The present invention relates to methods for the diagnosis of subjects that have or are at risk of having Alzheimer's disease (AD). In particular the present invention identifies individuals who have or are at risk of having AD through measurement of the levels of Afamin in combination with at least one other biomarker such as Alpha-1-antichymotrypsin, Alpha-2-macroglobulin, ApoB100, Complement C5, Serine threonine protein kinase TBK1 or Complement C3 in a fluid sample taken from a subject. Furthermore, genotype (Apolipoprotein E or glutathione S-transferase Omega) may also be taken into consideration and used within classification algorithms to determine the probability of a subject having or being at risk of having AD.