The present disclosure provides methods of determining A-beta in a mammal before and after treatment of an amyloid disorder, comprising obtaining a first blood sample from the mammal; administering to the mammal a treatment for an amyloid disorder; obtaining a second blood sample from the mammal; quantifying a level of A-beta in the first blood sample and in the second blood sample; and determining the level of A-beta in the mammal before and after treatment of the amyloid disorder.