Effects of interleukin-6 signal inhibition on Treg subpopulations and association of Tregs with clinical outcomes in rheumatoid arthritis.

OBJECTIVES: Anti-IL-6 receptor antibodies are clinically efficacious in the management of rheumatoid arthritis (RA) with an associated increase in regulatory T cells (Tregs); however, the role of functional Treg subsets has yet to be clarified. This study aimed to evaluate how functional Treg subsets are altered by IL-6 receptor blockade and to analyze the relationship between these Treg subsets and the clinical outcome of RA. METHODS: We collected frozen peripheral blood mononuclear cells (PBMCs) from 40 patients with RA who started tocilizumab (TCZ) with or without MTX and 11 healthy controls (HCs). We fractionated Tregs with flow cytometry based on markers of phenotype and function and measured the proportions of detailed Treg subsets sequentially from baseline to week 52. RESULTS: The proportions of resting Tregs (rTregs) and rTregs+activated Tregs (aTregs) were significantly lower in RA patients at baseline than in HCs. The proportions of all those CD127low Tregs, rTregs, aTregs, and rTregs+aTregs were significantly increased with TCZ treatment. In patients treated with TCZ without MTX, rTreg were increased. Patients with an increase in the proportion of rTregs at week 12 had significantly less arthritis flares during the observation period. CONCLUSIONS: Blocking IL-6 receptor with TCZ increased the proportion of rTregs, a functional Treg subpopulation. Patients with an early increase in rTregs showed a favorable treatment course, and this increase in rTregs may reflect molecular remission induced by IL-6 signal inhibition.

Acidic growth conditions stabilize the ribosomal RNA gene cluster and extend lifespan through noncoding transcription repression.

Blackcurrant (Ribes nigrum L.) is a classical fruit that has long been used to make juice, jam, and liqueur. Blackcurrant extract is known to relieve cells from DNA damage caused by hydrogen peroxide (H2 O2 ), methyl methane sulfonate (MMS), and ultraviolet (UV) radiation. We found that blackcurrant extract (BCE) stabilizes the ribosomal RNA gene cluster (rDNA), one of the most unstable regions in the genome, through repression of noncoding transcription in the intergenic spacer (IGS) which extended the lifespan in budding yeast. Reduced formation of extrachromosomal circles (ERCs) after exposure to fractionated BCE suggested that acidity of the growth medium impacted rDNA stability. Indeed, alteration of the acidity of the growth medium to pH ~4.5 by adding HCl increased rDNA stability and extended the lifespan. We identified RPD3 as the gene responsible for this change, which was mediated by the RPD3L histone deacetylase complex. In mammals, as inflammation sites in a tissue are acidic, DNA maintenance may be similarly regulated to prevent genome instability from causing cancer.

Is Kidney Function Associated with Age-Related Macular Degeneration?: Findings from the Asian Eye Epidemiology Consortium.

PURPOSE: Chronic kidney disease (CKD) may elevate susceptibility to age-related macular degeneration (AMD) because of shared risk factors, pathogenic mechanisms, and genetic polymorphisms. Given the inconclusive findings in prior studies, we investigated this association using extensive datasets in the Asian Eye Epidemiology Consortium. DESIGN: Cross-sectional study. PARTICIPANTS: Fifty-one thousand two hundred fifty-three participants from 10 distinct population-based Asian studies. METHODS: Age-related macular degeneration was defined using the Wisconsin Age-Related Maculopathy Grading System, the International Age-Related Maculopathy Epidemiological Study Group Classification, or the Beckman Clinical Classification. Chronic kidney disease was defined as estimated glomerular filtration rate (eGFR) of less than 60 ml/min per 1.73 m2. A pooled analysis using individual-level participant data was performed to examine the associations between CKD and eGFR with AMD (early and late), adjusting for age, sex, hypertension, diabetes, body mass index, smoking status, total cholesterol, and study groups. MAIN OUTCOME MEASURES: Odds ratio (OR) of early and late AMD. RESULTS: Among 51 253 participants (mean age, 54.1 ± 14.5 years), 5079 had CKD (9.9%). The prevalence of early AMD was 9.0%, and that of late AMD was 0.71%. After adjusting for confounders, individuals with CKD were associated with higher odds of late AMD (OR, 1.46; 95% confidence interval [CI], 1.11-1.93; P = 0.008). Similarly, poorer kidney function (per 10-unit eGFR decrease) was associated with late AMD (OR, 1.12; 95% CI, 1.05-1.19; P = 0.001). Nevertheless, CKD and eGFR were not associated significantly with early AMD (all P ≥ 0.149). CONCLUSIONS: Pooled analysis from 10 distinct Asian population-based studies revealed that CKD and compromised kidney function are associated significantly with late AMD. This finding further underscores the importance of ocular examinations in patients with CKD. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Associations between fatty acid intake and diabetic retinopathy in a Japanese population.

Residents of Chikusei City, aged 40-74 years, underwent systemic and ophthalmological screening, and participants with diabetes were included in this analysis. Dietary intake was assessed using a food frequency questionnaire and calculated as a percentage of the total energy. The presence of diabetic retinopathy (DR) was defined as Early Treatment Diabetic Retinopathy Study levels ≥ 20 in either eye. The association between dietary fatty acid intake and DR has been examined in a cross-sectional study. Among the 647 diabetic participants, 100 had DR. The mean total fat and saturated fatty acid (SFA) intakes were 22.0% and 7.3% of the total energy intake, respectively. After adjusting for potential confounders, the highest quartiles of total fat and SFA intake were positively associated with the presence of DR compared with the lowest quartiles (odds ratios (95% confidence intervals), 2.61 (1.07-6.39), p for trend = 0.025, and 2.40 (1.12-5.17), p for trend = 0.013, respectively). No significant associations were found between DR prevalence and monounsaturated or unsaturated fatty acid intake. These results suggest that a high intake of fat and SFA may affect the development of DR, even in individuals whose total fat intake is generally much lower than that of Westerners.

Spt4 promotes cellular senescence by activating non-coding RNA transcription in ribosomal RNA gene clusters.

Genome instability can drive aging in many organisms. The ribosomal RNA gene (rDNA) cluster is one of the most unstable regions in the genome and the stability of this region impacts replicative lifespan in budding yeast. To understand the underlying mechanism, we search for yeast mutants with stabler rDNA and longer lifespans than wild-type cells. We show that absence of a transcription elongation factor, Spt4, results in increased rDNA stability, reduced levels of non-coding RNA transcripts from the regulatory E-pro promoter in the rDNA, and extended replicative lifespan in a SIR2-dependent manner. Spt4-dependent lifespan restriction is abolished in the absence of non-coding RNA transcription at the E-pro locus. The amount of Spt4 increases and its function becomes more important as cells age. These findings suggest that Spt4 is a promising aging factor that accelerates cellular senescence through rDNA instability driven by non-coding RNA transcription.

Association Between Fatty Acid Intakes and Age-Related Macular Degeneration in a Japanese Population: JPHC-NEXT Eye Study.

Purpose: To determine the associations between fatty acid intakes and the prevalence of age-related macular degeneration (AMD) under a population-based cross-sectional study. Methods: Residents of Chikusei City aged ≥40 years underwent systemic and eye screening. AMD was graded according to a modified version of the Age-Related Eye Disease Study classification. Dietary intake was assessed using a food frequency questionnaire and was adjusted for total energy intake. Results: Altogether, 10,788 eyes of 5394 participants, 2116 men (mean [standard deviation (SD)] age, 62.4 [9.4] years) and 3278 women (60.6 [9.5] years), were included. The mean daily total fat intakes were 52.8 g and 59.0 g in men and women, respectively. After adjustments for potential confounders, saturated fatty acid (SFA) intake was inversely associated with the prevalence of any AMD in men (for each energy-adjusted 1-SD increase: odds ratio [OR], 0.86; 95% confidence interval [CI], 0.74-1.00). Significant trends were found for decreasing odds ratios of AMD with increasing SFA, monounsaturated fatty acid (MUFA), and polyunsaturated fatty acid (PUFA) intake (P for trend = 0.02, 0.04, and 0.04, respectively). In women, only a significant association was observed between the second quartile of linolenic acid intake and the prevalence of any AMD (OR, 0.78; 95% CI, 0.62-0.99). Conclusions: We found an inverse association of SFA intake and a weak inverse association of MUFA and PUFA intakes with the prevalence of any AMD in a Japanese population. Translational Relevance: Adequate fatty acid intake may be necessary to prevent or decelerate AMD.

Distinct gene signatures of monocytes and B cells in patients with giant cell arteritis: a longitudinal transcriptome analysis.

BACKGROUND: Giant cell arteritis (GCA) is a primary large-vessel vasculitis (LVV) of unknown origin. Its management is a challenge due to the late onset of disease symptoms and frequent relapse; therefore, clarifying the pathophysiology of GCA is essential to improving treatment. This study aimed to identify the transition of molecular signatures in immune cells relevant to GCA pathogenesis by analyzing longitudinal transcriptome data in patients. METHODS: We analyzed the whole blood transcriptome of treatment-naive patients with GCA, patients with Takayasu arteritis (TAK), age-matched, old healthy controls (HCs), and young HCs. Characteristic genes for GCA were identified, and the longitudinal transition of those genes was analyzed using cell-type identification by estimating relative subsets of RNA transcripts (CIBERSORT). RESULTS: Repeated measures analysis of variance revealed 739 differentially expressed genes among all patients and HCs. Of the 739 genes, 15 were characteristically upregulated and 36 were downregulated in patients with GCA compared to those with TAK and HCs. Pathway enrichment analysis showed that downregulated genes in GCA were associated with B cell activation. CIBERSORT analysis revealed that upregulation of "M0-macrophages" and downregulation of B cells were characteristic of GCA. Upregulation of "M0-macrophages" reflects the activation of monocytes in GCA toward M0-like phenotypes, which persisted under 6 weeks of treatment. Combined treatment with prednisolone and an interleukin-6 receptor antagonist normalized molecular profiles more efficiently than prednisolone monotherapy. CONCLUSIONS: Gene signatures of monocyte activation and B cell inactivation were characteristic of GCA and associated with treatment response.

Longitudinal monitoring of circulating immune cell phenotypes in anti-neutrophil cytoplasmic antibody-associated vasculitis.

Anti-neutrophil cytoplasmic antibody-associated vasculitis (AAV) is a necrotizing multiorgan autoimmune disease that affects small- to medium-sized blood vessels. Despite the improvements in treatments, half of the patients with AAV still experience disease relapses. In this review, we focus on peripheral leukocyte properties and phenotypes in patients with AAV. In particular, we explore longitudinal changes in circulating immune cell phenotypes during the active phase of the disease and treatment. The numbers and phenotypes of leukocytes in peripheral blood were differs between AAV and healthy controls, AAV in active versus inactive phase, AAV in treatment responders versus non-responders, and AAV with and without severe infection. Therefore, biomarkers detected in peripheral blood immune cells may be useful for longitudinal monitoring of disease activity in AAV.

Regulatory processes that maintain or alter ribosomal DNA stability during the repair of programmed DNA double-strand breaks.

Organisms have evolved elaborate mechanisms that maintain genome stability. Deficiencies in these mechanisms result in changes to the nucleotide sequence as well as copy number and structural variations in the genome. Genome instability has been implicated in numerous human diseases. However, genomic alterations can also be beneficial as they are an essential part of the evolutionary process. Organisms sometimes program genomic changes that drive genetic and phenotypic diversity. Therefore, genome alterations can have both positive and negative impacts on cellular growth and functions, which underscores the need to control the processes that restrict or induce such changes to the genome. The ribosomal RNA gene (rDNA) is highly abundant in eukaryotic genomes, forming a cluster where numerous rDNA copies are tandemly arrayed. Budding yeast can alter the stability of its rDNA cluster by changing the rDNA copy number within the cluster or by producing extrachromosomal rDNA circles. Here, we review the mechanisms that regulate the stability of the budding yeast rDNA cluster during repair of DNA double-strand breaks that are formed in response to programmed DNA replication fork arrest.

Anti-idiotype monoclonal antibodies against emicizumab enable accurate procoagulant and anticoagulant assays, irrespective of the test base, in the presence of emicizumab.

INTRODUCTION: Emicizumab markedly shortens the activated partial thromboplastin time (aPTT), resulting in inaccurate measurements of procoagulant and anticoagulant factor activities. We have recently reported that mixtures of two different anti-idiotype monoclonal antibodies against emicizumab (anti-emicizumab-mAbs) allow measurement of factor (F)VIII activity (FVIII:C) and FVIII inhibitor in emicizumab-containing plasmas. It is unknown whether anti-emicizumab mAbs can work for other aPTT-based procoagulant and anticoagulant assays. AIM: To investigate whether anti-emicizumab mAbs were measured by all of the aPTT-based assays tested. METHODS: Two anti-emicizumab-mAbs (300 µg/mL each) were preincubated with emicizumab (200 µg/mL)-spiked FVIII-deficient plasma; we then measured FVIII:C, FIX:C, FXI:C, FXII:C, protein (P)C:C, PS:C, global PC-FV (aPTT-based), and prothrombin time (PT), diluted Russel's viper venom time (dRVVT), chromogenic-based FVIII:C, FIX:C and PC:C (non-aPTT-based). Emicizumab (100 µg/mL)-spiked haemophilia (H)A plasmas from patients (n = 23) were also measured. RESULTS: Emicizumab shortened the clotting time in all aPTT-based assays, resulting in high levels of FVIII:C, FIX:C, FXI:C and FXII:C; low levels of PC:C and PS:C; and false-positive results for activated PC resistance. The addition of anti-emicizumab-mAbs to emicizumab-added plasma restored all factors to the initial levels without emicizumab. Chromogenic FVIII:C measurement by human FIXa/FX was affected by emicizumab, but anti-emicizumab mAbs cancelled this effect. PT-based assays and dRVVT, chromogenic FIX:C and PC:C assays showed no effect with emicizumab. Twenty-three plasma samples from HA patients also showed similar patterns. CONCLUSION: Anti-emicizumab mAbs in vitro could cancel the effect of emicizumab, irrespective of the test base, resulting in accurate measurements of procoagulant and anticoagulant factor activity.

Early Stages of Age-Related Macular Degeneration: Racial/Ethnic Differences and Proposal of a New Classification Incorporating Emerging Concept of Choroidal Pathology.

The progression of age-related macular degeneration (AMD) is determined by environmental and genetic factors, and phenotypic or molecular risk factors have been investigated extensively. Interestingly, risk factor profiles for advanced AMD differ among individuals, and one of the causes of variation may be explained by their ethnic background. Recent advances in retinal imaging technology have led to the identification of previously unrecognized risk factors for advanced AMD on optical coherence tomography (OCT) and OCT angiography, which expands the concept of traditional imaging risk factors such as drusen and pigmentary abnormalities visible on color fundus photographs. This OCT imaging modality has identified novel pathognomonic changes for early AMD, including the associated photoreceptor, retinal pigment epithelium, and underlying choroidal changes. Regarding features of multimodal imaging associated with the presence or progression of geographic atrophy, there is an international expert consensus classification system; however, features associated with the progression of macular neovascularization (MNV) are still obscure. To make a consensus towards understanding features associated with the risk of MNV, this review focuses on the early stages of AMD by summarizing imaging characteristics and early signs and classifications in view of advanced multimodal imaging technology. Recent evidence suggests that neovascular AMD is not a single disease entity but a heterogeneous disease characterized by MNV. Besides drusen, OCT features associated with pigment abnormalities, such as shallow irregular RPE elevation (SIRE, also known as double-layer sign), pachychoroid pigment epitheliopathy, and choriocapillaris ischemia, seem to confer a high risk of MNV developing, especially for Asian populations.

Relationship between blood pressure and intraocular pressure in the JPHC-NEXT eye study.

Although a positive link between hypertension and intraocular pressure (IOP) has been suggested, the individual effects of systolic and diastolic blood pressure (SBP and DBP, respectively) on IOP remain unclear, particularly among Japanese populations. Here, we conducted a large-scale, cross-sectional study to determine individual and combined effects of SBP/DBP and hypertension on IOP. In total, 6783 Japanese people aged over 40 years underwent systemic and ophthalmological examinations, including measurements of blood pressure and IOP, conducted using non-contact tonometers. After adjusting for a priori known confounding factors, SBP and DBP levels were found to be positively correlated with IOP levels. The multivariable-adjusted odds ratio when comparing the hypertensive and normotensive groups for the prevalence of ocular hypertension was 1.88 (95% confidence interval, 1.14-3.08). When analysing the combined effects of SBP and DBP on ocular hypertension, SBP elevation had a greater effect on ocular hypertension than DBP increase. In conclusion, SBP and DBP levels and the prevalence of systemic hypertension were found to be positively associated with IOP levels and the prevalence of ocular hypertension in an ophthalmologically healthy Japanese population. Our findings suggest that systemic blood pressure control may be key for controlling IOP.

Treatment of diabetic macular edema in real-world clinical practice: The effect of aging.

AIMS/INTRODUCTION: In older patients, the management of diabetic macular edema (DME) can be complicated by comorbidities, geriatric syndrome, and socioeconomic status. This study aims to evaluate the effects of aging on the management of DME. MATERIALS AND METHODS: This is a real-world clinical study including 1,552 patients with treatment-naïve center-involved DME. The patients were categorized into 4 categories by age at baseline (C1, <55; C2, 55-64; C3, 65-74; and C4, ≥75 years). The outcomes were the change in logarithm of the minimum angle of resolution best-corrected visual acuity (logMAR BCVA) and central retinal thickness (CRT), and the number of treatments from baseline to 2 years. RESULTS: From baseline to 2 years, the mean changes in logMAR BCVA from baseline to 2 years were -0.01 in C1, -0.06 in C2, -0.07 in C3, and 0.01 in C4 (P = 0.016), and the mean changes in CRT were -136.2 µm in C1, -108.8 µm in C2, -100.6 µm in C3, and -89.5 µm in C4 (P = 0.008). Treatments applied in the 2 year period exhibited decreasing trends with increasing age category on the number of intravitreal injections of anti-VEGF agents (P = 0.06), selecting local corticosteroid injection (P = 0.031), vitrectomy (P < 0.001), and laser photocoagulation outside the great vascular arcade (P < 0.001). CONCLUSIONS: Compared with younger patients with DME, patients with DME aged ≥75 years showed less frequent treatment, a lower BCVA gain, and a smaller CRT decrease. The management and visual outcome in older patients with DME would be unsatisfactory in real-world clinical practice.

Heterogeneous coagulant potential of emicizumab in neonatal factor VIII-deficient plasma.

BACKGROUND: Emicizumab prophylaxis reduces bleeding in hemophilia A (HA) patients. However, there are few data on emicizumab treatment in neonates with HA (neonate-HA), and the procoagulant effects of emicizumab in these patients are unknown. AIM: To investigate the coagulation activity of emicizumab in vitro in a plasma model of neonate-HA. METHODS: Plasmas from 84 neonates with non-HA were enrolled. However, due to the limited plasma volumes in some cases, 50 plasmas were assigned to two different assay groups. To prepare the neonate-HA model, plasma was first preincubated with an antifactor (F) VIII A2 monoclonal antibody (mAb). After further incubation with emicizumab, global coagulation activity was measured: adjusted maximum coagulation velocity (Ad|min1|) in clot waveform analysis (CWA) and peak thrombin in thrombin generation assay (TGA). RESULTS: Because the addition of anti-FVIII mAb to 22 of 43 samples showed little decrease in Ad|min1|, the remaining 21 samples were analyzed by CWA. The addition of emicizumab increased Ad|min1| in 18 of the 19 cases (effective group) but not in the remaining 3 cases (noneffective group). Similarly, TGA found that emicizumab (effective group) improved peak thrombin in seven of the nine samples tested, but two cases did not respond (noneffective group). Although the effective group had lower levels of FX, there was no significant difference between the effective and noneffective groups in terms of FIX, protein S, protein C, antithrombin, and fibrinogen. CONCLUSIONS: The in vitro coagulant potentials of emicizumab in the neonate-HA model were more heterogeneous than those recorded in the adult-HA model.

Dietary Patterns and Their Associations with Intermediate Age-Related Macular Degeneration in a Japanese Population.

This population-based cross-sectional study investigated the influence of dietary patterns on age-related macular degeneration (AMD) in a Japanese population. The Tsuruoka Metabolomics Cohort Study enrolled a general population aged 35-74 years from among participants in annual health check-up programs in Tsuruoka City, Japan. Eating habits were assessed using a food frequency questionnaire. Principal component analysis was used to identify dietary patterns among food items. The association between quartiles of scores for each dietary pattern and intermediate AMD was assessed using multivariate logistic regression models. Of 3433 participants, 415 had intermediate AMD. We identified four principal components comprising the Vegetable-rich pattern, Varied staple food pattern, Animal-rich pattern, and Seafood-rich pattern. After adjusting for potential confounders, higher Varied staple food diet scores were associated with a lower prevalence of intermediate AMD (fourth vs. first quartile) (OR, 0.63; 95% confidence interval [CI], 0.46-0.86). A significant trend of decreasing ORs for intermediate AMD associated with increasing Varied staple food diet scores was noted (p for trend = 0.002). There was no significant association between the other dietary patterns and intermediate AMD. In a Japanese population, individuals with a dietary pattern score high in the Varied staple food pattern had a lower prevalence of intermediate AMD.

Retinal Nerve Fiber Layer Thickness and Rim Area Profiles in Asians: Pooled Analysis from the Asian Eye Epidemiology Consortium.

PURPOSE: To evaluate ethnic variations, ocular and systemic determinants of retinal nerve fiber layer (RNFL) thickness, and neuroretinal rim area among Asians using a large consortium of population-based eye studies. DESIGN: Cross-sectional pooled analysis. PARTICIPANTS: Twenty-two thousand four hundred thirty-six participants (22 436 eyes) from 10 population-based studies (in China, Hong Kong, India, Japan, Russia, and Singapore) of the Asian Eye Epidemiology Consortium. METHODS: Participants 40 years of age or older without glaucoma were included. All participants underwent spectral-domain OCT imaging and systemic and ocular examinations. Data were pooled from each study. Multivariable regression was performed to evaluate interethnic differences, intermachine variations, and ocular and systemic factors associated with RNFL thickness and rim area, adjusting for age, gender, diabetes, intraocular pressure (IOP), spherical equivalent (SE), ethnicity, OCT model, and study group. When evaluating body mass index, smoking, and hypertension as exposures, these factors were additionally adjusted for in the model. MAIN OUTCOME MEASURES: Average RNFL thickness (in micrometers) and rim area (in square millimeters). RESULTS: Indian and Japanese eyes have thinner RNFLs than those of other Asian ethnicities (ß values range, 7.31-12.76 µm; P < 0.001 for all pairwise comparisons). Compared with measurements by Cirrus HD-OCT (Carl Zeiss Meditec, Inc), RNFL on average was 7.29 µm thicker when measured by Spectralis (Heidelberg Engineering), 12.85 µm thicker when measured by RS-3000 (NIDEK Co, Ltd), and 17.48 µm thicker when measured by iVue/RTVue (Optovue, Inc) devices (all P < 0.001). Additionally, older age (per decade, ß = -2.70), diabetes (ß = -0.72), higher IOP (per 1 mmHg, ß = -0.07), more myopic SE (per diopter, ß = -1.13), cardiovascular disease (ß = -0.94), and hypertension (ß = -0.68) were associated with thinner RNFL (all P ≤ 0.003). Similarly, older age (ß = -0.019), higher IOP (ß = -0.010), and more myopic SE (ß = -0.025) were associated with smaller rim area (all P < 0.001). CONCLUSIONS: In this large pooled analysis of Asian population studies, Indian and Japanese eyes were observed to have thinner RNFL profiles. These findings suggest the need for an ethnic-specific normative database to improve glaucoma detection.

[Retinal Imaging as Potential Biomarkers for Dementia].

Alzheimer's disease (AD) is a leading cause of dementia, and the current diagnostic methods of AD, such as positron emission tomography imaging, have a high cost and poor accessibility. Amyloidß accumulates in the brain long before the symptomatic onset of AD, and can also be found in the inner retina. Anatomically and developmentally, the retina is an extension of the brain, and is the only part of the central nervous system that can be imaged non-invasively. Therefore, retinal imaging has potential as a potential biomarker for dementia. Previous studies have demonstrated that inner retinal thinning (measured using optical coherence tomography [OCT]) is associated with an increased risk of dementia, including AD. In addition, retinal vascular changes assessed using fundus photographs and OCT angiography were associated with dementia. We propose that artificial intelligence algorithms could be applied to process these retinal images and contribute to the automated interpretation of retinal images and screening for dementia. In addition, amyloidß in the retina has been identified using hyperspectral imaging, a non-invasive retinal imaging, as a surrogate marker of brain amyloidß. Retinal imaging may provide a novel biomarker and contribute to screening individuals at risk of dementia, monitoring disease progression, and assessing therapeutic efficacy.