Different inflammatory signatures based on CSF biomarkers relate to preserved or diminished brain structure and cognition.

Neuroinflammation is a hallmark of Alzheimer's disease (AD) and both positive and negative associations of individual inflammation-related markers with brain structure and cognitive function have been described. We aimed to identify inflammatory signatures of CSF immune-related markers that relate to changes of brain structure and cognition across the clinical spectrum ranging from normal aging to AD. A panel of 16 inflammatory markers, Aß42/40 and p-tau181 were measured in CSF at baseline in the DZNE DELCODE cohort (n = 295); a longitudinal observational study focusing on at-risk stages of AD. Volumetric maps of gray and white matter (GM/WM; n = 261) and white matter hyperintensities (WMHs, n = 249) were derived from baseline MRIs. Cognitive decline (n = 204) and the rate of change in GM volume was measured in subjects with at least 3 visits (n = 175). A principal component analysis on the CSF markers revealed four inflammatory components (PCs). Of these, the first component PC1 (highly loading on sTyro3, sAXL, sTREM2, YKL-40, and C1q) was associated with older age and higher p-tau levels, but with less pathological Aß when controlling for p-tau. PC2 (highly loading on CRP, IL-18, complement factor F/H and C4) was related to male gender, higher body mass index and greater vascular risk. PC1 levels, adjusted for AD markers, were related to higher GM and WM volumes, less WMHs, better baseline memory, and to slower atrophy rates in AD-related areas and less cognitive decline. In contrast, PC2 related to less GM and WM volumes and worse memory at baseline. Similar inflammatory signatures and associations were identified in the independent F.ACE cohort. Our data suggest that there are beneficial and detrimental signatures of inflammatory CSF biomarkers. While higher levels of TAM receptors (sTyro/sAXL) or sTREM2 might reflect a protective glia response to degeneration related to phagocytic clearance, other markers might rather reflect proinflammatory states that have detrimental impact on brain integrity.

Single-value brain activity scores reflect both severity and risk across the Alzheimer's continuum.

Single-value scores reflecting the deviation from (FADE score) or similarity with (SAME score) prototypical novelty-related and memory-related functional magnetic resonance imaging (fMRI) activation patterns in young adults have been proposed as imaging biomarkers of healthy neurocognitive aging. Here, we tested the utility of these scores as potential diagnostic and prognostic markers in Alzheimer's disease (AD) and risk states like mild cognitive impairment (MCI) or subjective cognitive decline (SCD). To this end, we analyzed subsequent memory fMRI data from individuals with SCD, MCI, and AD dementia as well as healthy controls (HC) and first-degree relatives of AD dementia patients (AD-rel) who participated in the multi-center DELCODE study (N = 468). Based on the individual participants' whole-brain fMRI novelty and subsequent memory responses, we calculated the FADE and SAME scores and assessed their association with AD risk stage, neuropsychological test scores, CSF amyloid positivity, and ApoE genotype. Memory-based FADE and SAME scores showed a considerably larger deviation from a reference sample of young adults in the MCI and AD dementia groups compared to HC, SCD and AD-rel. In addition, novelty-based scores significantly differed between the MCI and AD dementia groups. Across the entire sample, single-value scores correlated with neuropsychological test performance. The novelty-based SAME score further differed between Aß-positive and Aß-negative individuals in SCD and AD-rel, and between ApoE ε4 carriers and non-carriers in AD-rel. Hence, FADE and SAME scores are associated with both cognitive performance and individual risk factors for AD. Their potential utility as diagnostic and prognostic biomarkers warrants further exploration, particularly in individuals with SCD and healthy relatives of AD dementia patients.

A generalizable data-driven model of atrophy heterogeneity and progression in memory clinic settings.

Memory clinic patients are a heterogeneous population representing various aetiologies of pathological ageing. It is not known whether divergent spatiotemporal progression patterns of brain atrophy, as previously described in Alzheimer's disease patients, are prevalent and clinically meaningful in this group of older adults. To uncover distinct atrophy subtypes, we applied the Subtype and Stage Inference (SuStaIn) algorithm to baseline structural MRI data from 813 participants enrolled in the DELCODE cohort (mean ± standard deviation, age = 70.67 ± 6.07 years, 52% females). Participants were cognitively unimpaired (n = 285) or fulfilled diagnostic criteria for subjective cognitive decline (n = 342), mild cognitive impairment (n = 118) or dementia of the Alzheimer's type (n = 68). Atrophy subtypes were compared in baseline demographics, fluid Alzheimer's disease biomarker levels, the Preclinical Alzheimer Cognitive Composite (PACC-5) as well as episodic memory and executive functioning. PACC-5 trajectories over up to 240 weeks were examined. To test whether baseline atrophy subtype and stage predicted clinical trajectories before manifest cognitive impairment, we analysed PACC-5 trajectories and mild cognitive impairment conversion rates of cognitively unimpaired participants and those with subjective cognitive decline. Limbic-predominant and hippocampal-sparing atrophy subtypes were identified. Limbic-predominant atrophy initially affected the medial temporal lobes, followed by further temporal regions and, finally, the remaining cortical regions. At baseline, this subtype was related to older age, more pathological Alzheimer's disease biomarker levels, APOE ε4 carriership and an amnestic cognitive impairment. Hippocampal-sparing atrophy initially occurred outside the temporal lobe, with the medial temporal lobe spared up to advanced atrophy stages. This atrophy pattern also affected individuals with positive Alzheimer's disease biomarkers and was associated with more generalized cognitive impairment. Limbic-predominant atrophy, in all participants and in only unimpaired participants, was linked to more negative longitudinal PACC-5 slopes than observed in participants without or with hippocampal-sparing atrophy and increased the risk of mild cognitive impairment conversion. SuStaIn modelling was repeated in a sample from the Swedish BioFINDER-2 cohort. Highly similar atrophy progression patterns and associated cognitive profiles were identified. Cross-cohort model generalizability, at both the subject and the group level, was excellent, indicating reliable performance in previously unseen data. The proposed model is a promising tool for capturing heterogeneity among older adults at early at-risk states for Alzheimer's disease in applied settings. The implementation of atrophy subtype- and stage-specific end points might increase the statistical power of pharmacological trials targeting early Alzheimer's disease.

The effect of depressive symptoms on quality of life and its different facets in the oldest age population: evidence from the AgeQualiDe prospective cohort study.

PURPOSE: The present study aims to investigate the prospective effect of depressive symptoms on overall QoL in the oldest age group, taking into account its different facets. METHODS: Data were derived from the multicenter prospective AgeCoDe/AgeQualiDe cohort study, including data from follow-up 7-9 and n = 580 individuals 85 years of age and older. Overall QoL and its facets were assessed using the WHOQOL-OLD instrument. The short form of the geriatric depression scale (GDS-15) was applied to assess depressive symptoms. Cognitively impaired individuals were excluded. Linear mixed-effects models were used to assess the effect of depressive symptoms on QoL. RESULTS: Depressive symptoms were significantly associated with overall QoL and each of the different facets of WHOQOL-OLD, also after adjustment for time and sociodemographic characteristics such as age, gender, education, marital status, living situation, and cognitive status. Higher age and single as well as divorced marital status were also associated with a lower QoL. CONCLUSION: This work provides comprehensive longitudinal results on the relationship between depressive symptoms and QoL in the oldest age population. The results underscore the relevance of tailored and targeted care planning and the development of customized interventions.

Plasma amyloid beta X-42/X-40 ratio and cognitive decline in suspected early and preclinical Alzheimer's disease.

INTRODUCTION: Blood-based biomarkers are a cost-effective and minimally invasive method for diagnosing the early and preclinical stages of amyloid positivity (AP). Our study aims to investigate our novel immunoprecipitation-immunoassay (IP-IA) as a test for predicting cognitive decline. METHODS: We measured levels of amyloid beta (Aß)X-40 and AßX-42 in immunoprecipitated eluates from the DELCODE cohort. Receiver-operating characteristic (ROC) curves, regression analyses, and Cox proportional hazard regression models were constructed to predict AP by Aß42/40 classification in cerebrospinal fluid (CSF) and conversion to mild cognitive impairment (MCI) or dementia. RESULTS: We detected a significant correlation between AßX-42/X-40 in plasma and CSF (r = 0.473). Mixed-modeling analysis revealed a substantial prediction of AßX-42/X-40 with an area under the curve (AUC) of 0.81 for AP (sensitivity: 0.79, specificity: 0.74, positive predictive value [PPV]: 0.71, negative predictive value [NPV]: 0.81). In addition, lower AßX-42/X-40 ratios were associated with negative PACC5 slopes, suggesting cognitive decline. DISCUSSION: Our results suggest that assessing the plasma AßX-42/X-40 ratio via our semiautomated IP-IA is a promising biomarker when examining patients with early or preclinical AD. HIGHLIGHTS: New plasma Aß42/Aß40 measurement using immunoprecipitation-immunoassay Plasma Aß42/Aß40 associated with longitudinal cognitive decline Promising biomarker to detect subjective cognitive decline at-risk for brain amyloid positivity.

Genome-wide meta-analyses reveal novel loci for verbal short-term memory and learning.

Understanding the genomic basis of memory processes may help in combating neurodegenerative disorders. Hence, we examined the associations of common genetic variants with verbal short-term memory and verbal learning in adults without dementia or stroke (N = 53,637). We identified novel loci in the intronic region of CDH18, and at 13q21 and 3p21.1, as well as an expected signal in the APOE/APOC1/TOMM40 region. These results replicated in an independent sample. Functional and bioinformatic analyses supported many of these loci and further implicated POC1. We showed that polygenic score for verbal learning associated with brain activation in right parieto-occipital region during working memory task. Finally, we showed genetic correlations of these memory traits with several neurocognitive and health outcomes. Our findings suggest a role of several genomic loci in verbal memory processes.

Matrix metalloproteinase 10 is linked to the risk of progression to dementia of the Alzheimer's type.

Alzheimer's disease has a long asymptomatic phase that offers a substantial time window for intervention. Using this window of opportunity will require early diagnostic and prognostic biomarkers to detect Alzheimer's disease pathology at predementia stages, thus allowing identification of patients who will most probably progress to dementia of the Alzheimer's type and benefit from specific disease-modifying therapies. Consequently, we searched for CSF proteins associated with disease progression along with the clinical disease staging. We measured the levels of 184 proteins in CSF samples from 556 subjective cognitive decline and mild cognitive impairment patients from three independent memory clinic longitudinal studies (Spanish ACE, n = 410; German DCN, n = 93; German Mannheim, n = 53). We evaluated the association between protein levels and clinical stage, and the effect of protein levels on the progression from mild cognitive impairment to dementia of the Alzheimer's type. Mild cognitive impairment subjects with increased CSF level of matrix metalloproteinase 10 (MMP-10) showed a higher probability of progressing to dementia of the Alzheimer's type and a faster cognitive decline. CSF MMP-10 increased the prediction accuracy of CSF amyloid-ß 42 (Aß42), phospho-tau 181 (P-tau181) and total tau (T-tau) for conversion to dementia of the Alzheimer's type. Including MMP-10 to the [A/T/(N)] scheme improved considerably the prognostic value in mild cognitive impairment patients with abnormal Aß42, but normal P-tau181 and T-tau, and in mild cognitive impairment patients with abnormal Aß42, P-tau181 and T-tau. MMP-10 was correlated with age in subjects with normal Aß42, P-tau181 and T-tau levels. Our findings support the use of CSF MMP-10 as a prognostic marker for dementia of the Alzheimer's type and its inclusion in the [A/T/(N)] scheme to incorporate pathologic aspects beyond amyloid and tau. CSF level of MMP-10 may reflect ageing and neuroinflammation.

Social isolation in the oldest-old: determinants and the differential role of family and friends.

PURPOSE: To examine the association of sociodemographic and health-related determinants with social isolation in relation to family and friends in the oldest-old. METHODS: Database was the multi-center prospective AgeCoDe/AgeQualiDe cohort study assessed at follow-up wave 5 (N = 1148; mean age 86.6 years (SD 3.0); 67% female). Social isolation was assessed using the short form of the Lubben Social Network Scale (LSNS-6). The LSNS-6 contains two sets of items establishing psychometrically separable subscales for isolation from family and friends (ranges 0-15 points), with lower scores indicating higher isolation. Cross-sectional linear (OLS) regression analyses were used to examine multivariate associations of sociodemographic and health-related determinants with social isolation from family and friends. RESULTS: Overall, n = 395 participants (34.6%) were considered socially isolated. On average, isolation was higher from friends (mean 6.0, SD 3.8) than from family (mean 8.0, SD 3.5). Regression results revealed that in relation to family, males were more socially isolated than females (ß = - 0.68, 95% CI - 1.08, - 0.28). Concerning friends, increased age led to more isolation (ß = - 0.12, 95% CI - 0.19, - 0.05) and functional activities of daily living to less isolation (ß = 0.36, 95% CI 0.09, 0.64). Independent of the social context, depression severity was associated with more social isolation, whereas cognitive functioning was associated with less social isolation. CONCLUSIONS: Different determinants unequally affect social isolation in relation to family and friends. The context of the social network should be incorporated more strongly regarding the detection and prevention of social isolation to sustain mental and physical health.

Disentangling the relationship of subjective cognitive decline and depressive symptoms in the development of cognitive decline and dementia.

INTRODUCTION: Subjective cognitive decline (SCD) and depressive symptoms (DS) frequently co-occur prior to dementia. However, the temporal sequence of their emergence and their combined prognostic value for cognitive decline and dementia is unclear. METHODS: Temporal relationships of SCD, DS and memory decline were examined by latent difference score modeling in a high-aged, population-based cohort (N = 3217) and validated using Cox-regression of dementia-conversion. In 334 cognitively unimpaired SCD-patients from memory-clinics, we examined the association of DS with cognitive decline and with cerebrospinal fluid (CSF) Alzheimer's disease (AD) biomarkers. RESULTS: In the population-based cohort, SCD preceded DS. High DS were associated with increased risk of dementia conversion in individuals with SCD. In SCD-patients from memory-clinics, high DS were associated with greater cognitive decline. CSF Aß42 predicted increasing DS. DISCUSSION: SCD typically precedes DS in the evolution to dementia. SCD-patients from memory-clinics with DS may constitute a high-risk group for cognitive decline. HIGHLIGHTS: Subjective cognitive decline (SCD) precedes depressive symptoms (DS) as memory declines. Emerging or persistent DS after SCD reports predict dementia. In SCD patients, more amyloid pathology relates to increasing DS. SCD patients with DS are at high risk for symptomatic progression.

Altered limbic functional connectivity in individuals with subjective cognitive decline: Converging and diverging findings across Chinese and German cohorts.

INTRODUCTION: It remains unclear whether functional brain networks are consistently altered in individuals with subjective cognitive decline (SCD) of diverse ethnic and cultural backgrounds and whether the network alterations are associated with an amyloid burden. METHODS: Cross-sectional resting-state functional magnetic resonance imaging connectivity (FC) and amyloid-positron emission tomography (PET) data from the Chinese Sino Longitudinal Study on Cognitive Decline and German DZNE Longitudinal Cognitive Impairment and Dementia cohorts were analyzed. RESULTS: Limbic FC, particularly hippocampal connectivity with right insula, was consistently higher in SCD than in controls, and correlated with SCD-plus features. Smaller SCD subcohorts with PET showed inconsistent amyloid positivity rates and FC-amyloid associations across cohorts. DISCUSSION: Our results suggest an early adaptation of the limbic network in SCD, which may reflect increased awareness of cognitive decline, irrespective of amyloid pathology. Different amyloid positivity rates may indicate a heterogeneous underlying etiology in Eastern and Western SCD cohorts when applying current research criteria. Future studies should identify culture-specific features to enrich preclinical Alzheimer's disease in non-Western populations. HIGHLIGHTS: Common limbic hyperconnectivity across Chinese and German subjective cognitive decline (SCD) cohorts was observed. Limbic hyperconnectivity may reflect awareness of cognition, irrespective of amyloid load. Further cross-cultural harmonization of SCD regarding Alzheimer's disease pathology is required.

Genome-wide meta-analysis for Alzheimer's disease cerebrospinal fluid biomarkers.

Amyloid-beta 42 (Aß42) and phosphorylated tau (pTau) levels in cerebrospinal fluid (CSF) reflect core features of the pathogenesis of Alzheimer's disease (AD) more directly than clinical diagnosis. Initiated by the European Alzheimer & Dementia Biobank (EADB), the largest collaborative effort on genetics underlying CSF biomarkers was established, including 31 cohorts with a total of 13,116 individuals (discovery n = 8074; replication n = 5042 individuals). Besides the APOE locus, novel associations with two other well-established AD risk loci were observed; CR1 was shown a locus for Aß42 and BIN1 for pTau. GMNC and C16orf95 were further identified as loci for pTau, of which the latter is novel. Clustering methods exploring the influence of all known AD risk loci on the CSF protein levels, revealed 4 biological categories suggesting multiple Aß42 and pTau related biological pathways involved in the etiology of AD. In functional follow-up analyses, GMNC and C16orf95 both associated with lateral ventricular volume, implying an overlap in genetic etiology for tau levels and brain ventricular volume.

Social support and health-related quality of life among the oldest old - longitudinal evidence from the multicenter prospective AgeCoDe-AgeQualiDe study.

PURPOSE: The aim of this study was to examine the longitudinal within-association between social support and health-related quality of life among the oldest old. METHODS: Longitudinal data (follow-up waves 7 to 9) were used from the multicenter prospective cohort study "Needs, health service use, costs and health-related quality of life in a large sample of oldest-old primary care patients (85 +)" (AgeQualiDe). n = 648 individuals were included in the analytical sample. At FU wave 7, mean age was 88.8 years (SD: 2.9 years, from 85 to 99 years). Social support was quantified using the Lubben Social Network Scale (6-item version). Health-related quality of life was assessed using the EQ-5D-3L including problems in five health dimensions, and its visual analogue scale (EQ VAS). It was adjusted for several covariates in conditional logistic and linear fixed effects regressions. RESULTS: Intraindividual decreases in social support were associated with an increased likelihood of developing problems in 'self-care', 'usual activities', 'pain/discomfort' and 'anxiety/depression' (within individuals over time). In contrast, intraindividual changes in social support were not associated with intraindividual changes in the EQ VAS score. CONCLUSION: Findings indicate a longitudinal intraindividual association between social support and problems, but only in some health dimensions. Further research in this area based on longitudinal studies among the oldest old (from different countries) is required.

Social Support and Functional Decline in the Oldest Old.

OBJECTIVE: Longitudinal studies investigating the link between social support and functional decline are limited among the oldest old. Thus, the aim of this study was to examine whether changes in social support are associated with functional decline among the oldest old longitudinally using panel regression models. METHODS: Longitudinal data from 3 waves (waves 7, 8, and 9) of a multicenter prospective cohort study covering primary care patients aged ≥85 years were used. In the analytical sample, n equaled 624 individuals. The validated Lawton and Brody Instrumental Activities of Daily Living (IADL) scale and the well-established Barthel Index (ADL) were used to quantify functional status. The psychometrically sound Lubben Social Network Scale was used to measure social support. Several potential confounders such as age, marital status, cognitive decline, or depressive symptoms were included in the fixed effects (FE) regression models. RESULTS: Linear FE regressions showed that a decrease in social support is associated with functional decline (IADL: ß = 0.03, p < 0.05; ADL: ß = 0.27, p < 0.05) in men but not in women. With IADL as outcome measure, the interaction term (sex × social support) achieved statistical significance (p < 0.01). With regard to covariates, functional decline (IADL and ADL) was consistently associated with increasing age, an increase in the number of chronic conditions (except for women [ADL]), and cognitive decline (except for men [ADL]). Furthermore, functional decline (ADL) was associated with an increase in depressive symptoms. DISCUSSION: Our findings highlight the meaning of social support for functional status among the oldest old. Finding ways to sustain social support in highest age may be a promising approach in order to postpone functional decline.

Factors Leading to Institutionalization among the Oldest Old: Longitudinal Findings from the AgeCoDe-AgeQualiDe Study.

INTRODUCTION: Due to the strong association between old age and the need for long-term care, the number of individuals in need for care is projected to increase noticeably. The aim of this study was to examine the determinants of institutionalization among the oldest old longitudinally. METHODS: Longitudinal data (follow-up [FU] wave 7-9) were gathered from a multicenter prospective cohort study ("Study on needs, health service use, costs and health-related quality of life in a large sample of oldest old primary care patients [85+]," AgeQualiDe). At FU wave 7, in 2014, complete measures were available for 763 individuals. The average age was 88.9 (standard deviation 2.9) years (range 85-100), and 68% were female. Sociodemographic and health-related independent variables (e.g., depressive symptoms or functioning) were included in the regression model. Institutionalization (admission to assisted living home or nursing home) was used as an outcome measure. Logistic random-effects models were used. RESULTS: Regressions revealed that among oldest old, the odds of being institutionalized were lower for men (odds ratio [OR] = 0.03; 95% confidence interval [CI] 0.00-0.16). Institutionalization was associated with an increased age (OR = 1.27; 95% CI 1.04-1.55). Additionally, widowed individuals (ref. non-widowed) had higher odds of being institutionalized (OR = 8.95; 95% CI 1.61-49.81). Institutionalization was also associated with functional decline (OR = 0.16; 95% CI 0.11-0.23), whereas it was not significantly associated with cognitive decline, depressive symptoms, and social support. CONCLUSION: Our findings stress the importance of gender, age, widowhood, and functional decline for institutionalization among the oldest old. Preventing or at least postponing functional decline might help to delay institutionalization as far as possible.

Effects of APOE e4-allele and mental work demands on cognitive decline in old age: Results from the German Study on Ageing, Cognition, and Dementia in Primary Care Patients (AgeCoDe).

OBJECTIVES: Previous studies have observed protective effects of high mental demands at work on cognitive functioning and dementia risk. However, it is unclear what types of demands drive this effect and whether this effect is subject to a person's genetic risk. We investigated to what extent eight different types of mental demands at work together with the APOE e4 allele, a major risk gene for late-onset Alzheimer's disease, affect cognitive functioning in late life. METHODS/DESIGN: The population-based German Study on Ageing, Cognition, and Dementia in Primary Care Patients (AgeCoDe, n = 2 154) followed cognitively healthy individuals aged 75 years and older in seven assessment waves. Cognitive functioning was assessed via the mini-mental status examination. RESULTS: Mixed-effects modeling (adjusted for education, gender, marital status, stroke, depression, and diabetes) indicated that participants who had an occupational history of working in jobs with high compared to low demands in "Language & Knowledge", "Pattern detection", "Information processing", and "Service" had a slower cognitive decline. APOE e4-allele carriers had an accelerated cognitive decline, but this decline was significantly smaller if they had a medium compared to a low level of demands in contrast to non-carriers. CONCLUSIONS: Our longitudinal observations suggest that cognitive decline could be slowed by an intellectually enriched lifestyle even in risk gene carriers. Fostering intellectual engagement throughout the life-course could be a key prevention initiative to promote better cognitive health in old age.

PLCG2 protective variant p.P522R modulates tau pathology and disease progression in patients with mild cognitive impairment.

A rare coding variant (rs72824905, p.P522R) conferring protection against Alzheimer's disease (AD) was identified in the gene encoding the enzyme phospholipase-C-γ2 (PLCG2) that is highly expressed in microglia. To explore the protective nature of this variant, we employed latent process linear mixed models to examine the association of p.P522R with longitudinal cognitive decline in 3595 MCI patients, and in 10,097 individuals from population-based studies. Furthermore, association with CSF levels of pTau181, total tau, and Aß1-42 was assessed in 1261 MCI patients. We found that MCI patients who carried the p.P522R variant showed a slower rate of cognitive decline compared to non-carriers and that this effect was mediated by lower pTau181 levels in CSF. The effect size of the association of p.P522R with the cognitive decline and pTau181 was similar to that of APOE-ε4, the strongest genetic risk factor for AD. Interestingly, the protective effect of p.P522R was more pronounced in MCI patients with low Aß1-42 levels suggesting a role of PLCG2 in the response to amyloid pathology. In line with this hypothesis, we observed no protective effect of the PLCG2 variant on the cognitive decline in population-based studies probably due to the lower prevalence of amyloid positivity in these samples compared to MCI patients. Concerning the potential biological underpinnings, we identified a network of co-expressed proteins connecting PLCG2 to APOE and TREM2 using unsupervised co-regulatory network analysis. The network was highly enriched for the complement cascade and genes differentially expressed in disease-associated microglia. Our data show that p.P522R in PLCG2 reduces AD disease progression by mitigating tau pathology in the presence of amyloid pathology and, as a consequence, maintains cognitive function. Targeting the enzyme PLCG2 might provide a new therapeutic approach for treating AD.

Correction to: A nonsynonymous mutation in PLCG2 reduces the risk of Alzheimer's disease, dementia with Lewy bodies and frontotemporal dementia, and increases the likelihood of longevity.

The IPDGC (The International Parkinson Disease Genomics Consortium) and EADB (Alzheimer Disease European DNA biobank) are listed correctly as an author to the article, however, they were incorrectly listed more than once.

Mild cognitive impairment and quality of life in the oldest old: a closer look.

PURPOSE: Mild cognitive impairment (MCI) is a widespread phenomenon, especially affecting older individuals. We will analyze in how far MCI affects different facets of quality of life (QOL). METHODS: We used a sample of 903 participants (110 with MCI) from the fifth follow-up of the German Study on Ageing, Cognition, and Dementia in Primary Care Patients (AgeCoDe), a prospective longitudinal study, to analyze the effects of MCI on different facets of the WHOQOL-OLD. We controlled for age, gender, marital status, education, living situation, daily living skills, and the ability to walk, see, and hear. RESULTS: Univariate analyses showed that individuals with MCI exhibited lower QOL with regard to the facets autonomy; past, present, and future activities; social participation; and intimacy, but less fears related to death and dying. No significant difference was shown with regard to the facet sensory abilities. In multivariate analyses controlling for age, gender, marital status, education, living situation, daily living skills, and the ability to walk, see and hear, MCI-status was significantly associated with QOL in the facet autonomy. CONCLUSION: Effects of MCI go beyond cognition and significantly impact the lives of those affected. Further research and practice will benefit from utilizing specific facets of QOL rather than a total score.

Prediction of dementia of Alzheimer type by different types of subjective cognitive decline.

INTRODUCTION: Subjective cognitive decline (SCD) is a risk condition for dementia, including dementia of Alzheimer type (DAT). METHODS: We report sensitivity, specificity, positive and negative predictive values (PPV, NPV) for conversion to all-cause dementia, and DAT in different SCD types (decline in memory, assocated worries, longitudinal consitency, of the AgeCoDe study (n = 2.402, 12 years follow-up). RESULTS: 82.7% of those converting to any dementia and 84.4% of those converting with DAT at follow-up, reported memory decline and fulfilled criteria of SCD at least at one time point before. SCD with worries at two consecutive time points showed a specificity of 92.2% for any dementia and also for DAT as well as a PPV of 44.3% for any dementia and of 36.9% for DAT at follow-up at the expense of low sensitivity. DISCUSSION: Different SCD subtypes were either sensitive or specific for future all-cause dementia and DAT in cognitively unimpaired individuals. Modest PPV of the most specific SCD subtypes were achieved in this low prevalence population.

A nonsynonymous mutation in PLCG2 reduces the risk of Alzheimer's disease, dementia with Lewy bodies and frontotemporal dementia, and increases the likelihood of longevity.

The genetic variant rs72824905-G (minor allele) in the PLCG2 gene was previously associated with a reduced Alzheimer's disease risk (AD). The role of PLCG2 in immune system signaling suggests it may also protect against other neurodegenerative diseases and possibly associates with longevity. We studied the effect of the rs72824905-G on seven neurodegenerative diseases and longevity, using 53,627 patients, 3,516 long-lived individuals and 149,290 study-matched controls. We replicated the association of rs72824905-G with reduced AD risk and we found an association with reduced risk of dementia with Lewy bodies (DLB) and frontotemporal dementia (FTD). We did not find evidence for an effect on Parkinson's disease (PD), amyotrophic lateral sclerosis (ALS) and multiple sclerosis (MS) risks, despite adequate sample sizes. Conversely, the rs72824905-G allele was associated with increased likelihood of longevity. By-proxy analyses in the UK Biobank supported the associations with both dementia and longevity. Concluding, rs72824905-G has a protective effect against multiple neurodegenerative diseases indicating shared aspects of disease etiology. Our findings merit studying the PLCγ2 pathway as drug-target.