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

Diffuse neurofibrillary tangles with calcification (DNTC) represents a prim ary and sporadic presenile dementia that is characterized by temporal or fr onto-temporal atrophy with diffuse neurofibrillary tangles (NFTs), neuropil threads and Fahr-type calcification without senile plaques. We examined th e tau pathology in five autopsy cases of DNTC by immunoblotting and immunoh istochemistry using phosphorylation-dependent and -independent anti-tau ant ibodies. The pattern of staining for different epitopes of beta-amyloid (A beta) was also investigated. NFTs were immunopositive with ail 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 A beta in DNTC. T hese results suggest that Alzheimer's disease-like tau pathology could exis t independently of A beta deposits in DNTC. NeuroReport 11:2473-2477 (C) 20 00 Lippincott Williams & Wilkins.