Antibody, characterised in that it binds to A~ peptides or variants thereof, wherein said A~ peptides or variants thereof are selected from the group consisting of: pGlu-Aâ3-38 pGlu-Aâ3-40 pGlu-Aâ3-42, and pGlu-Aâ3-x variants, wherein x is an integer between 10 and 42 and wherein the variable part of the light chain of said antibody has a nucleotide sequence selected from SEQ ID NOs: 49, 53, 57 and 61, or an amino acid sequence selected from SEQ ID NOs: 50, 54, 58, and 62 and wherein the variable part of the heavy chain of said antibody has a nucleotide sequence selected from SEQ ID NOs: 51, 55, 59 and 63, or an amino acid sequence selected from SEQ ID NOs: 52, 56, 60 and 64.
