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

Abstract

The prevalence of basophilic invasion (BI) and degenerative changes in the neurohypophysis of humans with neurodegenerative disease is not established. 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 59age-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). 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 59controls (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. 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.