A tau PET study of primary age‐related tauopathy in healthy volunteers

Abstract

AbstractBackgroundThe term “primary age‐related tauopathy” (PART) was recently introduced to describe a pathology that is commonly observed in the brain of aged individuals. Symptoms in persons with PART usually range from normal cognition to amnesia. The aim of the study is to explore the tau aggregates accumulation in the brain of healthy volunteers by PET with [18F]PM‐PBB3 ( [18F]APN‐1607).MethodFifty‐three healthy individuals (28 men and 25 women ranging in age from 23 to 79 years with a mean of 60) without any history of psychiatric and neurological diseases participated in this study. All subjects underwent neurological examination, cognitive tests, brain MRI, [11C]PiB PET (Aβ imaging), and [18F]PM‐PBB3 PET. [11C]PiB PET images (50‐70 min) was visually assessed. An automated analysis of the volumes of interest in [18F]PM‐PBB3 images (90‐110 min) was performed using the PNEURO module in the PMOD software. Standardized uptake value ratio (SUVR) values were obtained using the cerebellar cortex as a reference region. Pearson correlation analysis was performed between [18F]PM‐PBB3 SUVR and age.ResultNeurological examination revealed no significant finding except for hand tremors in one subject. Cognitive tests were normal in all subjects. Two men were Aβ positive and excluded from the following analysis. There was a positive correlation between age and tau PET signal in the parahippocampus (r = 0.30, P < 0.03), fusiform gyrus (r = 0.41, P < 0.003), and middle and inferior temporal cortex (r = 0.28, P < 0.05) of 51 subjects. No positive correlation between age and [18F]PM‐PBB3 SUVR was found in any other brain regions.ConclusionThe present result supports the concept of PART and the detectability of PART‐type tau deposits by PET with [18F]PM‐PBB3.