[Definitive diagnosis of Alzheimer's disease using olfactory mucosal biopsy]

Characteristic changes appearing in the biopsied olfactory mucosa of Alzheimer's disease (AD) patients were investigated using immunohistochemical staining. Specimens were obtained from 6 patients who were clinically diagnosed with AD, 2 patients with cerebrovascular dementia and 5 age-matched patients with olfactory disturbance without dementia. In most AD cases, polyclonal tau protein immunoreactivity was seen in the dendrites, perikarya of the olfactory receptor cells in the olfactory epithelium and the olfactory nerve bundles in the lamina propria. In a few cases, tau protein immunoreactivity was found in the extracellular mass in the epithelium. Ubiquitin immunoreactivity was seen is the dendrites of olfactory receptor cells. On the other hand, in control cases, only dendrites and olfactory nerve bundles reacted to anti-polyclonal tau protein antiserum in a few cases. These results indicate that the neurofibrillary tangle-like tau protein immunoreactivity in the perikarya senile plaque-like extracellular mass and ubiquitin immunoreactivity in the olfactory epithelium were characteristic changes in AD, and olfactory mucosal biopsy is a useful method for the definitive diagnosis of AD.