Scientists at the Higher School of Economics and the Russian Academy of Science’s Koltsov Institute of Developmental Biology have developed a new methodology for identifying biomarkers (indicators) of both early- and late-stage Parkinson’s disease. Their findings were published in the journal Molecular Neurobiology.
The researchers found that 20% of the biomarkers found in the blood of patients with late-stage Parkinson’s are disease-specific, and these make it possible to diagnose the disease in its early stages.
What makes Parkinson’s so insidious is that motor impairment can occur decades after the onset of the disease. In order to prevent these symptoms – the tremors, stiffness, and in the later stages, difficulty in controlling the body that are caused by the death of 70%-80% of neurons producing the neurotransmitter dopamine – it is necessary to detect and treat the disease in its early stages.
Until now, only positron emission tomography (PET) could detect Parkinson’s disease at an early stage. However, because the technique is complex and expensive, it is not generally used to perform medical diagnoses.
For 30 years scientists have been searching for a practical way to detect the disease at an early stage, focusing their efforts on identifying Parkinson’s-specific biomarkers in patients’ blood. These include changes in the blood’s chemical composition, gene expressions, and lymphocytes. What’s more, clinical (late) stage markers of the disease differ from preclinical (early) stage markers.
“In medicine, and not only in neurology and psychiatry, the main difficulty lies in diagnosing a chronic disease at the preclinical stage, when the pathological process has just begun and has not yet manifested itself in the form of symptoms,”said Mikhail Ugryumov, HSE professor and head of the Russian Academy of Science’s Koltzov Institute of Developmental Biology. “This is necessary in order to start preventative treatment.”
Researchers found markers of the late phase of the disease in patients’ blood and modeled both early and late stages of Parkinson’s in mice by giving them the neurotoxin MPTP that induces symptoms of the illness. The authors of the study then compared the markers from the late phase of the disease in humans with the early- and late-stage markers in mice. Markers that matched in both instances were considered disease-specific, making them useful for early-stage diagnosis of Parkinson’s.
“The new methodology will make it possible to search for specific markers in people who have not yet manifested motor symptoms of the disease and to identify those who are at risk. Then a definite diagnosis can be obtained using PET,” said Mikhail Ugryumov.