Murray, Melissa E.

AbstractBackgroundGenetic variation at the microtubule‐associated protein tau locus is associated with clinical parkinsonism. However, it is unclear as to whether microtubule‐associated protein tau H1 subhaplotypes are associated with the burden of neuropathological features of Lewy body disease.ObjectivesTo evaluate associations of microtubule‐associated protein tau haplotypes with severity of Lewy body pathology and markers of SN neuronal loss in Lewy body disease cases.MethodsFive hundred eighty‐five autopsy‐confirmed Lewy body disease cases were included. Six microtubule‐associated protein tau variants (rs1467967, rs242557, rs3785883, rs2471738, rs8070723, and rs7521) were genotyped to define common microtubule‐associated protein tau haplotypes. Lewy body counts were measured in five cortical regions. Ventrolateral and medial SN neuronal loss were assessed semiquantitatively. Nigrostriatal dopaminergic degeneration was quantified by image analysis of tyrosine hydroxylase immunoreactivity in the dorsolateral and ventromedial putamen.ResultsThe common microtubule‐associated protein tau H2 haplotype did not show a strong effect on pathological burden in Lewy body disease. The rare H1j haplotype (1.3%) was significantly associated with a lower dorsolateral putaminal tyrosine hydroxylase immunoreactivity (and therefore greater dopaminergic degeneration) compared to other microtubule‐associated protein tau haplotypes (P = 0.0016). Microtubule‐associated protein tau H1j was also nominally (P ≤ 0.05) associated with a lower ventromedial putaminal tyrosine hydroxylase immunoreactivity (P = 0.010), but this did not survive multiple testing correction. Other nominally significant associations between microtubule‐associated protein tau H1 subhaplotypes and neuropathological outcomes were observed.ConclusionsA rare microtubule‐associated protein tau H1 subhaplotype (H1j) may be associated with more severe putaminal dopaminergic degeneration in Lewy body disease cases. Microtubule‐associated protein tau H1j has been associated previously with an increased risk of PD, and therefore our exploratory findings provide insight into the mechanism by which H1j modulates PD risk. © 2019 International Parkinson and Movement Disorder Society

Abstract Introduction Neuroimaging biomarkers are important for early diagnosis of Alzheimer's disease, and comparing multimodality neuroimaging to autopsy data is essential. Methods We compared the pathologic findings from a prospective autopsy cohort (n = 100) to Pittsburgh compound B PET (PiB‐PET), 18 F‐fluorodeoxyglucose PET (FDG‐PET), and MRI. Correlations between neuroimaging biomarkers and neuropathologic schemes were assessed. Results PiB‐PET showed strong correlations with Thal amyloid phase and Consortium to Establish a Registry for Alzheimer's Disease score and categorized 44% of Thal phase 1 participants as positive. FDG‐PET and MRI correlated modestly with Braak tangle stage in Alzheimer's type pathology. A subset of participants with “none” or “sparse” neuritic plaque scores had elevated PiB‐PET signal due to diffuse amyloid plaque. Participants with findings characterized as “suspected non‐Alzheimer's pathophysiology” represented 15% of the group. Discussion PiB‐PET is associated with Alzheimer's disease, neuritic plaques, and diffuse plaques. FDG‐PET and MRI have modest correlation with neuropathologic schemes. Participants with findings characterized as suspected non‐Alzheimer's pathophysiology most commonly had primary age‐related tauopathy.

AbstractIntroductionPrimary age‐related tauopathy (PART) is characterized by the presence of neurofibrillary tangles and absent‐minimal β‐amyloid deposition. Transactive response DNA‐binding protein of 43 kDa (TDP‐43), a third protein, has recently garnished a lot of attention in Alzheimer's disease where it is associated with memory loss and amygdala and hippocampal atrophy. We aimed to determine whether TDP‐43 is associated with brain atrophy in PART.MethodsWe assessed the frequency of TDP‐43 in PART and performed voxel‐level analysis in SPM12, as well as region‐of‐interest analysis using linear regression modeling, controlling for variables of interest, to assess for associations between TDP‐43 and brain atrophy.ResultsOf 116 PART cases, 31 (26.7%) had TDP‐43. The presence of TDP‐43 was associated with significantly greater amygdala, hippocampal, and anterior temporal atrophy in both the region‐of‐interest and the voxel level analyses.DiscussionTDP‐43 is associated with greater brain atrophy in PART.

AbstractIntroductionOur primary goal was to examine demographic and clinicopathologic differences across an ethnoracially diverse autopsy‐confirmed cohort of Alzheimer's disease cases.MethodsA retrospective study was conducted in the Florida Autopsied Multi‐Ethnic cohort on 1625 Alzheimer's disease cases, including decedents who self‐reported as Hispanic/Latino (n = 67), black/African American (n = 19), and white/European American (n = 1539).ResultsHispanic decedents had a higher frequency of family history of cognitive impairment (58%), an earlier age at onset (median age of 70 years), longer disease duration (median of 12 years), and lower MMSE proximal to death (median of 4 points) compared with the other ethnoracial groups. Black decedents had a lower Braak tangle stage (stage V) and higher frequency of coexisting hippocampal sclerosis (21%); however, only hippocampal sclerosis differences survived adjustment for sex, age at onset, and disease duration. Neither Thal amyloid phase nor coexisting Lewy body disease differed across ethnoracial groups.DiscussionDespite a smaller sample size, Hispanics demonstrated longer disease duration with Alzheimer's disease, but not greater lifespan. Neuropathologic differences across ethnoracial groups supported differences in tau pathology distribution and coexisting hippocampal sclerosis, which may impact biomarker studies.