Pedraza, Otto

AbstractIntroductionWe sought to determine if a proteomic profile approach developed to detect Alzheimer's disease would distinguish patients with Lewy body disease from normal controls, and if it would distinguish dementia with Lewy bodies (DLB) from Parkinson's disease (PD).MethodsStored plasma samples were obtained from 145 patients (DLB n = 57, PD without dementia n = 32, normal controls n = 56) enrolled from patients seen in the Behavioral Neurology or Movement Disorders clinics at the Mayo Clinic, Florida. Proteomic assays were conducted and analyzed as per our previously published protocols.ResultsIn the first step, the proteomic profile distinguished the DLB‐PD group from controls with a diagnostic accuracy of 0.97, sensitivity of 0.91, and specificity of 0.86. In the second step, the proteomic profile distinguished the DLB from PD groups with a diagnostic accuracy of 0.92, sensitivity of 0.94, and specificity of 0.88.DiscussionThese data provide evidence of the potential utility of a multitiered blood‐based proteomic screening method for detecting DLB and distinguishing DLB from PD.

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.

AbstractIntroductionWe sought to assess the individual and combined contribution of limbic and neocortical α‐synuclein, tau, and amyloid β (Aβ) to duration of illness in dementia with Lewy bodies (DLB).MethodsQuantitative digital pathology of limbic and neocortical α‐synuclein, tau, and Aβ was assessed in 49 patients with clinically probable DLB. Regression modeling examined the unique and shared contribution of each pathology to the variance of illness duration.ResultsPatients with diffuse Lewy body disease had more severe pathology of each type and a shorter duration of illness than individuals with transitional Lewy body disease. The three pathologies accounted for 25% of the total variance of duration of illness, with 19% accounted for by α‐synuclein alone or in combination with tau and Aβ. When the diffuse Lewy body disease group was examined separately, α‐synuclein deposition significantly exceeded that of tau and Aβ. In this model, 20% of 24% total variance in the model for duration of illness was accounted for independently by α‐synuclein.DiscussionIn DLB, α‐synuclein is an important predictor of disease duration, both independently and synergistically with tau and Aβ.