The diabetes drug Symlin (pramlintide) may help scientists develop novel and faster diagnostic tests for Alzheimer’s disease (AD), a study indicates.
The research, “An amylin analog used as a challenge test for Alzheimer’s disease,” was published in the journal Alzheimer’s & Dementia: Translational Research & Clinical Interventions.
At the moment, diagnosing Alzheimer’s involves complex, costly and invasive procedures such as lumbar punctures to detect biomarkers in cerebrospinal fluid (CSF) and positron emission tomography (PET) imaging scans.
The burden of Alzheimer’s is rapidly increasingly. Simpler diagnostic tests, such as those that look for disease biomarkers in blood samples, would lead to faster and cheaper diagnoses.
Amylin is a small hormone secreted by the pancreas. Its drug analogue, Symlin, is used to treat diabetes.
Researchers have learned that Symlin reduces neuronal deterioration and improves memory and learning in mouse models of Alzheimer’s.
Symlin also prompts a marker for Alzheimer’s – amyloid beta – to travel from the brain to the blood.
“If a drug can mobilize AD biomarkers from the brain into blood, the sensitivity and specificity of these AD biomarkers in the test can be enhanced to reveal the brain pathology [condition]. These kinds of drugs may also become therapeutic for AD,” the researchers wrote.
To test their hypothesis, they recruited 50 patients from the Boston University Alzheimer’s Disease Center who had no diabetes. The participants received a single 60-ug injection of Symlin, which the Food and Drug Administration (FDA) has approved as a therapy for diabetes.
The treatment led to higher amyloid beta levels in the participants’ blood than in controls who did not receive Symlin, lowering the amyloid burden on the brain.
“A single injection of pramlintide into our patients was well tolerated and reduced the amyloid burden as well as lowered the concentrations of amyloid-β peptides, a major component of AD in the brain,” the lead author of the study, Wendy Qiu, MD, PhD, said in a press release. She is associate professor of psychiatry and pharmacology and experimental therapeutics at Boston University School of Medicine.
These results suggest that Symlin triggers an increase in the Alzheimer’s biomarker amyloid beta in blood and that it is safe for patients without diabetes.
“Our study suggests a potential role for the creation of a blood test that relies on pramlintide, which could cross the blood-brain barrier and help to translocate the biomarkers related to AD pathology, including amyloid-β peptides and neuroinflammation, from the brain into the bloodstream, where they can be detected,” Qiu concluded.