The role of visual rating and automated brain volumetry in early detection and differential diagnosis of Alzheimer's disease

BACKGROUND

Medial temporal lobe atrophy (MTA) is a diagnostic marker for mild cognitive impairment (MCI) and Alzheimer's disease (AD), but the accuracy of quantitative MTA (QMTA) in diagnosing early AD is unclear. This study aimed to investigate the accuracy of QMTA and its related components (inferior lateral ventricle [ILV] and hippocampus) with MTA in the early diagnosis of MCI and AD.

METHODS

This study included four groups: normal (NC), MCI stable (MCIs), MCI converted to AD (MCIs), and mild AD (M-AD) groups. Magnetic resonance image analysis software was used to quantify the hippocampus, ILV, and QMTA. MTA was rated by two experienced neurologists. Receiver operating characteristic area under the curve (AUC) analysis was performed to compare their capability in differentiating AD from NC and MCI, and optimal thresholds were determined using the Youden index.

RESULTS

QMTA distinguished M-AD from NC and MCI with higher diagnostic accuracy than MTA, hippocampus, and ILV (AUCNC = 0.976, AUCMCI = 0.836, AUCMCIs = 0.894, AUCMCIc = 0.730). The diagnostic accuracy of QMTA was superior to that of MTA, the hippocampus, and ILV in differentiating MCI from AD. The diagnostic accuracy of QMTA was found to remain the best across age, sex, and pathological subgroups analyzed. The sensitivity (92.45%) and specificity (90.64%) were higher in this study when a cutoff value of 0.635 was chosen for QMTA.

CONCLUSIONS

QMTA may be a better choice than the MTA scale or the associated quantitative components alone in identifying AD patients and MCI individuals with higher progression risk.

Cognitively defined Alzheimer's dementia subgroups have distinct atrophy patterns

INTRODUCTION

We sought to determine structural magnetic resonance imaging (MRI) characteristics across subgroups defined based on relative cognitive domain impairments using data from the Alzheimer's Disease Neuroimaging Initiative (ADNI) and to compare cognitively defined to imaging-defined subgroups.

METHODS

We used data from 584 people with Alzheimer's disease (AD) (461 amyloid positive, 123 unknown amyloid status) and 118 amyloid-negative controls. We used voxel-based morphometry to compare gray matter volume (GMV) for each group compared to controls and to AD-Memory.

RESULTS

There was pronounced bilateral lower medial temporal lobe atrophy with relative cortical sparing for AD-Memory, lower left hemisphere GMV for AD-Language, anterior lower GMV for AD-Executive, and posterior lower GMV for AD-Visuospatial. Formal asymmetry comparisons showed substantially more asymmetry in the AD-Language group than any other group (p = 1.15 × 10-10 ). For overlap between imaging-defined and cognitively defined subgroups, AD-Memory matched up with an imaging-defined limbic predominant group.

DISCUSSION

MRI findings differ across cognitively defined AD subgroups.

Utility of left ventricular ejection fraction in atrial fibrillation patients without pre-existing heart failure

AIMS

Atrial fibrillation (AF) increases the risk of heart failure (HF); however, little focus has been placed on the prevention of HF in patients with AF. Left ventricular ejection fraction (LVEF) is an established echocardiographic parameter in HF patients. We sought to investigate the association of LVEF with HF events in AF patients without pre-existing HF.

METHODS AND RESULTS

The Fushimi AF Registry is a community-based prospective survey of AF patients in Fushimi-ku, Japan. In this analysis, we excluded patients with pre-existing HF (defined as having one of the following: prior HF hospitalization, New York Heart Association class ≥ 2 in association with heart disease, or LVEF < 40%). Among 3233 AF patients without pre-existing HF, we investigated 2459 patients with the data of LVEF at enrolment. We divided the patients into three groups stratified by LVEF [mildly reduced LVEF (40-49%), below normal LVEF (50-59%), and normal LVEF (≥60%)] and compared the backgrounds and incidence of HF hospitalization between the groups. Of 2459 patients [mean age: 72.4 ± 10.5 years, female: 917 (37%), paroxysmal AF: 1405 (57%), and mean CHA2 DS2 -VASc score: 3.0 ± 1.6], the mean LVEF was 66 ± 8% [mildly reduced LVEF: 114 patients (5%), below normal LVEF: 300 patients (12%), and normal LVEF: 2045 patients (83%)]. Patients with lower LVEF demonstrated lower prevalence of female and paroxysmal AF (both P < 0.01), but age and CHA2 DS2 -VASc score were comparable between the three groups (both P > 0.05). During the median follow-up period of 6.0 years, 255 patients (10%) were hospitalized for HF (annual incidence: 1.9% per person-year). Multivariable Cox regression analysis demonstrated that lower LVEF strata were independently associated with the risk of HF [mildly reduced LVEF (40-49%): hazard ratio = 2.98, 95% confidence interval = 1.99-4.45 and below normal LVEF (50-59%): hazard ratio = 2.01, 95% confidence interval = 1.44-2.82, compared with normal LVEF (≥60%)] after adjustment by age, sex, type of AF, and CHA2 DS2 -VASc score. LVEF < 60% was significantly associated with the higher risk of HF hospitalization across all major subgroups without significant interaction (P for interaction; all P > 0.05). LVEF had an independent and incremental prognostic value for HF hospitalization in addition to natriuretic peptide levels in AF patients without pre-existing HF.

CONCLUSIONS

Lower LVEF was significantly associated with the higher incidence of HF hospitalization in AF patients without pre-existing HF, leading to the future risk stratification for and prevention of incident HF in AF patients.

Enhanced chondrogenic differentiation of iPS cell-derived mesenchymal stem/stromal cells via neural crest cell induction for hyaline cartilage repair

Background: To date, there is no effective long-lasting treatment for cartilage tissue repair. Primary chondrocytes and mesenchymal stem/stromal cells are the most commonly used cell sources in regenerative medicine. However, both cell types have limitations, such as dedifferentiation, donor morbidity, and limited expansion. Here, we report a stepwise differentiation method to generate matrix-rich cartilage spheroids from induced pluripotent stem cell-derived mesenchymal stem/stromal cells (iMSCs) via the induction of neural crest cells under xeno-free conditions. Methods: The genes and signaling pathways regulating the chondrogenic susceptibility of iMSCs generated under different conditions were studied. Enhanced chondrogenic differentiation was achieved using a combination of growth factors and small-molecule inducers. Results: We demonstrated that the use of a thienoindazole derivative, TD-198946, synergistically improves chondrogenesis in iMSCs. The proposed strategy produced controlled-size spheroids and increased cartilage extracellular matrix production with no signs of dedifferentiation, fibrotic cartilage formation, or hypertrophy in vivo. Conclusion: These findings provide a novel cell source for stem cell-based cartilage repair. Furthermore, since chondrogenic spheroids have the potential to fuse within a few days, they can be used as building blocks for biofabrication of larger cartilage tissues using technologies such as the Kenzan Bioprinting method.

Fast three-dimensional image generation for healthy brain aging using diffeomorphic registration

Predicting brain aging can help in the early detection and prognosis of neurodegenerative diseases. Longitudinal cohorts of healthy subjects scanned through magnetic resonance imaging (MRI) have been essential to understand the structural brain changes due to aging. However, these cohorts suffer from missing data due to logistic issues in the recruitment of subjects. This paper proposes a methodology for filling up missing data in longitudinal cohorts with anatomically plausible images that capture the subject-specific aging process. The proposed methodology is developed within the framework of diffeomorphic registration. First, two novel modules are introduced within Synthmorph, a fast, state-of-the-art deep learning-based diffeomorphic registration method, to simulate the aging process between the first and last available MRI scan for each subject in three-dimensional (3D). The use of image registration also makes the generated images plausible by construction. Second, we used six image similarity measurements to rearrange the generated images to the specific age range. Finally, we estimated the age of every generated image by using the assumption of linear brain decay in healthy subjects. The methodology was evaluated on 2662 T1-weighted MRI scans from 796 healthy participants from 3 different longitudinal cohorts: Alzheimer's Disease Neuroimaging Initiative, Open Access Series of Imaging Studies-3, and Group of Neuropsychological Studies of the Canary Islands (GENIC). In total, we generated 7548 images to simulate the access of a scan per subject every 6 months in these cohorts. We evaluated the quality of the synthetic images using six quantitative measurements and a qualitative assessment by an experienced neuroradiologist with state-of-the-art results. The assumption of linear brain decay was accurate in these cohorts (R2  ∈ [.924, .940]). The experimental results show that the proposed methodology can produce anatomically plausible aging predictions that can be used to enhance longitudinal datasets. Compared to deep learning-based generative methods, diffeomorphic registration is more likely to preserve the anatomy of the different structures of the brain, which makes it more appropriate for its use in clinical applications. The proposed methodology is able to efficiently simulate anatomically plausible 3D MRI scans of brain aging of healthy subjects from two images scanned at two different time points.

Polyethylene glycol 20 kDa-induced vacuolation does not impair phagocytic function of human monocyte-derived macrophages

Conjugation to polyethylene glycol (PEG) is commonly used to enhance drug delivery and efficacy by extending the half-life of the drug molecule. This has important implications for reducing treatment burden in diseases that require chronic prophylaxis, such as hemophilia. Clearance of PEG molecules with high molecular weights (≥ 40 kDa) has been reported to cause cellular vacuolation in mammals. Rurioctocog alfa pegol (PEGylated recombinant coagulation factor VIII) contains a 20-kDa PEG. This study investigated the effects of exposure to 20-kDa PEG (10 μg/ml to 10 mg/ml) on the morphology and function of human monocyte-derived macrophages (MDMs) in vitro. Exposure to PEG for 24 hours was associated with significant vacuolation only at concentrations of 1 mg/ml or more, which far exceed the levels associated with clinically relevant doses of rurioctocog alfa pegol. Immunofluorescence staining of PEG was detected in the cytoplasm of MDMs, indicating uptake into the cells. No impairment of MDM phagocytic activity (ability to ingest fluorescently labeled Escherichia coli) was observed with 24-hour exposure to PEG, even at concentrations associated with significant vacuolation. Furthermore, PEG exposure did not have significant effects on cytokine secretion in resting or lipopolysaccharide-stimulated MDMs, or on the expression of cell surface markers in stimulated MDMs. Cell viability was not affected by 24-hour exposure to PEG. In conclusion, vacuolation of human MDMs after exposure to 20-kDa PEG only occurred with PEG concentrations far in excess of those equivalent to clinically relevant doses of rurioctocog alfa pegol and did not affect MDM viability or functionality. Together, these results support the concept that PEG-mediated vacuolation is an adaptive cellular response rather than a toxic effect.

Short-term safety of an anti-severe acute respiratory syndrome coronavirus 2 messenger RNA vaccine for patients with advanced lung cancer treated with anticancer drugs: A multicenter, prospective, observational study

BACKGROUND

Since 2020, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has become prevalent worldwide. In severe cases, the case fatality rate is high, and vaccine prevention is important. This study evaluated the safety of receiving SARS-CoV-2 vaccine in patients with advanced lung cancer receiving anticancer therapy.

METHODS

We prospectively enrolled patients receiving anticancer drugs for advanced lung cancer who planned to receive SARS-CoV-2 vaccination. Early adverse events within 7 days of vaccine injection were evaluated using patient-reported surveys. The chi-square test and multivariate logistic regression analyses were used.

RESULTS

Among 120 patients receiving lung cancer treatment, 73 were men; the mean age of the patients was 73.5 years. The treatments received for lung cancer at the time of the first vaccine injection were chemotherapy, ICIs, combined chemotherapy and ICIs, and targeted therapies, including tyrosine kinase inhibitors, in 30, 28, 17, and 45 patients, respectively. All patients received SARS-CoV-2 messenger RNA (mRNA) vaccine. After the second mRNA vaccine dose, 15.4% of patients had fever of 38°C (95% confidence interval: 9.34%-23.2%); this rate was slightly higher than that for healthy participants at the time of the BNT162b2 trial. Patients treated with cytotoxic anticancer drugs tended to have high fever. In the multivariate analyses, male sex was associated with higher fever frequencies. However, there were no serious early adverse events due to vaccination.

CONCLUSIONS

Anti-SARS-CoV-2 mRNA vaccination tends to be safe, but fever following vaccination tends to be more common among patients undergoing lung cancer treatment than among healthy individuals.

Reduced TREM2 activation in microglia of patients with Alzheimer's disease

Loss-of-function variants of triggering receptor expressed on myeloid cells 2 (TREM2) increase the risk of developing Alzheimer's disease (AD). The mechanism through which TREM2 contributes to the disease (TREM2 activation vs inactivation) is largely unknown. Here, we analyzed changes in a gene set downstream of TREM2 to determine whether TREM2 signaling is modified by AD progression. We generated an anti-human TREM2 agonistic antibody and defined TREM2 activation in terms of the downstream expression changes induced by this antibody in microglia developed from human induced pluripotent stem cells (iPSC). Differentially expressed genes (DEGs) following TREM2 activation were compared with the gene set extracted from microglial single nuclear RNA sequencing data of patients with AD, using gene set enrichment analysis. We isolated an anti-TREM2-specific agonistic antibody, Hyb87, from anti-human TREM2 antibodies generated using binding and agonism assays, which helped us identify 300 upregulated and 251 downregulated DEGs. Pathway enrichment analysis suggested that TREM2 activation may be associated with Th2-related pathways. TREM2 activation was lower in AD microglia than in microglia from healthy subjects or patients with mild cognitive impairment. TREM2 activation also showed a significant negative correlation with disease progression. Pathway enrichment analysis of DEGs controlled by TREM2 activity indicated that TREM2 activation in AD may lead to anti-apoptotic signaling, immune response, and cytoskeletal changes in the microglia. We showed that TREM2 activation decreases with AD progression, in support of a protective role of TREM2 activation in AD. In addition, the agonistic anti-TREM2 antibody can be used to identify TREM2 activation state in AD microglia.

Frailty in patients with acute decompensated heart failure in a super-aged regional Japanese cohort

AIMS

The aim of this study was to investigate clinical characteristics of frail patients based on a comprehensive frailty assessment in patients hospitalized for acute decompensated heart failure (HF) (ADHF) in super-aged regional Japanese cohort.

METHODS AND RESULTS

We established the Kochi Registry of Subjects with Acute Decompensated Heart Failure (Kochi YOSACOI) study, which was a prospective multicentre community-based cohort study in six participating hospitals in Kochi Prefecture, Japan. We enrolled 1061 patients (median age, 81 years; 50.0% men) hospitalized for ADHF between June 2017 and December 2019 in this registry. Patients were classified into the three groups by the severity of frailty using the Kihon Checklist: we identified frailty in 510 patients (53.7%), prefrailty in 293 patients (30.9%), and non-frailty in 146 patients (15.4%). Compared with prefrail and non-frail patients, frail patients were older (84 years interquartile range [IQR, 77-88] vs. 79 years [IQR, 69-86] and 72 years [IQR 65-81], P < 0.001) and more often had prior HF hospitalization (29.6% vs. 21.8% and 16.4%, P < 0.05), chronic kidney disease (81.6% vs. 71.7% and 61.0%, P < 0.01), anaemia (75.3% vs. 61.4% and 50.0%, P < 0.001), cerebrovascular accident (19.0% vs. 9.9% and 4.1%, P < 0.01). The proportion of patients with three or more comorbidities was larger in the frailty group than in the other groups (78.0% vs. 67.2% and 63.0%, P < 0.01). The frequency of functional decline in all domains increased with frailty status. Approximately 70% of frail patients were identified as functional decline in physical function and socialization domains. Fifty to sixty per cent of frail patients had functional decline in instrumental activities of daily living, cognitive function, and depression domains. The percentage of worsening walking ability during hospitalization was increasing with the frailty status (frailty, 27.5%; prefrailty, 21.8%; non-frailty, 8.9%). In multivariate logistic regression analysis, frailty was associated with age [odds ratio (OR) 1.031, 95% confidence interval (CI) 1.011-1.052, P = 0.003], prior HF hospitalization (OR 1.789, 95% CI 1.165-2.764, P = 0.008), brain natriuretic peptide level at discharge (OR 1.001, 95% CI 1.000-1.001, P = 0.020) and prior cerebrovascular accident (OR 2.549, 95% CI 1.484-4.501, P < 0.001).

CONCLUSIONS

More than half of patients with ADHF were frail and had functional decline across multiple domains, not only physical function domain. The Kihon Checklist provided useful and valuable information for easily identifying frail patients and comprehensive management of HF.

Intronic Haplotypes in the GBA Gene Do Not Predict Age at Diagnosis of Parkinson's Disease

BACKGROUND

GBA mutations are a common risk factor for Parkinson's disease (PD). A recent study has suggested that GBA haplotypes, identified by intronic variants, can affect age at diagnosis of PD.

OBJECTIVES

In this study, we assess this hypothesis using long reads across a large cohort and the publicly available Accelerating Medicines Partnership-Parkinson's Disease (AMP-PD) cohort.

METHODS

We recruited a PD cohort through the Remote Assessment of Parkinsonism Supporting Ongoing Development of Interventions in Gaucher Disease study (RAPSODI) and sequenced GBA using Oxford Nanopore technology. Genetic and clinical data on the full AMP-PD cohort were obtained from the online portal of the consortium.

RESULTS

A total of 1417 participants were analyzed. There was no significant difference in age at PD diagnosis between the two main haplotypes of the GBA gene.

CONCLUSIONS

GBA haplotypes do not affect age at diagnosis of PD in the two independent cohorts studied. © 2021 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.