Tau pathology in diffuse neurofibrillary tangles with calcification (DNTC): Biochemical and immunohistochemical investigation

Diffuse neurofibrillary tangles with calcification (DNTC) represents a primary and sporadic presenile dementia that is characterized by temporal or fronto-temporal atrophy with diffuse neurofibrillary, tangles (NFTs), neuropil threads and Fahr-type calcification without senile plaques. We examined the tau pathology in five autopsy cases of DNTC by immunoblotting and immunohistochemistry using phosphorylation-dependent and -independent anti-tau antibodies. The pattern of staining for different epitopes of β-amyloid (Aβ) was also investigated. NFTs were immunopositive with all the anti-tau antibodies used in this study. On the immunoblots, sarkosyl-insoluble tau appeared as three major bands of 60, 64 and 68 kDa, and as a minor band at 72 kDa. The majority of extracellular NFTs were weakly immunopositive only with the antibody recognizing the 40 carboxyl-terminal of Aβ in DNTC. These results suggest that Alzheimer's disease-like tau pathology could exist independently of Aβ deposits in DNTC. (C) 2000 Lippincott Williams and Wilkins.