Lewy body pathology modifies risk factors for cerebral amyloid angiopathy when comorbid with Alzheimer's disease pathology

INTRODUCTION

Cerebral amyloid angiopathy (CAA) often accompanies dementia-associated pathologies and is important in the context of anti-amyloid monoclonal therapies and risk of hemorrhage.

METHODS

We conducted a retrospective neuropathology-confirmed study of 2384 participants in the National Alzheimer Coordinating Center cohort (Alzheimer's disease [AD], n = 1175; Lewy body pathology [LBP], n = 316; and mixed AD and LBP [AD-LBP], n = 893). We used logistic regression to evaluate age, sex, education, APOE ε4, neuritic plaques, and neurofibrillary tangles (NFTs) in CAA risk.

RESULTS

APOE ε4 increased CAA risk in all three groups, while younger age and higher NFT stages increased risk in AD and AD-LBP. In AD-LBP, male sex and lower education were additional risk factors. The odds of APOE ε4 carrier homozygosity related to CAA was higher in LBP (25.69) and AD-LBP (9.50) than AD (3.17).

DISCUSSION

AD and LBPs modify risk factors for CAA and should be considered in reviewing the risk of CAA.

HIGHLIGHTS

Lewy body pathology modifies risk factors for cerebral amyloid angiopathy (CAA) when present along with Alzheimer's disease (AD) neuropathology. In the context of anti-amyloid monoclonal therapies and their associated risks for hemorrhage, the risk of underlying CAA in mixed dementia with Lewy body pathology needs to be considered.

Exploratory Transcriptomic Profiling Reveals the Role of Gut Microbiota in Vascular Dementia

Stroke is the second most common cause of cognitive impairment and dementia. Vascular dementia (VaD), a cognitive impairment following a stroke, is common and significantly impacts the quality of life. We recently demonstrated via gut microbe transplant studies that the gut microbe-dependent trimethylamine-N-oxide (TMAO) pathway impacts stroke severity, both infarct size and long-term cognitive outcomes. However, the molecular mechanisms that underly the role of the microbiome in VaD have not been explored in depth. To address this issue, we performed a comprehensive RNA-sequencing analysis to identify differentially expressed (DE) genes in the ischemic cerebral cortex of mouse brains at pre-stroke and post-stroke day 1 and day 3. A total of 4016, 3752 and 7861 DE genes were identified at pre-stroke and post-stroke day 1 and day 3, respectively. The Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis indicated pathways of neurodegeneration in multiple diseases, chemokine signaling, calcium signaling, and IL-17 signaling as the key enriched pathways. Inflammatory response genes interleukin-1 beta (Il-1β), chemokines (C-X-C motif chemokine ligand 10 (Cxcl10), chemokine ligand 2 (Ccl2)), and immune system genes (S100 calcium binding protein 8 (S100a8), lipocalin-2 (Lcn2)) were among the most significantly upregulated genes. Hypocretin neuropeptide precursor (Hcrt), a neuropeptide, and transcription factors such as neuronal PAS domain protein 4 (Npas4), GATA binding protein 3 (Gata3), and paired box 7 (Pax7) were among the most significantly downregulated genes. In conclusion, our results indicate that higher plasma TMAO levels induce differential mRNA expression profiles in the ischemic brain tissue in our pre-clinical stroke model, and the predicted pathways provide the molecular basis for regulating the TMAO-enhanced neuroinflammatory response in the brain.

Abstract TP100: Transfer Learning Based Cerebral Microbleed Detection As An Mri Biomarker For Cerebral Amyloid Angiopathy Spectrum Diseases

Objectives: Quantifying cerebral microbleeds (CMBs) in cerebral amyloid angiopathy (CAA) is important, however manual counting of CMBs on brain MRI is laborious. This work aims to develop a novel automatic deep learning segmentation algorithm for fast and accurate quantification of CMBs on brain MRIs.

Method: We used (a) internal dataset (susceptibility-weighted imaging [SWI] clinical scans from 83 patients with CAA) with heterogeneous protocols on 1.5T and 3T scanners and manual CMB segmentation by 2 readers, and (b) public dataset (57 SWI scans from 30 patients with Alzheimer’s and CMB locations). The data was split into training, validation, and testing subsets (internal: 50/20/13; Public: 38/9/10). Preprocessing included N3 bias field correction, brain extraction, and up-sampling to a fixed in-plane resolution (0.2mm). Model used multi-channel 2D input (Fig1.b) and mimicked manual CMB segmentation. We trained base-model initially using the public dataset and then applied transfer learning using the internal dataset to segment CMBs in clinical scans. We evaluated model’s performance by sensitivity (S), precision (P), number of false positives per scan (FPC) and F1-score (F1).

Results: On 10 public test scans, base model performed well (S 0.81, P 0.74, FPC 0.60, F1 0.77) but had high FPC for 13 internal test scans (S 1.00, P 0.15, FPC 4.31, F1 0.26). After transfer learning, the precision, FPC and F1-score were improved for internal scans (S 0.80, P 0.80, FPC 0.15, F1 0.80).

Conclusion: Refined deep-learning based CMB counting algorithms could quantify CMBs for heterogeneous clinical MRI dataset with good sensitivity, precision, and false positivity. This method may accelerate further CAA clinical diagnosis and research.

Association of Variation in Behavioral Symptoms With Initial Cognitive Phenotype in Adults With Dementia Confirmed by Neuropathology

IMPORTANCE

Behavioral and psychological symptoms of dementia (BPSDs) in association with amnestic and nonamnestic cognitive phenotypes have not been evaluated across diagnoses of Alzheimer disease pathology (ADP), Lewy body-related pathology (LRP), and mixed pathology (ADP-LRP).

OBJECTIVES

To determine the clinical phenotypes at the initial visit that are associated with the nature and severity of BPSDs in patients with ADP, LRP, and ADP-LRP.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective longitudinal cohort study included 2422 participants with neuropathologically confirmed ADP, LRP, or mixed ADP-LRP in the National Alzheimer Coordinating Center database from June 20, 2005, to September 4, 2019. Participants had a mean (SD) interval of 5.5 (2.8) years from initial visit to autopsy.

MAIN OUTCOMES AND MEASURES

Clinician-determined diagnosis of change across 10 BPSDs (agitation, apathy, depression, delusions, disinhibition, auditory hallucinations, visual hallucinations, irritability, personality change, and rapid eye movement [REM] sleep behavior) and the highest severity score for behavioral change on the Neuropsychiatric Inventory Questionnaire (NPI-Q).

RESULTS

A total of 2422 participants (1187 with ADP, 904 with ADP-LRP, and 331 with LRP) were included in the analysis (1446 men [59.7%]; mean [SD] age, 74.4 [10.1] years). Compared with initial amnestic symptoms, executive symptoms were associated with a higher risk for 7 of the 10 BPSDs (hazard ratio [HR] range, 1.28-2.45), and visuospatial symptoms were associated with a higher risk for 2 of the 10 BPSDs (HR range, 1.91-2.51), but neither were associated with a low risk for any BPSD. Language symptoms were associated with a low risk of onset for 3 of 10 BPSDs (HR range, 0.43-0.79) and a high risk for 1 BPSD (personality change) (HR, 1.42 [95% CI, 1.10-1.83]). Participants with LRP had a lower risk for agitation (HR, 0.74 [95% CI, 0.60-0.92]), disinhibition (HR, 0.78 [95% CI, 0.62-0.99]), and irritability (HR, 0.81 [95% CI, 0.68-0.96]) and a higher risk for apathy (HR, 1.19 [95% CI, 1.02-1.38]), depression (HR, 1.32 [95% CI, 1.12-1.55]), auditory (HR, 2.00 [95% CI, 1.37-2.93]) and visual (HR, 2.78 [95% CI, 2.21-3.49]) hallucinations, and REM sleep behavior changes (HR, 4.77 [95% CI, 3.61-6.31]) compared with the ADP group. The ADP-LRP group had a higher risk for delusions (HR, 1.27 [95% CI, 1.08-1.48]), auditory (HR, 1.62 [95% CI, 1.21-2.15]) and visual (HR, 1.57 [95% CI, 1.30-1.89]) hallucinations, and REM sleep behavior changes (HR, 2.10 [95% CI, 1.63-2.70]) than the ADP group and a lower risk for visual hallucinations (HR, 0.56 [95% CI, 0.45-0.71]) and REM sleep behavior changes (HR, 0.44 [95% CI, 0.34-0.57) than the LRP group. Overall, women showed a lower risk of agitation (HR, 0.86 [95% CI, 0.75-0.98]), apathy (HR, 0.79 [95% CI, 0.71-0.87]), visual hallucinations (HR, 0.76 [95% CI, 0.64-0.90]), irritability (HR, 0.77 [95% CI, 0.69-0.86]), and REM sleep behavior change (HR, 0.45 [95% CI, 0.35-0.58]) and a higher risk of depression (HR, 1.26 [95% CI, 1.13-1.41]). Older age was associated with a lower risk of most BPSDs (HR range, 0.98-0.99) except delusions (HR, 1.00 [95% CI, 1.00-1.01]) and auditory hallucinations (HR, 0.99 [95% CI, 0.97-1.00]) and a low NPI-Q composite score (β = -0.07 [95% CI, -0.08 to -0.05]; P < .001).

CONCLUSIONS AND RELEVANCE

These findings suggest that the risks of BPSDs differ with respect to the initial cognitive phenotype, underlying neuropathology, age, and sex. Awareness of these associations could be helpful in dementia management.

Advances in Management of Neuropsychiatric Syndromes in Neurodegenerative Diseases

PURPOSE OF REVIEW

Neuropsychiatric syndromes (NPS) are common in neurodegenerative disorders (NDD). This review describes the role of NPS in the diagnosis of NDD, criteria for the diagnosis of NPS, management of NPS, and agents in clinical trials for NPS.

RECENT FINDINGS

NPS play an increasingly important role in the diagnosis of NDD. Consensus diagnostic criteria have evolved for psychosis, depression, agitation, and apathy in NDD. With one exception-pimavanserin is approved for the treatment of hallucinations and delusions in Parkinson's disease-there are no drugs approved by the FDA for treatment of NPS in NDD. Trials show that atypical antipsychotics reduce psychosis in AD and in Parkinson's disease, although side effect concerns have constrained their use. Antidepressants show benefit in treatment of Parkinson's disease with depression. Several agents are in clinical trials for treatment of NPS in NDD. Neuropsychiatric syndromes play a major role in NDD diagnosis. Clinical criteria allow recognition of NPS in NDD. Psychotropic medications are often useful in the treatment of NPS in NDD; efficacious, safe, and approved agents are needed.

Science and regulation. Probiotics: finding the right regulatory balance

Some products marketed as drugs should be excused from Phase I trials, but safety and efficacy claims for dietary supplements should be more tightly regulated.

Consent to the use of stored DNA for genetics research: a survey of attitudes in the Jewish population

The use of anonymized stored tissue is a routine practice in genetic research. Investigators who utilize stored samples are neither required nor able to obtain informed consent before each use. Many genetic studies, however, are conducted on specific ethnic populations (e.g., Ashkenazi Jews). The results in these cases, although individually anonymous, are not anonymous with respect to the ethnicity of the participants. This lack of group anonymity has led to concern about the possibility of stigmatization and discrimination based on the results of the genetic research. In the present study we surveyed Jewish individuals about their attitudes regarding the practice of using stored DNA samples for genetic research. Specifically, we were interested in whether attitudes about informed consent and willingness to participate in genetics research using stored DNA would depend on the circumstances in which the material was collected (i.e., clinical setting vs. research setting) and the characteristics of the disease or trait under investigation. Overall, most respondents reported that written informed consent should be required and that they would be willing to provide such consent. Participants were most willing to provide consent, however, when the sample had been collected in a research rather than clinical setting. Further, participants were more likely to endorse the need for obtaining consent when the sample was collected in a clinical setting. Finally, participants were significantly less willing to participate in research that examined stereotypical or potentially stigmatizing traits as opposed to research that examined medical or mental illnesses.

Genetic information and the workplace: legislative approaches and policy changes

The use of genetic information in the workplace poses societal risks that have an impact on employment possibilities, health insurance, and privacy. Individuals who might otherwise believe they can benefit from genetic testing may decline it because of their fear of employment discrimination and lack of privacy in the workplace. As a consequence, the future of research on the benefits and risks of predictive genetic testing may also be compromised. Thus, policy-makers need to evaluate legislative and regulatory strategies to address these concerns. This paper analyzes state and federal legislative approaches to genetic information in the workplace and concludes with a discussion of policy considerations and recommendation.

The determination of antibody to Streptococcus mutans serotypes in saliva for children ages 3 to 7 years

The saliva of 29 children ages 3 to 7 years was followed by indirect immunoflourescence to determine the antibody reacting with the 5 different serotypes of S mutans. Fluorescent antisera specific for alpha chain and gamma chain were used. Statistical analysis of the data demonstrated a significant negative correlation between antibody of immunoglobin class (IgA) to S mutans type b and the decayed, extracted and filled surfaces of deciduous teeth.