The biomarker-based diagnosis of Alzheimer's disease. 1-ethical and societal issues

Enhancing post-diagnostic care in Australian memory clinics: Health professionals' insights into current practices, barriers and facilitators, and desirable support

INTRODUCTION

Providing integrated and evidence-based support to individuals and families following a diagnosis of dementia is essential in order to optimise their quality of life and assist them to live well. Memory clinics provide multidisciplinary services specialising in the assessment and post-diagnostic treatment of people with dementia. This study sought to identify current practices, barriers and facilitators to provision of postdiagnostic support and to obtain health professionals' opinion of ideal post-diagnostic support to be offered in Australian memory clinics.

METHODOLOGY

This was a cross-sectional qualitative exploratory study. Data was collected from health professionals familiar with the process of diagnosis and post-diagnostic support through two expert panel meetings (n = 22). In addition, 5 focus groups (n = 22) were conducted including health professionals who are employed in Australian memory clinics. Data was collected between October 2020 and November 2021. Reflexive thematic analysis was undertaken.

RESULTS

Seven themes and three subthemes were identified under the three topics: Current Practices, Barriers and Facilitators, and Desirable Support. Themes relating to Current Practices were: Tailored Communication and feedback about diagnosis; Prescription of medications and follow-up; and Referrals to health and community services. Themes relating to Barriers and Facilitators were: The structure of the current system; Lack of funding; Lack of resources; Call for government investment. Themes relating to Desirable support were: A key/single point of support; Cognitive interventions; and Counselling and education.

CONCLUSION

Post-diagnostic support in Australian memory clinics focused primarily on ensuring people understood their diagnosis, information about postdiagnostic support was provided, and dementia medications were prescribed. There were notable differences in practices in metropolitan compared to regional areas. A key concern was the need for increased funding, particularly to support the establishment of a single point of contact to facilitate continuity of care.

Impact of sharing Alzheimer's disease biomarkers with individuals without dementia: A systematic review and meta-analysis of empirical data

INTRODUCTION

We conducted a systematic literature review and meta-analysis of empirical evidence on expected and experienced implications of sharing Alzheimer's disease (AD) biomarker results with individuals without dementia.

METHODS

PubMed, Embase, APA PsycInfo, and Web of Science Core Collection were searched according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Results from included studies were synthesized, and quantitative data on psychosocial impact were meta-analyzed using a random-effects model.

RESULTS

We included 35 publications. Most personal stakeholders expressed interest in biomarker assessment. Learning negative biomarker results led to relief and sometimes frustration, while positive biomarkers induced anxiety but also clarity. Meta-analysis of five studies including 2012 participants (elevated amyloid = 1324 [66%], asymptomatic = 1855 [92%]) showed short-term psychological impact was not significant (random-effect estimate = 0.10, standard error = 0.23, P = 0.65). Most professional stakeholders valued biomarker testing, although attitudes and practices varied considerably.

DISCUSSION

Interest in AD biomarker testing was high and sharing their results did not cause psychological harm.

HIGHLIGHTS

Most personal stakeholders expressed interest in Alzheimer's disease biomarker assessment. Personal motivations included gaining insight, improving lifestyle, or preparing for the future. There was no short-term psychological impact of sharing biomarker status, implying it can be safe. Most professional stakeholders valued biomarker testing, believing the benefits outweigh the risk. Harmonized guidelines on biomarker testing and sharing results are required.

A comparison of diagnostic performance of word-list and story recall tests for biomarker-determined Alzheimer's disease

BACKGROUND

Wordlist and story recall tests are routinely employed in clinical practice for dementia diagnosis. In this study, our aim was to establish how well-standard clinical metrics compared to process scores derived from wordlist and story recall tests in predicting biomarker determined Alzheimer's disease, as defined by CSF ptau/Aβ42 ratio.

METHODS

Data from 295 participants (mean age = 65 ± 9.) were drawn from the University of Wisconsin - Madison Alzheimer's Disease Research Center (ADRC) and Wisconsin Registry for Alzheimer's Prevention (WRAP). Rey's Auditory Verbal Learning Test (AVLT; wordlist) and Logical Memory Test (LMT; story) data were used. Bayesian linear regression analyses were carried out with CSF ptau/Aβ42 ratio as outcome. Sensitivity analyses were carried out with logistic regressions to assess diagnosticity.

RESULTS

LMT generally outperformed AVLT. Notably, the best predictors were primacy ratio, a process score indexing loss of information learned early during test administration, and recency ratio, which tracks loss of recently learned information. Sensitivity analyses confirmed this conclusion.

CONCLUSIONS

Our study shows that story recall tests may be better than wordlist tests for detection of dementia, especially when employing process scores alongside conventional clinical scores.

Biomarkers of aging

Aging biomarkers are a combination of biological parameters to (i) assess age-related changes, (ii) track the physiological aging process, and (iii) predict the transition into a pathological status. Although a broad spectrum of aging biomarkers has been developed, their potential uses and limitations remain poorly characterized. An immediate goal of biomarkers is to help us answer the following three fundamental questions in aging research: How old are we? Why do we get old? And how can we age slower? This review aims to address this need. Here, we summarize our current knowledge of biomarkers developed for cellular, organ, and organismal levels of aging, comprising six pillars: physiological characteristics, medical imaging, histological features, cellular alterations, molecular changes, and secretory factors. To fulfill all these requisites, we propose that aging biomarkers should qualify for being specific, systemic, and clinically relevant.

Ethical Aspects of Prodromal Synucleinopathy Prognostic Counseling

Alpha-synucleinopathies can be identified in their prodromal phase, raising several ethical issues. In this review, we first provide definitions of prodromal α-synucleinopathies and discuss the importance of distinguishing between prodromes and risk factors. Next, we discuss the implications of a diagnosis of prodromal α-synucleinopathy and considerations regarding prognostic counseling in both clinical and research settings. We review available data on patient preferences regarding disclosure as well as providers' perspectives. We examine the pros and cons of disclosing a diagnosis of prodromal α-synucleinopathy, taking into consideration the differences between clinical and research settings. Asking about willingness to know in clinical and research settings and the shared decision-making process applied to prognostic counseling is discussed. Concerning research settings, ethical aspects regarding clinical trials are addressed. Availability of direct-to-consumer technologies will likely lead to novel contexts requiring prognostic counseling, and future neuroprotective or neuromodulating treatments may require further considerations on the timing, role, and importance of prognostic counseling. Recommendations on how to address ethical gaps should be a priority for patients, medical professional societies, and research workgroups. Ethical issues must be considered as an integral part of the overall clinical and research approach to prodromal synucleinopathies.

Change in the Quick Dementia Rating System Across Time in Older Adults with and without Cognitive Impairment

BACKGROUND

The Quick Dementia Rating System (QDRS) is a brief, informant-reported dementia staging tool that approximates scores on the Clinical Dementia Rating Scale in patients with Alzheimer's disease (AD).

OBJECTIVE

The current study sought to examine change in the QDRS across time, which is necessary for clinical and research efforts.

METHODS

One-hundred ten older adults (intact, mild cognitive impairment [MCI], mild AD, classified with Alzheimer's Disease Neuroimaging Initiative criteria) were rated on the QDRS by an informant and had an amyloid positron emission tomography scan at baseline. The informant re-rated each participant on the QDRS after one year. Dependent t-tests compared the entire sample and various subgroups (e.g., cognitive status, amyloid status) on baseline and follow-up QDRS scores.

RESULTS

In the entire sample, the Total score on the QDRS significantly increased (i.e., worsened) on follow-up (p < 0.001). When subgroups were analyzed, the MCI and mild AD subjects showed increasing (i.e., worsening) QDRS Total scores (both p < 0.001), but the intact subjects remained stable over time (p = 0.28). Additionally, those classified as being amyloid positive at baseline showed significantly increased QDRS Total scores at follow-up (p < 0.001) compared to those who were amyloid negative at baseline, whose QDRS Total scores remained stable over time (p = 0.63).

CONCLUSION

The QDRS can potentially demonstrate worsening functioning status across one year, especially in those who have MCI or mild AD and those who are amyloid positive. Therefore, the current results preliminarily suggest that the QDRS may provide an efficient tool for tracking progression in clinical trials in AD.

Clinical research in dementia: A perspective on implementing innovation

The increasing global prevalence of dementia demands concrete actions that are aimed strategically at optimizing processes that drive clinical innovation. The first step in this direction requires outlining hurdles in the transition from research to practice. The different parties needed to support translational processes have communication mismatches; methodological gaps hamper evidence-based decision-making; and data are insufficient to provide reliable estimates of long-term health benefits and costs in decisional models. Pilot projects are tackling some of these gaps, but appropriate methods often still need to be devised or adapted to the dementia field. A consistent implementation perspective along the whole translational continuum, explicitly defined and shared among the relevant stakeholders, should overcome the "research-versus-adoption" dichotomy, and tackle the implementation cliff early on. Concrete next steps may consist of providing tools that support the effective participation of heterogeneous stakeholders and agreeing on a definition of clinical significance that facilitates the selection of proper outcome measures.

Considerations regarding a diagnosis of Alzheimer's disease before dementia: a systematic review

BACKGROUND

The NIA-AA research framework proposes a purely biological definition of Alzheimer's disease (AD). This implies that AD can be diagnosed based on biomarker abnormalities, irrespective of clinical manifestation. While this brings opportunities, it also raises challenges. We aimed to provide an overview of considerations regarding the disclosure of AD pathology before the onset of dementia.

METHODS

A systematic literature review was conducted and reported according to PRISMA guidelines. We searched PubMed, Embase, APA PsycINFO, and Web of Science Core Collection (on 10 December 2020) for references on conveying AD biomarker results to individuals without dementia. Our query combined variations on the terms Alzheimer's disease, disclosure, or diagnosis, preclinical or prodromal, and biomarkers. Two reviewers independently screened the resulting 6860 titles and abstracts for eligibility and examined 162 full-text records for relevance. We included theoretical articles in English, on communicating amyloid and/or tau results to individuals with mild cognitive impairment, subjective cognitive decline, or normal cognition. MAXQDA-software was used for inductive data analysis.

RESULTS

We included 27 publications. From these, we extracted 26 unique considerations, which we grouped according to their primary relevance to a clinical, personal, or societal context. Clinical considerations included (lack of) validity, utility, and disclosure protocols. Personal considerations covered psychological and behavioral implications, as well as the right to (not) know. Finally, societal considerations comprised the risk of misconception, stigmatization, and discrimination. Overall, views were heterogeneous and often contradictory, with emphasis on harmful effects.

CONCLUSIONS

We found 26 diverse and opposing considerations, related to a clinical, personal, or societal context, which are relevant to diagnosing AD before dementia. The theoretical literature tended to focus on adverse impact and rely on common morality, while the motivation for and implications of biomarker testing are deeply personal. Our findings provide a starting point for clinicians to discuss biomarker-based diagnosis with their patients, which will become even more relevant in light of the conditional approval of a first disease-modifying drug for AD.

Ethics of Early Intervention in Alzheimer's Disease

Alzheimer's disease (AD) research, treatment, and prevention focus increasingly on developing personalized interventions based on personal genetic, biological, phenotypic data, for early intervention (EI) to limit harm. This approach has much to recommend it, but important ethical and philosophical challenges follow that should be considered, which we analyze here. We argue that advancing understanding of the causes of AD undermines the clarity of the distinction between primary and secondary prevention. This makes it increasingly unclear how primary and secondary categories can be appealed to as the basis for making judgements about what interventions are permissible, and for distinguishing between acceptably vs unacceptably early points in life to intervene. Timely efforts at prevention are vital for limiting harm from AD and given the logic of EI is that, in presence of risk, earlier is better, one might assume that earliest is best. This may or may not be the case; however, the permissibility of intervening in different ways at different stages of life is complex and turns on numerous contextual factors. We consider the particular ethical implications of intervening at different points in the life course, presenting a valuable resource for negotiating clinical and policy implications of EI in AD.

Biomarker-Based Risk Prediction of Alzheimer’s Disease Dementia in Mild Cognitive Impairment: Psychosocial, Ethical, and Legal Aspects

Background: Today, a growing number of individuals with mild cognitive impairment (MCI) wish to assess their risk of developing Alzheimer’s disease (AD) dementia. The expectations as well as the effects on quality of life (QoL) in MCI patients and their close others through biomarker-based dementia risk estimation are not well studied. Objective: The PreDADQoL project aims at providing empirical data on effects of such prediction on QoL and at developing an ethical and legal framework of biomarker-based dementia risk estimation in MCI. Methods: In the empirical study, 100 MCI-patients and their close others will be recruited from two sites (Germany and Spain). They receive standardized counselling on cerebrospinal fluid (CSF) biomarker-based prediction of AD dementia and a risk disclosure based on their AD biomarker status. A mixed methods approach will be applied to assess outcomes. Results: The pilot-study yielded a specification of the research topics and newly developed questionnaires for the main assessment. Within this binational quantitative and qualitative study, data on attitudes and expectations toward AD risk prediction, QoL, risk communication, coping strategies, mental health, lifestyle changes, and healthcare resource utilization will be obtained. Together with the normative part of the project, an empirically informed ethical and legal framework for biomarker-based dementia risk estimation will be developed. Conclusion: The empirical research of the PreDADQoL study together with the ethical and legal considerations and implications will help to improve the process of counselling and risk disclosure and thereby positively affect QoL and health of MCI-patients and their close others in the context of biomarker-based dementia risk estimation.

The strategic biomarker roadmap for the validation of Alzheimer's diagnostic biomarkers: methodological update

Background

The 2017 Alzheimer’s disease (AD) Strategic Biomarker Roadmap (SBR) structured the validation of AD diagnostic biomarkers into 5 phases, systematically assessing analytical validity (Phases 1–2), clinical validity (Phases 3–4), and clinical utility (Phase 5) through primary and secondary Aims. This framework allows to map knowledge gaps and research priorities, accelerating the route towards clinical implementation. Within an initiative aimed to assess the development of biomarkers of tau pathology, we revised this methodology consistently with progress in AD research.

Methods

We critically appraised the adequacy of the 2017 Biomarker Roadmap within current diagnostic frameworks, discussed updates at a workshop convening the Alzheimer’s Association and 8 leading AD biomarker research groups, and detailed the methods to allow consistent assessment of aims achievement for tau and other AD diagnostic biomarkers.

Results

The 2020 update applies to all AD diagnostic biomarkers. In Phases 2–3, we admitted a greater variety of study designs (e.g., cross-sectional in addition to longitudinal) and reference standards (e.g., biomarker confirmation in addition to clinical progression) based on construct (in addition to criterion) validity. We structured a systematic data extraction to enable transparent and formal evidence assessment procedures. Finally, we have clarified issues that need to be addressed to generate data eligible to evidence-to-decision procedures.

Discussion

This revision allows for more versatile and precise assessment of existing evidence, keeps up with theoretical developments, and helps clinical researchers in producing evidence suitable for evidence-to-decision procedures. Compliance with this methodology is essential to implement AD biomarkers efficiently in clinical research and diagnostics.

Ambivalent anticipation: How people with Alzheimer's disease value diagnosis in current and envisioned future practices

Emergent biomarkers for Alzheimer's disease (AD) are expected to provide earlier and more precise diagnoses. However, even if biomarkers live up to these expectations, it cannot be taken for granted that patients actually would value an earlier and more precise AD diagnosis. Based on an interview study, we aim to give more insight into the value of an AD diagnosis for patients, in existing as well as future practices, by describing how a diagnosis enables or may enable knowing, foreseeing, and acting in relation to one's illness. Our findings show that how people with AD value a diagnosis is not only characterised by great variety, as previous studies have shown, but also by profound ambivalence for the individual. With lack of treatment and poor prognostics as the status quo, this ambivalence and the way people deal with it are particularly linked to the far-from-straightforward capacity of an AD diagnosis to support anticipation of the future. We argue that in otherwise unchanged practices the envisioned future biomarker-based diagnostics are unlikely to reduce the ambivalence about receiving an AD diagnosis and, in particular, the challenges of anticipation that it entails. Rather, biomarker-based innovations may even reinforce some of the main issues involved.

European Psychiatric Association policy paper on ethical aspects in communication with patients and their families

BACKGROUND

Establishing a valid communication is not only a basic clinical need to be met but also a relevant ethical commitment.

METHODS

On the basis of the relevant literature, ethical issues arising from specific, important situations in clinical practice were identified.

RESULTS

The main ethical problems regarding communication about the disorder, both in general and in relation to prodromal stages, were described and discussed together with those regarding communication about voluntary and involuntary treatments, "dual roles" enacted in clinical practice, genetic counseling, and end-of-life conditions; on the basis of what emerged, ethically driven indications and suggestions were provided.

CONCLUSIONS

Several situations put the psychiatrist in front of relevant dilemmas and doubts which are no easy to face with; an ethically driven approach based upon the principle of the best interest of patients may support clinicians in their decisions.

Genetic testing for Alzheimer's disease: trends, challenges and ethical considerations

PURPOSE OF REVIEW

Advances in personal genomics have made predictive genetic testing increasingly popular. The purpose of this review is to examine and summarize recent literature regarding the ethical concerns and considerations surrounding genetic testing for Alzheimer's disease.

RECENT FINDINGS

Four basic bioethical principles can be applied in the context of genetic testing: autonomy, nonmaleficence, beneficence and justice. The concepts of clinical validity, clinical utility and personal utility are also necessary for the ethical deliberation of genetic testing for Alzheimer's disease. Ethical considerations can differ among three distinct settings present in the literature: research, clinical and direct-to-consumer services. Studies have found that the negative psychosocial impact of genetic test results on the individual is limited, but emphasize the importance of pre/posttesting genetic counselling.

SUMMARY

The literature should ideally inform policy-making around genetic testing. There exists an urgent need for regulation, particularly in the direct-to-consumer (DTC) market, since interest for testing in this context is rapidly growing. Standardized protocols for disclosure should be developed, and there is a need to find ways to meet the growing need for genetic counselling. Importantly, comprehensive, evidence-based regulation requires that research be conducted in different contexts with more diverse participants.

Health Outcome Prioritization in Alzheimer's Disease: Understanding the Ethical Landscape

BACKGROUND

Dementia has been described as the greatest global health challenge in the 21st Century on account of longevity gains increasing its incidence, escalating health and social care pressures. These pressures highlight ethical, social, and political challenges about healthcare resource allocation, what health improvements matter to patients, and how they are measured. This study highlights the complexity of the ethical landscape, relating particularly to the balances that need to be struck when allocating resources; when measuring and prioritizing outcomes; and when individual preferences are sought.

OBJECTIVE

Health outcome prioritization is the ranking in order of desirability or importance of a set of disease-related objectives and their associated cost or risk. We analyze the complex ethical landscape in which this takes place in the most common dementia, Alzheimer's disease.

METHODS

Narrative review of literature published since 2007, incorporating snowball sampling where necessary. We identified, thematized, and discussed key issues of ethical salience.

RESULTS

Eight areas of ethical salience for outcome prioritization emerged: 1) Public health and distributive justice, 2) Scarcity of resources, 3) Heterogeneity and changing circumstances, 4) Knowledge of treatment, 5) Values and circumstances, 6) Conflicting priorities, 7) Communication, autonomy and caregiver issues, and 8) Disclosure of risk.

CONCLUSION

These areas highlight the difficult balance to be struck when allocating resources, when measuring and prioritizing outcomes, and when individual preferences are sought. We conclude by reflecting on how tools in social sciences and ethics can help address challenges posed by resource allocation, measuring and prioritizing outcomes, and eliciting stakeholder preferences.

Italian consensus recommendations for a biomarker-based aetiological diagnosis in mild cognitive impairment patients

BACKGROUND AND PURPOSE

Biomarkers support the aetiological diagnosis of neurocognitive disorders in vivo. Incomplete evidence is available to drive clinical decisions; available diagnostic algorithms are generic and not very helpful in clinical practice. The aim was to develop a biomarker-based diagnostic algorithm for mild cognitive impairment patients, leveraging on knowledge from recognized national experts.

METHODS

With a Delphi procedure, experienced clinicians making variable use of biomarkers in clinical practice and representing five Italian scientific societies (neurology - Società Italiana di Neurologia per le Demenze; neuroradiology - Associazione Italiana di Neuroradiologia; biochemistry - Società Italiana di Biochimica Clinica; psychogeriatrics - Associazione Italiana di Psicogeriatria; nuclear medicine - Associazione Italiana di Medicina Nucleare) defined the theoretical framework, relevant literature, the diagnostic issues to be addressed and the diagnostic algorithm. An N-1 majority defined consensus achievement.

RESULTS

The panellists chose the 2011 National Institute on Aging and Alzheimer's Association diagnostic criteria as the reference theoretical framework and defined the algorithm in seven Delphi rounds. The algorithm includes baseline clinical and cognitive assessment, blood examination, and magnetic resonance imaging with exclusionary and inclusionary roles; dopamine transporter single-photon emission computed tomography (if no/unclear parkinsonism) or metaiodobenzylguanidine cardiac scintigraphy for suspected dementia with Lewy bodies with clear parkinsonism (round VII, votes (yes-no-abstained): 3-1-1); ¹⁸ F-fluorodeoxyglucose positron emission tomography for suspected frontotemporal lobar degeneration and low diagnostic confidence of Alzheimer's disease (round VII, 4-0-1); cerebrospinal fluid for suspected Alzheimer's disease (round IV, 4-1-0); and amyloid positron emission tomography if cerebrospinal fluid was not possible/accepted (round V, 4-1-0) or inconclusive (round VI, 5-0-0).

CONCLUSIONS

These consensus recommendations can guide clinicians in the biomarker-based aetiological diagnosis of mild cognitive impairment, whilst guidelines cannot be defined with evidence-to-decision procedures due to incomplete evidence.

Cerebrospinal Fluid Biomarkers in Alzheimer's Disease: An Invaluable Tool for Clinical Diagnosis and Trial Enrichment

Alzheimer's disease (AD) is the most common neurodegenerative disorder, affecting around 35 million people worldwide. Cerebrospinal fluid (CSF) biomarkers entered the diagnostic criteria as support for early diagnosis. The classical biochemical signature of AD includes total tau (T-tau), phosphorylated tau (P-tau), and the 42 amino acid peptide (Aβ42) of amyloid-β. Recent observations suggest that the use of CSF Aβ42:Aβ40 ratio rather than CSF Aβ42 alone could contribute to reduce inter-laboratory variation in Aβ values and increasing diagnostic performance of the CSF AD biomarkers in routine practice. However, research efforts aimed at enriching the CSF biomarker panel are ongoing. The CSF AD signature is also crucial for the design of clinical trials for AD, since it best guarantees AD pathology as the cause of cognitive impairment. Accordingly, CSF biomarkers have been now reported in the inclusion criteria of Phase I, Phase II, and Phase III clinical trials as enrichment strategy. So far, one of the most important reasons for the failure of AD clinical trials was the inclusion of participants with unlikely AD pathology. In order to implement the use of CSF biomarkers in AD routine diagnostic work-up and as accepted strategy for enriching trial populations, inter-laboratory variability should be minimized. Increasing efforts should also be devoted to promote data sharing practices, encouraging individual participant data meta-analyses.

Detecting Diagnostic Biomarkers of Alzheimer's Disease by Integrating Gene Expression Data in Six Brain Regions

Alzheimer's disease (AD) is a neurodegenerative and progressive disease, which often causes irreversible damages to the cerebrum. The pathogenesis of AD is far from being fully understood, while there are some popular hypotheses. So far, the diagnosis of AD relies only on clinical screening in the form of imaging techniques or cerebrospinal fluid analysis, which may lead to inaccurate evaluation and then cause the delay of suitable treatments. While molecular biomarkers provide promising alternatives of establishing correct relationships between genotypes and phenotypes of clinical symptoms. In this paper, we propose a machine-learning-based method of identifying potential diagnostic biomarkers of AD based on gene coexpression network by integrating gene expression profiles in six brain regions. After building an integrated gene coexpression network of multiple brain regions, we decompose the differential network into some subnetwork modules. The module candidates from these coexpressed gene communities are then identified by screening their discriminative powers in control from disease samples. The potential biomarkers are then validated by multiple cross-validations and functional enrichment analyses. If the biomarkers successfully pass clinical significance tests, they can be used as a reference for clinical diagnosis after wet-experimental validations.

What matters to people with memory problems, healthy volunteers and health and social care professionals in the context of developing treatment to prevent Alzheimer's dementia? A qualitative study

Background

Alzheimer's disease (AD) is recognized as one of the greatest global public health challenges. There is increasing consensus that optimal disease modification using pharmaceuticals may best be achieved earlier in the disease continuum before symptoms occur. However, more needs to be understood about what outcomes are meaningful to potential participants in clinical trials within this preventative paradigm and how people make trade‐offs between risks and benefits. The Electronic Person‐Specific Outcome Measure (ePSOM) programme is developing an app to capture person‐specific outcomes and preferences in clinical trials.

Objective

As one phase in the ePSOM programme, this study explored what matters when developing new treatments to prevent AD and how trade‐offs are made between risks and benefits, from three perspectives.

Design

Focus groups were conducted with people living with memory problems (n = 21) and healthy volunteers (n = 10), and telephone interviews with health and social care professionals (n = 10). Differences and overlap between the three groups were explored.

Results

Outcomes that matter lie in five key domains in relation to what matters in everyday life: Everyday Functioning; Relationships and Social Connections; Enjoying Life; Sense of Identity; and Alleviating  Symptoms. Insights were gained into the significance of reducing the risk of developing dementia with drugs and the processes of weighing up risks versus benefits.

Discussion and conclusions

The key domains identified are being used to inform the next stage of the ePSOM programme which is to develop a survey to be distributed nationally in the UK to explore these issues further.

Estimation of lifetime risks of Alzheimer's disease dementia using biomarkers for preclinical disease

INTRODUCTION

Lifetime risks are the probabilities of progressing to Alzheimer's disease (AD) dementia during one's lifespan. Here, we report the first estimates of the lifetime and ten-year risks of AD dementia based on age, gender, and biomarker tests for preclinical disease.

METHODS

We used a multistate model for the disease process together with US death rates.

RESULTS

Lifetime risks of AD dementia vary considerably by age, gender, and the preclinical or clinical disease state of the individual. For example, the lifetime risks for a female with only amyloidosis are 8.4% for a 90-year old and 29.3% for a 65-year old. Persons younger than 85 years with mild cognitive impairment, amyloidosis, and neurodegeneration have lifetime risks of AD dementia greater than 50%.

DISCUSSION

Most persons with preclinical AD will not develop AD dementia during their lifetimes. Lifetime risks help interpret the clinical significance of biomarker screening tests for AD.

At, with and beyond risk: expectations of living with the possibility of future dementia

Biomedical research aimed at the development of therapies for chronic and late-onset conditions increasingly concentrates on the early treatment of symptom-less disease. This broad trend is evidenced in prominent shifts in contemporary dementia research. Revised diagnostic criteria and new approaches to clinical trials propose a focus on earlier stages of disease and prompt concerns about the implications of communicating test results associated with the risk of developing dementia when no effective treatments are available. This article examines expectations of the implications of learning test results related to dementia risk, based on focus group research conducted in the UK and Spain. It points to the extended social and temporal aspects of the dementia risk experience. Three key dimensions of this risk experience are elaborated: living 'at risk', represented in efforts to reduce risk and plan for the future; 'with risk', through vigilance towards cognitive health and earlier or prolonged contact with healthcare services; and finally, 'beyond risk' through a cessation of the self in its current social, legal and financial form. A virtual abstract of this paper can be viewed at: https://www.youtube.com/channel/UC_979cmCmR9rLrKuD7z0ycA.

Paper-based electrochemiluminescence sensor for highly sensitive detection of amyloid-β oligomerization: Toward potential diagnosis of Alzheimer's disease

Development of a rapid and sensitive method for Aβ(1-42) aggregation detection is of great importance to overcome the limitations of conventional techniques. In this study, we developed a label-free paper-based electrochemiluminescence sensor for amyloid-β aggregation detection toward potential diagnosis of Alzheimer's disease (AD). The paper-based chip used in the system serves as a low-cost and disposable detection method. In this detection platform, the bonding of [Ru(phen)2dppz]2+ to Aβ(1-42) aggregates results in enhanced electrochemiluminescence due to the change in the polarity of the microenvironment when [Ru(phen)2dppz]2+ intercalated into the β-sheets during oligomerization. The oligomerization process of Aβ(1-42) can be monitored in real time by the novel method, and as low as 100 pM equivalent monomer concentration of Aβ(1-42) could be detected simultaneously. In addition, the cerebrospinal fluid of transgenic AD model mice was tested by this method, which is highly consistent with genetic identification. In addition, we demonstrated that this detection platform could be a potential new method for the screening of Aβ(1-42) aggregation inhibitors, highlighting the practical application capacity of this platform. The platform is label free, low cost and sensitive. Therefore, the proposed platform holds great promise for the diagnosis of AD.

Advance directives as a tool to respect patients' values and preferences: discussion on the case of Alzheimer's disease

Background

The proposal of the new criteria for the diagnosis of Alzheimer’s disease (AD) based on biomarker data is making possible a diagnosis of AD at the mild cognitive impairment (MCI) or predementia/prodromal– stage. Given the present lack of effective treatments for AD, the opportunity for the individuals to personally take relevant decisions and plan for their future before and if cognitive deterioration occurs is one the main advantages of an early diagnosis.

Main body

Advance directives are largely seen as an effective tool for planning medical care in the event the subject becomes incompetent. Nevertheless, their value has been questioned with regard to people with dementia by scholars who refer to the arguments of personal identity and of patient’s changing interests before and after the onset of dementia.

In this paper, I discuss the value of advance directives in Alzheimer’s disease and other kind of dementia. Despite critics, I argue that advance directives are especially advisable in dementia and provide reasons in favor of their promotion at an early stage of the disease as a valuable tool to respect patients’ values and preferences on medical treatment, including participation in research and end of life decisions. I mainly support advance directives that include both decisions regarding health care and the appointment of an attorney in fact.

Conclusion

I conclude that patients with AD at a prodromal or early stage should be offered the opportunity to execute an advance directive, and that not to honor a demented individual’s directive would be an unacceptable form of discrimination towards those patients.

The biomarker-based diagnosis of Alzheimer's disease. 2-lessons from oncology

Biomarkers for the diagnosis of Alzheimer's disease (AD) are not yet validated for use in clinical settings. We aim to provide a methodological framework for their systematic validation, by reference to that developed for oncology biomarkers. As for this discipline, the steps for the systematic validation of AD biomarkers need to target analytical validity, clinical validity, and clinical utility. However, the premises are different from oncology: the nature of disease (neurodegeneration vs. cancer), the purpose (improve diagnosis in clinically affected vs. screening preclinical individuals), and the target population (mild cognitive impairment patients referring to memory clinics vs. general population) lead to important differences, influencing both the design of validation studies and the use of selected biomarkers. This framework is applied within a wider initiative to assess the current available evidence on the clinical validity of biomarkers for AD, for the final aim to identify gaps and research priorities, and to inform coordinated research efforts boosting AD biomarkers research.

Clinical validity of delayed recall tests as a gateway biomarker for Alzheimer's disease in the context of a structured 5-phase development framework

Although Alzheimer's disease criteria promote the use of biomarkers, their maturity in clinical routine still needs to be assessed. In the light of the oncology framework, we conducted a literature review on measures used to assess delayed recall impairment due to medial temporal lobe dysfunction (i.e., free and cued word list recall tests). Ample evidence is available for phases 1 (rationale for use), 2 (discriminative ability), and 3 (early detection ability) for many of the tests in routine use. Evidence about phase 4 (performance in real world) and phase 5 (quantify impact and costs) is yet to come. Administration procedures have been standardized and cutoff scores are well validated in large Alzheimer's disease and mild cognitive impaired series. Some aspects (e.g., different task formats), however, hamper the comparability of results among different populations and the reproducibility between laboratories. No definite guideline for their use can thus be proposed at the moment. Accordingly, the maturity of such markers is not yet sufficient and requires future investigation to promote the proper use of memory measures in clinical settings.

Interplay between protein glycosylation pathways in Alzheimer's disease

Deviations from the normal nucleoplasmic protein O-GlcNAcylation, as well as from normal protein sialylation and N-glycosylation in the secretory pathway, have been reported in Alzheimer's disease (AD). However, the interplay between the cytoplasmic protein O-GlcNAcylation and the secretory N-/O-glycosylation in AD has not been described. We present a comprehensive analysis of the N-, O-, and O-GlcNAc-glycomes in AD-affected brain regions as well as in AD patient serum. We detected marked differences in levels of glycan involved in both protein O-GlcNAcylation and N-/O-glycosylation between patients and healthy individuals and revealed brain region-specific glycosylation-related pathology in patients. These alterations are not general for other neurodegenerative conditions, such as frontotemporal dementia and corticobasal degeneration. The alterations in the AD glycome in the serum could potentially lead to novel glyco-based biomarkers for AD progression. Strikingly, negative interrelationship was found between the pathways of protein O-GlcNAcylation and N-/O-glycosylation, suggesting a novel intracellular cross-talk.

Strategic roadmap for an early diagnosis of Alzheimer's disease based on biomarkers

The diagnosis of Alzheimer's disease can be improved by the use of biological measures. Biomarkers of functional impairment, neuronal loss, and protein deposition that can be assessed by neuroimaging (ie, MRI and PET) or CSF analysis are increasingly being used to diagnose Alzheimer's disease in research studies and specialist clinical settings. However, the validation of the clinical usefulness of these biomarkers is incomplete, and that is hampering reimbursement for these tests by health insurance providers, their widespread clinical implementation, and improvements in quality of health care. We have developed a strategic five-phase roadmap to foster the clinical validation of biomarkers in Alzheimer's disease, adapted from the approach for cancer biomarkers. Sufficient evidence of analytical validity (phase 1 of a structured framework adapted from oncology) is available for all biomarkers, but their clinical validity (phases 2 and 3) and clinical utility (phases 4 and 5) are incomplete. To complete these phases, research priorities include the standardisation of the readout of these assays and thresholds for normality, the evaluation of their performance in detecting early disease, the development of diagnostic algorithms comprising combinations of biomarkers, and the development of clinical guidelines for the use of biomarkers in qualified memory clinics.