well as to predict the effectiveness of an Alzheimer's disease treatment.