Abstract
Synopsis: Histocompatibility antigens were examined in 124 patients with Alzheimer's disease (AD), and the frequency of HLA-B15 was found to be significantly increased over controls. Pooling of data from the present and similar studies suggests that AD is not strongly associated with any particular HLA antigen, although there may be a weak association with HLA-A2, B15 and Cw3. In a family study of 34 patients with AD, secondary cases of AD were identified in 9·7% of the first-degree relatives, and cases of presenile dementia and senile dementia of the Alzheimer type were found to occur within individual families.