Combining plasma Aß and p-tau217 improves detection of brain amyloid in non-demented elderly.

BACKGROUND: Maximizing the efficiency to screen amyloid-positive individuals in asymptomatic and non-demented aged population using blood-based biomarkers is essential for future success of clinical trials in the early stage of Alzheimer's disease (AD). In this study, we elucidate the utility of combination of plasma amyloid-ß (Aß)-related biomarkers and tau phosphorylated at threonine 217 (p-tau217) to predict abnormal Aß-positron emission tomography (PET) in the preclinical and prodromal AD. METHODS: We designed the cross-sectional study including two ethnically distinct cohorts, the Japanese trial-ready cohort for preclinica and prodromal AD (J-TRC) and the Swedish BioFINDER study. J-TRC included 474 non-demented individuals (CDR 0: 331, CDR 0.5: 143). Participants underwent plasma Aß and p-tau217 assessments, and Aß-PET imaging. Findings in J-TRC were replicated in the BioFINDER cohort including 177 participants (cognitively unimpaired: 114, mild cognitive impairment: 63). In both cohorts, plasma Aß(1-42) (Aß42) and Aß(1-40) (Aß40) were measured using immunoprecipitation-MALDI TOF mass spectrometry (Shimadzu), and p-tau217 was measured with an immunoassay on the Meso Scale Discovery platform (Eli Lilly). RESULTS: Aß-PET was abnormal in 81 participants from J-TRC and 71 participants from BioFINDER. Plasma Aß42/Aß40 ratio and p-tau217 individually showed moderate to high accuracies when detecting abnormal Aß-PET scans, which were improved by combining plasma biomarkers and by including age, sex and APOE genotype in the models. In J-TRC, the highest AUCs were observed for the models combining p-tau217/Aß42 ratio, APOE, age, sex in the whole cohort (AUC = 0.936), combining p-tau217, Aß42/Aß40 ratio, APOE, age, sex in the CDR 0 group (AUC = 0.948), and combining p-tau217/Aß42 ratio, APOE, age, sex in the CDR 0.5 group (AUC = 0.955), respectively. Each subgroup results were replicated in BioFINDER, where the highest AUCs were seen for models combining p-tau217, Aß42/40 ratio, APOE, age, sex in cognitively unimpaired (AUC = 0.938), and p-tau217/Aß42 ratio, APOE, age, sex in mild cognitive impairment (AUC = 0.914). CONCLUSIONS: Combination of plasma Aß-related biomarkers and p-tau217 exhibits high performance when predicting Aß-PET positivity. Adding basic clinical information (i.e., age, sex, APOE Îµ genotype) improved the prediction in preclinical AD, but not in prodromal AD. Combination of Aß-related biomarkers and p-tau217 could be highly useful for pre-screening of participants in clinical trials of preclinical and prodromal AD.

Simplifying Alzheimer's Disease Monitoring: A Novel Machine-Learning Approach to Estimate the Clinical Dementia Rating Sum of Box Changes Using the Mini-Mental State Examination and Functional Activities Questionnaire.

Background: Primary outcome measure in the clinical trials of disease modifying therapy (DMT) drugs for Alzheimer's disease (AD) has often been evaluated by Clinical Dementia Rating sum of boxes (CDRSB). However, CDR testing requires specialized training and 30-50 minutes to complete, not being suitable for daily clinical practice. Objective: Herein, we proposed a machine-learning method to estimate CDRSB changes using simpler cognitive/functional batteries (Mini-Mental State Examination [MMSE] and Functional Activities Questionnaire [FAQ]), to replace CDR testing. Methods: Baseline data from 944 ADNI and 171 J-ADNI amyloid-positive participants were used to build machine-learning models predicting annualized CDRSB changes between visits, based on MMSE and FAQ scores. Prediction performance was evaluated with mean absolute error (MAE) and R2 comparing predicted to actual rmDeltaCDRSB/rmDeltayear. We further assessed whether decline in cognitive function surpassing particular thresholds could be identified using the predicted rmDeltaCDRSB/rmDeltayear. RESULTS: The models achieved the minimum required prediction errors (MAE < 1.0) and satisfactory prediction accuracy (R2>0.5) for mild cognitive impairment (MCI) patients for changes in CDRSB over periods of 18 months or longer. Predictions of annualized CDRSB progression>0.5, >1.0, or >1.5 demonstrated a consistent performance (i.e., Matthews correlation coefficient>0.5). These results were largely replicated in the J-ADNI case predictions. CONCLUSIONS: Our method effectively predicted MCI patient deterioration in the CDRSB based solely on MMSE and FAQ scores. It may aid routine practice for disease-modifying therapy drug efficacy evaluation, without necessitating CDR testing at every visit.

Impact of Istradefylline on Levodopa Dose Escalation in Parkinson's Disease: ISTRA ADJUST PD Study, a Multicenter, Open-Label, Randomized, Parallel-Group Controlled Study.

INTRODUCTION: A higher levodopa dose is a risk factor for motor complications in Parkinson's disease (PD). Istradefylline (IST) is used as adjunctive treatment to levodopa in PD patients with off episodes, but its impact on levodopa dose titration remains unclear. The objective of this study was to investigate the effect of IST on levodopa dose escalation in PD patients with wearing-off. METHODS: This was a multicenter, open-label, randomized, parallel-group controlled study (ISTRA ADJUST PD) in which PD patients experiencing wearing-off (n = 114) who were receiving levodopa 300-400 mg/day were randomized to receive IST or no IST (control). Levodopa dose was escalated according to clinical severity. The primary endpoint was cumulative additional levodopa dose, and secondary endpoints were changes in symptom rating scales, motor activity determined by a wearable device, and safety outcomes. RESULTS: The cumulative additional levodopa dose throughout 37 weeks and dose increase over 36 weeks were significantly lower in the IST group than in the control group (both p < 0.0001). The Movement Disorder Society Unified Parkinson's Disease Rating Scale Part I and device-evaluated motor activities improved significantly from baseline to 36 weeks in the IST group only (all p < 0.05). Other secondary endpoints were comparable between the groups. Adverse drug reactions (ADRs) occurred in 28.8% and 13.2% of patients in the IST and control groups, respectively, with no serious ADRs in either group. CONCLUSION: IST treatment reduced levodopa dose escalation in PD patients, resulting in less cumulative levodopa use. Adjunctive IST may improve motor function more objectively than increased levodopa dose in patients with PD. TRIAL REGISTRATION: Japan Registry of Clinical Trials: jRCTs031180248.

Advertisement by medical facilities as an opportunity route of APOE genetic testing in Japan: a website analysis.

The APOE-ε4 allele(s) is a strong risk factor for Alzheimer's disease (AD). A significant point of access for this allele testing is through services provided by medical facilities in Japan, which advertise out-of-insurance APOE testing on their websites. There is a concern that website advertisements for APOE testing may influence the ability for individuals to adequately self-determine whether to undergo APOE testing. We conducted a cross-sectional survey on medical facility websites in Japan advertising APOE genetic testing. We predefined desirable features for advertisement descriptions based on legal regulations and guidelines published by relevant professional societies and evaluated each website according to these features. We identified 220 medical facilities that had posted advertisements on their websites for the provision of APOE genetic testing, of which 85% were small clinics. Contact information, details, and costs of testing were described in most of the websites. Meanwhile, features such as "explaining APOE as a risk gene," "notes on interpreting APOE results," or "explaining examination methods" (e.g., blood sampling) were described to a variable degree depending on individual facilities. "Notes on genetic testing" or "referring to genetic counseling" were hardly referred to, and specialists with appropriate expertise were considered to participate in clinical practice in approximately one-third of these facilities providing APOE testing services. These website evaluation results showed moderate to substantial reliability between independent raters. These results suggest that self-determination of pursuing out-of-insurance APOE testing at some medical facilities in Japan may possibly be influenced in an inappropriate manner, at least in its entry route of taking the test.

Detailed Assessment of 18F-THK5351 Distribution Pattern in the Midbrain: Comparison With Progressive Supranuclear Palsy and Corticobasal Syndrome.

BACKGROUND: 18F-THK5351 PET is used to image ongoing astrogliosis by estimating monoamine oxidase B levels. 18F-THK5351 preferentially accumulates around the substantia nigra (SN) and periaqueductal gray (PG) in the midbrain under healthy conditions and exhibits a "trimodal pattern." In progressive supranuclear palsy (PSP) and corticobasal syndrome (CBS), the midbrain 18F-THK5351 uptake can be increased by astrogliosis, collapsing the "trimodal pattern." We aimed to elucidate cases in which the "trimodal pattern" collapses in PSP and CBS. PATIENTS AND METHODS: Participants in the PSP (n = 11), CBS (n = 17), Alzheimer disease (n = 11), and healthy control (n = 8) groups underwent 18F-THK5351 PET. Volumes of interest (VOIs) were placed on the SN, PG, and their midpoints. The midbrain uptake ratio (MUR) was calculated to assess the trimodal pattern as follows: MUR = (VOI value on the midpoint)/(VOI value on the SN and PG). Approximately, the trimodal pattern can be identified at MUR <1 but not at MUR >1. RESULTS: Compared with the healthy control group, MUR significantly increased in the PSP (P < 0.01) and CBS (P < 0.01) groups, but was unchanged in the Alzheimer disease group (P = 0.10). In the PSP group, all patients, including 2 with mild symptoms and a short disease duration, showed MUR >1. In the CBS group, MUR varied widely. CONCLUSIONS: In PSP, the trimodal pattern can collapse even in the early phase when symptoms are mild. In CBS, the trimodal pattern may or may not collapse depending on the underlying pathology.

High sensitivity of asymmetric 18F-THK5351 PET abnormality in patients with corticobasal syndrome.

Corticobasal syndrome (CBS) is characterized by symptoms related to the asymmetric involvement of the cerebral cortex and basal ganglia. However, early detection of asymmetric imaging abnormalities can be challenging. Previous studies reported asymmetric 18F-THK5351 PET abnormalities in CBS patients, but the sensitivity for detecting such abnormalities in larger patient samples, including early-stage cases, remains unclear. Patients clinically diagnosed with CBS were recruited. All patients displayed asymmetric symptoms in the cerebral cortex and basal ganglia. Asymmetric THK5351 PET abnormalities were determined through visual assessment. Brain MRI, perfusion SPECT, and dopamine transporter (DAT) SPECT results were retrospectively reviewed. The 15 patients had a median age of 72 years (59-86 years) and a disease duration of 2 years (0.5-7 years). Four patients met the probable and 11 met the possible CBS criteria according to Armstrong criteria at the time of PET examination. All patients, including early-stage cases, exhibited asymmetric tracer uptake contralateral to their symptom-dominant side in the cerebral cortex/subcortical white matter and striatum (100%). The sensitivity for detecting asymmetric imaging abnormalities contralateral to the symptom-dominant side was 86.7% for brain MRI, 81.8% for perfusion SPECT, and 90% for DAT SPECT. White matter volume reduction was observed in the subcortical region of the precentral gyrus with increased THK5351 uptake, occurring significantly more frequently than gray matter volume reduction. THK5351 PET may be a sensitive imaging technique for detecting asymmetric CBS pathologies, including those in early stages.

Correlations between cerebrospinal fluid homovanillic acid and dopamine transporter SPECT in degenerative parkinsonian syndromes.

Both cerebrospinal fluid (CSF) homovanillic acid (HVA) and striatal dopamine transporter (DAT) binding on single-photon emission computed tomography (SPECT) reflect nigrostriatal dopaminergic function, but studies on the relationship between the two have been limited. It is also unknown whether the reported variance in striatal DAT binding among diseases reflects the pathophysiology or characteristics of the subjects. We included 70 patients with Parkinson's disease (PD), 12 with progressive supranuclear palsy (PSP), 12 with multiple system atrophy, six with corticobasal syndrome, and nine with Alzheimer's disease as disease control, who underwent both CSF analysis and 123I-N-ω-fluoropropyl-2ß-carbomethoxy-3ß-(4-iodophenyl)nortropane (123I-ioflupane) SPECT. We evaluated the correlation between CSF HVA concentration and the specific binding ratio (SBR) of striatal DAT binding. We also compared the SBR for each diagnosis, controlling for CSF HVA concentration. The correlations between the two were significant in patients with PD (r = 0.34, p = 0.004) and PSP (r = 0.77, p = 0.004). The mean SBR value was the lowest in patients with PSP and was significantly lower in patients with PSP than in those with PD (p = 0.037) after adjusting for CSF HVA concentration. Our study demonstrates that striatal DAT binding correlates with CSF HVA concentration in both PD and PSP, and striatal DAT reduction would be more advanced in PSP than in PD at an equivalent dopamine level. Striatal DAT binding may correlate with dopamine levels in the brain. The pathophysiology of each diagnosis may explain this difference.

CSF P-Tau181 and Other Biomarkers in Patients With Neuronal Intranuclear Inclusion Disease.

BACKGROUND AND OBJECTIVES: CSF tau phosphorylated at threonine 181 (p-tau181) is a widely used biomarker for Alzheimer disease (AD) and has recently been regarded to reflect ß-amyloid and/or p-tau deposition in the AD brain. Neuronal intranuclear inclusion disease (NIID) is a neurodegenerative disease characterized by intranuclear inclusions in neurons, glial cells, and other somatic cells. Symptoms include dementia, neuropathy, and others. CSF biomarkers were not reported. The objective of this study was to investigate whether CSF biomarkers including p-tau181 are altered in patients with NIID. METHODS: This was a retrospective observational study. CSF concentrations of p-tau181, total tau, amyloid-beta 1-42 (Aß42), monoamine metabolites homovanillic acid (HVA), and 5-hydroxyindole acetic acid (5-HIAA) were compared between 12 patients with NIID, 120 patients with Alzheimer clinical syndrome biologically confirmed based on CSF biomarker profiles, and patients clinically diagnosed with other neurocognitive disorders (dementia with Lewy bodies [DLB], 24; frontotemporal dementia [FTD], 13; progressive supranuclear palsy [PSP], 21; and corticobasal syndrome [CBS], 13). Amyloid PET using Pittsburgh compound B (PiB) was performed in 6 patients with NIID. RESULTS: The mean age of patients with NIID, AD, DLB, FTD, PSP, and CBS was 71.3, 74.6, 76.8, 70.2, 75.5, and 71.9 years, respectively. CSF p-tau181 was significantly higher in NIID (72.7 ± 24.8 pg/mL) compared with DLB, PSP, and CBS and was comparable between NIID and AD. CSF p-tau181 was above the cutoff value (50.0 pg/mL) in 11 of 12 patients with NIID (91.7%). Within these patients, only 2 patients showed decreased CSF Aß42, and these patients showed negative or mild local accumulation in PiB PET, respectively. PiB PET scans were negative in the remaining 4 patients tested. The proportion of patients with increased CSF p-tau181 and normal Aß42 (A-T+) was significantly higher in NIID (75%) compared with DLB, PSP, and CBS (4.2%, 4.8%, and 7.7%, respectively). CSF HVA and 5-HIAA concentrations were significantly higher in patients with NIID compared with disease controls. DISCUSSION: CSF p-tau181 was increased in patients with NIID without amyloid accumulation. Although the deposition of p-tau has not been reported in NIID brains, the molecular mechanism of tau phosphorylation or secretion of p-tau may be altered in NIID.

A first-in-human study of the anti-inflammatory profibrinolytic TMS-007, an SMTP family triprenyl phenol.

AIMS: TMS-007, an SMTP family member, modulates plasminogen conformation and enhances plasminogen-fibrin binding, leading to promotion of endogenous fibrinolysis. Its anti-inflammatory action, mediated by soluble epoxide hydrolase inhibition, may contribute to its efficacy. Evidence suggests that TMS-007 can effectively treat experimental thrombotic and embolic strokes with a wide time window, while reducing haemorrhagic transformation. We aim to evaluate the safety, pharmacokinetics and pharmacodynamics of TMS-007 in healthy volunteers. METHODS: This was a randomized, placebo-controlled, double blind, dose-escalation study, administered as a single intravenous infusion of TMS-007 in cohorts of healthy male Japanese subjects. Six cohorts were planned, but only five were completed. In each cohort (n = 8), individuals were randomized to receive one of five doses of TMS-007 (3, 15, 60, 180 or 360 mg; n = 6) or placebo (n = 2). RESULTS: TMS-007 was generally well tolerated, and no serious adverse events were attributed to the drug. A linear dose-dependency was observed for plasma TMS-007 levels. No symptoms of bleeding were observed on brain MRI analysis, and no bleeding-related responses were found on laboratory testing. The plasma levels of the coagulation factor fibrinogen and the anti-fibrinolysis factor α2 -antiplasmin levels were unchanged after TMS-007 dosing. A slight increase in the plasma level of plasmin-α2 -antiplasmin complex, an index of plasmin formation, was observed in the TMS-007 group in cohort 2. CONCLUSIONS: TMS-007 is generally well tolerated and exhibits favourable pharmacokinetic profiles that warrant further clinical development.

Different AT(N) profiles and clinical progression classified by two different N markers using total tau and neurofilament light chain in cerebrospinal fluid.

Background: The AT(N) classification was proposed for categorising individuals according to biomarkers. However, AT(N) profiles may vary depending on the markers chosen and the target population. Methods: We stratified 177 individuals who participated in the Japanese Alzheimer's Disease Neuroimaging Initiative by AT(N) classification according to cerebrospinal fluid (CSF) biomarkers. We compared the frequency of AT(N) profiles between the classification using total tau and neurofilament light chain (NfL) as N markers (AT(N)tau and AT(N)NfL). Baseline characteristics, and longitudinal biological and clinical changes were examined between AT(N) profiles. Results: We found that 9% of cognitively unimpaired subjects, 49% of subjects with mild cognitive impairment, and 61% of patients with Alzheimer's disease (AD) dementia had the biological AD profile (ie, A+T+) in the cohort. The frequency of AT(N) profiles substantially differed between the AT(N)tau and AT(N)NfL classifications. When we used t-tau as the N marker (AT(N)tau), those who had T- were more frequently assigned to (N)-, whereas those who had T+were more frequently assigned to (N)+ than when we used NfL as the N marker (AT(N)NfL). During a follow-up, the AD continuum group progressed clinically and biologically compared with the normal biomarker group in both the AT(N)tau and AT(N)NfL classifications. More frequent conversion to dementia was observed in the non-AD pathological change group in the AT(N)tau classification, but not in the AT(N)NfL classification. Conclusions: AT(N)tau and AT(N)NfL in CSF may capture different aspects of neurodegeneration and provide a different prognostic value. The AT(N) classification aids in understanding the AD continuum biology in various populations.

Efficacy and Cost-effectiveness of Promotion Methods to Recruit Participants to an Online Screening Registry for Alzheimer Disease Prevention Trials: Observational Study.

BACKGROUND: Web-based screening may be suitable for identifying individuals with presymptomatic latent diseases for recruitment to clinical studies, as such people do not often visit hospitals in the presymptomatic stage. The promotion of such online screening studies is critical to their success, although it remains uncertain how the effectiveness of such promotion can differ, depending on the different promotion methods, domains of interest, or countries of implementation. OBJECTIVE: The Japanese Trial-Ready Cohort (J-TRC) web study is our ongoing online screening registry to identify individuals with presymptomatic Alzheimer disease (AD), aimed at facilitating the clinical trials for AD prevention. Within the first 9 months of its 2019 launch, the J-TRC web study recruited thousands of online participants via multiple methods of promotion, including press releases, newspaper advertisements, web advertisements, or direct email invitations. Here, we aimed to quantitatively evaluate efficacy and cost-effectiveness of each of these multimodal promotion methods. METHODS: We applied the vector-autoregression model to assess the degree of contribution of each type of promotion to the following target metrics: number of daily visitors to the J-TRC website, number of daily registrants to the J-TRC web study, daily rate of registration among visitors, daily rate of eligible participants among registrants, and median age of daily registrants. The average cost-effectiveness for each promotion method was also calculated using the total cost and the coefficients in the vector-autoregression model. RESULTS: During the first 9 months of the reviewed period from October 31, 2019 to June 17, 2020, there were 48,334 website visitors and 4429 registrations (9.16% of 48,334 visitors), of which 3081 (69.56%) were eligible registrations. Initial press release reports and newspaper advertisements had a marked effect on increasing the number of daily visitors and daily registrants. Web advertisements significantly contributed to the increase in daily visitors (P<.001) but not to the daily registrants, and it also lowered the rate of registrations and the median age of daily registrants. Website visitors from the direct email invitation sent to other cognitive registries seem to have registered with the highest reliability. The calculated average cost-effectiveness for the initial press release was US $24.60 per visitor and US $96.10 per registrant, while the calculated average cost-effectiveness for the newspaper advertisements was US $28.60 per visitor and US $227.90 per registrant. CONCLUSIONS: Our multivariate time-series analysis showed that each promotion method had different features in their effect of recruiting participants to the J-TRC web study. Under the advertisement condition settings thus far, newspaper advertisements and initial press releases were the most effective promotion methods, with fair cost-effectiveness that was equivalent to earlier online studies. These results can provide important suggestions for future promotions for the recruitment of presymptomatic participants to AD clinical trials in Japan.

Predicting amyloid risk by machine learning algorithms based on the A4 screen data: Application to the Japanese Trial-Ready Cohort study.

BACKGROUND: Selecting cognitively normal elderly individuals with higher risk of brain amyloid deposition is critical to the success of prevention trials for Alzheimer's disease (AD). METHODS: Based on the Anti-Amyloid Treatment in Asymptomatic Alzheimer's Disease study data, we built machine-learning models and applied them to our ongoing Japanese Trial-Ready Cohort (J-TRC) webstudy participants registered within the first 9 months (n = 3081) of launch to predict standard uptake value ratio (SUVr) of amyloid positron emission tomography. RESULTS: Age, family history, online Cognitive Function Instrument and CogState scores were important predictors. In a subgroup of J-TRC webstudy participants with known amyloid status (n = 37), the predicted SUVr corresponded well with the self-reported amyloid test results (area under the curve = 0.806 [0.619-0.992]). DISCUSSION: Our algorithms may be usable for automatic prioritization of candidate participants with higher amyloid risks to be preferentially recruited from the J-TRC webstudy to in-person study, maximizing efficiency for the identification of preclinical AD participants.

Effect of apolipoprotein E ε4 allele on the progression of cognitive decline in the early stage of Alzheimer's disease.

INTRODUCTION: Possession of the apolipoprotein E (APO E) ε4 allele advances amyloid ß (Aß) deposition and symptomatic onset of Alzheimer's disease (AD), whereas its effect on the rate of cognitive decline remained controversial. We examined the effects of APOE ε4 allele on cognition in biomarker-confirmed late mild cognitive impairment (LMCI) and mild AD subjects in the Japanese Alzheimer's Disease Neuroimaging Initiative (J-ADNI) and North American ADNI (NA-ADNI). METHODS: The "early AD" (ie, combined LMCI and mild AD) cohort of 649 subjects from J-ADNI and NA-ADNI were selected based on positivity of Aß confirmed by amyloid positron emission tomography (PET) or cerebrospinal fluid testing. The rates of cognitive decline in the Mini Mental State Examination (MMSE), the Clinical Dementia Rating Sum of Boxes (CDR-SB), and the Alzheimer's Disease Assessment Scale-cognitive subscale 13 (ADAS-Cog) from baseline were examined using mixed-effects model. The effect of ε4 on time to conversion to dementia was also analyzed in LMCI using the Kaplan-Meier estimator and log-rank test. RESULTS: The rates of cognitive decline were not significantly different between ε4 carriers and ε4 non-carriers in the total early AD cohort, which were affected neither by region nor by the number of ε4 alleles. In LMCI, ε4 carriers showed almost the same progression rates as ε4 non-carriers, except for a significantly faster decline in MMSE (P = .0282). Time to conversion to demenita was not significantly different between ε4 carriers and ε4 non-carriers. In ε4-positive mild AD, the rates of decline in MMSE (P = .003) and CDR-SB (P = .0071) were slower than those in ε4 non-carriers. DISCUSSION: The APOE ε4 allele had little effect on the rates of cognitive decline in the overall biomarker-confirmed early AD, regardless of region and number of ε4 alleles, with a slight variability in different clinical stages, the ε4 allele being slightly accelerative in LMCI, while decelerative in mild AD.

Identification of prognostic factors to predict cognitive decline of patients with early Alzheimer's disease in the Japanese Alzheimer's Disease Neuroimaging Initiative study.

INTRODUCTION: The objective of this study was to determine the factors including neuropsychological test performances and cerebrospinal fluid (CSF) biomarkers which can predict disease progression of early Alzheimer's disease (AD) in a Japanese population. METHODS: The group classification on early AD population in both Japanese Alzheimer's Disease Neuroimaging Initiative (J-ADNI) and North American ADNI (NA-ADNI) was performed using the inclusion criteria including brain amyloid positivity on positron emission tomography or CSF. Participants with early AD from each cohort were stratified into two groups based on a cutoff 1.0 of Clinical Dementia Rating Scale Sum of Boxes (CDR-SB) change at month 24 (m24): participants in "progress group" have CDR-SB change ≥ 1.0 and participants in "stable group" have CDR-SB change < 1.0. Then, we performed identification of prognostic factors from baseline items including neuropsychological scores (Assessment Scale-Cognitive Subscale[ADAS-cog 13], Mini-Mental State Examination (MMSE), CDR, FAQ, and Geriatric Depression Scale ), CSF markers (t-tau, p-tau, and beta-amyloid 1-42), vital signs (body weight, pulse rate, etc.,), by using two statistical approaches, Welch's t-test and simple linear regression by ordinary least squares. Comparisons between participants with J-ADNI and participants with NA-ADNI were also performed. RESULTS: Trends of CDR-SB changes were very similar between J-ADNI and NA-ADNI early AD population enrolled in this study. Baseline levels of CSF t-tau, p-tau, Mini-Mental State Examination, FAQ, and ADAS-cog13 were identified as prognostic factors in both J-ADNI and NA-ADNI. Based on a detailed subscale analysis on ADAS-cog13, four subscales (Q1: word recall, Q3: construction, Q4: delayed word recall, and Q8: word recognition) were identified as prognostic factors in both J-ADNI and NA-ADNI. DISCUSSION: Characterizing population with early AD can provide benefits for promoting efficiency in conducting AD clinical trials for disease-modifying treatments. Thus, implementing these prognostic factors into clinical trials may be potentially a good method to enrich participants with early AD who are suitable for evaluating treatment effects.

Visualizing modules of coordinated structural brain atrophy during the course of conversion to Alzheimer's disease by applying methodology from gene co-expression analysis.

OBJECTIVE: We aimed to identify modularized structural atrophy of brain regions with a high degree of connectivity and its longitudinal changes associated with the progression of Alzheimer's disease (AD) using weighted gene co-expression network analysis (WGCNA), which is an unsupervised hierarchical clustering method originally used in genetic analysis. METHODS: We included participants with late mild cognitive impairment (MCI) at baseline from the Japanese Alzheimer's Disease Neuroimaging Initiative (J-ADNI) study. We imputed normalized and Z-transformed structural volume or cortical thickness data of 164 parcellated brain regions/structures based on the calculations of the FreeSurfer software. We applied the WGCNA to extract modules with highly interconnected structural atrophic patterns and examined the correlation between the identified modules and clinical AD progression. RESULTS: We included 204 participants from the baseline dataset, and performed a follow-up with 100 in the 36-month dataset of MCI cohort participants from the J-ADNI. In the univariate correlation or variable importance analysis, baseline atrophy in temporal lobe regions/structures significantly predicted clinical AD progression. In the WGCNA consensus analysis, co-atrophy modules associated with MCI conversion were first distributed in the temporal lobe and subsequently extended to adjacent parietal cortical regions in the following 36 months. CONCLUSIONS: We identified coordinated modules of brain atrophy and demonstrated their longitudinal extension along with the clinical course of AD progression using WGCNA, which showed a good correspondence with previous pathological studies of the tau propagation theory. Our results suggest the potential applicability of this methodology, originating from genetic analyses, for the surrogate visualization of the underlying pathological progression in neurodegenerative diseases not limited to AD.

Lower Serum Calcium as a Potentially Associated Factor for Conversion of Mild Cognitive Impairment to Early Alzheimer's Disease in the Japanese Alzheimer's Disease Neuroimaging Initiative.

BACKGROUND: Effect of serum calcium level to the incidence of mild cognitive impairment (MCI) conversion to early Alzheimer's disease (AD) remains uncertain. OBJECTIVE: To investigate association between baseline serum calcium and the MCI conversion in the Japanese Alzheimer's Disease Neuroimaging Initiative (J-ADNI) study cohort. METHODS: In this sub-analysis of J-ADNI study, we reviewed data from MCI participants at baseline regarding their conversion to early AD during the 3 years of observation period and assessed the associated factors including serum calcium level. In addition, we compared our results from the J-ADNI study with the corresponding results from the North American (NA)-ADNI. RESULTS: Of 234 eligible MCI participants from the J-ADNI cohort, 121 (51.7%) converted to AD during the first 36 months of observation. Using univariate analysis, being female, having shorter years of education, and lower serum calcium level were correlated with increased risk of MCI-to-AD conversion exclusively in J-ADNI cohort. The lower corrected serum calcium level remained as one of conversion-associated factors in the J-ADNI cohort even after adjustment for multiple confounding variables, although this was not observed in the NA-ADNI cohort. CONCLUSION: Our findings suggest that lower serum calcium may be associated with an increased risk of MCI conversion to AD in Japanese cohorts. The reason for this correlation remains unclear and further external validation using other Asian cohorts is needed. It would be interesting for future AD studies to obtain serum calcium levels and other related factors, such as vitamin D levels, culture-specific dietary or medication information.

Clinical and cognitive characteristics of preclinical Alzheimer's disease in the Japanese Alzheimer's Disease Neuroimaging Initiative cohort.

INTRODUCTION: The objective of this study was to determine the frequency and clinical and cognitive characteristics of preclinical Alzheimer's disease (AD) in a Japanese population to effectively design and conduct future preventive trials on preclinical AD. METHODS: Three-year longitudinal data from cognitively normal participants who underwent cerebrospinal fluid biomarker measurement and/or amyloid positron emission tomography in the Japanese Alzheimer's Disease Neuroimaging Initiative, were analyzed. Comparisons between participants with and without amyloid ß (Aß) accumulation, and between those with and without elevated tau levels tau among participants with Aß accumulation were performed. RESULTS: Among 84 participants with available cerebrospinal fluid biomarker and/or amyloid positron emission tomography data, 19 (22.6%) exhibited Aß accumulation. The frequency of APOE ε4 alleles was significantly higher in participants with Aß accumulation. There were no significant differences in any of the cognitive tests at the baseline; however, participants with Aß accumulation exhibited a decline in clock drawing test (linear mixed-effects model, P = .008) and a tendency toward loss of practice effects in the Mini-Mental State Examination and the logical memory over time. Although it did not reach statistical significance, the analysis indicated a decline in measurements of executive function over time in participants with elevated tau levels compared with those with normal tau levels. DISCUSSION: The frequency of preclinical AD in the Japanese Alzheimer's Disease Neuroimaging Initiative was lower than in similar studies because of the younger age of the participants and lower frequency of APOE ε4 carriage. Although limitations in sample size precluded definitive conclusions, the results suggest that even in the preclinical phase of AD, loss of practice effects in episodic memory tests and at a later stage, decline in executive function, are present. These findings may be useful for recruitment of individuals with preclinical AD and establishing a novel cognitive composite for use in clinical trials on preclinical AD.

Relative neuron loss in hippocampal sclerosis of aging and Alzheimer's disease.

OBJECTIVE: To characterize the pattern of neuron loss in hippocampal sclerosis of aging (HS-Aging) and age-related diseases and to evaluate its contribution to cognitive impairment in the elderly. METHODS: Participants (n = 1,361) came from longitudinal observational studies of aging at the Knight Alzheimer Disease Research Center, Washington University (St. Louis, MO). Relative neuron loss in the hippocampus of HS-Aging was measured using unbiased stereological methods. Transactive response DNA-binding protein of 43 kDa (TDP-43) proteinopathy, a putative marker of HS-Aging, was assessed. Clinical and cognitive data were analyzed using parametric statistical methods. RESULTS: Ninety-three cases had HS-Aging (6.8%), 8 cases had "pure" HS-Aging, and 37 cases had comorbid intermediate or high Alzheimer's disease neuropathological change (i/h ADNC). Relative neuron loss (ratio of neuron number in hippocampal subfield CA1 to the neuron number in parahippocampal gyrus) was 0.15 for HS-Aging; this was significantly lower than 0.64 for i/h ADNC and 0.66 for control cases (Kruskal-Wallis test, p < 0.0001; p = 0.0003, respectively). TDP-43 proteinopathy was present in 92.4% of HS-Aging cases, higher than that in i/h ADNC (52%) and control (25%) cases. Pure HS-Aging cases were more likely to have cognitive impairment in the memory domain. INTERPRETATION: Relative neuron loss in the hippocampus compared to the parahippocampus gyrus may be useful in distinguishing HS-Aging in the context of comorbid ADNC. HS-Aging contributes to cognitive impairment, which phenotypically resembles AD dementia. TDP proteinopathy is a frequent comorbidity in HS-Aging and may contribute to cognitive impairment to a modest degree. Ann Neurol 2018;84:749-761.

Japanese and North American Alzheimer's Disease Neuroimaging Initiative studies: Harmonization for international trials.

INTRODUCTION: We conducted Japanese Alzheimer's Disease Neuroimaging Initiative (J-ADNI) and compared the basic characteristics and progression profiles with those of ADNI in North America. METHODS: A total of 537 Japanese subjects with normal cognition, late amnestic mild cognitive impairment (LMCI), or mild Alzheimer's disease (AD) were enrolled using the same criteria as ADNI. Rates of changes in representative cognitive or functional measures were compared for amyloid positron emission tomography- or cerebrospinal fluid amyloid ß(1-42)-positive LMCI and mild AD between J-ADNI and ADNI. RESULTS: Amyloid positivity rates were significantly higher in normal cognition of ADNI but at similar levels in LMCI and mild AD between J-ADNI and ADNI. Profiles of decline in cognitive or functional measures in amyloid-positive LMCI in J-ADNI (n = 75) and ADNI (n = 269) were remarkably similar, whereas those in mild AD were milder in J-ADNI (n = 73) compared with ADNI (n = 230). DISCUSSION: These results support the feasibility of bridging of clinical trials in the prodromal stage of AD between Asia and western countries.