Methods: 80 serum samples from patients of a psychiatric clinic (50 AD or probable AD, 25 other neurodegenerative diseases with probable AD component (OD), 20 control sera from healthy people under the age of 35 (C), and 33 saliva samples (4 AD, 7 normal, 26 postmenstrual women with depression including 14 who were treated with calcitonin) were tested with the ELISAs.
Results: All samples from the psychiatric clinic were positive for either the antibody or the antigen or for both, except for 3 samples, 2 AD and 1 OD, which were negative for antigen and antibody. Values for antigen and antibody within in the "grey zone" of the assay were obtained for 22 % of AD and 6 % of OD samples. All sera from young controls had neither antibody nor antigen. Saliva samples from AD patients and calcitonin treated women were 100 % positive for the antibody while the women who were not treated with calcitonin had no antibody.
Conclusion: This pilot study shows that the above ELISAs can detect AD in diagnosed patients and AD components in other neurodegenerative diseases in serum and in saliva, and opens the possibility that saliva can also be used for the detection of other general diseases which involve specific antibodies.