Proteomic Markers and Early Prediction of Alzheimer's Disease.

Alzheimer's disease (AD) is the most common socially significant neurodegenerative pathology, which currently affects more than 30 million elderly people worldwide. Since the number of patients grows every year and may exceed 115 million by 2050, and due to the lack of effective therapies, early prediction of AD remains a global challenge, solution of which can contribute to the timely appointment of a preventive therapy in order to avoid irreversible changes in the brain. To date, clinical assays for the markers of amyloidosis in cerebrospinal fluid (CSF) have been developed, which, in conjunction with the brain MRI and PET studies, are used either to confirm the diagnosis based on obligate clinical criteria or to predict the risk of AD developing at the stage of mild cognitive impairment (MCI). However, the problem of predicting AD at the asymptomatic stage remains unresolved. In this regard, the search for new protein markers and studies of proteomic changes in CSF and blood plasma are of particular interest and may consequentially identify particular pathways involved in the pathogenesis of AD. Studies of specific proteomic changes in blood plasma deserve special attention and are of increasing interest due to the much less invasive method of sample collection as compared to CSF, which is important when choosing the object for large-scale screening. This review briefly summarizes the current knowledge on proteomic markers of AD and considers the prospects of developing reliable methods for early identification of AD risk factors based on the proteomic profile.

Prognosis of Alzheimer's Disease Using Quantitative Mass Spectrometry of Human Blood Plasma Proteins and Machine Learning.

Early recognition of the risk of Alzheimer's disease (AD) onset is a global challenge that requires the development of reliable and affordable screening methods for wide-scale application. Proteomic studies of blood plasma are of particular relevance; however, the currently proposed differentiating markers are poorly consistent. The targeted quantitative multiple reaction monitoring (MRM) assay of the reported candidate biomarkers (CBs) can contribute to the creation of a consistent marker panel. An MRM-MS analysis of 149 nondepleted EDTA-plasma samples (MHRC, Russia) of patients with AD (n = 47), mild cognitive impairment (MCI, n = 36), vascular dementia (n = 8), frontotemporal dementia (n = 15), and an elderly control group (n = 43) was performed using the BAK 125 kit (MRM Proteomics Inc., Canada). Statistical analysis revealed a significant decrease in the levels of afamin, apolipoprotein E, biotinidase, and serum paraoxonase/arylesterase 1 associated with AD. Different training algorithms for machine learning were performed to identify the protein panels and build corresponding classifiers for the AD prognosis. Machine learning revealed 31 proteins that are important for AD differentiation and mostly include reported earlier CBs. The best-performing classifiers reached 80% accuracy, 79.4% sensitivity and 83.6% specificity and were able to assess the risk of developing AD over the next 3 years for patients with MCI. Overall, this study demonstrates the high potential of the MRM approach combined with machine learning to confirm the significance of previously identified CBs and to propose consistent protein marker panels.

Cerebrolysin in the therapy of mild cognitive impairment and dementia due to Alzheimer's disease: 30 years of clinical use.

Alzheimer's disease (AD) is the most common neurocognitive disorder and a global health problem. The prevalence of AD is growing dramatically, especially in low- and middle-income countries, and will reach 131.5 million cases worldwide by 2050. Therefore, developing a disease-modifying therapy capable of delaying or even preventing the onset and progression of AD has become a world priority, and is an unmet need. The pathogenesis of AD, considered as the result of an imbalance between resilience and risk factors, begins many years before the typical clinical picture develops and involves multiple pathophysiological mechanisms. Since the pathophysiology of AD is multifactorial, it is not surprising that all attempts done to modify the disease course with drugs directed towards a single therapeutic target have been unsuccessful. Thus, combined modality therapy, using multiple drugs with a single mechanism of action or multi-target drugs, appears as the most promising strategy for both effective AD therapy and prevention. Cerebrolysin, acting as a multitarget peptidergic drug with a neurotrophic mode of action, exerts long-lasting therapeutic effects on AD that could reflect its potential utility for disease modification. Clinical trials demonstrated that Cerebrolysin is safe and efficacious in the treatment of AD, and may enhance and prolong the efficacy of cholinergic drugs, particularly in moderate to advanced AD patients. In this review, we summarize advances of therapeutic relevance in the pathogenesis and the biomarkers of AD, paying special attention to neurotrophic factors, and present results of preclinical and clinical investigations with Cerebrolysin in AD.

Mild cognitive impairment due to Alzheimer disease: Contemporary approaches to diagnostics and pharmacological intervention.

Alzheimer disease (AD) and related forms of dementia are among the main medical and social problems in the economically developed countries. It is connected with significant increase in human life span in these regions and with the absence of efficient medicines for treatment and prevention of such diseases. Lack of positive results in the developing of novel drugs for AD treatment stimulates special attention on problem of early diagnosis and drug discovery for pharmacotherapy on the very early stages of dementia, in particular, on mild cognitive impairments (MCI) due to AD. Here we review the state of art in the field of MCI diagnostics and analyze the data on the pharmacological agents developed for MCI treatment, which currently are in preclinical and clinical trials. The conclusion was made that only the agents that act on the very early pathogenetic stages of the disease, when the damage of cholinergic neurons is not observed, can be efficient for pharmacotherapeutic intervention of MCI. Therefore, the focused search and design of "disease-modifying" medicines should be accepted as the most (and may be the only) efficient strategy for treatment and prevention of MCI.

Effect of dimebon on cognition, activities of daily living, behaviour, and global function in patients with mild-to-moderate Alzheimer's disease: a randomised, double-blind, placebo-controlled study.

BACKGROUND: Although treatments for Alzheimer's disease sometimes improve cognition, functional ability, or behaviour compared with baseline levels, such improvements are inconsistent across studies and measures, and effects diminish over time. More effective treatments are needed. We assessed the safety, tolerability, and efficacy of dimebon in the treatment of patients with mild-to-moderate Alzheimer's disease. METHODS: We enrolled 183 patients with mild-to-moderate Alzheimer's disease (mini-mental state examination [MMSE] scores 10-24) at 11 sites in Russia. Patients were randomly assigned by a computer-generated randomisation scheme to receive oral dimebon, 20 mg three times a day (60 mg/day [n=89]), or matched placebo (n=94). Other antidementia drugs were not allowed. The primary outcome measure assessed cognition, the difference in mean change from baseline to week 26, or last completed observation on the cognitive subscale of the Alzheimer's disease assessment scale (ADAS-cog). All patients and study personnel were blinded throughout the study. We compared dimebon with placebo with an intention-to-treat analysis, with last observation carried forward (ITT-LOCF) imputation. Analyses were repeated on the fully evaluable population, defined as all patients in the intention-to-treat population who had an ADAS-cog at week 26 and at least 80% compliance. 134 patients (68 in dimebon group, 66 in placebo group) enrolled in the 6-month blinded extension phase of the study. This trial is registered with Clinicaltrials.gov, number NCT00377715. FINDINGS: 155 (85%) patients completed the trial (78 [88%] in dimebon group, 77 [82%] in placebo group). Treatment with dimebon resulted in significant benefits in ADAS-cog compared with placebo (ITT-LOCF) at week 26 (mean drug-placebo difference -4.0 [95% CI -5.73 to -2.28]; p<0.0001). Results of the ITT-LOCF and the evaluable population analyses were much the same for all measures. Patients given dimebon were significantly improved over baseline for ADAS-cog (mean difference -1.9 [-2.92 to -0.85]; p=0.0005). Dimebon was well tolerated: dry mouth and depressed mood or depression were the most common adverse events associated with dimebon (12 [14%] patients for each symptom by week 26). The percentage of patients who had adverse events in the two groups did not differ. INTERPRETATION: Dimebon was safe, well tolerated, and significantly improved the clinical course of patients with mild-to-moderate Alzheimer's disease.

Helping carers to care--the 10/66 dementia research group's randomized control trial of a caregiver intervention in Russia.

OBJECTIVES: Dementia is a rapidly growing public health problem in low and middle income countries. There is an urgent need, in the absence of formal services, to develop interventions designed to improve the lives of people with dementia, and their families. This study tests the effectiveness of the 10/66 caregiver intervention among people with dementia, and their carers. DESIGN: A single blind parallel group randomized controlled trial (ISRCTN41039907). SETTING: Moscow. PARTICIPANTS: Sixty family caregivers of people aged 65 and over with dementia were randomized to receive the intervention and medical care as usual (n = 30) or medical care as usual only (n = 30). Caregiver and person with dementia outcomes were assessed at baseline and after 6 months. INTERVENTION: The caregiver education and training intervention was delivered over five, weekly, half-hour sessions and was made up of three modules: (i) assessment (one session); (ii) basic education about dementia (two sessions); and (iii) training regarding specific problem behaviors (two sessions). MEASUREMENTS: Dementia was diagnosed using DSM-IV criteria. Caregiver: Zarit Carer Burden Interview; carer psychological distress (SRQ 20); and carer Quality of Life (WHOQOL-BREF). Person with dementia: Behavioural and Psychological symptoms (NPI-Q); quality of life (DEMQOL). RESULTS: Caregivers in the intervention group reported large and statistically significant net improvements at 6-month follow-up in burden compared to controls. No group differences were found on caregiver psychological distress and patient and caregiver quality of life. CONCLUSIONS: The low-level intervention seems to be as, if not more, effective than similar interventions applied in high income countries.

The protocols for the 10/66 dementia research group population-based research programme.

BACKGROUND: Latin America, China and India are experiencing unprecedentedly rapid demographic ageing with an increasing number of people with dementia. The 10/66 Dementia Research Group's title refers to the 66% of people with dementia that live in developing countries and the less than one tenth of population-based research carried out in those settings. This paper describes the protocols for the 10/66 population-based and intervention studies that aim to redress this imbalance. METHODS/DESIGN: Cross-sectional comprehensive one phase surveys have been conducted of all residents aged 65 and over of geographically defined catchment areas in ten low and middle income countries (India, China, Nigeria, Cuba, Dominican Republic, Brazil, Venezuela, Mexico, Peru and Argentina), with a sample size of between 1000 and 3000 (generally 2000). Each of the studies uses the same core minimum data set with cross-culturally validated assessments (dementia diagnosis and subtypes, mental disorders, physical health, anthropometry, demographics, extensive non communicable disease risk factor questionnaires, disability/functioning, health service utilisation, care arrangements and caregiver strain). Nested within the population based studies is a randomised controlled trial of a caregiver intervention for people with dementia and their families (ISRCTN41039907; ISRCTN41062011; ISRCTN95135433; ISRCTN66355402; ISRCTN93378627; ISRCTN94921815). A follow up of 2.5 to 3.5 years will be conducted in 7 countries (China, Cuba, Dominican Republic, Venezuela, Mexico, Peru and Argentina) to assess risk factors for incident dementia, stroke and all cause and cause-specific mortality; verbal autopsy will be used to identify causes of death. DISCUSSION: The 10/66 DRG baseline population-based studies are nearly complete. The incidence phase will be completed in 2009. All investigators are committed to establish an anonymised file sharing archive with monitored public access. Our aim is to create an evidence base to empower advocacy, raise awareness about dementia, and ensure that the health and social care needs of older people are anticipated and met.

Study of Alzheimer family case reveals hemochromotosis-associated HFE mutation.

We report a family case of type II early-onset Alzheimer's disease (AD) inherited over three generations. None of the patients in the family had mutations in the genes believed to be the major risk factors for AD, such as APP, presenilin 1 or 2. Targeted exome sequencing of 249 genes that were previously reported to be associated with AD revealed a rare mutation in hemochromatosis (HFE) gene known to be associated with hemochromotosis. Compared to previous studies, we show that HFE mutation can possess the risk of AD in transferrin-, APOE- and APP-normal patients.

Why (not) go east? Comparison of findings from FDA Investigational New Drug study site inspections performed in Central and Eastern Europe with results from the USA, Western Europe, and other parts of the world.

Since the mid-1990s, investigational sites in the countries of Central and Eastern Europe (CEE) have been increasingly utilized by pharmaceutical companies because of their high productivity in terms of patient enrolment into clinical trials. Based on the FDA's publicly accessible Clinical Investigator Inspection List, we present an analysis of findings and outcome classifications from FDA inspections during Investigational New Drug (IND) studies and compare the results for the CEE region to those from Western European countries and the USA. Data from all 5531 FDA clinical trials inspections that occurred between 1994 (when the FDA first performed inspections in CEE) and the end of 2010 were entered into the database for comparative analysis. Of these, 4865 routine data audit (DA) inspections were analyzed: 401 from clinical trials performed in Western Europe, 230 in CEE, 3858 in the USA, and 376 in other countries. The average number of deficiencies per inspection ranged between 0.99 for CEE and 1.97 in Western Europe. No deficiencies were noted during 16.6%, 39.0%, and 21.5% of the inspections in Western Europe, CEE and USA, respectively. The percentages of inspections after which no follow-up action was indicated were 36.9% for Western Europe, 55.7% for CEE, and 44.3% for US sites. CEE was also the region with the lowest percentage of inspections that required official or voluntary action. On the basis of FDA inspection data, the high productivity of CEE sites appears to be accompanied by regulatory compliance as well as by data quality standards that are not inferior to those in Western regions.