March 22 (UPI) -- A new study has identified a urinary biomarker that may help track the progression of amyotrophic lateral sclerosis, or ALS, and potentially help with evaluation of new therapies.
ALS is a fatal neurodegenerative disease in which motor neurons, the cells that control muscle activity, gradually die off, leading to paralysis. There is no cure for ALS, also known as Lou Gehrig's disease.
The study, conducted by the National Institutes of Health, found that levels of the protein p75ECD in urine samples from 54 people with ALS increased as the disease progressed over a two-year period, and that monitoring levels of the protein can help monitor disease progression and may determine treatment efficacy.
"It was encouraging to see changes in p75ECD over the course of the study, because it suggests an objective new method for tracking the progression of this aggressive disease," Dr. Amelie Gubitz, program director of the National Institute of Neurological Disorders and Stroke, or NINDS, said in a press release. "In addition, it indicates the possibility of assessing whether levels of that protein decrease while patients try future treatments, to tell us whether the therapies are having any beneficial effects."
Researchers found patients who began the study with lower levels of urinary p75ECD survived longer than patients with higher initial levels of the protein, meaning it may be a prognostic marker of the disease and could inform patients about the illness. This finding could also help researchers identify patients for clinical trials in the future.
The protein p75ECD is significant in early life but does not appear in adults unless motor neurons have been injured. Previous studies in mice have shown that mouse models of ALS showed that p75 was re-expressed in motor neurons as the mice became sick.
The p75ECD was found in the urine of mice even before they exhibited symptoms of muscle weakness or the disease.
"As we move potential new therapies into phase-2 clinical trials, our findings suggest that p75ECD may tell us a lot about how well the treatments are working," said Dr. Michael Benatar, a professor of neurology at the University of Miami. "Additionally, the ease of obtaining urine samples could help reduce the burden of patient participation in clinical studies."
The study was published in Neurology.
