Basophilic invasion in the neurohypophysis is increased in patients with Alzheimer's disease.

PURPOSE: The prevalence of basophilic invasion (BI) and degenerative changes in the neurohypophysis of humans with neurodegenerative disease is not established. MATERIALS AND METHODS: We evaluated 122 pituitary glands reviewed at autopsy including 45 with Alzheimer's disease (AD) Braak and Braak stage V or VI, 18 with Lewy body disease (LBD), and 59 age-matched controls for BI. In addition, pituitary glands from 51 patients including 25 patients with AD and 18 aged-matched controls were studied with a periodic acid Schiff (PAS) stain and immunohistochemistry with a polyclonal antibody to nestin. Samples were graded as negative (0) or positive (1). RESULTS: BI was seen in 35 of 45 patients with AD (0.78 ± 0.06 mean and SE: 78%) and was significantly higher than 30 of 59 controls (0.51 ± 0.07; 51%) (p = 0.0236). BI was seen in 7 of 18 patients with LBD (0.39 ± 0.12; 39%) compared to controls (p = 0.387). BI was also significantly higher in AD compared to LBD (p = 0.0001). Nestin immunoreactivity was detected in the neurohypophysis of all patients. Definite nestin was not found in BI but was seen in Herring body-like structures, in pituicytes and axons. Phospho-τ-immunoreactive Herring bodies were seen in 65% with AD but phospho-τ-immunoreactive neurofibrillary tangles were not found. CONCLUSION: BI is increased in AD compared to controls or LBD but not associated with nestin immunoreactivity. The significance and role of BI as a marker for AD warrants additional study.