A blood test can be used to diagnose ALS and other neurodegenerative diseases, a study indicates.
The biomarker development company DiamiR came up with the test, which measures levels of small RNA molecules in blood.
It is much less invasive than other ways of diagnosing the diseases, according to researchers at DiamiR and its partner in the study, the Perelman School of Medicine at the University of Pennsylvania.
The collaborators published their research, “Circulating brain-enriched microRNAs as novel biomarkers for detection and differentiation of neurodegenerative diseases,” in the journal Alzheimer’s Research and Therapy.
MicroRNAs are a special type of RNA molecule. Unlike messenger RNAs, they do not help a gene code for the production of a protein. Instead, they fine-tune what the gene is doing.
Research has shown that microRNA levels are different in people with a number of diseases than in healthy people. In some disorders they are higher, and in some lower.
These differences mean doctors may be able to use microRNA levels as biomarkers of disease. In fact, they are already using them as markers for some cancers.
Researchers wondered if they could use blood levels of microRNA found in brain cells as biomarkers of neurodegenerative diseases. The approach would be less invasive and cheaper than current approaches, such as taking cerebrospinal fluid samples.
The team measured levels of 37 microRNAs in the blood of 200 people with a neurodegenerative disease and in 50 healthy controls. The 37 microRNAs, which are found in high levels in the brain, are associated with inflammation.
Patients had either amyotrophic lateral sclerosis, Alzheimer’s disease, Parkinson’s disease, or frontotemporal dementia.
Measuring microRNA combinations proved a good diagnostic tool, researchers said. The combo measurements distinguished between people with a neurodegenerative disease and a healthy person with 83 to 90 percent accuracy. And they could distinguish one neurodegenerative disease from another with 75 to 93 percent accuracy.
The combinations consisted of either two or three microRNAs.
Researchers found three pairs of microRNAs that could distinguish between people with ALS and controls with 83 percent accuracy. Other pairs could distinguish between men with ALS and healthy men with 92 percent accuracy, and between women with ALS and healthy women with 98 percent accuracy.
The results suggested that microRNA levels are a good way to diagnose a neurodegenerative disease.
“In this study we demonstrated the ability of our targeted diagnostic technology to differentiate four neurodegenerative pathologies [diseases] from control and from each other,” Dr. Samuil Umansky, DiamiR’s chief scientific officer, said in a press release.
“Minimally invasive specific biomarkers for differential diagnosis and prognosis of neurodegenerative diseases can facilitate selection of more homogeneous [similar] patient groups for relevant clinical trials,” he said. “Blood biomarkers reflective of brain processes can also be used for disease progression and treatment monitoring,” he added.