Lecanemab in Early Alzheimer's Disease

Independent and joint associations of cardiometabolic multimorbidity and depression on cognitive function: findings from multi-regional cohorts and generalisation from community to clinic

Background

Cardiometabolic multimorbidity (CMM) and depression are often co-occurring in older adults and associated with neurodegenerative outcomes. The present study aimed to estimate the independent and joint associations of CMM and depression on cognitive function in multi-regional cohorts, and to validate the generalizability of the findings in additional settings, including clinical.

Methods

Data harmonization was performed across 14 longitudinal cohort studies within the Cohort Studies of Memory in an International Consortium (COSMIC) group, spanning North America, South America, Europe, Africa, Asia, and Australia. Three external validation studies with distinct settings were employed for generalization. Participants were eligible for inclusion if they had data for CMM and were free of dementia at baseline. Baseline CMM was defined as: 1) CMM 5, ≥2 among hypertension, hyperlipidemia, diabetes, stroke, and heart disease and 2) CMM 3 (aligned with previous studies), ≥2 among diabetes, stroke, and heart disease. Baseline depression was primarily characterized by binary classification of depressive symptom measurements, employing the Geriatric Depression Scale and the Center for Epidemiological Studies-Depression scale. Global cognition was standardized as z-scores through harmonizing multiple cognitive measures. Longitudinal cognition was calculated as changes in global cognitive z-scores. A pooled individual participant data (IPD) analysis was utilized to estimate the independent and joint associations of CMM and depression on cognitive outcomes in COSMIC studies, both cross-sectionally and longitudinally. Repeated analyses were performed in three external validation studies.

Findings

Of the 32,931 older adults in the 14 COSMIC cohorts, we included 30,382 participants with complete data on baseline CMM, depression, and cognitive assessments for cross-sectional analyses. Among them, 22,599 who had at least 1 follow-up cognitive assessment were included in the longitudinal analyses. The three external studies for validation had 1964 participants from 3 multi-ethnic Asian older adult cohorts in different settings (community-based, memory clinic, and post-stroke study). In COSMIC studies, each of CMM and depression was independently associated with cross-sectional and longitudinal cognitive function, without significant interactions between them (Ps > 0.05). Participants with both CMM and depression had lower cross-sectional cognitive performance (e.g. β = -0.207, 95% CI = (-0.255, -0.159) for CMM5 (+)/depression (+)) and a faster rate of cognitive decline (e.g. β = -0.040, 95% CI = (-0.047, -0.034) for CMM5 (+)/depression (+)), compared with those without either condition. These associations remained consistent after additional adjustment for APOE genotype and were robust in two-step random-effects IPD analyses. The findings regarding the joint association of CMM and depression on cognitive function were reproduced in the three external validation studies.

Interpretation

Our findings highlighted the importance of investigating age-related co-morbidities in a multi-dimensional perspective. Targeting both cardiometabolic and psychological conditions to prevent cognitive decline could enhance effectiveness.

Funding

Natural Science Foundation of China and National Institute on Aging/National Institutes of Health.

Implications of treatment duration and frequency for value and cost-effective price of Alzheimer treatments

BACKGROUND

Disease-modifying Alzheimer treatments are becoming available. The value of the treatments will be attenuated by their complexity of delivery and monitoring, creating additional medical cost and caregiver burden.

OBJECTIVE

To estimate net treatment value using different assumptions for treatment duration and intensity.

METHODS

We estimated the lifetime value of hypothetical treatments that reduce disease progression by 30% from a payer perspective, which considers cost offsets, i.e., reduced medical and formal social care costs, and quality-adjusted life-year gains, and a societal perspective, which adds reduction in caregiver burden. Estimates for gross value of the treatment were based on a prior publication, medical cost on Medicare payment rates, and caregiver time use on a survey of 21 clinics. We analyzed 5 hypothetical treatment scenarios: treatment until progression to moderate dementia with (1) biweekly and (2) 4-weekly infusions, and time-limited infusions every 4 weeks for (3) 72, (4) 52, and (5) 24 weeks.

RESULTS

Treatment until progression to moderate dementia would take 5.7 years and generate gross value of $20,734 in direct cost offsets, $83,761 from a payer and $87,749 from a societal perspective, respectively. Added medical cost and caregiver burden for the 5 scenarios would be $44,179, $24,875, $21,632, $20,416, and $14,350, respectively. The maximum value-based price per year would be $7,687, $11,088, $47,708, $67,273, and $158,954.

CONCLUSIONS

Assuming identical efficacy and safety, the net value generation of time-limited treatment is projected to be larger than that of chronic treatment. Such determination of net lifetime value can be useful to determine value-based prices for different treatment types.

Beta amyloid PET scans for dementia diagnoses: Practice and research implications from CARE-IDEAS

Beta amyloid PET scans are a minimally invasive biomarker that may inform Alzheimer's disease (AD) diagnosis. The Caregiver's Reactions and Experience (CARE) study, an IDEAS supplement, aimed to understand experiences of PET scan recipients and their care partners regarding motivations for scans, reporting and interpreting results, and impact of results. Patients with mild cognitive impairment or dementia who agreed to join the CARE-IDEAS study and their care partners participated in a baseline survey and follow-up survey approximately 18 months later, supplemented by in-depth qualitative interviews with subsets of participants. Patients who received scans and volunteered for follow-up research were more likely to be male, better educated, and have higher income than the general population. Survey information was merged with Medicare data. This article integrates findings from several CARE-IDEAS publications and provides implications for practice and research. Although most participants accurately reported scan results, they were often confused about their meaning for prognosis. Some participants reported distress with results, but there were no significant changes in measured depression, burden, or economic strain over time. Many respondents desired more information about prognosis and supportive resources. Scan results were not differentially associated with changes in service use over time. Findings suggest a need for carefully designed and tested tools for clinicians to discuss risks and benefits of scans and their results, and resources to support patients and care partners in subsequent planning. Learning of scan results provides a point-of-contact that should be leveraged to facilitate shared decision-making and person-centered longitudinal AD care.

Sex-dependent APOE4 neutrophil-microglia interactions drive cognitive impairment in Alzheimer's disease

APOE4 is the strongest genetic risk factor for Alzheimer's disease (AD), with increased odds ratios in female carriers. Targeting amyloid plaques shows modest improvement in male non-APOE4 carriers. Leveraging single-cell transcriptomics across APOE variants in both sexes, multiplex flow cytometry and validation in two independent cohorts of APOE4 female carriers with AD, we identify a new subset of neutrophils interacting with microglia associated with cognitive impairment. This phenotype is defined by increased interleukin (IL)-17 and IL-1 coexpressed gene modules in blood neutrophils and in microglia of cognitively impaired female APOE ε4 carriers, showing increased infiltration to the AD brain. APOE4 female IL-17+ neutrophils upregulated the immunosuppressive cytokines IL-10 and TGFβ and immune checkpoints, including LAG3 and PD-1, associated with accelerated immune aging. Deletion of APOE4 in neutrophils reduced this immunosuppressive phenotype and restored the microglial response to neurodegeneration, limiting plaque pathology in AD mice. Mechanistically, IL-17F upregulated in APOE4 neutrophils interacts with microglial IL-17RA to suppress the induction of the neurodegenerative phenotype, and blocking this axis supported cognitive improvement in AD mice. These findings provide a translational basis to target IL-17F in APOE ε4 female carriers with cognitive impairment.

Differential centiloid scale normalization techniques: comparison between hybrid PET/MRI and independently acquired MRI

OBJECTIVE

Centiloid (CL) scales play an important role in semiquantitative analyses of amyloid-β (Aβ) PET. CLs are derived from the standardized uptake value ratio (SUVR), which needs Aβ positron emission tomography (PET) normalization processing. There are two methods to collect the T1-weighted imaging (T1WI) for normalization: (i) anatomical standardization using simultaneously acquired T1WI (PET/MRI), usually adapted to PET images from PET/MRI scanners, and (ii) T1WI from a separate examination (PET + MRI), usually adapted to PET images from PET/CT scanners. This study aimed to elucidate the correlations and differences in CLs between when using the above two T1WI collection methods.

METHODS

Among patients who underwent Aβ PET/MRI (using 11C-Pittuberg compound B (11C-PiB) or 18F-flutemetamol (18F-FMM)) at our institution from 2015 to 2023, we selected 49 patients who also underwent other additional MRI examinations, including T1WI for anatomic standardization within 3 years. Thirty-one of them underwent 11C-PiB PET/MRI, and 18 participants underwent 18F-FMM PET/MRI. Twenty-five of them, additional MRI acquisition parameters were identical to simultaneous MRI during PET, and 24 participants were different. After normalization using PET/MRI or PET + MRI method each, SUVR was measured using the Global Alzheimer's Association Initiative Network cerebral cortical and striatum Volume of Interest templates (VOI) and whole cerebellum VOI. Subsequently, CLs were calculated using the previously established equations for each Aβ PET tracer.

RESULTS

Between PET/MRI and PET + MRI methods, CLs correlated linearly in 11C-PiB PET (y = 1.00x - 0.11, R2 = 0.999), 18F-FMM PET (y = 0.97x - 0.12, 0.997), identical additional MRI acquisition (y = 1.00x + 0.33, 0.999), different acquisition (y = 0.98x - 0.43, 0.997), and entire study group (y = 1.00x - 0.24, 0.999). Wilcoxon signed-rank test revealed no significant differences: 11C-PiB (p = 0.49), 18F-FMM (0.08), and whole PET (0.46). However, significant differences were identified in identical acquisition (p = 0.04) and different acquisition (p = 0.02). Bland-Altman analysis documented only a small bias between PET/MRI and PET + MRI in 11C-PiB PET, 18F-FMM PET, identical additional MRI acquisition, different acquisition, and whole PET (- 0.05, 0.67, - 0.30, 0.78, and 0.21, respectively).

CONCLUSIONS

Anatomical standardizations using PET/MRI and using PET + MRI can lead to almost equivalent CL. The CL values obtained using PET/MRI or PET + MRI normalization methods are consistent and comparable in clinical studies.

Lecanemab

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New insights into innate immunity in Alzheimer's disease: from APOE protective variants to therapies

Recent discoveries of rare variants of human APOE may shed light on novel therapeutic strategies for Alzheimer's disease (AD). Here, we highlight the newly identified protective variant [APOE3 Christchurch (APOE3ch, R136S)] as an example. We summarize human AD and mouse amyloidosis and tauopathy studies from the past 5 years that have been associated with this R136S variant. We also propose a potential mechanism for how this point mutation might lead to protection against AD pathology, from the molecular level, to cells, to mouse models, and potentially, to humans. Lastly, we extend our discussion of the recent insights gained regarding different APOE variants to putative therapeutic approaches in AD.

[Prevention of cognitive decline in old age : Selected primary preventive approaches]

There are currently 1.8 million people in Germany affected by dementia. Despite advances in research and new treatments, there is no cure for most cases of dementia. The evidence regarding the prevention of cognitive decline in old age is unclear. In addition to the optimized adjustment of drug treatment (e.g., arterial hypertension and diabetes mellitus), preventive measures that can be influenced by individuals themselves play an important role. These include areas such as physical and cognitive activity, remedying hearing loss, sleep, social contacts, abstaining from alcohol as well as tobacco consumption and nutrition. Multimodal concepts and digital approaches appear to be promising and an increase in evidence is expected in the coming years.

Histidine-containing dipeptide supplementation improves delayed recall: a systematic review and meta-analysis

CONTEXT

Histidine-containing dipeptides (carnosine, anserine, beta-alanine and others) are found in human muscle tissue and other organs like the brain. Data in rodents and humans indicate that administration of exogenous carnosine improved cognitive performance. However, RCTs results vary.

OBJECTIVES

To perform a systematic review and meta-analysis of randomized controlled trials (RCTs) of histidine-containing dipeptide (HCD) supplementation on cognitive performance in humans to assess its utility as a cognitive stabiliser.

DATA SOURCES

OVID Medline, Medline, EBM Reviews, Embase, and Cumulative Index to Nursing and Allied Health Literature databases from 1/1/1965 to 1/6/2022 for all RCT of HCDs were searched.

DATA EXTRACTION

2653 abstracts were screened, identifying 94 full-text articles which were assessed for eligibility. Ten articles reporting the use of HCD supplementation were meta-analysed.

DATA ANALYSIS

The random effects model has been applied using the DerSimonian-Laird method. HCD treatment significantly increased performance on Wechsler Memory Scale (WMS) -2 Delayed recall (Weighted mean difference (WMD) (95% CI (CI)) = 1.5 (0.6, 2.5), P < .01). Treatment with HCDs had no effect on Alzheimer's Disease Assessment Scale-Cognitive (WMD (95% CI) = -0.2 (-1.1, 0.7), P = .65, I2 = 0%), Mini-Mental State Examination (WMD (95% CI) = 0.7 (-0.2, 1.5), P = .14, I2 = 42%), The Wechsler Adult Intelligence Scale (WAIS) Digit span Backward (WMD (95% CI) = 0.1 (-0.3, 0.5), P = .51, I2 = 0%), WAIS digit span Forward (WMD (95% CI) = 0.0 (-0.3, 0.4), P = .85, I2 = 33%) and the WMS-1 Immediate recall (WMD (95% CI) = .7 (-.2, 1.5), P = .11, I2 = 0%). The effect on delayed recall remained in subgroup meta-analysis performed on studies of patients without mild cognitive impairment (MCI), and in those without MCI where average age in the study was above 65.

CONCLUSION

HCD, supplementation improved scores on the Delayed recall examination, a neuropsychological test affected early in Alzheimer's disease. Further studies are needed in people with early cognitive impairment with longer follow-up duration and standardization of carnosine doses to delineate the true effect.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration no. CRD42017075354.

Diverse signaling mechanisms and heterogeneity of astrocyte reactivity in Alzheimer's disease

Alzheimer's disease (AD) affects various brain cell types, including astrocytes, which are the most abundant cell types in the central nervous system (CNS). Astrocytes not only provide homeostatic support to neurons but also actively regulate synaptic signaling and functions and become reactive in response to CNS insults through diverse signaling pathways including the JAK/STAT, NF-κB, and GPCR-elicited pathways. The advent of new technology for transcriptomic profiling at the single-cell level has led to increasing recognition of the highly versatile nature of reactive astrocytes and the context-dependent specificity of astrocyte reactivity. In AD, reactive astrocytes have long been observed in senile plaques and have recently been suggested to play a role in AD pathogenesis and progression. However, the precise contributions of reactive astrocytes to AD remain elusive, and targeting this complex cell population for AD treatment poses significant challenges. In this review, we summarize the current understanding of astrocyte reactivity and its role in AD, with a particular focus on the signaling pathways that promote astrocyte reactivity and the heterogeneity of reactive astrocytes. Furthermore, we explore potential implications for the development of therapeutics for AD. Our objective is to shed light on the complex involvement of astrocytes in AD and offer insights into potential therapeutic targets and strategies for treating and managing this devastating neurodegenerative disorder.

The Alzheimer's Disease Neuroimaging Initiative Neuropathology Core: An update

INTRODUCTION

Biomarkers for Alzheimer's disease neuropathologic change (ADNC) have been instrumental in developing effective disease-modifying therapeutics. However, to prevent/treat dementia effectively, we require biomarkers for non-AD neuropathologies; for this, neuropathologic examinations and annotated tissue samples are essential.

METHODS

We conducted clinicopathologic correlation for the first 100 Alzheimer's Disease Neuroimaging Initiative (ADNI) Neuropathology Core (NPC) cases.

RESULTS

Clinical syndromes in this cohort showed 95% sensitivity and 79% specificity for predicting high/intermediate ADNC, a 21% false positive rate, and a ∼44% false negative rate. In addition, 60% with high/intermediate ADNC harbored additional potentially dementing co-pathologies.

DISCUSSION

These results suggest that clinical presentation imperfectly predicts ADNC and that accurate prediction of high/intermediate ADNC does not exclude co-pathology that may modify presentation, biomarkers, and therapeutic responses. Therefore, new biomarkers are needed for non-AD neuropathologies. The ADNI NPC supports this mission with well-characterized tissue samples (available through ADNI and the National Institute on Aging) and "gold-standard" diagnostic information (soon to include digital histology).

HIGHLIGHTS

The Alzheimer's Disease Neuroimaging Initiative (ADNI) Neuropathology Core (NPC) brain donation cohort now exceeds 200 cases. ADNI NPC data in National Alzheimer's Coordinating Center format are available through the Laboratory of Neuro Imaging. Digitized slide files from the ADNI NPC will be available in 2025. Requests for ADNI brain tissue samples can be submitted online for ADNI/National Institute on Aging evaluation. Clinical diagnoses of Alzheimer's disease (AD)/AD and related dementias (ADRD) do not always predict post mortem neuropathology. Neuropathology is essential for the development of novel AD/ADRD biomarkers.

Age-Specific Barriers and Facilitators to Research Participation Amongst African Americans in Observational Studies of Memory and Aging

BACKGROUND

Black/African Americans experience a high burden of Alzheimer disease and related dementias yet are critically underrepresented in corresponding research. Understanding barriers and facilitators to research participation among younger and older African Americans is necessary to inform age-specific strategies to promote equity in studies of early- and late-onset neurodegenerative diseases.

STUDY DESIGN

Survey respondents (n = 240) rated barriers and facilitators of research participation. Age-specific differences were evaluated using nonparametric Kruskal-Wallis tests across respondents aged 18-44 years (n = 76), 45-64 years (n = 83), and ≥ 65 years (n = 81). Strategies to mitigate barriers and promote facilitators were further explored via community-based focus groups. Pooled frequency of common themes discussed in focus groups were evaluated and compared across different ages including ≥ 45 years, ≥ 65 years, and mixed ages ≥ 45 years.

RESULTS

Younger respondents (aged 18-44 and 45-64 years) expressed a greater need for flexibility in when, where, and how research testing takes place versus adults ≥ 65 years. Focus groups emphasized long-lasting consequences of systemic racism and the need to build and foster trust to resolve barriers and promote research engagement amongst African Americans.

DISCUSSION

Age-specific strategies are needed to increase engagement, address recruitment disparities, and promote retention of African American participants in memory and aging studies across the lifespan.

Insights into the use of biomarkers in clinical trials in Alzheimer's disease

Biomarkers have been instrumental in population selection and disease monitoring in clinical trials of recently FDA-approved drugs targeting amyloid-β to slow the progression of Alzheimer's disease (AD). As new therapeutic strategies and biomarker techniques emerge, the importance of biomarkers in drug development is growing exponentially. In this emerging landscape, biomarkers are expected to serve a wide range of contexts of use in clinical trials focusing on AD and related dementias. The joint FDA-NIH BEST (Biomarkers, EndpointS, and other Tools) framework provides standardised terminology to facilitate communication among stakeholders in this increasingly complex field. This review explores various applications of biomarkers relevant to AD clinical trials, using the BEST resource as a reference. For simplicity, we predominantly provide contextual characterizations of biomarkers use from the perspective of drugs targeting amyloid-β and tau proteins. However, general definitions and concepts can be extrapolated to other targets.

DCRM 2.0: Multispecialty practice recommendations for the management of diabetes, cardiorenal, and metabolic diseases

The spectrum of cardiorenal and metabolic diseases comprises many disorders, including obesity, type 2 diabetes (T2D), chronic kidney disease (CKD), atherosclerotic cardiovascular disease (ASCVD), heart failure (HF), dyslipidemias, hypertension, and associated comorbidities such as pulmonary diseases and metabolism dysfunction-associated steatotic liver disease and metabolism dysfunction-associated steatohepatitis (MASLD and MASH, respectively, formerly known as nonalcoholic fatty liver disease and nonalcoholic steatohepatitis [NAFLD and NASH]). Because cardiorenal and metabolic diseases share pathophysiologic pathways, two or more are often present in the same individual. Findings from recent outcome trials have demonstrated benefits of various treatments across a range of conditions, suggesting a need for practice recommendations that will guide clinicians to better manage complex conditions involving diabetes, cardiorenal, and/or metabolic (DCRM) diseases. To meet this need, we formed an international volunteer task force comprising leading cardiologists, nephrologists, endocrinologists, and primary care physicians to develop the DCRM 2.0 Practice Recommendations, an updated and expanded revision of a previously published multispecialty consensus on the comprehensive management of persons living with DCRM. The recommendations are presented as 22 separate graphics covering the essentials of management to improve general health, control cardiorenal risk factors, and manage cardiorenal and metabolic comorbidities, leading to improved patient outcomes.

Lecanemab: A Humanized Monoclonal Antibody for the Treatment of Early Alzheimer Disease

OBJECTIVE

To review current pharmacology, pharmacokinetics/pharmacodynamics, safety, and efficacy of lecanemab in patients with Alzheimer disease.

DATA SOURCES

A literature search of PubMed (April 1, 2016-November 15, 2023) and ClinicalTrials.gov search were conducted using the following search terms: lecanemab and BAN2401. Additional articles were identified by hand from references.

STUDY SELECTION AND DATA EXTRACTION

We included English-language clinical trials, randomized controlled trials, reviews, and systematic reviews evaluating lecanemab pharmacology, efficacy, or safety in humans for the management of Alzheimer disease.

DATA SYNTHESIS

In the Clarity AD phase III trial, lecanemab led to a decrease in brain amyloid levels and showed moderate improvement in clinical measures of cognition and function. At 18 months, lecanemab 10 mg/kg biweekly exhibited a lower least squares mean change from baseline (1.21) compared to placebo (1.66) of Clinical Dementia Rating-Sum of Boxes score, signifying a significant difference of -0.45 (95% CI, -0.67 to -0.23; P < 0.001). In a subset of 698 participants, lecanemab reduced brain amyloid burden by -59.1 Centiloids (95% CI, -62.6 to -55.6). Lecanemab demonstrated favorable differences in Alzheimer Disease Assessment Scale-cognitive subscale 14, Alzheimer Disease Composite Score, and Alzheimer Disease Cooperative Study-Mild Cognitive Impairment-Activities of Daily Living scores. Adverse events included infusion-related reactions (26.4%) and amyloid-related imaging abnormalities (12.6%).

RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE

Lecanemab reduces cognitive decline but raises concerns about intravenous administration, cost, and magnetic resonance imaging needs. Ongoing trials exploring subcutaneous dosing and positron emission tomography scans may offer solutions.

CONCLUSION

Lecanemab is a humanized monoclonal antibody that is selective for soluble amyloid-beta (Aβ) aggregates. Lecanemab has exhibited a decrease in brain Aβ plaques and moderately less decline on clinical measures of cognitive function.

Emerging roles for ITAM and ITIM receptor signaling in microglial biology and Alzheimer's disease-related amyloidosis

Microglia are critical responders to amyloid beta (Aβ) plaques in Alzheimer's disease (AD). Therefore, the therapeutic targeting of microglia in AD is of high clinical interest. While previous investigation has focused on the innate immune receptors governing microglial functions in response to Aβ plaques, how microglial innate immune responses are regulated is not well understood. Interestingly, many of these microglial innate immune receptors contain unique cytoplasmic motifs, termed immunoreceptor tyrosine-based activating and inhibitory motifs (ITAM/ITIM), that are commonly known to regulate immune activation and inhibition in the periphery. In this review, we summarize the diverse functions employed by microglia in response to Aβ plaques and also discuss the innate immune receptors and intracellular signaling players that guide these functions. Specifically, we focus on the role of ITAM and ITIM signaling cascades in regulating microglia innate immune responses. A better understanding of how microglial innate immune responses are regulated in AD may provide novel therapeutic avenues to tune the microglial innate immune response in AD pathology.

Understanding the impact of slowing disease progression for individuals with biomarker-confirmed early symptomatic Alzheimer's disease

Recent advances in development of amyloid-targeting therapies support the potential to slow the rate of progression of Alzheimer's disease. We conducted a narrative review of published evidence identified through a targeted search of the MEDLINE and EMBASE databases (2020-2023), recent presentations at disease-specific conferences, and data updates from cohort studies in Alzheimer's disease to describe the trajectory of the progression of Alzheimer's disease. Our findings enable the interpretation of clinical trial results and the value associated with slowing disease progression across outcomes of relevance to patients, care partners, clinicians, researchers and policymakers. Even at the earliest stages, Alzheimer's disease imposes a substantial burden on individuals, care partners, and healthcare systems. The magnitude of the burden increases with the rate of disease progression and symptom severity, as worsening cognitive decline and physical impairment result in loss of functional independence. Data from cohort studies also indicate that slowing disease progression is associated with decreased likelihood of needing extensive clinical care over at least 5 years, decreased care partner burden, and substantial individual and societal cost savings. Slowed disease progression is of significant benefit to individuals with Alzheimer's disease, their loved ones, and the healthcare system. As clinicians and policymakers devise strategies to improve access to treatment earlier in the disease spectrum, they should carefully weigh the benefits of slowing progression early in the disease (e.g. preservation of cognitive and functional abilities, as well as relative independence) to individuals, their loved ones, and broader society.

Compound (E)-2-(3,4-dihydroxystyryl)-3-hydroxy-4H-pyran-4-one downregulation of Galectin-3 ameliorates Aβ pathogenesis-induced neuroinflammation in 5 × FAD mice

AIMS

Alzheimer's disease (AD) is characterized by β-amyloid (Aβ) aggregation and neuroinflammation, leading to progressive synaptic loss and cognitive decline. Recent evidence suggests that Galectin-3 (Gal-3) plays a critical role in Aβ pathogenesis. However, strategies to simultaneously target Gal-3 and Aβ are currently insufficient. This study evaluates the therapeutic efficacy of (E)-2-(3,4-dihydroxystyryl)-3-hydroxy-4H-pyran-4-one (D30), in reducing Gal-3 and Aβ pathogenesis.

MATERIALS AND METHODS

We applied exogenous oligomeric Aβ and used 5 × FAD mice to assess the impact of Aβ on Gal-3 deposition, microglial activation, and cognitive function. Thy1-EGFP mice were employed to observe dendritic spines. Comprehensive evaluations of D30's effects included behavioral studies, transcriptomic analysis, Western blotting, and immunofluorescent staining. The interaction between D30 and Gal-3 was examined using fluorescence resonance energy transfer (FRET) and microscale thermophoresis (MST).

KEY FINDINGS

D30 effectively reduced Aβ monomer production by inhibiting Amyloid Precursor Protein (APP) and presenilin 1 (PS1) expression, and decreased Aβ aggregation. Treatment with D30 improved cognitive functions, reversed dendritic spine loss, and increased PSD95 expression in 5 × FAD mice. Additionally, D30 significantly lowered Gal-3 levels in both plasma and hippocampal tissues. D30 binds to Gal-3 and disrupts the interaction between Gal-3 and TREM2, as confirmed by FRET and MST.

SIGNIFICANCE

Our findings underscore the interaction between Gal-3 and Aβ in AD and its role in systemic inflammation using the 5 × FAD mouse model. Being able to target and regulate Gal-3 together with Aβ is crucial for preventing neuroinflammation and protecting synapses, D30 emerged as a novel compound with promising potential for AD treatment.

Projected Annual Lecanemab Treatment Eligibility in an Irish Regional Specialist Memory Clinic

OBJECTIVES

The advent of Disease Modifying Therapies (DMTs) for the treatment of Alzheimer's Disease (AD) has the potential to transform the lives of those with early AD. Timely identification of eligible patients is needed to ensure treatments are delivered during a narrow window of therapeutic opportunity. Appropriate clinical service design will hinge on improved understanding of future demands, thus there is a pressing need to investigate patient eligibility in real world clinical cohorts. The primary aim of this study is to assess the eligibility by appropriate use criteria (AUC) for lecanemab therapy in a real-world, undifferentiated clinical patient cohort attending a Regional Specialist Memory Clinic (RSMC), with the secondary aims of determining the proportion of patients with biomarker positive Alzheimer's Disease (AD) who would be eligible for lecanemab therapy by AUC. Clinical trial eligibility criteria were also applied to both groups and discrepancies that exist between eligibility rates explored.

METHODS

A retrospective cohort study of all new patients attending a RSMC from 1st January 2022 to 31st December 2022 was conducted. Data collected included demographic details, outcomes of diagnostic assessments and comorbidities. MRI images, where indicated, were reviewed. Amyloid positivity was defined as either Amyloid and Tau positive (A+T+) or Amyloid positive with a positive P-Tau/Ab42 ratio on cerebrospinal fluid (CSF) testing. Appropriate use criteria (AUC) and clinical trial criteria for lecanemab were applied. Proportion of eligible patients was calculated.

RESULTS

Eleven (5.9%) of 188 new patient attenders were eligible (average age 66.7 years [SD 8.9], 63.6% female) by AUC, with 26.2% of patients with biomarker positive Alzheimer's Disease eligible for lecanemab therapy. The most common reason for exclusion was a lack of biomarker confirmation of AD pathology followed by cognitive ineligibility (based on defined cognitive testing cut-offs) at the time of referral and/or initial assessment. Only 40.4% of patients had CSF testing for AD biomarkers while almost 20% of the patients with biomarker positive AD were excluded due to lack of a screening MRI in the previous 12 months.

CONCLUSION

In this study, the potential eligibility rate by AUC of the entire patient cohort (5.9%) was limited by the small proportion of patients who had CSF testing for AD biomarkers. So while disease-modification with Lecanemab is a welcome therapeutic advance, although only a small proportion of people currently attending specialist services will be eligible. Successful delivery of DMTs will require significant resource allocation and optimisation of referral pathways to facilitate early identification of potentially eligible patients.

Identifying older adults at risk for dementia based on smartphone data obtained during a wayfinding task in the real world

Alzheimer's disease (AD), as the most common form of dementia and leading cause for disability and death in old age, represents a major burden to healthcare systems worldwide. For the development of disease-modifying interventions and treatments, the detection of cognitive changes at the earliest disease stages is crucial. Recent advancements in mobile consumer technologies provide new opportunities to collect multi-dimensional data in real-life settings to identify and monitor at-risk individuals. Based on evidence showing that deficits in spatial navigation are a common hallmark of dementia, we assessed whether a memory clinic sample of patients with subjective cognitive decline (SCD) who still scored normally on neuropsychological assessments show differences in smartphone-assisted wayfinding behavior compared with cognitively healthy older and younger adults. Guided by a mobile application, participants had to find locations along a short route on the medical campus of the Magdeburg university. We show that performance measures that were extracted from GPS and user input data distinguish between the groups. In particular, the number of orientation stops was predictive of the SCD status in older participants. Our data suggest that subtle cognitive changes in patients with SCD, whose risk to develop dementia in the future is elevated, can be inferred from smartphone data, collected during a brief wayfinding task in the real world.

Advanced nano delivery system for stem cell therapy for Alzheimer's disease

Alzheimer's Disease (AD) represents one of the most significant neurodegenerative challenges of our time, with its increasing prevalence and the lack of curative treatments underscoring an urgent need for innovative therapeutic strategies. Stem cells (SCs) therapy emerges as a promising frontier, offering potential mechanisms for neuroregeneration, neuroprotection, and disease modification in AD. This article provides a comprehensive overview of the current landscape and future directions of stem cell therapy in AD treatment, addressing key aspects such as stem cell migration, differentiation, paracrine effects, and mitochondrial translocation. Despite the promising therapeutic mechanisms of SCs, translating these findings into clinical applications faces substantial hurdles, including production scalability, quality control, ethical concerns, immunogenicity, and regulatory challenges. Furthermore, we delve into emerging trends in stem cell modification and application, highlighting the roles of genetic engineering, biomaterials, and advanced delivery systems. Potential solutions to overcome translational barriers are discussed, emphasizing the importance of interdisciplinary collaboration, regulatory harmonization, and adaptive clinical trial designs. The article concludes with reflections on the future of stem cell therapy in AD, balancing optimism with a pragmatic recognition of the challenges ahead. As we navigate these complexities, the ultimate goal remains to translate stem cell research into safe, effective, and accessible treatments for AD, heralding a new era in the fight against this devastating disease.

Transcranial alternating current stimulation for older adults with cognitive impairment: A bibliometric and knowledge map analysis

As the population ages, cognitive impairment leading to dementia and related disorders presents an increasingly significant societal burden. Transcranial alternating current stimulation emerges as a potential noninvasive treatment, yet remains an area of ongoing research. Using the Science Citation Index Expanded within the Web of Science Core Collection database, we identified 144 relevant articles spanning from 1965 to December 1st, 2023. Analyzing these papers with tools like 6.2.R5Citespace and 1.6.20VOS viewer revealed gamma frequency as the predominant stimulus (32), followed by theta (19), alpha (11), delta (2), beta (3), and others (32). This topic was relatively novel, showing an upward trend, albeit with gaps in some countries. Significant contributions were observed, particularly from authors in the USA, Germany, and Italy. Brain connectivity and oscillation stood out as the primary research subjects, with electroencephalography being the most widely used tool to detect underlying mechanisms. Our findings suggest promising applications of transcranial alternating current stimulation, particularly 40 Hz-gamma, in cognitive impairment among older adults, highlighting the need for further investigation using multimodal cognitive assessment tools and rigorous clinical research.

Amyloid related imaging abnormalities in the emergency setting

Since the 2021 FDA approval of the first monoclonal antibody (MAB) therapy for Alzheimer's disease (AD), treatment has progressed from symptom management to targeting and reducing amyloid β plaque burden. While these therapies offer hope of altering the disease course, they come with risks, such as amyloid-related imaging abnormalities (ARIA), which include ARIA-E (edema and effusion) and ARIA-H (hemorrhage). This report details the case of a 64-year-old woman undergoing donanemab treatment who developed severe ARIA, characterized by extensive vasogenic edema and multiple microhemorrhages. The increasing use of MABs necessitates heightened awareness and expertise among emergency radiologists to identify findings of ARIA effectively, ensuring timely and appropriate care for patients undergoing these novel therapies.

Dietary patterns and cardiorespiratory fitness in midlife and subsequent all-cause dementia: findings from the cooper center longitudinal study

BACKGROUND

Identifying lifestyle factors that independently or jointly lower dementia risk is a public health priority given the limited treatment options available to patients. In this cohort study, we examined the associations between Mediterranean or Dietary Approaches to Stop Hypertension (DASH) diet adherence and cardiorespiratory fitness (CRF) with later-life dementia, and assessed whether the associations between dietary pattern and dementia are modified by CRF.

METHODS

Data are from 9,095 adults seeking preventive care at the Cooper Clinic (1987-1999) who completed a 3-day dietary record and a maximal exercise test. Alzheimer's disease and related disorders or senile dementia (i.e., all-cause dementia) was identified from Medicare administrative claims (1999-2019). Illness-death models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for the associations between Mediterranean or DASH diet adherence (primary exposure), CRF (secondary exposure), and all-cause dementia, adjusted for demographic and clinical factors. An interaction term was included between diet score and CRF to assess effect modification by CRF.

RESULTS

The mean age at baseline was 50.6 (standard deviation [SD]: 8.4) years, and a majority of the study sample were men (77.5%) and White (96.4%). 1449 cases of all-cause dementia were identified over a mean follow-up of 9.2 (SD: 5.8) years. Neither Mediterranean nor DASH diet adherence was associated with dementia risk in fully adjusted models (HR per SD of Mediterranean diet score: 1.00, 95% CI: 0.94, 1.05; HR per SD of DASH diet score: 1.02, 95% CI: 0.96, 1.08). However, participants with higher CRF had a decreased hazard of dementia (HR, per metabolic equivalent of task [MET] increase, Mediterranean model: 0.95, 95% CI: 0.92, 0.98; HR, per MET increase, DASH model: 0.96, 95% CI: 0.92, 0.97). No effect modification by CRF was observed in the association between diet and dementia.

CONCLUSIONS

In this sample of apparently healthy middle-aged adults seeking preventive care, higher CRF at midlife was associated with a lower risk of all-cause dementia, though adherence to a Mediterranean or DASH diet was not, and CRF did not modify the diet-dementia association. CRF should be emphasized in multimodal interventions for dementia prevention and investigated among diverse samples.

A tau dephosphorylation-targeting chimeraselectively recruits protein phosphatase-1 to ameliorate Alzheimer's disease and tauopathies

Abnormal accumulation of hyperphosphorylated tau (pTau) is a major cause of neurodegeneration in Alzheimer's disease (AD) and related tauopathies. Therefore, reducing pTau holds therapeutic promise for these diseases. Here, we developed a chimeric peptide, named D20, for selective facilitation of tau dephosphorylation by recruiting protein phosphatase 1 (PP1) to tau. PP1 is one of the active phosphatases that dephosphorylates tau. In both cultured primary hippocampal neurons and mouse models for AD or related tauopathies, we demonstrated that single-dose D20 treatment significantly reduced pTau by dephosphorylation at multiple AD-related sites and total tau (tTau) levels were also decreased. Multiple-dose administration of D20 through tail vein injection in 3xTg AD mice effectively ameliorated tau-associated pathologies with improved cognitive functions. Importantly, at therapeutic doses, D20 did not cause detectable toxicity in cultured neurons, neural cells, or peripheral organs in mice. These results suggest that D20 is a promising drug candidate for AD and related tauopathies.

Contilisant+Tubastatin A Hybrids: Polyfunctionalized Indole Derivatives as New HDAC Inhibitor-Based Multitarget Small Molecules with In Vitro and In Vivo Activity in Neurodegenerative Diseases

Herein, we describe the design, synthesis, and biological evaluation of 15 Contilisant+Tubastatin A hybrids. These ligands are polyfunctionalized indole derivatives developed by juxtaposing selected pharmacophoric moieties of Contilisant and Tubastatin A to act as multifunctional ligands. Compounds 3 and 4 were identified as potent HDAC6 inhibitors (IC50 = 0.012 μM and 0.035 μM, respectively), so they were further evaluated in Drosophila and human cell models of Parkinson's disease (PD). Both compounds attenuated PD-like phenotypes, such as motor defects, oxidative stress, and mitochondrial dysfunction in PD model flies. Ligands 3 and 4 were also studied in the transgenic Caenorhabditis elegans CL2006 model of Alzheimer's disease (AD). Both compounds were nontoxic, did not induce undesirable animal functional changes, inhibited age-related paralysis, and improved cognition in the thrashing assay. These results highlight 3 and 4 as novel multifunctional ligands that improve the features of PD and AD hallmarks in the respective animal models.

Current status of professional memory clinics, inpatient services, and health professionals in China

INTRODUCTION

This study aims to explore the current status of dementia-specific diagnosis and treatment in China.

METHODS

This national survey was conducted in mainland China from September 2022 to February 2023, with strong support from the Cognitive Disorders Group of the Chinese Society of Neurology, Chinese Medical Association.

RESULTS

Among 2721 hospitals surveyed, 244 (8.97%) have dementia-specific clinics (DSCs) and 166 (6.10%) have dementia-specific inpatient departments (DSIDs). Almost all hospitals have brain structural imaging capabilities and basic hematological examinations, but dementia-specific medical staff (DSMS) equipped for DSCs or DSIDs are rare. The proportion of patients with cognitive impairment receiving care through a DSCs or DSIDs is low, and most patients present with advanced (moderate to severe) disease.

CONCLUSION

The survey shows that the proportion of DSCs and DSIDs is low, and the regional distribution varies significantly. Trained DSMS and specialized facilities for the diagnosis and treatment of dementia are inadequate.

HIGHLIGHTS

This study was a multi-center national research to comprehensively investigate the distribution and features of dementia-specific clinics and inpatient departments in mainland China, given that the limited literature was available regarding the dementia-specific centers. The study points to significant regional differences in the distribution of cognitive-specific clinics and inpatient departments in mainland China. More centers in Eastern Regions compared to Western Regions, a greater presence in provincial capitals as opposed to other cities, and a predominance of tertiary hospitals over non-tertiary ones. The aim is to provide data support for advancements in medical research within this field. Domestic dementia patients have inadequate access to specialized medical resources and expert assistance, which significantly contrasts with the growing number of dementia cases in China.

MEDI1814 selectively reduces free Aβ42 in cerebrospinal fluid of non-clinical species and Alzheimer's disease patients

INTRODUCTION

Small molecules and antibodies are being developed to lower amyloid beta (Aβ) peptides.

METHODS

We describe MEDI1814, a fully human high-affinity monoclonal antibody selective for Aβ42, the pathogenic self-aggregating species of Aβ.

RESULTS

MEDI1814 reduces free Aβ42 without impacting Aβ40 in the cerebrospinal fluid of rats and cynomolgus monkeys after systemic administration. MEDI1814 administration to patients with Alzheimer's disease (AD; n = 57) in single or repeat doses up to 1800 mg intravenously or 200 mg subcutaneously was associated with a favorable safety and tolerability profile. No cases of amyloid-related imaging abnormalities were observed. Predictable dose-proportional changes in serum exposures for MEDI1814 were observed across cohorts. Cerebrospinal fluid (CSF) analysis demonstrated central nervous system penetration of MEDI1814. Pharmacodynamic data showed dose-dependent suppression of free Aβ42, increases in total (bound and free) Aβ42, but no change in total Aβ40 in CSF across doses.

DISCUSSION

MEDI1814 offers a differentiated approach to impacting Aβ in AD via selective reduction of free Aβ42.

Reversibility of cognitive worsening observed with BACE inhibitor umibecestat in the Alzheimer's Prevention Initiative (API) Generation Studies

INTRODUCTION

The Alzheimer's Prevention Initiative (API) Generation Studies evaluated the BACE inhibitor umibecestat for Alzheimer's disease (AD) prevention. The studies were terminated early, and the reversibility of umibecestat's side effects was assessed.

METHODS

Cognitively unimpaired 60- to 75-year-old apolipoprotein E (APOE) ε4 homozygotes and heterozygotes (the latter with elevated brain amyloid deposition) (n = 1556) received umibecestat (50 or 15 mg daily) or placebo for 7 months on average and were followed for a median (interquartile range) of 4 (3 to 6) months after washout.

RESULTS

Compared to placebo, umibecestat-treated participants had small, non-progressive, but statistically significant decline in performance on certain cognitive batteries including Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) and API Preclinical Composite Cognitive test, but not Clinical Dementia Rating-Sum of Boxes. RBANS differences were no longer significant at the end of follow-up.

DISCUSSION

In people at genetic risk for AD, high-dose beta-site amyloid precursor protein cleaving enzyme (BACE) inhibition was associated with early mild cognitive worsening, which reversed shortly after washout, suggesting a symptomatic side effect not associated with neurodegeneration. Fully anonymized data, images, and samples are available upon request for further research on BACE inhibition.

HIGHLIGHTS

This is the first trial with blinded assessment of reversibility of BACE inhibitor side effects. Umibecestat was tested in cognitively unimpaired persons at genetic risk for AD. Umibecestat led to early mild cognitive decline that reversed shortly after washout. This suggests a potentially manageable effect not associated with neurodegeneration. Further research may determine the future of BACE inhibition in AD prevention.

A framework for translating tauopathy therapeutics: Drug discovery to clinical trials

The tauopathies are defined by pathological tau protein aggregates within a spectrum of clinically heterogeneous neurodegenerative diseases. The primary tauopathies meet the definition of rare diseases in the United States. There is no approved treatment for primary tauopathies. In this context, designing the most efficient development programs to translate promising targets and treatments from preclinical studies to early-phase clinical trials is vital. In September 2022, the Rainwater Charitable Foundation convened an international expert workshop focused on the translation of tauopathy therapeutics through early-phase trials. Our report on the workshop recommends a framework for principled drug development and a companion lexicon to facilitate communication focusing on reproducibility and achieving common elements. Topics include the selection of targets, drugs, biomarkers, participants, and study designs. The maturation of pharmacodynamic biomarkers to demonstrate target engagement and surrogate disease biomarkers is a crucial unmet need. HIGHLIGHTS: Experts provided a framework to translate therapeutics (discovery to clinical trials). Experts focused on the "5 Rights" (target, drug, biomarker, participants, trial). Current research on frontotemporal degeneration, progressive supranuclear palsy, and corticobasal syndrome therapeutics includes 32 trials (37% on biologics) Tau therapeutics are being tested in Alzheimer's disease; primary tauopathies have a large unmet need.

Molecular Therapeutics in Development to Treat Alzheimer's Disease

Until recently, only symptomatic therapies, in the form of acetylcholine esterase inhibitors and NMDA-receptor antagonists, have been available for the treatment of Alzheimer's disease. However, advancements in our understanding of the amyloid cascade hypothesis have led to a development of disease-modifying therapeutic strategies. These include immunotherapies based on an infusion of monoclonal antibodies against amyloid-β, three of which have been approved for the treatment of Alzheimer's disease in the USA (one of them, lecanemab, has also been approved in several other countries). They all lead to a dramatic reduction of amyloid plaques in the brain, whereas their clinical effects have been more limited. Moreover, they can all lead to side effects in the form of amyloid-related imaging abnormalities. Ongoing developments aim at facilitating their administration, further improving their effects and reducing the risk for amyloid-related imaging abnormalities. Moreover, a number of anti-tau immunotherapies are in clinical trials, but none has so far shown any robust effects on symptoms or pathology. Another line of development is represented by gene therapy. To date, only antisense oligonucleotides against amyloid precursor protein/amyloid-β and tau have reached the clinical trial stage but a variety of gene editing strategies, such as clustered regularly interspaced short palindromic repeats/Cas9-mediated non-homologous end joining, base editing, and prime editing, have all shown promise on preclinical disease models. In addition, a number of other pharmacological compounds targeting a multitude of biochemical processes, believed to be centrally involved in Alzheimer's disease, are currently being evaluated in clinical trials. This article delves into current and future perspectives on the treatment of Alzheimer's disease, with an emphasis on immunotherapeutic and gene therapeutic strategies.

Serum/glucocorticoid regulated kinase 1 (SGK1) in neurological disorders: pain or gain

Serum/Glucocorticoid Regulated Kinase 1 (SGK1), a serine/threonine kinase, is ubiquitous across a wide range of tissues, orchestrating numerous signaling pathways and associated with various human diseases. SGK1 has been extensively explored in diverse types of immune and inflammatory diseases, cardiovascular disorders, as well as cancer metastasis. These studies link SGK1 to cellular proliferation, survival, metabolism, membrane transport, and drug resistance. Recently, increasing research has focused on SGK1's role in neurological disorders, including a variety of neurodegenerative diseases (e.g., Alzheimer's disease, Huntington's disease and Parkinson's disease), brain injuries (e.g., cerebral ischemia and traumatic brain injury), psychiatric conditions (e.g., depression and drug addiction). SGK1 is emerging as an increasingly compelling therapeutic target across the spectrum of neurological disorders, supported by the availability of several effective agents. However, the conclusions of many studies observing the prevalence and function of SGK1 in neurological disorders are contradictory, necessitating a review of the SGK1 research within neurological disorders. Herein, we review recent literature on SGK1's primary functions within the nervous system and its impacts within different neurological disorders. We summarize significant findings, identify research gaps, and outline possible future research directions based on the current understanding of SGK1 to help further progress the understanding and treatment of neurological disorders.

Interrater agreement and variability in visual reading of [18F] flutemetamol PET images

OBJECTIVE

The purpose of this study was to validate the concordance of visual ratings of [18F] flutemetamol amyloid positron emission tomography (PET) images and to investigate the correlation between the agreement of each rater and the Centiloid (CL) scale.

METHODS

A total of 192 participants, clinically classified as cognitively normal (CN) (n = 59), mild cognitive impairment (MCI) (n = 65), Alzheimer's disease (AD) (n = 55), or non-AD dementia (n = 13), participated in this study. Three experts conducted visual ratings of the amyloid PET images for all 192 patients, assigning a confidence level to each rating on a three-point scale (certain, probable, or neither). The positive or negative determination of amyloid PET results was made by majority vote. The CL value was calculated using the CapAIBL pipeline.

RESULTS

Overall, 101 images were determined to be positive, and 91 images were negative. Of the 101 positive images, the three raters were in complete agreement for 92 images and in disagreement for 9 images. Of the 91 negative images, the three raters were in complete agreement for 75 images and in disagreement for 16 images. Interrater reliability among the three experts was particularly high, with both Fleiss' kappa and Conger's kappa measuring 0.83 (0.76-0.89). The CL values of the unanimous positive group were significantly greater than those of the other groups, whereas the CL values of the unanimous negative group were significantly lower than those of the other groups. Images with rater disagreement had intermediate CLs. In cases with a high confidence level, the positive or negative visual ratings were in almost complete agreement. However, as confidence levels decreased, experts' visual ratings became more variable. The lower the confidence level was, the greater the number of cases with disagreement in the visual ratings.

CONCLUSION

Three experts independently rated 192 amyloid PET images, achieving a high level of interrater agreement. However, in patients with intermediate amyloid accumulation, visual ratings varied. Therefore, determining positive and negative decisions in these patients should be performed with caution.

A machine learning-based prediction of tau load and distribution in Alzheimer's disease using plasma, MRI and clinical variables

Tau positron emission tomography (PET) is a reliable neuroimaging technique for assessing regional load of tau pathology in the brain, commonly used in Alzheimer's disease (AD) research and clinical trials. However, its routine clinical use is limited by cost and accessibility barriers. Here we explore using machine learning (ML) models to predict clinically useful tau-PET composites from low-cost and non-invasive features, e.g., basic clinical variables, plasma biomarkers, and structural magnetic resonance imaging (MRI). Results demonstrated that models including plasma biomarkers yielded the most accurate predictions of tau-PET burden (best model: R-squared=0.66-0.68), with especially high contribution from plasma P-tau217. In contrast, MRI variables stood out as best predictors (best model: R-squared=0.28-0.42) of asymmetric tau load between the two hemispheres (an example of clinically relevant spatial information). The models showed high generalizability to external test cohorts with data collected at multiple sites. Based on these results, we also propose a proof-of-concept two-step classification workflow, demonstrating how the ML models can be translated to a clinical setting. This study uncovers current potential in predicting tau-PET information from scalable cost-effective variables, which could improve diagnosis and prognosis of AD.

Investigating patient eligibility for anti-amyloid monoclonal antibody treatment of Alzheimer's disease: real-world data from an Austrian psychiatric memory clinic population

BACKGROUND

Pharmacological treatment options for patients with dementia owing to Alzheimer's disease are limited to symptomatic therapy. Recently, the US Food and Drug Administration approved the monoclonal antibody lecanemab for the treatment of amyloid-positive patients with mild cognitive impairment (MCI) and early Alzheimer´s dementia. European approval is expected in 2024. Data on the applicability and eligibility for treatment with anti-amyloid monoclonal antibodies outside of a study population are lacking.

AIMS

This study examined eligibility criteria for lecanemab in a real-world memory clinic population between 1 January 2022 and 31 July 2023.

METHOD

We conducted a retrospective, single-centre study applying the clinical trial eligibility criteria for lecanemab to out-patients of a specialised psychiatric memory clinic. Eligibility for anti-amyloid treatment was assessed following the phase 3 inclusion and exclusion criteria and the published recommendations for lecanemab.

RESULTS

The study population consisted of 587 out-patients. Two-thirds were diagnosed with Alzheimer's disease (probable or possible Alzheimer's disease dementia in 43.6% of cases, n = 256) or MCI (23%, n = 135), and 33.4% (n = 196) were diagnosed with dementia or neurocognitive disorder owing to another aetiology. Applying all lecanemab eligibility criteria, 11 (4.3%) patients with dementia and two (1.5%) patients with MCI would have been eligible for treatment with this compound, whereas 13 dementia (5.1%) and 14 (10.4%) MCI patients met clinical inclusion criteria, but had no available amyloid status.

CONCLUSIONS

Even in a memory clinic with a good infrastructure and sufficient facilities for dementia diagnostics, most patients do not meet the eligibility criteria for treatment with lecanemab.

Limitations and potential strategies of immune checkpoint blockade in age-related neurodegenerative disorders

Neurological disorders such as Alzheimer's disease (AD), and Parkinson's disease (PD) have no disease-modifying treatments, resulting in a global dementia crisis that affects more than 50 million people. Amyloid-beta (Aβ), tau, and alpha-synuclein (α-Syn) are three crucial proteins that are involved in the pathogenesis of these age-related neurodegenerative diseases. Only a few approved AD medications have been used in the clinic up to this point, and their results are only partial symptomatic alleviation for AD patients and cannot stop the progression of AD. Immunotherapies have attracted considerable interest as they target certain protein strains and conformations as well as promote clearance. Immunotherapies also have the potential to be neuroprotective: as they limit synaptic damage and spread of neuroinflammation by neutralizing extracellular protein aggregates. Lately, disease-modifying therapies (DMTs) that can alter the pathophysiology that underlies AD with anti-Aβ monoclonal antibodies (MAbs) (e.g., aducanumab, lecanemab, gantenerumab, donanemab, solanezumab, crenezumab, tilavonemab). Similarly, in Parkinson's disease (PD), DMTs utilizing anti-αSyn (MAbs) (e.g., prasinezumab, cinpanemab,) are progressively being developed and evaluated in clinical trials. These therapies are based on the hypothesis that both AD and PD may involve systemic impairments in cell-dependent clearance mechanisms of amyloid-beta (Aβ) and alpha-synuclein (αSyn), respectively, meaning the body's overall inability to effectively remove Aβ and αSyn due to malfunctioning cellular mechanisms. In this review we will provide possible evidence behind the use of immunotherapy with MAbs in AD and PD and highlight the recent clinical development landscape of anti-Aβ (MAbs) and anti-αSyn (MAbs) from these clinical trials in order to better investigate the therapeutic possibilities and adverse effects of these anti-Aβ and anti-αSyn MAbs on AD and PD.

Beyond the usual suspects: multi-factorial computational models in the search for neurodegenerative disease mechanisms

From Alzheimer's disease to amyotrophic lateral sclerosis, the molecular cascades underlying neurodegenerative disorders remain poorly understood. The clinical view of neurodegeneration is confounded by symptomatic heterogeneity and mixed pathology in almost every patient. While the underlying physiological alterations originate, proliferate, and propagate potentially decades before symptomatic onset, the complexity and inaccessibility of the living brain limit direct observation over a patient's lifespan. Consequently, there is a critical need for robust computational methods to support the search for causal mechanisms of neurodegeneration by distinguishing pathogenic processes from consequential alterations, and inter-individual variability from intra-individual progression. Recently, promising advances have been made by data-driven spatiotemporal modeling of the brain, based on in vivo neuroimaging and biospecimen markers. These methods include disease progression models comparing the temporal evolution of various biomarkers, causal models linking interacting biological processes, network propagation models reproducing the spatial spreading of pathology, and biophysical models spanning cellular- to network-scale phenomena. In this review, we discuss various computational approaches for integrating cross-sectional, longitudinal, and multi-modal data, primarily from large observational neuroimaging studies, to understand (i) the temporal ordering of physiological alterations, i(i) their spatial relationships to the brain's molecular and cellular architecture, (iii) mechanistic interactions between biological processes, and (iv) the macroscopic effects of microscopic factors. We consider the extents to which computational models can evaluate mechanistic hypotheses, explore applications such as improving treatment selection, and discuss how model-informed insights can lay the groundwork for a pathobiological redefinition of neurodegenerative disorders.

Osmundacetone ameliorates Alzheimer's-like pathologies by inhibiting β-amyloid fibrillation, oxidative damage and neuroinflammation in APP/PS1 transgenic mice

BACKGROUND

β-Amyloid (Aβ) fibrillation is critical for Aβ deposition and cytotoxicity during the progression of Alzheimer's disease (AD). Consequently, anti-Aβ monoclonal antibody drugs targeting Aβ oligomers and aggregation are considered potential therapeutic strategies for AD treatment. Similar to the working mechanisms of anti-Aβ monoclonal antibody drugs, our study identified osmundacetone (OAC), a small-molecule compound isolated from the traditional Chinese medicine Rhizoma Osmundae, as exerting anti-AD effects by targeting Aβ.

PURPOSE

This study sought to determine whether OAC influences the Aβ burden in APP/PS1 mice and to identify potential regulatory mechanisms.

METHODS

Five-month-old APP/PS1 mice were injected intraperitoneally with OAC at a dose of 1 mg/kg for 12 weeks. The cognitive functions of the mice were assessed via the Morris water maze test and the open field test. Osmundacetone was analyzed via molecular docking, an isothermal dose‒response fingerprint-cellular context thermal shift assay, a thioflavine T fluorescence assay, and an atomic force microscopy assay to analyze the effects of OAC on Aβ fibrillation. Immunofluorescence, immunoblotting, and immunohistochemistry were used to assess Aβ clearance, AD pathology, oxidative stress, and inflammatory responses.

RESULTS

The innovative biochemical and physical data illustrated that the ability of OAC to inhibit Aβ fibrillation was accomplished by binding directly to Aβ, which differed from the majority of previously reported natural polyphenols that modulate the Aβ content and structure in an indirect manner. The inhibition of Aβ fibrosis by OAC subsequently promoted Aβ lysosomal degradation, resulting in a decreased Aβ burden in APP/PS1 mice. Furthermore, OAC treatment inhibited oxidative damage by upregulating glutathione peroxidase expression and attenuated the production of inflammatory factors by downregulating nuclear factor-kB phosphorylation in APP/PS1 mice.

CONCLUSION

These findings demonstrate, for the first time, that OAC could reduce the brain Aβ burden in APP/PS1 mice by inhibiting Aβ fibrillation through direct binding to Aβ and improve cognitive dysfunction by attenuating oxidative damage and neuroinflammation. These findings indicate that OAC may be a promising candidate for the treatment of AD.

Cathepsin B modulates microglial migration and phagocytosis of amyloid β in Alzheimer's disease through PI3K-Akt signaling

The approval of anti-amyloid β (Aβ) monoclonal antibodies (lecanemab) for the treatment of patients with early preclinical stage of Alzheimer's disease (AD) by the Food and Drug Administration, suggests the reliability and importance of brain Aβ clearance for AD therapy. Microglia are the main phagocytes that clear Aβ in the brain, but the underlying regulatory mechanism is unclear. Here, we investigate the critical role of cathepsin B (CatB) in modulating microglial Aβ clearance from mouse brain. Wild-type or CatB-/- mice were injected with Aβ into the hippocampus from 1 to 3 weeks. Mice were evaluated for cognitive change, Aβ metabolism, neuroinflammation. Microglia and neuron cultures were prepared to verify the in vivo results. The statistical analyses were performed by student's t test, one-way ANOVA with a post hoc Tukey's test using the GraphPad Prism software package. CatB deficiency significantly reduces Aβ clearance efficiency and aggravates mouse cognitive decline. Exogenous Aβ markedly increases CatB expression in activated microglia. Transcriptome analysis and in vitro cell culture experiments demonstrate that CatB is associated with gene clusters involved in migration, phagocytosis, and inflammation. In addition, transcriptome analysis and immunoblotting suggest that CatB modulates microglial Aβ clearance via PI3K-AKT activation. Our study unveils a previously unknown role of CatB in promoting microglial functionality during Aβ clearance.

Blood-derived factors to brain communication in brain diseases

Brain diseases, mainly including acute brain injuries, neurodegenerative diseases, and mental disorders, have posed a significant threat to human health worldwide. Due to the limited regenerative capability and the existence of the blood-brain barrier, the brain was previously thought to be separated from the rest of the body. Currently, various cross-talks between the central nervous system (CNS) and peripheral organs have been widely described, including the brain-gut axis, the brain-liver axis, the brain-skeletal muscle axis, and the brain-bone axis. Moreover, several lines of evidence indicate that leveraging systemic biology intervention approaches, including but not limited to lifestyle interventions, exercise, diet, blood administration, and peripheral immune responses, have demonstrated a significant influence on the progress and prognosis of brain diseases. The advancement of innovative proteomic and transcriptomic technologies has enriched our understanding of the nuanced interplay between peripheral organs and brain diseases. An array of novel or previously underappreciated blood-derived factors have been identified to play pivotal roles in mediating these communications. In this review, we provide a comprehensive summary of blood-to-brain communication following brain diseases. Special attention is given to the instrumental role of blood-derived signals, positing them as significant contributors to the complex process of brain diseases. The insights presented here aim to bridge the current knowledge gaps and inspire novel therapeutic strategies for brain diseases.

Understanding Proton Magnetic Resonance Spectroscopy Neurochemical Changes Using Alzheimer's Disease Biofluid, PET, Postmortem Pathology Biomarkers, and APOE Genotype

In vivo proton (1H) magnetic resonance spectroscopy (MRS) is a powerful non-invasive method that can measure Alzheimer's disease (AD)-related neuropathological alterations at the molecular level. AD biomarkers include amyloid-beta (Aβ) plaques and hyperphosphorylated tau neurofibrillary tangles. These biomarkers can be detected via postmortem analysis but also in living individuals through positron emission tomography (PET) or biofluid biomarkers of Aβ and tau. This review offers an overview of biochemical abnormalities detected by 1H MRS within the biologically defined AD spectrum. It includes a summary of earlier studies that explored the association of 1H MRS metabolites with biofluid, PET, and postmortem AD biomarkers and examined how apolipoprotein e4 allele carrier status influences brain biochemistry. Studying these associations is crucial for understanding how AD pathology affects brain homeostasis throughout the AD continuum and may eventually facilitate the development of potential novel therapeutic approaches.

"I'm worth saving"- A Qualitative Study of People with Alzheimer's Disease Considering Lecanemab Treatment

Importance

People with Alzheimer's disease (AD) now have access to disease-modifying treatment with anti-amyloid monoclonal antibodies (mAbs). Their perception of risks and benefits and approach to treatment decisions remain unknown.

Objective

To understand how people with early AD consider benefits and costs of anti-amyloid mAbs and make decisions about treatment.

Design

Qualitative semi-structured interviews.

Setting

Memory care clinics at two academic medical centers.

Participants

People with biomarker or imaging-confirmed early AD referred for evaluation for treatment with anti-amyloid mAbs.

Main Outcomes and Measures

Themes identified through content analysis.

Results

Among 22 participants, mean age was 70 years, 8 (36%) were women, 22 (100%) were White, 8 (36%) had less than a college degree, 11 (50%) had annual income less than $100,000, and 6 (27%) lived in a rural area. The analysis revealed 3 major themes and associated subthemes: 1) People with AD sought and obtained information from different sources-advocacy organizations, the Internet, and clinicians; 2) hopes, expected benefits, and the existential threat of dementia drove willingness and readiness to start lecanemab-hopes included more time feeling like themselves and doing enjoyable activities; expected benefits included stalling progression, reversing cognitive decline or cure; 3) individual traits and preferences, family factors, and degree of trust in expertise influenced how people balanced risks and benefits- some would accept treatment at any cost; others carefully weighed risks and burdens carefully, but were motivated to pursue treatment by supportive families, insurance coverage, and trust in expertise; for a few, costs decidedly outweighed their personal benefits. People with AD desired more individualized information on risks and benefits and wanted to hear more from patients who took the medication.

Conclusions and Relevance

Results from this qualitative analysis inform clinician, health system and policy efforts to promote individualized treatment decisions for anti-amyloid mAb treatment through multimodal education and outreach, evidence-based communication skills, and adaptation of similar care models.

Key Points

Question: How do people with Alzheimer's disease (AD) decide on treatment with newly available anti-amyloid monoclonal antibodies?Findings: In this qualitative analysis, people with AD considering treatment relied on multiple information sources; were motivated by hope to delay cognitive decline and preserve independence; and worried side effects would impair quality of life. Personality traits, family support, and trust in expertise determined how they balanced these tradeoffs. People with AD wanted more personalized information and to hear from others who had taken the medications.Meaning: As access to treatment expands, these findings inform how clinicians can help people with AD make individualized treatment decisions.

A cell-autonomous role for border-associated macrophages in ApoE4 neurovascular dysfunction and susceptibility to white matter injury

Apolipoprotein E4 (ApoE4), the strongest genetic risk factor for sporadic Alzheimer's disease, is also a risk factor for microvascular pathologies leading to cognitive impairment, particularly subcortical white matter injury. These effects have been attributed to alterations in the regulation of the brain blood supply, but the cellular source of ApoE4 and the underlying mechanisms remain unclear. In mice expressing human ApoE3 or ApoE4, we report that border-associated macrophages (BAMs), myeloid cells closely apposed to neocortical microvessels, are both sources and effectors of ApoE4 mediating the neurovascular dysfunction through reactive oxygen species. ApoE4 in BAMs is solely responsible for the increased susceptibility to oligemic white matter damage in ApoE4 mice and is sufficient to enhance damage in ApoE3 mice. The data unveil a new aspect of BAM pathobiology and highlight a previously unrecognized cell-autonomous role of BAM in the neurovascular dysfunction of ApoE4 with potential therapeutic implications.

Profiling aducanumab as a treatment option for Alzheimer's disease: an overview of efficacy, safety and tolerability

INTRODUCTION

Alzheimer's disease is the most common form of dementia worldwide. Aducanumab, a monoclonal antibody targeting amyloid-beta, became the first disease-modifying treatment for mild cognitive impairment due to Alzheimer's disease (AD) and mild AD dementia and suggested that removing amyloid from the brain, especially in early AD, might make a difference in slowing cognitive decline.

AREAS COVERED

In this review, the authors outline aducanumab's clinical efficacy as shown through key clinical trials and discuss its approval by the Food and Drug Administration under the accelerated pathway, which sparked both hope and controversy. We also discuss the importance of amyloid-related imaging abnormalities as a major side effect of aducanumab and all subsequent monoclonal antibodies targeting amyloid-beta.

EXPERT OPINION

Aducanumab, became the first monoclonal antibody that provided at least partial support for the amyloid hypothesis by demonstrating slowed cognitive decline by removing amyloid from the brain, although full FDA approval now seems unlikely due to discontinuation of its development. Its introduction raised awareness of ARIA, highlighted the significant costs and need for informed consent in treatment, and emphasized the importance of long-term, diverse, and combination therapy data for future AD treatments targeting amyloid and tau.

Plasma markers of neurodegeneration, latent cognitive abilities and physical activity in healthy aging

Blood-based biomarkers of neurodegeneration demonstrate great promise for the diagnosis and prognosis of Alzheimer's disease. Ultra-sensitive plasma assays now allow for quantification of the lower concentrations in cognitively unimpaired older adults, making it possible to investigate whether these markers can provide insight also into the early neurodegenerative processes that affect cognitive function and whether the markers are influenced by modifiable risk factors. Adopting an exploratory approach in 93 healthy older adults (65-75 years), we used structural equation modelling to investigate cross-sectional associations between multiple latent cognitive abilities (working memory, episodic memory, spatial and verbal reasoning) and plasma amyloid beta (Aβ42/Aβ40 ratio), phosphorylated-tau 181 (ptau-181), glial fibrillary acidic protein (GFAP), and neurofilament light (NfL), as well as the influence of device-measured habitual physical activity on these associations. The results showed that NfL was negatively associated with working memory, and that NfL interacted with moderate-to-vigorous physical activity in its association with episodic memory. The study has thereby demonstrated the potential of neurodegenerative plasma markers for improving understanding of normative cognitive aging and encourages future research to test the hypothesis that high levels of NfL, indicative of white matter pathology, limit the beneficial effect of physical activity on episodic memory in healthy aging.

Pilot implementation of the revised criteria for staging of Alzheimer's disease by the Alzheimer's Association Workgroup in a tertiary memory clinic

INTRODUCTION

We aimed to evaluate the feasibility of the 2024 Alzheimer's Association Workgroup's integrated clinical-biological staging scheme in outpatient settings within a tertiary memory clinic.

METHODS

The 2018 syndromal cognitive staging system, coupled with a binary biomarker classification, was implemented for 236 outpatients with cognitive concerns. The 2024 numeric clinical staging framework, incorporating biomarker staging, was specifically applied to 154 individuals within the Alzheimer's disease (AD) continuum.

RESULTS

The 2024 staging scheme accurately classified 95.5% AD. Among these, 56.5% exhibited concordant clinical and biological stages (canonical), 34.7% demonstrated more advanced clinical stages than biologically expected (susceptible), and 8.8% displayed the inverse pattern (resilient). The susceptible group was characterized by a higher burden of neurodegeneration and inflammation than anticipated from tau, whereas the resilient group showed the opposite.

DISCUSSION

The 2024 staging scheme is generally feasible. A discrepancy between clinical and biological stages is relatively frequent among symptomatic patients with AD.

HIGHLIGHTS

The 2024 AA staging scheme is generally feasible in a tertiary memory clinic. A discrepancy between clinical and biological stages is relatively frequent in AD. The mismatch may be influenced by a non-specific pathological process involved in AD. Individual profiles like aging and lifestyles may contribute to such a mismatch. Matched and mismatched cases converge toward similar clinical outcomes.

Hearing and vision rehabilitation for people with dementia in five European countries (SENSE-Cog): a randomised controlled trial

BACKGROUND

The effect of hearing and vision difficulties on the risk of developing dementia and worsening outcomes in people already living with dementia is well established. We evaluated the clinical impact of a hearing and vision rehabilitation and support programme on quality of life in people with mild-to-moderate dementia and concurrent sensory difficulties.

METHODS

We conducted a parallel-group, multicentre, observer-blind, superiority randomised controlled trial in seven older adult clinics in five European countries (Cyprus, France, Greece, Ireland, and the UK). People with mild-to-moderate dementia with adult-acquired hearing difficulties, vision difficulties, or both were randomly assigned (1:1) along with their care partner to an 18-week home-basedsensory support intervention (SSI) of tailored hearing and vision rehabilitation and support, or to care as usual. Randomisation was blocked (block size of four, six, or eight) and stratified by country, with allocation assigned via a remote web-based system. The SSI included: full hearing assessment, vision assessment, or both; fitting of hearing aids, glasses, or other sensory aids; and home-based support from a sensory support therapist to assist adherence and uptake of sensory aids, foster social networking, and optimise the home sensory environment. Care as usual involved no additional intervention beyond services normally available to people with dementia at the respective sites. The primary outcome was health-related quality of life (Dementia Quality of Life Instrument [DEMQoL]) score at 36 weeks, reported as an adjusted mean difference. Analyses were done according to the intention-to-treat principle. This trial is registered with the ISRCTN Registry, ISRCTN17056211.

FINDINGS

Between May 4, 2018, and May 6, 2021, 252 people with mild-to-moderate dementia were randomly assigned, of whom 251 (n=126 in the SSI group and n=125 in the care as usual group) were included in the analysis. The mean age of participants was 79·6 years (SD 5·8), and 132 (53%) were women. After a median follow-up time of 37·7 weeks (IQR 36·2-39·0), the mean DEMQoL score was 92·8 (SD 15·2) in the SSI group and 92·8 (14·0) in the care as usual group (adjusted difference 0·18, 95% CI -2·13 to 2·30, p=0·87). Among 114 adverse events reported for 56 (44%) participants in the SSI group, ten events in nine participants were related or possibly related to the intervention (medical device pain or discomfort n=6, ear pain n=1, scratch to the ear n=1, sore eye n=1, redness n=1; all of grade 1). Serious adverse events were reported for 25 (20%) participants in the SSI group and 16 (13%) in the care as usual group. Six (5%) participants in the SSI group and five (4%) in the care as usual group died. None of the serious adverse events or deaths were related to the study intervention or procedures.

INTERPRETATION

This study showed no improvement in quality in life in participants who received the intervention in the longer term. Sensory difficulties are common in people with dementia and interventions aimed at improving sensory-cognitive health should be explored further.

FUNDING

EU Horizon 2020.