Researchers at the University Health Network (UHN) and the University of Toronto have developed a skin-based test that can detect the signature features of progressive supranuclear palsy (PSP), a rare neurodegenerative disease.
The advancement could lead to more accurate and quicker diagnoses compared to current methods, which often rely on symptom-based assessments.
In neurodegenerative diseases, proteins like alpha synuclein or tau misfold, accumulating in brain and nervous system cells and causing damage.
While the misfolded proteins can be detected in cerebrospinal fluid through lumbar puncture, the procedure is not always feasible for all patients.
The limitation often results in misdiagnoses, especially for rarer diseases like PSP.
UHN’s Krembil Brain Institute Rossy Progressive Supranuclear Palsy Centre scientific associate Ivan Martinez-Valbuena said: “This assay is important for assigning patients to the correct clinical trials, but it will be even more important in the future as researchers develop targeted, precision treatments for PSP
“We need diagnostic tools to be developed hand-in-hand with new treatments, so that as these treatments become available, we can identify the patients who would benefit most.”
“It will be important to pair this skin-based assay together with a patient’s clinical symptoms, and this will give us a much better picture of the patient’s diagnosis.
“Once we have precision treatments targeting these misfolded proteins, we will have a better idea of the treatment each patient should receive.”
The new test builds on previous research by Martinez-Valbuena and his team, who developed a skin test to detect misfolded alpha synuclein in Parkinson’s patients.
Using similar technology, they have now created a test to identify misfolded tau specific to PSP, validated with patient samples from the Rossy Progressive Supranuclear Palsy Centre.
In trials, the skin biopsies of PSP patients showed misfolded tau, unlike those with Parkinson’s disease or healthy controls.
The test demonstrated 90% sensitivity and 90% specificity, making it a promising tool for more precise diagnoses and targeted clinical trials.
The team is currently validating the test in a clinical trial across five PSP centres in North America and Europe.
The Toronto researchers aim to ensure the test is practical for use outside major research centres, potentially incorporating it into a broader panel of diagnostic tools.
UHN neuropathologist, Martinez-Valbuena’s supervisor and Tanz Centre principal investigator Gabor Kovacs said: “Following a meticulous and innovative strategy, Ivan reported for the first time in the literature that disease-associated tau protein can be detected in the skin in living patients with high accuracy.”
Sinai Health Lunenfeld-Tanenbaum Research Institute senior investigator and Tanz Centre director Graham Collingridge said: “I am so delighted to see this exciting development of a new biomarker for this rare neurodegenerative disease, made possible by the close collaboration of world-leading scientists in Toronto.”
