Potential new blood test could advance treatment for Alzheimer’s disease

This interview is part of a larger blog post on the Michigan Medicine Health Lab blog. Please visit the link here for the full article.

New research from the annual Alzheimer’s Association International Conference shows promising results for a blood biomarker. Our experts weigh in on how this year’s research compares to blood biomarker findings in the past, and what this could mean for the field.

Dementia has always posed many challenges for diagnosis. In our last issue, we shared about our bimonthly Clinical-Pathological Correlation Conferences which routinely bring to light the complexity of an accurate dementia diagnosis, and the necessity for a great deal more research to support both clinicians and patients. Currently, testing for Alzheimer’s disease is conducted through brain imaging (such as an MRI) and behavioral tests. Both of these techniques are costly and leave room for error, especially if the disease is in its early stages. However, recent research developments presented at the Alzheimer’s Association International Conference show a promising blood test that may detect Alzheimer’s disease before symptoms appear. Not only would this help for early detection, a blood test is also typically affordable, and easily accessible for patients. To share what this could mean for the future of Alzheimer’s disease testing, our Center Director, Dr. Henry Paulson, and Dr. Nicholas Kanaan, Associate Professor of Translational Neuroscience at Michigan State University and Co-Lead of our Center’s new Biomarker Core came together to answer some key questions.

How is Alzheimer’s disease usually detected, and what are the challenges with these methods?

Paulson: Doctors usually make a clinical diagnosis of Alzheimer’s disease based on the history of the illness, a cognitive assessment, a neurological examination, and often standard brain imaging (such as MRI). It is an imperfect science and we are not always correct in concluding that the diagnosis is Alzheimer’s rather than another form of dementia. Testing the cerebrospinal fluid for Alzheimer’s biomarkers can lead to a more precise diagnosis, but many patients are not eager to undergo the spinal tap procedure (lumbar puncture), and sometimes insurance companies won’t pay for the test. New imaging methods such as PET allow us to visualize the key Alzheimer’s proteins in the brain, namely beta-amyloid and tau, but this imaging is expensive and not yet covered by insurance. As a result, this typically remains a research test. A simple and sensitive blood test that could pinpoint the Alzheimer’s disease process well before any cognitive symptoms would allow us to give any potential disease-slowing therapy — anti-amyloid, anti-tau, anti-inflammatory — at a very early point in the disease process. Doing so likely will increase our chances of finding an effective therapy.

What makes this new blood test different than previous attempts?

Paulson: Our ability to detect signals in blood of specific proteins linked to disease has gotten better over time. This success is due to the fact that the technology is now much better and the specific biomarker being detected is closely linked to the underlying pathology of Alzheimer’s disease. That is why it seems so promising.

Could this potential blood test help with accessibility to testing and treatment?

Kanaan: Yes, the emerging blood tests would be highly accessible in a clinical research setting, like our Center. (This is why we take a blood sample from each of our research participants!) Whether blood tests such as these become a component of standard clinical practice for dementia management will require additional development and testing, but this is certainly one of the main directions in which we and others are moving. The continuing enrichment of the biomarker toolkit for clinicians and scientists will ultimately provide several useful advantages to clinical care for dementia. Among these advantages: it will facilitate better clinical trials, monitoring of therapeutic efficacy, and may even identify important biological processes involved in brain diseases.

How could an earlier diagnosis of Alzheimer’s disease affect the treatment and care of patients?

Kanaan: Early detection of Alzheimer’s disease and related dementias is a critical factor in furthering our understanding of disease etiology and progression. Indeed, identifying a disease like Alzheimer’s accurately and early, before significant cognitive decline occurs, could provide a therapeutic window in which administration of future therapeutics could slow or stop the disease. It is important to note that currently treatments do not slow or stop the disease. But as part of a powerful and comprehensive management strategy we want to pursue early disease detection and novel therapeutics in parallel.

What should the public take away from these recent findings?

Kanaan: One of the most exciting takeaways from the recent development in blood tests is that we’re getting even closer to a highly accurate and reliable approach (blood biomarkers) to aid in diagnosing Alzheimer’s and excluding other dementias. Prior blood tests were not as robust as the newly identified tests. Another exciting aspect of these tests is that they provide a route to assess biomarker and disease status in a highly accessible, less invasive and relatively inexpensive fashion. Any progress is exciting in the context of devastating diseases like Alzheimer’s and related dementias. At this point, the testing and validation of these new tests will expand dramatically as groups like ours work vigilantly to make progress towards the clinical implementation of these and other novel blood tests for Alzheimer’s disease.

Want to learn more about what took place at AAIC?

Many of our faculty presented their own research at the Alzheimer’s Association International Conference (AAIC) this summer. A few examples include Dr. Scott Roberts who presented a seminar on the Ethical and Practical Challenges in Disclosure of APOE Genotype and Dr. DeAnnah Byrd of Wayne State University who presented on the Interactive Effects of Chronic Health Conditions and Financial Hardship on Episodic Memory among Older Blacks. For a full list of our faculty presentations at AAIC, visit our website at alzheimers.med.umich.edu/news.

For a comprehensive summary of the latest resarch coming out of AAIC, visit alz.org/aaic/news_highlights.asp.