Biomarkers pave way for blood test to predict Parkinson's progression
When Parkinson’s patients are diagnosed with the condition, there are still many unknowns around how the disease will develop and how it will impact their lives. While it is no crystal ball, a new blood test developed at Newcastle University and Cambridge University in the UK is offering hope of better patient management, with an ability to recognize early indicators of cognitive decline, dementia and progression of motor symptoms.
The study involved almost 250 subjects, of which more than 150 were patients recently diagnosed with Parkinson’s disease (PD). The idea was to draw blood samples from the Parkinson’s patients and measure certain biomarkers to see how reliably they could serve as predictors of cognitive and motor decline over the following three years.
More specifically, the team looked for signs of inflammation and cellular senescence, which is when cells have lost the ability to divide. Senescent cells are the focus of much research into age-related decline, and can be thought of as the opposite of stem cells, which conversely have infinite potential to divide.
“The cumulative incidence of dementia associated with PD is approaching 80 percent, and individuals with PD are five to six times more likely to develop cognitive impairment than age-matched controls,” explains lead investigator Gabriele Saretzki. “PD is known to be associated with inflammation, and we have previously published data demonstrating that a more pro-inflammatory profile in the blood predicts more rapid clinical progression. In this new study, we sought to replicate this finding as well as to study markers of cell senescence, a process that is known to be associated with inflammation and neurodegeneration.”
These blood samples revealed that the PD group had shorter telomeres, a sign of cellular senescence, both at the outset of the study and 18 months later. The patients who went on to develop dementia after three years then exhibited “significantly shorter” telomeres than study participants without dementia.
The team also identified other senescence and inflammatory biomarkers at the start of the study that proved to be indicators of accelerated motor and cognitive decline across the three-year period. With further work, the team hopes these could help to form the basis for a new type of blood test that can guide treatment plans for Parkinson’s patients before the symptoms begin to worsen.
“The development of suitable blood-based biomarkers to predict outcomes is important for neurodegenerative diseases such as PD, which progress over many years,” notes Dr. Saretzki. “The markers that we have identified need to be validated in further studies but could ultimately help with planning more targeted management for patients earlier in their disease course. Furthermore, a better understanding of the biological changes that predict disease course has implications for possible future therapies for the disease.”
The research was published in the Journal of Parkinson's Disease.
Source: IOS Press