Citations

Abstract Although social determinants of health (SDoH) investigations have shown limited analyses of socioeconomic and race-ethnic status on certain hematologic malignancies, the impact of factors beyond those across a fuller scope of hematologic cancers remains unknown. The Social Vulnerability Index (SVI), a tool for assessing varied US census–derived sociodemographic factors, allows for the specific quantification of SDoH in dynamic, regional contexts for their associations with hematologic malignancy inequities. To assess the summative influence of varied SDoH factors on hematologic malignancy outcomes and discern which SDoH factors contributed the largest associations toward disparities, 796 005 adults with hematologic malignancies between 1975 to 2017 were identified for this retrospective cohort study. Vulnerability in 15 SDoH factors was measured using composite and subcategory SVI scores geographically matched to patients. Regressions between SVI factors and follow-up time after diagnosis and survival period were performed. Increasing overall SVI correlated with significantly decreased surveillance period in 11 of 14 hematologic malignancies, with decreases upward of 33.4% (39.0-26.0 months for acute lymphocytic leukemia). Increasing SVI significantly associated with decreased survival period across 11 of 14 hematologic malignancies, with decreases upward of 47.2% (89.5-47.3 months for Hodgkin lymphoma). Socioeconomic status and housing and transportation vulnerabilities showed the largest magnitude of contributions, followed by minority language and household composition. Significant decreases in hematologic malignancy prognosis associate with increasing overall SDoH vulnerability in varied sociodemographic contexts in the United States. Furthermore, there are quantifiable differences in which types of SDoH contribute more to trends per malignancy type. These findings demonstrate specific SDoH targets for further research and policy initiatives to combat hematologic malignancy disparity more effectively.

Abstract There are ~100 genes or copy number variants (CNVs) used in genetic testing for Autism Spectrum Disorder (ASD, or autism). These genes are protein-coding, and the associated phenotypes often extend beyond socio-behavioral traits seen in autism including cognitive/medical complexities, epilepsy, and ADHD. Here, we characterize 27 males with ASD through whole genome sequencing (WGS), delineating X-chromosome microdeletions that implicate the long non-coding RNA (lncRNA) PTCHD1-AS as an ASD-susceptibility gene (OR=2.56, p=0.01). Two Ptchd1-as knockout (KO) murine models, created by removing the evolutionarily conserved exon-3, show ASD-like features in males, increasing repetitive behaviors and impairing typical social behavior and communication without overt cognitive comorbidities or ADHD-like behaviors. Hippocampus-dependent synaptic function, complex learning, and locomotor activity are unaffected in KO mice. Native nuclear-enriched mouse Ptchd1-as showed sustained expression from post-natal day-7 onward in the dorsal striatum, a predominantly GABAergic brain region implicated in ASD. Multi-omics revealed transcriptomic alterations in striatal oligodendrocyte, astrocyte and neurons impacting myelination and plasticity pathways. Disrupting Ptchd1-as led to reductions in conventional Protein Kinase-C, altered Src and GSK3α/β phosphorylation, and an enhancement of synaptic plasticity (long-term potentiation and long-term depression). Together, these findings implicate striatal molecular and circuit level dysregulation via Ptchd1-as in ASD etiology.

AbstractBackgroundNeuritic plaques with fibrillar beta‐amyloid (Aβ) peptides and tau‐protein neurofibrillary tangles, hallmark features of Alzheimer’s disease (AD) pathology, have been concomitantly associated with white matter (WM) integrity loss, while a unique effect of each pathology on WM integrity in a more demographically diverse population remains unknown.MethodTo examine the degree to which each pathology affects WM integrity in a more diverse non‐demented cohort, Aβ and tau PET, diffusion‐weighted imaging (DWI), and cognition (memory and executive function composites) were examined from the U.S. POINTER neuroimaging participants (N=608; age=68.34±5.2; 61.8% females; 29% Aβ+) and a subset of Alzheimer’s Disease Neuroimaging Initiative (ADNI) participants (N=291; age=72.85±7.3; 50% females; 39% Aβ+) (Table). Aβ‐positivity was determined using tracer‐specific standardized cut‐offs. Tau SUVR was estimated for each Braak stage. For WM integrity, voxel‐based GLMs were applied to FSL‐processed fractional anisotropy (FA) maps using Braak stage tau SUVR and Aβ‐positivity status, along with covariates of age, sex, and b‐value profiles.ResultIn U.S. POINTER, independent from Aβ‐positivity status, greater tau burden in Braak stages I and II was related to lower FA across the tracts including the superior longitudinal fasciculus, fornix (cres), corpus callosum, and anterior thalamic radiation (Figure). Average FA from supra‐threshold clusters for Braak I and II significantly predicted executive function but not episodic memory. No association between FA and tau burden in Braak stages III/IV or V/VI was found. In the ADNI sample, greater tau burden in Braak I was related to lower FA mostly in left inferior longitudinal fasciculus and left uncinate fasciculus, while negative associations with FA became more diffuse with tau load in Braak III/IV and V/VI. Average FA from supra‐threshold clusters significantly predicted both episodic memory and executive function scores. Across both samples, after accounting for tau burden in each Braak stage, there were no association between Aβ‐positivity status and WM integrity.ConclusionDistinct associations between tau burden, WM integrity, and cognition were found across the studies, indicating greater impact of early tau burden on WM integrity in U.S. POINTER, accounting for Aβ‐positivity status. Factors contributing to the distinct associations across studies need further investigation.

AbstractBackgroundCortical structural changes in the temporal lobes including global and hippocampal volume loss and decrease in cortical thickness are well‐associated findings linked to cognitive decline in MCI and dementia patients. Neurite orientation dispersion and density imaging (NODDI) is a multishell diffusion MRI method enabling assessment of tissue microstructural integrity at the axonal and dendritic level. We wished to determine whether changes in temporal cortex orientation dispersion index (ODI) & neurite density index (NDI) correlate with decreases in memory function.MethodThe MCALT_ADIR122 cortical atlas was used for ROI designation. NODDI imaging was obtained on a 3T Siemens Prisma scanner with 2 mm isotropic resolution. Participants (ages 60‐95 years) were cognitively unimpaired (CU) or had mild cognitive impairment (MCI). CU & MCI subjects were enrolled in the Mayo Clinic Study of Aging (MCSA) and underwent neuropsychological testing including 3 memory tests from which a composite memory z score was calculated. A generalized additive regression model was used to estimate z scores as a smooth function of ODI, NDI and cortical thickness or volume with adjustment for age, gender, education, MCSA cycle number, WMH and intracranial volume.ResultThe Table displays demographic data. Figures 1 and 2 show the relationship of NDI and ODI measures to memory z scores across participants in individual ROIs both before and after adjustment for cortical thickness (“structural MRI”) as well as for confounds listed above. Both higher cortical thickness and higher NDI values in the hippocampus and entorhinal cortex were associated with significantly higher memory z‐scores (p<0.001) (Figure 1). Higher ODI values in addition to greater cortical thickness in temporal lobe regions, including within the hippocampus, parahippocampal gyrus, entorhinal cortex and inferior temporal gyrus, were associated with higher memory z‐scores (Figure 2). These significant associations (p <=0.01) were maintained after adjusting for cortical thickness in all these regions except entorhinal cortex for ODI.ConclusionNODDI‐derived measures of microstructural integrity (NDI & ODI) within the temporal cortex may provide information about memory decline, beyond what cortical thickness analysis provides, and may be potentially useful for monitoring therapeutic effects of AD immunotherapy in the future.

AbstractBackgroundAlzheimer disease (AD) related cognitive decline occurs at relatively young ages in individuals with Down syndrome (DS, early‐mid 50s) and in those with autosomal dominant mutations (ADAD, 40‐50s). Both groups show similar patterns of amyloid accumulation. We examined if brain volumes are similarly affected by AD pathology in individuals with DS and ADAD.MethodData for cognitively stable and declining participants was obtained from the Alzheimer Biomarker Consortium‐Down Syndrome (ABC‐DS) and the Dominantly Inherited Alzheimer Network (DIAN). Stability/decline was identified based on cognitive testing and interview of individuals and caregivers by trained assessors. Cognitively stable family members without DS/ADAD mutations were recruited as controls from both studies. Participants underwent MRI and amyloid positron emission tomography (PET) scans from which brain volumes and amyloid (centiloids) were derived, respectively. Participants from DIAN had Pittsburgh Compound‐B (PIB) scans, ABC‐DS had PIB or florbetapir. Nonlinear cross‐sectional associations between regional brain volumes and estimated years to onset of cognitive decline (EYO, negative values before onset, positive after) and centiloid were evaluated using generalized additive models while controlling for sex and random effects of family. EYO was set to 52 for all participants with DS and based on parental decline/mutation type for participants with ADAD. EYO for controls was based on the EYO of their family member.ResultData from 239 participants with DS (47 declining), and 340 participants with ADAD (122 declining), and 263 familial controls were included. Higher EYO and centiloid values were associated with lower brain volumes in almost all regions. At earlier EYOs, individuals with DS typically had smaller regional volumes than ADAD or sibling controls, with volume declining linearly across the EYO range. By contrast, ADAD mutation carriers had similar volumes to non‐carriers at early EYOs, with volumes diverging as early as 10 years before decline. Brain volumes and centiloid values were inversely related in ADAD and DSAD. Volume in key cortical regions were similar by the expected year of onset in both groups.ConclusionADAD and DSAD demonstrated different temporal patterns of regional neurodegeneration prior to cognitive change despite being similarly affected by early onset amyloid.

AbstractBackgroundNeuritic plaques with fibrillar beta‐amyloid (Aß) peptides and tau‐protein neurofibrillary tangles, hallmark features of Alzheimer’s disease (AD) pathology, have been concomitantly associated with white matter (WM) integrity loss, while a unique effect of each pathology on WM integrity in a more demographically diverse population remains unknown.MethodTo examine the degree to which each pathology affects WM integrity in a more diverse non‐demented cohort, Aß and tau PET, diffusion‐weighted imaging (DWI), and cognition (memory and executive function composites) were examined from the U.S. POINTER neuroimaging participants (N = 608; age = 68.34±5.2; 61.8% females; 29% Aß+) and a subset of Alzheimer’s Disease Neuroimaging Initiative (ADNI) participants (N = 291; age = 72.85±7.3; 50% females; 39% Aß+) (Table). Aß‐positivity was determined using tracer‐specific standardized cut‐offs. Tau SUVR was estimated for each Braak stage. For WM integrity, voxel‐based GLMs were applied to FSL‐processed fractional anisotropy (FA) maps using Braak stage tau SUVR and Aß‐positivity status, along with covariates of age, sex, and b‐value profiles.ResultIn U.S. POINTER, independent from Aß‐positivity status, greater tau burden in Braak stages I and II was related to lower FA across the tracts including the superior longitudinal fasciculus, fornix (cres), corpus callosum, and anterior thalamic radiation (Figure). Average FA from supra‐threshold clusters for Braak I and II significantly predicted executive function but not episodic memory. No association between FA and tau burden in Braak stages III/IV or V/VI was found. In the ADNI sample, greater tau burden in Braak I was related to lower FA mostly in left inferior longitudinal fasciculus and left uncinate fasciculus, while negative associations with FA became more diffuse with tau load in Braak III/IV and V/VI. Average FA from supra‐threshold clusters significantly predicted both episodic memory and executive function scores. Across both samples, after accounting for tau burden in each Braak stage, there were no association between Aß‐positivity status and WM integrity.ConclusionDistinct associations between tau burden, WM integrity, and cognition were found across the studies, indicating greater impact of early tau burden on WM integrity in U.S. POINTER, accounting for Aß‐positivity status. Factors contributing to the distinct associations across studies need further investigation.

AbstractBackgroundCortical structural changes in the temporal lobes including global and hippocampal volume loss and decrease in cortical thickness are well‐associated findings linked to cognitive decline in MCI and dementia patients. Neurite orientation dispersion and density imaging (NODDI) is a multishell diffusion MRI method enabling assessment of tissue microstructural integrity at the axonal and dendritic level. We wished to determine whether changes in temporal cortex orientation dispersion index (ODI) & neurite density index (NDI) correlate with decreases in memory function.MethodThe MCALT_ADIR122 cortical atlas was used for ROI designation. NODDI imaging was obtained on a 3T Siemens Prisma scanner with 2 mm isotropic resolution. Participants (ages 60‐95 years) were cognitively unimpaired (CU) or had mild cognitive impairment (MCI). CU & MCI subjects were enrolled in the Mayo Clinic Study of Aging (MCSA) and underwent neuropsychological testing including 3 memory tests from which a composite memory z score was calculated. A generalized additive regression model was used to estimate z scores as a smooth function of ODI, NDI and cortical thickness or volume with adjustment for age, gender, education, MCSA cycle number, WMH and intracranial volume.ResultThe Table displays demographic data. Figures 1 and 2 show the relationship of NDI and ODI measures to memory z scores across participants in individual ROIs both before and after adjustment for cortical thickness (“structural MRI”) as well as for confounds listed above. Both higher cortical thickness and higher NDI values in the hippocampus and entorhinal cortex were associated with significantly higher memory z‐scores (p<0.001) (Figure 1). Higher ODI values in addition to greater cortical thickness in temporal lobe regions, including within the hippocampus, parahippocampal gyrus, entorhinal cortex and inferior temporal gyrus, were associated with higher memory z‐scores (Figure 2). These significant associations (p <=0.01) were maintained after adjusting for cortical thickness in all these regions except entorhinal cortex for ODI.ConclusionNODDI‐derived measures of microstructural integrity (NDI & ODI) within the temporal cortex may provide information about memory decline, beyond what cortical thickness analysis provides, and may be potentially useful for monitoring therapeutic effects of AD immunotherapy in the future.

Abstract INTRODUCTION The Alzheimer's Association and the Society of Nuclear Medicine and Molecular Imaging convened a multidisciplinary workgroup to update appropriate use criteria (AUC) for amyloid positron emission tomography (PET) and to develop AUC for tau PET. METHODS The workgroup identified key research questions that guided a systematic literature review on clinical amyloid/tau PET. Building on this review, the workgroup developed 17 clinical scenarios in which amyloid or tau PET may be considered. A modified Delphi approach was used to rate each scenario by consensus as “rarely appropriate,” “uncertain,” or “appropriate.” Ratings were performed separately for amyloid and tau PET as stand‐alone modalities. RESULTS For amyloid PET, seven scenarios were rated as appropriate, two as uncertain, and eight as rarely appropriate. For tau PET, five scenarios were rated as appropriate, six as uncertain, and six as rarely appropriate. DISCUSSION AUC for amyloid and tau PET provide expert recommendations for clinical use of these technologies in the evolving landscape of diagnostics and therapeutics for Alzheimer's disease. Highlights A multidisciplinary workgroup convened by the Alzheimer's Association and the Society of Nuclear Medicine and Molecular Imaging updated the appropriate use criteria (AUC) for amyloid positron emission tomography (PET) and to develop AUC for tau PET. The goal of these updated AUC is to assist clinicians in identifying clinical scenarios in which amyloid or tau PET may be useful for guiding the diagnosis and management of patients who have, or are at risk for, cognitive decline These updated AUC are intended for dementia specialists who spend a significant proportion of their clinical effort caring for patients with cognitive complaints, as well as serve as a general reference for a broader audience interested in implementation of amyloid and tau PET in clinical practice.

Purpose of review Once considered to have only local influences on the gut mucosa, short-chain fatty acids (SCFAs) now appear to have a much wider anti-inflammatory, immune-modulating, systemic effect. This article reviews recent evidence to suggest a much wider clinical application of this valued dietary substrate. Recent findings SCFAs act systemically through stimulation of G protein receptors (GPRs) and inhibition of histone deacetylases (HDACs). SCFAs cause appetite suppression, reduce systemic inflammation, improve insulin sensitivity, increase energy expenditure, promote mitochondrial function, stimulate satiety, reduce blood pressure, and improve cognitive function from various neurologic maladies. Summary Dietary strategies should be implemented to provide this beneficial substrate across a wide spectrum of disease conditions. Use of prebiotic fiber or liquid supplements containing high SCFA-producing organisms should be considered as therapeutic targets for multiple metabolic, immunologic, and neurodegenerative diseases.

AbstractBackgroundThe efficacy of Calorie Restriction (CR) in enhancing cognition, promoting healthy aging, and extending lifespan is well‐established. Yet, it remains unclear whether the apolipoprotein E (APOE) genotype, a known modifier for aging and age‐related disorders, influences the beneficial effects of CR in countering aging.MethodsTo investigate this question, we utilized humanized APOE mouse models, which express APOE2, APOE3, or APOE4 alleles systematically (refer to as E2, E3, and E4 mice). These mice were subjected to either ad libitum (AL) feeding or 30% CR feeding, starting from 12 months and continuing up to 20 months of age (N = 11‐20/ genotype /group, mixed sex). We monitored energy expenditure using the Comprehensive Laboratory Animal Monitoring System (CLAMS). Additionally, we evaluated anxiety levels and memory capabilities through various behavioral tests. Finally, we collected brain, blood, and feces samples for transcriptomic, lipidomic, and microbiomic analyses.ResultsCLAMS measurements showed that CR significantly decreased the metabolic rate in E3 and E4 mice, but not E2 mice, during the non‐feeding period of the CR group, compared to the AL group. Furthermore, CR reduced anxiety and enhanced associative memory in E3 and E4 mice relative to the AL group. Brain transcriptomics revealed that CR upregulated the cholesterol synthesis pathway, potentially improving myelination‐related pathways in E3 and E4 mice. This finding was further validated by the increased staining intensity of myelin basic protein (MBP) observed in E3 and E4 mice from an independent cohort. In contrast, these effects were not pronounced in E2 mice. Additionally, while CR’s impact on the brain lipid profile was minor across all APOE genotypes, it significantly altered blood lipid profile of E2 mice, with minimal changes observed in E3 and E4 mice. Finally, in microbiomics, CR led to notable changes in the abundance of Bifidobacterium species in E3 and E4 mice and Lactobacillus species in E2 mice.ConclusionsOur study highlights the role of APOE genotypes in modulating the diverse effects of CR on cognition, brain transcriptomics, lipid metabolism, and the microbiome, providing a crucial foundation for considering APOE genotypes in developing prevention strategies for aging and age‐related disorders.