The present invention relates to an antibody preparation comprising modified antibodies of an animal or derivatives or fragments thereof, specific for an antigen, characterized in that • the antibodies or derivatives or fragments thereof comprise an N-glycan structure free of fucose and xylose, and • at least 90%, preferably at least 95%, more preferred at least 99%, most preferred at least 100% of the modified antibodies, derivatives or fragments thereof lack a C-terminal lysine residue.