What's New in Basic Science & Drug Research?
Research is constantly being done to discover new information about the detection, prevention, treatment, and cure of Alzheimer’s disease. What the public sees as “breakthroughs” are typically years and years in the making. There are lots of new discoveries being made public for Alzheimer’s disease, bringing new tests and treatments to the forefront and bringing a cure closer to reality.
Genome-wide association studies
Genome-wide association studies use rapidly scanning markers over complete sets of DNA of many different people in order to find genetic variations that are associated with certain diseases.1 When associations are found, that information can then be used to find new strategies for prevention and treatment. There have been several genome-wide association studies for Alzheimer’s disease, with several risk and causative genes potentially being found, as well as biological factors in the disease.2
Biomarkers are measures of things that are occurring in a living body, as shown by lab and imaging tests.3 Things like cholesterol and blood pressure can be used as biomarkers for heart disease. Biomarkers can help physicians diagnose diseases, monitor treatment responses, and assess how the disease affects the body over time. In Alzheimer’s disease, researchers can monitor brain changes in people who may or may not have the disease, to see how various changes may play a role in the progression of Alzheimer’s.3 The most commonly used biomarkers for Alzheimer’s disease measure changes in the size and function of the brain, as well as various proteins found on brain scans and in cerebrospinal fluid (CSF) and blood.3Brain imaging like CT scans, PET scans, and MRI are used for biomarker studies, and lumbar punctures to get CSF are used. Specific biomarkers for Alzheimer’s that are measured include the proteins beta-amyloid 42, the main factor in amyloid plaques in the brain, tau, and phospho-tau (which is a major factor in tangles in the brain).3Blood tests and genetic testing may also be used.
It is hoped that biomarker studies can help further Alzheimer’s treatment by aiding in the development of more specific and effective drugs for the disease, better imaging tests that can identify specific Alzheimer-related changes in the brain to differentiate it from other dementias and cognitive decline, and develop earlier ways to diagnose the disease.
Amyloid PET scan
Since there is no way to definitively diagnose Alzheimer’s until autopsy, diagnosis traditionally depends on a medical history, physical exams, and cognitive and neurological testing. Brain imaging can’t really differentiate between Alzheimer’s disease and other neurodegenerative disorders – until now, with amyloid PET (positron emission tomography) scans. A PET scan usually involves a radioactive tracer injected into the bloodstream (or swallowed), and various organs and tissues absorb the material. The tracer is generally collected in areas of high chemical activity, and show up as bright spots on the scan. An amyloid PET scan can detect plaques that are in the brain, which are thought to be the reason behind the nerve cell death in Alzheimer’s disease.4 This scan allows physicians to visualize what was previously only able to be seen on autopsy. Scientists are also developing PET compounds to identify neurofibrillary tangles, another hallmark of Alzheimer’s disease which damages neurons. In addition, PET scans are being developed to identify the loss of neuron connections early in the disease, with the hopes of detecting the disease before neurons die.
This scan may not be appropriate for everyone, is not available everywhere, and may not be covered by a patient’s insurance. If a patient is interested in whether amyloid PET scan would be an option or if it would be beneficial, they should speak with their doctor.
There are multiple clinical trials underway for a variety of aspects of diagnosis, monitoring, prevention, and treatment of Alzheimer’s disease. Clinical trials focusing on prevention include The Alzheimer’s Prevention Initiative (API), which includes the Autosomal Dominant Alzheimer’s Disease (ADAD) trial and the Generation Study; the Dominantly Inherited Alzheimer Network Trials Unit (DIAN-TU), and the Anti-Amyloid Treatment in Asymptomatic Alzheimer’s Disease (A4) study.5 The goal of these studies is to determine if immunotherapy, an antibody against amyloid beta, will prevent the accumulation of plaques in the brain and prevent the progression of cognitive symptoms. These studies include patients identified to be at high risk for developing Alzheimer’s disease so it can be determined whether the starting immunotherapy treatments as early as possible, even before symptoms emerge, are most effective. There are also multiple clinical trials looking at drugs targeting certain neurological components of Alzheimer’s disease like beta-amyloid, beta-secretase (BACE), tau protein, inflammation, and the 5-HT2A receptor.5 If a patient or their family is interested in learning more about clinical trials and whether participation is an option, it is recommended they speak with the doctor. Clinical trials aren’t for everyone, but may be a beneficial option for some people.
Finally, many research laboratories across the country are performing “basic science” research identifying novel therapeutic targets for Alzheimer’s disease, identifying novel mechanisms that cause the disease, and determining what makes some people resilient to developing Alzheimer’s disease. These kinds of studies are critical for finding a way to cure Alzheimer’s disease.