Association of plasma biomarkers with cognition, cognitive decline, and daily function across and within neurodegenerative diseases: Results from the Ontario Neurodegenerative Disease Research Initiative

INTRODUCTION

We investigated whether novel plasma biomarkers are associated with cognition, cognitive decline, and functional independence in activities of daily living across and within neurodegenerative diseases.

METHODS

Glial fibrillary acidic protein (GFAP), neurofilament light chain (NfL), phosphorylated tau (p-tau)181 and amyloid beta (Aβ)42/40 were measured using ultra-sensitive Simoa immunoassays in 44 healthy controls and 480 participants diagnosed with Alzheimer's disease/mild cognitive impairment (AD/MCI), Parkinson's disease (PD), frontotemporal dementia (FTD) spectrum disorders, or cerebrovascular disease (CVD).

RESULTS

GFAP, NfL, and/or p-tau181 were elevated among all diseases compared to controls, and were broadly associated with worse baseline cognitive performance, greater cognitive decline, and/or lower functional independence. While GFAP, NfL, and p-tau181 were highly predictive across diseases, p-tau181 was more specific to the AD/MCI cohort. Sparse associations were found in the FTD and CVD cohorts and for Aβ42/40 .

DISCUSSION

GFAP, NfL, and p-tau181 are valuable predictors of cognition and function across common neurodegenerative diseases, and may be useful in specialized clinics and clinical trials.

Association of Dual-Task Gait Cost and White Matter Hyperintensity Burden Poststroke: Results From the ONDRI

BACKGROUND

Acute change in gait speed while performing a mental task [dual-task gait cost (DTC)], and hyperintensity magnetic resonance imaging signals in white matter are both important disability predictors in older individuals with history of stroke (poststroke). It is still unclear, however, whether DTC is associated with overall hyperintensity volume from specific major brain regions in poststroke.

METHODS

This is a cohort study with a total of 123 older (69 ± 7 years of age) participants with history of stroke were included from the Ontario Neurodegenerative Disease Research Initiative. Participants were clinically assessed and had gait performance assessed under single- and dual-task conditions. Structural neuroimaging data were analyzed to measure both, white matter hyperintensity (WMH) and normal appearing volumes. Percentage of WMH volume in frontal, parietal, occipital, and temporal lobes as well as subcortical hyperintensities in basal ganglia + thalamus were the main outcomes. Multivariate models investigated associations between DTC and hyperintensity volumes, adjusted for age, sex, years of education, global cognition, vascular risk factors, APOE4 genotype, residual sensorimotor symptoms from previous stroke and brain volume.

RESULTS

There was a significant positive global linear association between DTC and hyperintensity burden (adjusted Wilks' λ = .87, P = .01). Amongst all WMH volumes, hyperintensity burden from basal ganglia + thalamus provided the most significant contribution to the global association (adjusted β = .008, η² = .03; P = .04), independently of brain atrophy.

CONCLUSIONS

In poststroke, increased DTC may be an indicator of larger white matter damages, specifically in subcortical regions, which can potentially affect the overall cognitive processing and decrease gait automaticity by increasing the cortical control over patients' locomotion.

Characteristics of the Ontario Neurodegenerative Disease Research Initiative cohort

INTRODUCTION

Understanding synergies between neurodegenerative and cerebrovascular pathologies that modify dementia presentation represents an important knowledge gap.

METHODS

This multi-site, longitudinal, observational cohort study recruited participants across prevalent neurodegenerative diseases and cerebrovascular disease and assessed participants comprehensively across modalities. We describe univariate and multivariate baseline features of the cohort and summarize recruitment, data collection, and curation processes.

RESULTS

We enrolled 520 participants across five neurodegenerative and cerebrovascular diseases. Median age was 69 years, median Montreal Cognitive Assessment score was 25, median independence in activities of daily living was 100% for basic and 93% for instrumental activities. Spousal study partners predominated; participants were often male, White, and more educated. Milder disease stages predominated, yet cohorts reflect clinical presentation.

DISCUSSION

Data will be shared with the global scientific community. Within-disease and disease-agnostic approaches are expected to identify markers of severity, progression, and therapy targets. Sampling characteristics also provide guidance for future study design.

APOE alleles are associated with sex-specific structural differences in brain regions affected in Alzheimer's disease and related dementia

Alzheimer's disease is marked by intracellular tau aggregates in the medial temporal lobe (MTL) and extracellular amyloid aggregates in the default network (DN). Here, we examined codependent structural variations between the MTL's most vulnerable structure, the hippocampus (HC), and the DN at subregion resolution in individuals with Alzheimer's disease and related dementia (ADRD). By leveraging the power of the approximately 40,000 participants of the UK Biobank cohort, we assessed impacts from the protective APOE ɛ2 and the deleterious APOE ɛ4 Alzheimer's disease alleles on these structural relationships. We demonstrate ɛ2 and ɛ4 genotype effects on the inter-individual expression of HC-DN co-variation structural patterns at the population level. Across these HC-DN signatures, recurrent deviations in the CA1, CA2/3, molecular layer, fornix's fimbria, and their cortical partners related to ADRD risk. Analyses of the rich phenotypic profiles in the UK Biobank cohort further revealed male-specific HC-DN associations with air pollution and female-specific associations with cardiovascular traits. We also showed that APOE ɛ2/2 interacts preferentially with HC-DN co-variation patterns in estimating social lifestyle in males and physical activity in females. Our structural, genetic, and phenotypic analyses in this large epidemiological cohort reinvigorate the often-neglected interplay between APOE ɛ2 dosage and sex and link APOE alleles to inter-individual brain structural differences indicative of ADRD familial risk.

Genome-wide identification of the genetic basis of amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is a complex disease that leads to motor neuron death. Despite heritability estimates of 52%, genome-wide association studies (GWASs) have discovered relatively few loci. We developed a machine learning approach called RefMap, which integrates functional genomics with GWAS summary statistics for gene discovery. With transcriptomic and epigenetic profiling of motor neurons derived from induced pluripotent stem cells (iPSCs), RefMap identified 690 ALS-associated genes that represent a 5-fold increase in recovered heritability. Extensive conservation, transcriptome, network, and rare variant analyses demonstrated the functional significance of candidate genes in healthy and diseased motor neurons and brain tissues. Genetic convergence between common and rare variation highlighted KANK1 as a new ALS gene. Reproducing KANK1 patient mutations in human neurons led to neurotoxicity and demonstrated that TDP-43 mislocalization, a hallmark pathology of ALS, is downstream of axonal dysfunction. RefMap can be readily applied to other complex diseases.

Matrin3: Disorder and ALS Pathogenesis

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder characterized by the degeneration of both upper and lower motor neurons in the brain and spinal cord. ALS is associated with protein misfolding and inclusion formation involving RNA-binding proteins, including TAR DNA-binding protein (TDP-43) and fused in sarcoma (FUS). The 125-kDa Matrin3 is a highly conserved nuclear DNA/RNA-binding protein that is implicated in many cellular processes, including binding and stabilizing mRNA, regulating mRNA nuclear export, modulating alternative splicing, and managing chromosomal distribution. Mutations in MATR3, the gene encoding Matrin3, have been identified as causal in familial ALS (fALS). Matrin3 lacks a prion-like domain that characterizes many other ALS-associated RNA-binding proteins, including TDP-43 and FUS, however, our bioinformatics analyses and preliminary studies document that Matrin3 contains long intrinsically disordered regions that may facilitate promiscuous interactions with many proteins and may contribute to its misfolding. In addition, these disordered regions in Matrin3 undergo numerous post-translational modifications, including phosphorylation, ubiquitination and acetylation that modulate the function and misfolding of the protein. Here we discuss the disordered nature of Matrin3 and review the factors that may promote its misfolding and aggregation, two elements that might explain its role in ALS pathogenesis.

Rare Variant Burden Analysis within Enhancers Identifies CAV1 as an ALS Risk Gene

Amyotrophic lateral sclerosis (ALS) is an incurable neurodegenerative disease. CAV1 and CAV2 organize membrane lipid rafts (MLRs) important for cell signaling and neuronal survival, and overexpression of CAV1 ameliorates ALS phenotypes in vivo. Genome-wide association studies localize a large proportion of ALS risk variants within the non-coding genome, but further characterization has been limited by lack of appropriate tools. By designing and applying a pipeline to identify pathogenic genetic variation within enhancer elements responsible for regulating gene expression, we identify disease-associated variation within CAV1/CAV2 enhancers, which replicate in an independent cohort. Discovered enhancer mutations reduce CAV1/CAV2 expression and disrupt MLRs in patient-derived cells, and CRISPR-Cas9 perturbation proximate to a patient mutation is sufficient to reduce CAV1/CAV2 expression in neurons. Additional enrichment of ALS-associated mutations within CAV1 exons positions CAV1 as an ALS risk gene. We propose CAV1/CAV2 overexpression as a personalized medicine target for ALS.

3293Atherothrombotic risk and outcomes following guided de-escalation of antiplatelet treatment in patients with acute coronary syndrome:a post-hoc analysis of the TROPICAL-ACS trial

Background

A de-escalation of P2Y12-inhibitor treatment guided by platelet function testing (PFT) has been identified as a safe and alternative treatment strategy in acute coronary syndrome (ACS) patients undergoing percutaneous coronary intervention (PCI). However, no specific data are available on the efficacy of such strategy in patients with high atherothrombotic risk (ATR).

Purpose

To investigate the safety and efficacy of guided de-escalation of P2Y12-inhibitor treatment in patients with low- vs. high-ATR.

Methods

The TROPICAL-ACS trial randomized 2,610 biomarker-positive ACS patients 1:1 to either conventional treatment with prasugrel for 12 months (control group) or to a PFT guided de-escalation treatment strategy (guided de-escalation group). The primary endpoint was defined as the composite of cardiovascular mortality (CVM), myocardial infarction (MI), stroke, and clinically overt bleeding (bleeding ≥ grade 2 according to the BARC criteria). The ischemic endpoint was defined as the composite of CVM, MI or stroke. We used semi-parametric Cox regression analysis and interaction testing to assess the effect of low- vs. high-ATR on the primary and ischemic endpoints. High-ATR was defined as one of the following: (i) age ≥65 years or (ii) age <65 and either history of peripheral artery disease or at least two of the following risk-factors: diabetes mellitus, current smoking or renal dysfunction.

Results

Patients with high- (n=990) versus low-ATR (n=1,620) exhibited a higher risk for the primary endpoint (11.0% vs. 6.7%; HR 1.67; 95% CI 1.28–2.18; p<0.001). Guided de-escalation was non-inferior to conventional treatment for the primary endpoint in both patients with high- (10.5% vs. 11.5%; pnon-inferiority = 0.029; Figure 1A) and low-ATR (5.6% vs. 7.7%; pnon-inferiority=0.001; Figure 1B). Moreover, there was no significant interaction in the prognostic value of guided de-escalation between high- and low-ATR groups for both the primary (HR 0.90 [0.61–1.32]; p=0.586 in patients with high-ART vs. 0.71 [0.48–1.04; p=0.082 in patients with low-ATR; pinteraction= 0.394) and combined ischemic endpoints (HR 0.83 [0.44–1.56]; p=0.567 in patients with high-ATR vs. 0.68 [0.35–1.34]; p=0.262 in patients with low-ATR; pinteraction =0.666).

Kaplan-Meier curves

Conclusion

A guided DAPT de-escalation strategy appears to be safe and effective in ACS patients regardless of the atherothrombotic risk. Further studies are needed for refining antiplatelet treatment strategies in ACS patients with varying levels of atherothrombotic risk.

Acknowledgement/Funding

Klinikum der Universität München, Roche Diagnostics, Eli Lilly, and Daiichi Sankyo.

P1966Impact of coronary artery calcification on long-term outcomes after implantation of first and second-generation drug-eluting stents: a patient-level analysis of 18 randomized trials

Background

Available data on the long-term impact of coronary artery calcification (CAC) after percutaneous coronary intervention (PCI) with drug-eluting stents (DES) are limited.

Purpose

We evaluated the long-term impact of CAC on outcomes after PCI and the respective performance of first- and second-generation DES.

Methods

We pooled patient-level data from 18 randomized trials evaluating DES categorized according to the presence of angiographic core lab-confirmed moderate or severe CAC in any target lesion. Outcome measures of interest were the patient-oriented composite endpoint (POCE; death, myocardial infarction [MI], or any revascularization), the device-oriented composite endpoint of target lesion failure (TLF; cardiac death, target vessel MI or ischemia-driven target lesion revascularization), and definite or probable stent thrombosis (ST). Multivariable Cox proportional regression with study as a random effect was used to assess 5-year outcomes.

Results

A total of 19,833 patients were included. Moderate or severe CAC was present in 6211 (31.3%) patients and associated with increased 5-year risk of the POCE (adjHR 1.12, 95% CI 1.05–1.20, p<0.001), TLF (adjHR 1.21, 95% CI 1.09–1.35, p<0.001), and a trend for greater ST (adjHR 1.24, 95% CI 0.99–1.54, p=0.06). In patients with CAC, second-generation DES were associated with a reduction in the 5-year risk of TLF and ST, and a trend for reduced POCE compared with first-generation DES (Table).

Conclusion

In this large-scale study, target lesion moderate or severe CAC was associated with adverse patient- and device-related outcomes at 5 years, risks that were reduced but not eliminated with second-generation DES.

Acknowledgement/Funding

This investigator-sponsored study was funded by Abbott Vascular.

Diabetic specific aspects in antithrombotic therapy in patients with coronary artery disease

The use of combined antithrombotic medication in optimal dosages is mandatory for diabetic patients. Moreover, specific antiplatelet therapy in DM has been shown to reduce early and late atherothrombotic events in patients referred for elective and acute angiography and intervention as well as for secondary prevention of recurrent ischemic events in patients with coronary artery disease (CAD). Among these antiplatelet agents prasugrel has been recently demonstrated to lower adverse events in diabetic patients with acute coronary syndromes (ACS) significantly more effective than clopidogrel without increasing severe bleeding hazards. Also glycoprotein IIb-IIIa receptor inhibitors (GPI) had a greater effect in diabetic subjects with ACS undergoing percutaneous coronary intervention (PCI) on adverse clinical events compared to non-diabetics. In contrast to antiplatelet therapy, all commercially available antithrombins except enoxaparin have been shown to be equal or less effective in diabetics compared to non-diabetics. Enoxaparin was superior to unfractionated heparin (UFH) in reducing adverse events in diabetics with acute ST-elevation myocardial infarction (STEMI) undergoing thrombolytic therapy. The role of several new antithrombins, i.e. direct factor Xa inhibitors or direct antithrombins in diabetic patients with stable or unstable CAD is still under investigation.

The use of statins may prolong survival of non-small cell lung cancer patients: Final update from 1,205 cases

7638

Background: Hypercholesterolemia is one of the most common morbidities in United States. Statins have been proven as effective cholesterol-lowering agents and have been widely used in this country. They have been reported reducing the incidence and risk of various cancer types. However, the impact of using statins on the survival of 407 patients with diagnosed non-small cell lung cancer (NSCLC) was initially reported (Wang, et al. Abstract #7149, ASCO Meeting 2006). Methods: 1,233 patients with diagnosed non-small cell lung cancer were identified from the Tumor Registry at Henry Ford Health System between January 1999 and December 2004. The data from 1,206 patients were extracted from their available electronic medical records. Statistical analyses were performed and stratified for statin users versus non statin users. Results: Data from 1,205 eligible patients were included in this updated report. There were 391 patients with hypercholesterolemia, 250 of them were statin users at the time of their non-small cell lung cancer diagnosis. Average age was 68 (range 46–90) years for statin users and 65.9 (range 29–94) years for non statin users. Overall median survival of 1,205 subjects was 9.85 months. After stratifying for statin use, the median survival of statin users was 13.9 (95% C.I. 9.9 - 17.4) months while the median survival of non statin users was 9.6 (95% C.I. 8.1 - 10.4) months, with a P value of 0.0001. After having several prognostic variables (age, stage, co-morbids, other cancers, performance status, anti-cancer therapies, and serum albumin, etc.) adjusted, statin use still demonstrated protection from death with a hazard ratio of 0.74 (95% C.I. 0.59 - 0.95, P=0.017). Conclusion: The trend of survival benefit from NSCLC among statin users was shown in our previous report and it has maintained with further enhanced statistical significance in this update. Though statin use will unlikely become an independent anti-cancer regimen by itself, the choice of continuation of statin among NSCLC patients may still provide survival benefit to this population. The favorable impact of statin use on NSCLC patients is intriguing; a prospective study of co-morbidity management with statins in patients with non-small cell lung cancer is warranted.

No significant financial relationships to disclose.

The use of statins may prolong survival of non-small cell lung cancer patients

7149

Background: Hypercholesterolemia is one of the most common morbidities in United States. Statins have been proven as effective cholesterol-lowering agents and have been widely used in this country. They have been reported reducing the incidence and risk of various cancer types. However, the impact of using statins on the survival of patients with diagnosed non-small cell lung cancer is unknown. Methods: Ongoing retrospective study involves a cohort of 1,233 patients with diagnosed non-small cell lung cancer. Patients were identified from the Tumor Registry at Henry Ford Health System between January 1999 and December 2004. To date, the electronic medical records from 407 of the 1,233 cases were reviewed. Statistical analyses were performed and stratified for statin users versus non statin users. Results: Data from 407 patients were included in this analysis. There were 109 patients with hypercholesterolemia, 54 of them were statin users at the time of their non-small cell lung cancer diagnosis. Average age was 70 (range 46–85) years for statin users and 65 (range 29–93) years for non statin users. Median survival of 407 subjects was 9.82 months. After stratifying for statin use, the median survival of statin users was 12.38 months while the median survival of non statin users was 9.75 months, with a p value of 0.012. Conclusion: Though small sample size, this study is the first time ever suggesting a possible survival benefit of statin use in patients with non-small cell lung cancer who have received their standard anti-tumor regimens. Other variables that may contribute to this result will be further clarified and discussed after completing the data collection and analysis of this entire cohort. Based on our preliminary result, a prospective study of co-morbidity management with statins in patients with non-small cell lung cancer is warranted.

No significant financial relationships to disclose.

The use of statins and the effect on survival in patients with small cell lung cancer

17121

Background: Hypercholesterolemia is one of the most common morbidities in United States. Statins have been proven as effective cholesterol-lowering agents and have been widely used in this country. They have been reported reducing the incidence and risk of various cancer types. However, the impact of using statins on the survival of patients with diagnosed small cell lung cancer is unknown. Methods: A retrospective study involved a cohort of 282 patients with diagnosed small cell lung cancer. Patients were identified from the Tumor Registry at Henry Ford Health System between January 1995 and December 2002. Electronic medical records of these patients were reviewed. Statistical analyses were performed and stratified for statin users versus non statin users. Results: Out of 282 patients, there were 73 patients with hypercholesterolemia, 37 of them were statin users at the time of their small cell lung cancer diagnosis. Average age was 65 (range 34–87) years for non statin users and 69 (range 52–85) years for statin users. Median survival of 282 subjects was 7.37 months. After stratifying for statin use, the median survival of statin users was 8.66 months while the median survival of non statin users was 7.17 months (p = 0.29). Conclusion: Though slightly prolonged median survival in statin-users was observed, no survival benefit is demonstrated from this patient population. Factors that may have contributed to this result will be further discussed. With the trend of an increase in median survival among statin users, whenever possible, continuation of statins as co-morbidity management may still benefit patients with small cell lung cancer, during their receiving standard anti-tumor therapies.

No significant financial relationships to disclose.

Fibrinolytic dysfunction in insulin-resistant women with previous gestational diabetes

BACKGROUND

Women with a history of gestational diabetes (p-GDM) are at increased risk of developing type 2 diabetes mellitus (DM2) later in life, and therefore at increased risk for future cardiovascular disease.

MATERIALS AND METHODS

Three months after delivery we investigated the plasma levels of plasminogen activator inhibitor type 1 (PAI-1), tissue plasminogen activator (t-PA), fibrinogen and von Willebrand factor (vWF) in 74 women with p-GDM and 20 healthy females with normal glucose tolerance during and after pregnancy, as well as the relation of fibrinolytic parameters to insulin resistance and glycaemic control. All women underwent an oral (OGTT) as well as an intravenous glucose tolerance test (FSIGT). Mathematical model analysis disclosed that 50% (n=37 each) of the p-GDM subjects had normal (NIS) or impaired (IIS) insulin sensitivity. Parameters of interest were determined using commercially available test systems.

RESULTS

Women with p-GDM and IIS had significantly increased body fat mass (BFM) (P<or=0.001) compared with women with p-GDM and NIS and controls, whereas the waist to hip ratio (WHR) was similar in both p-GDM groups but was higher compared with the controls (P<or=0.001). Mean PAI-1 and t-PA as well as fasting and stimulated plasma concentrations of proinsulin, C-peptide and insulin were elevated, whereas the disposition index was lower in women with p-GDM and IIS compared with women with p-GDM and NIS and the controls (P<0.001). Plasma levels of fibrinogen and vWF did not differ between the groups. Obese women with IIS had higher PAI-1 levels than lean women with IIS (P<or=0.001). PAI-1 inversely correlated with the insulin sensitivity index (SI) but only in women with IIS (P<0.0001). On regression analysis, only fasting proinsulin and WHR remained significant independent predictors of PAI-1 elevation in IIS (P<or=0.0001 and P<or=0.001). The PAI-1/SI ratio was elevated in women with IIS independently of their glucose tolerance status (P<0.001 vs. NIS and controls).

CONCLUSIONS

Plasminogen activator inhibitor type 1 is elevated in p-GDM women with IIS and depends on plasma proinsulin and abdominal obesity. An increase of the PAI-1/SI ratio further characterizes obese insulin-resistant p-GDM women who may be at risk for diabetes and angiopathy.