Background: Alzheimer disease is associated with degeneration of brain by deposition of beta-A4 amyloid protein. Above protein is a product of amyloid protein precursor proteolysis. This protein is coded by chromosom 21 together with histocompatibility antigens on surface of thyroid follicle. Until now the study suggest coexistence of autoimmune thyroid disease and Alzheimer disease. The aim of the study was evaluation of thyroid autoantibodies in Alzheimer disease.
Material and methods: Study were performed in 34 Alzheimer disease patients. Sera of control subjects were obtained from 20 patients with vascular dementia. Incidence of thyroid autoantibodies was assessed by polyacrylamide electrophoresis gel and western-blotting. Thyroid microsomes were obtained from human thyroid tissues by ultracentrifugation and solubilization in 1% desoxycholic acid.
Results: In 21 sera from 34 we detected autoantibodies against thyroid microsomal antigens reacting with 91 kDa antigen. 16 sera were reacting with 97 kDa, 13 sera with 55 kDa, and 7 sera with 67 kDa proteins.
Conclusions: In sera of Alzheimer disease patients autoantibodies against thyroid microsomal antigens can be frequently detected. The most frequent are antibodies against 91 kDa. It is important to note that Alzheimer disease patients should be screen for thyroid hormones.