%0 Journal Article %J J Alzheimers Dis %D 2018 %T Assay of Plasma Phosphorylated Tau Protein (Threonine 181) and Total Tau Protein in Early-Stage Alzheimer's Disease. %A Yang, Che-Chuan %A Chiu, Ming-Jang %A Chen, Ta-Fu %A Chang, Hui-Ling %A Liu, Bing-Hsien %A Yang, Shieh-Yueh %K Aged %K Aged, 80 and over %K Alzheimer Disease %K Amyloid beta-Peptides %K Biomarkers %K Case-Control Studies %K Female %K Humans %K Magnetic Resonance Imaging %K Male %K Middle Aged %K Neuropsychological Tests %K Phosphorylation %K tau Proteins %X

The feasibility of assaying plasma phosphorylated tau protein (threonine 181), denoted p-tau181, using immunomagnetic reduction (IMR) is explored. The reagent for assaying p-tau181 with IMR was synthesized, and its analytic performances were characterized. Seventy-three subjects were recruited. Each participant was examined with neuropsychological tests, magnetic resonance imaging, and IMR assay for plasma p-tau181. Using commercially available IMR kits, the plasma total tau protein (T-tau) of each subject was assayed. The dynamic range for assaying p-tau181 using IMR was 1.96×10-2 pg/ml to 104 pg/ml. There was no significant interference from total tau protein in the assay of p-tau181. The measured concentrations of plasma p-tau181 were 2.46±1.09 pg/ml for healthy controls, 4.41±1.85 pg/ml for MCI due to AD, and 6.14±1.59 pg/ml for very mild AD. Meanwhile, the measured concentrations of plasma T-tau were 18.85±10.16 pg/ml for healthy controls, 32.98±10.18 pg/ml for MCI due to AD, and 37.54±12.29 pg/ml for very mild AD. A significant difference in plasma p-tau181 was observed between healthy controls and MCI due to AD (p < 0.001) and between MCI due to AD and very mild AD (p < 0.001). However, for the plasma T-tau concentration, a significant difference existed only between healthy controls and MCI due to AD (p < 0.001). This implies that the plasma p-tau181 level is correlated more to AD severity than plasma T-tau is. Additionally, p-tau181 was observed as approximately 14% of T-tau in human plasma.

%B J Alzheimers Dis %V 61 %P 1323-1332 %8 2018 %G eng %N 4 %1 http://www.ncbi.nlm.nih.gov/pubmed/29376870?dopt=Abstract %R 10.3233/JAD-170810 %0 Journal Article %J J Alzheimers Dis %D 2016 %T Clinical Dementia Rating Scale Detects White Matter Changes in Older Adults at Risk for Alzheimer's Disease. %A Chang, Yu-Ling %A Yen, Yu-Shiuan %A Chen, Ta-Fu %A Yan, Sui-Hing %A Tseng, Wen-Yih Isaac %K Aged %K Aged, 80 and over %K Alzheimer Disease %K Brain %K Cognition Disorders %K Female %K Humans %K Image Processing, Computer-Assisted %K Magnetic Resonance Imaging %K Male %K Memory %K Middle Aged %K Neuropsychological Tests %K Risk Factors %K White Matter %X

This study investigated the putative changes in regional gray matter and cingulum bundle segments in mild cognitive impairment (MCI) by using two diagnostic criteria. Participants comprised 50 older adults with MCI and 22 healthy older controls (HC). The older adults with MCI were further divided into two groups defined by a global Clinical Dementia Rating (CDR) score of 0.5 and with (the CDR/NPT MCI group) or without (the CDR MCI group) objective cognitive impairments determined using neuropsychological tests (NPTs). Comparable regional gray matter integrity was observed among the three groups. However, the integrity of the right inferior segment of the cingulum bundle in the two MCI groups was more reduced than that in the HC group, and the CDR/NPT MCI group exhibited additional disruption in the left inferior cingulum bundle. The results also demonstrated that neuropsychological measures have greater predictive value for changes in white matter beyond the contribution of an informant-based instrument alone. Overall, the findings confirm the utility of informant-based assessment in detecting microstructural brain changes in high-risk older adults, even before objective cognitive impairment is evident. The findings also suggest that combining the neuropsychological measures with the informant-based assessment provided the greatest predictive value in assessing white matter disruption. The essential role of the white matter measurement as a biomarker for detecting individuals at a high risk of developing dementia was highlighted.

%B J Alzheimers Dis %V 50 %P 411-23 %8 2016 %G eng %N 2 %1 http://www.ncbi.nlm.nih.gov/pubmed/26639963?dopt=Abstract %R 10.3233/JAD-150599