If there is Alzheimer’s pathology in the brain, could there be markers of it in the blood before cognitive symptoms appear?
Thomas Karikari, assistant professor of psychiatry in the School of Medicine, has dedicated his research career to finding an easier way to test for Alzheimer’s disease by finding biomarkers in the blood. The most widely used tests for Alzheimer’s disease are invasive, expensive and approved for use only after symptoms emerge. This means the brain is already damaged and there are only so many treatments that can help.
While other experts in the field said that blood could not reveal neurodegenerative pathology, Karikari hypothesized that it might show more than people thought. His team and collaborators reviewed autopsy reports and clinical information and performed molecular studies of human brain tissue and their matched blood samples obtained during life to identify any potential connections. They found that specific forms of tau protein could be detected in blood plasma nearly a decade before it would show up on a PET scan.
By capturing information in the blood before symptoms emerge, these blood biomarkers allow physicians to track disease progression for those at risk for Alzheimer’s. But not everyone who has biomarkers will develop symptoms. While Karikari and his team hope to use those special cases to identify why some people develop Alzheimer’s and others do not, it opens the door to some ethical dilemmas.
“The question becomes: Should we tell someone they have biomarkers evidence of Alzheimer’s?” says Karikari. “Many people with altered biomarker levels will never develop symptoms, but those who do could benefit from earlier treatment interventions.”
“Once we figure out the logistics of the lab testing, this testing could make a huge difference for communities without traditional access to health care, who often need it the most.”
To handle this dilemma, Karikari aims to develop a predictive model that correlates biomarker changes with cognitive assessments to best identify who will need treatment most. As he works toward this goal, Karikari emphasizes the need for testing and treatment to be accessible to the masses.
“The beauty of blood biomarker testing is that it can be implemented nearly anywhere,” he says. “Once we figure out the logistics of the lab testing, this testing could make a huge difference for communities without traditional access to health care, who often need it the most.”