Simple skin test detects rare brain disease

Diagnosis of rare brain diseases may become easier, researchers from the University of Toronto and UHN Clinic believe. Their team has created a test that detects the characteristic signs of progressive supranuclear palsy (PNP) in a routine skin biopsy. This could revolutionize the approach to detecting the disease, which impairs movement, coordination and even the ability to swallow.

The method has already shown to be highly accurate: almost all patients with confirmed PUP had defective tau protein in their skin, while people with other disorders – such as Parkinson’s disease – had no such changes. This is an important step, because nowadays, the diagnosis of PUD is most often made on the basis of symptoms alone, which means it is not always correct.

There are still few alternative methods. One of them is to analyze cerebrospinal fluid obtained through lumbar puncture. But this procedure is painful, requires special conditions and is not suitable for everyone. The new skin test is an opportunity to replace invasive methods with more gentle and convenient ones.

The idea did not arise from nothing. Previously, the same group of scientists had developed a skin test to detect another protein, alpha-synuclein, in patients with Parkinson’s disease. After receiving encouraging data, the researchers decided to use similar technology to diagnose PUP – and they were right on target.

The importance of this test goes far beyond diagnosis. It could change the course of clinical trials. Today, many patients are mistakenly enrolled in trials targeting the wrong protein – confusing PUP with Parkinson’s, for example. This reduces the effectiveness of therapy and slows scientific progress.

According to lead author Ivan Martinez-Valbuena, this method is especially important now that scientists are beginning to develop personalized treatment approaches based on the precise biology of the disease. The more accurate the diagnosis, the higher the chances that the patient will receive the right treatment.

Developers have already begun testing the test on more patients in clinics in North America and Europe. The goal is to make the method available not only in large research centers, but also in ordinary medical institutions.

If all goes according to plan, in the future the skin test could become part of a broad panel of tests that integrates symptom, blood and tissue data. This would allow doctors to make more accurate diagnoses and patients to receive more appropriate treatment.