Biomarkers and New Treatments for Alzheimer’s Disease

Abstract

Alzheimer’s disease is a progressive, irreversible neurodegenerative disorder which disrupts thinking, concentration and memory in the affected individuals. Although existing therapeutics can help to improve some of the symptoms there are still no treatments available to halt or delay the incessant progression towards cognitive decline. Currently, more than 46 million people worldwide live with this disease and most of these are over the age of 65 years. The economic impact is huge with a worldwide cost estimated at almost one trillion dollars in the USA alone. Much of this could be averted if early diagnosis and better treatments options were available. Towards this end, this chapter looks at recent developments in diagnostic criteria and identification of peripheral biomarkers under development for early diagnosis of this high burden disease. There is now an attempt at moving beyond the current diagnostic approaches which are based mostly on clinical and neurological examinations. Clinicians today have access to sensitive tests which can reveal cognitive impairment before the disturbances reach the level of dementia and before brain structural damage has already occurred. New plasma and serum biomarkers that have been proposed are based on hallmark pathophysiological features of Alzheimer’s disease such as the formation of central amyloid plaques and neurofibrillary tangles which disrupt neurotransmission, along with those associated with increased inflammation, insulin resistance, vascular complications, perturbed oxidative stress and abnormal lipid metabolism. These analytes are currently undergoing testing as biomarker algorithms in combination with clinical and imaging data in attempts to achieve an earlier diagnosis. In this way, disease modifying treatments can be initiated early to delay or prevent progression to the full disease before too much neuronal damage has already occurred. This will be facilitated by co-development of novel treatments which can slow or even prevent disease onset.