Suemoto, Cláudia Kimie

Abstract INTRODUCTION Apolipoprotein E allele 4 (APOE ε4) is the main genetic risk factor for late‐onset Alzheimer's disease (AD), but most evidence comes from White populations in high‐income countries. We investigated APOE and AD pathology in an ethnically diverse Brazilian autopsy cohort. METHODS This cross‐sectional study used Biobank for Aging Studies (BAS) data. AD pathology was evaluated with Braak, Consortium to Establish a Registry for Alzheimer's Disease, and Thal criteria. APOE genotypes were obtained from blood or brain tissue. Regression models were adjusted for age, sex, race, and education; interaction with race was tested. RESULTS Among 1391 participants (mean age 75.1 ± 12.4 years, 50% women, 64% White), APOE ε4showed a dose response with greater AD pathological burden and higher odds of AD diagnosis, while APOE ε2/X was protective. APOE ε4/ε4 did not show full penetrance across age groups. Associations were similar in White and Black individuals. DISCUSSION APOE ε4was strongly associated with AD pathology, with consistent associations across racial groups. Highlights APOE ε4 increased AD neuropathological burden in Brazilians. APOE ε2/εX was protective against AD pathology. APOE ε4/ε4did not show full penetrance across age groups. Associations between APOE and AD pathology were similar by race. Large multiethnic autopsy study expands evidence beyond high‐income country studies.

ABSTRACT Background Dementia often goes undetected in hospital settings, where cognitive assessments are challenging due to illness severity and delirium. This study aimed to (1) evaluate the accuracy of the Clinical Dementia Rating (CDR), based solely on knowledgeable informant reports, for detecting preexisting dementia and cognitive impairment in hospitalized patients compared to a gold‐standard diagnosis, (2) and compare its performance to the 16‐item Informant Questionnaire on Cognitive Decline in the Elderly (IQCODE‐16). Methods This cross‐sectional study assessed consecutive patients aged ≥ 65 admitted to inpatient units from five hospitals in Brazil. The informant‐based CDR was administered to knowledgeable informants within 48 h of admission, capturing patients' cognitive status 3 months before hospitalization to avoid the influence of acute cognitive impairments. Blinded experts provided a gold standard clinical diagnosis of dementia or cognitive impairment no dementia (CIND) based on a 90‐min comprehensive assessment, including a standardized neuropsychology battery. Areas under the curve (AUC) examined diagnostic accuracy. Results Of 65 participants (mean age = 79.4 years; women = 54%), 34% had dementia and 32% had CIND . Compared to the gold standard, the informant‐based CDR showed excellent diagnostic accuracy for detecting dementia ( AUC = 0.92; 95% confidence interval [ CI ] = 0.86–0.98) and cognitive impairment ( AUC = 0.93; 95% CI = 0.88–0.98), with a cutoff of ≥ 1 showing 98% specificity for dementia and a cutoff of ≥ 0.5 showing 98% sensitivity for cognitive impairment. Compared to the IQCODE ‐16, the informant‐based CDR had similar performance in detecting dementia and a nonsignificant slight advantage in identifying cognitive impairment ( AUC = 0.93 vs. 0.84, p = 0.069), reducing unrecognized cognitive impairment based on medical record documentation from 70% to 2%. Conclusions Informant‐based CDR is a valid and efficient tool for detecting dementia and cognitive impairment in hospitalized older adults, supporting early diagnosis and guiding multidisciplinary interventions in acute care. Its use in routine hospitals may help clinicians reduce undetected cognitive impairment, enhance decision making, and improve patient care.

AbstractBackgroundIndividuals meeting neuropathological criteria for Alzheimer’s disease (AD) may manifest with atypical clinical syndromes. Past work showed that the neurobiological basis for these differences is related to specific neuronal vulnerabilities for tau pathology. For instance, amnestic cases have a higher burden of neurofibrillary changes in CA1. In contrast, logopenic variant primary progressive aphasia (lvPPA) cases have a higher tau burden in the superior temporal gyrus (STG). Single‐cell technology enables investigations on the molecular basis of differential neuronal vulnerability in AD. Consequently, we delved into the factors that underlie this selective vulnerability by analyzing brain samples from individuals exclusively afflicted with AD but exhibiting diverse clinical manifestations.MethodsnRNA Sequencing using the Chromium Single Cell 3′ (10X Genomics, USA) on nuclei cells extracted from the CA1 sector and posterior STG of postmortem brain tissue of 48 individuals either meeting pathological criteria for AD (A3B3C3; 24 amnestic and eleven lvPPA) and healthy controls (A≤1B≤1C≤1; n = 13) (Table 1, Fig. 1A/B). Bioinformatics analyses were conducted using Cell Ranger and R software. Comparisons between cell subpopulations were conducted with the Wald statistical test, and p‐values < .05 were considered significant.ResultAfter quality control, we recovered more than 250k nuclei with a mean of 2,130 genes per nuclei. Upon cross‐sample alignment and t‐stochastic neighborhood embedding clustering (Fig. 1C), we found 21 excitatory neuronal subpopulations (Exc‐sub) in CA1 and 26 in STG, and 22 and 25 inhibitory neuronal subpopulations (Inh‐sub) in CA1 and STG, respectively; 16 astrocytes subpopulations in both areas and 20 microglia subpopulations in CA1 and 17 in STG (Fig. 2). One STG Exc‐sub, expressing CUX2 and LAMP5 genes showed vulnerability in lvPPA patients. Also, one STG Inh‐sub, expressing the ADARB2 gene, showed vulnerability for all AD patients.ConclusionOur preliminary study identified a vulnerable population of excitatory neurons related to lvPPA. We are conducting validation studies using quantitative pathology to confirm these results. Furthermore, analysis of a higher number of cases is ongoing and will continue to inform on factors associated with neuronal vulnerability.

AbstractINTRODUCTIONWhile Latin America (LatAm) is facing an increasing burden of dementia due to the rapid aging of the population, it remains underrepresented in dementia research, diagnostics, and care.METHODSIn 2023, the Alzheimer's Association hosted its eighth satellite symposium in Mexico, highlighting emerging dementia research, priorities, and challenges within LatAm.RESULTSSignificant initiatives in the region, including intracountry support, showcased their efforts in fostering national and international collaborations; genetic studies unveiled the unique genetic admixture in LatAm; researchers conducting emerging clinical trials discussed ongoing culturally specific interventions; and the urgent need to harmonize practices and studies, improve diagnosis and care, and use affordable biomarkers in the region was highlighted.DISCUSSIONThe myriad of topics discussed at the 2023 AAIC satellite symposium highlighted the growing research efforts in LatAm, providing valuable insights into dementia biology, genetics, epidemiology, treatment, and care.

AbstractBackgroundMulticentric initiatives to study brain cognition in the elderly offers us a unique collection of brain imaging data accompanied by detailed neuroclinical and neuropsychological evaluations. U.S. POINTER and LatAm‐FINGERS, part of the World Wide FINGERS, are both large‐scale investigations of lifestyle interventions and its impact on cognitive function. These large‐scale detailed data may offer an unprecedented opportunity to compare diverse populations.MethodBaseline MRI of subjects from multiple US centers (POINTER‐US), distributed in 5 geographical regions, and from 9 latin‐american countries (LatAm‐FINGERS). The protocols vary from basic (3D T1, 3D FLAIR,T2* GRE, Cor T2 hippocampus, DWI) to advanced which also included ASL, rs‐FMRI and DTI. Demographic information and clinical, cognitive and neuropsychological assessment were also included.ResultMRI data was collected from 662 participants in the United States (about 65% of the total anticipated U.S. POINTER neuroimaging sample) and from 542 subjects from 9 countries in latin‐america (about 80% of the total anticipated LatAm‐FINGERS neuroimaging sample), with around 1200 participants scanned (table1).All participants have 3D T1, 3D FLAIR, T2* GRE images and either DWI or DTI images.Comparative demographics from the 2 datasets shows similar mean age, a predominance of females, and slight differences in education (table 2). This will allow us to compare multiethnic and multicultural volumetric and functional brain MRI information, as well as disease markers, associated with thorough neurological and clinical assessment. Reasons for not acquiring MRI were mainly due to claustrophobia or scanner unavailability.ConclusionThis is an exceptional opportunity to have comparative large‐scale databases, with anatomical and functional brain imaging from different populations, allowing us to study real world diverse brain data and better understand its relationships with demographics, health and risk characteristics, and cognition.

AbstractBackgroundIndividuals with neuropathological criteria for Alzheimer’s disease (AD) may manifest with atypical clinical syndromes. Past work showed that the neurobiological basis for these differences is related to specific neuronal vulnerabilities for tau pathology. For instance, amnestic cases have a higher burden of neurofibrillary changes in CA1. In contrast, logopenic variant primary progressive aphasia (lvPPA) cases have a higher tau burden in the superior temporal gyrus (STG). Single‐cell technology enables investigations on the molecular basis of differential neuronal vulnerability in AD. Therefore, we investigated factors underlying selective vulnerability using brain samples from individuals with pure AD with different clinical manifestations.MethodsnRNA Sequencing using the Chromium Single Cell 3′ (10X Genomics, USA) on nuclei cells extracted from the CA1 sector and posterior STG of postmortem brain tissue of 24 individuals either meeting pathological criteria for AD (A3B3C3; 12 amnestic and eight lvPPA) and healthy controls (A≤1B≤1C≤1; n = 4) (Table 1, Fig. 1A/B). Bioinformatics analyses were conducted using Cell Ranger and R software. Comparisons between cell subpopulations were conducted with Wald statistical test, and p‐values < .05 were considered significant.ResultAfter quality control, we recovered 98,180 nuclei with a mean of 2,130 genes per nuclei. Upon cross‐sample alignment and t‐stochastic neighborhood embedding clustering (Fig. 1C), we found 21 excitatory neuronal subpopulations (Exc‐sub) in CA1 and 26 in STG, and 22 and 27 inhibitory neuronal subpopulations (Inh‐sub) in CA1 and STG, respectively; 16 astrocytes subpopulations in both areas and 20 microglia subpopulations in CA1 and 17 in STG (Fig. 2). One STG Exc‐sub, expressing CUX2 and LAMP5 genes showed vulnerability in lvPPA patients. Also, one STG Inh‐sub, expressing the ADARB2 gene, showed vulnerability for all AD patients. Furthermore, two astrocytes subpopulations (one in both areas and one in STG) and three STG microglia subpopulations showed proportional composition changes comparing AD patients and HC.ConclusionOur preliminary study identified a vulnerable population of excitatory neurons related to lvPPA. We are conducting validation studies using quantitative pathology to confirm these results. Furthermore, analysis of a higher number of cases is ongoing and will continue to inform on factors associated with neuronal vulnerability.