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Could a new testing method help doctors diagnose Parkinson’s disease before motor symptoms set in? Image credit: moaan/Getty Images.
  • Researchers have developed a highly accurate technique to identify people with Parkinson’s disease, which could help detect the disease earlier. Previously, no test could provide a conclusive diagnosis in this way.
  • The alpha-synuclein seed amplification assay (SAA) technique was used in a cross-sectional study of 1,123 participants and was found to detect at-risk individuals and those with early non-motor symptoms of Parkinson’s disease prior to diagnosis.
  • These findings suggest that the SAA technique could be used as a biomarker to aid in early detection of Parkinson’s disease.

Parkinson’s disease is a condition that impacts the nervous system and causes movement issues. Some of the early symptoms include tremors, difficulty coordinating movements, and a reduced sense of smell.

According to new research, published in The Lancet Neurology, the identification of abnormal protein deposits associated with Parkinson’s using a specific technique may help detect the disease earlier.

The study’s results validate the effectiveness of the alpha-synuclein seed amplification assay (SAA) in accurately identifying people with Parkinson’s disease.

The test could identify those who are at risk of developing the disease and those with initial non-motor symptoms, even before an official diagnosis.

Parkinson’s disease is characterized by the presence of a specific type of protein that builds up in the brain, causing problems with movement and other symptoms.

Previous research has shown that the SAA test can detect this protein. However, a more comprehensive study involving a large group of carefully selected participants had not been done until now.

In the new study, the researchers wanted to investigate if SAA could identify early signs of Parkinson’s disease and distinguish between different forms of this disease.

They studied over 1,000 people with Parkinson’s disease or at risk of developing it, including those with some symptoms but not the typical shaking or stiffness. The goal was to see if the test could predict who might develop Parkinson’s disease in the future.

The researchers analyzed samples of cerebrospinal fluid taken from each participant using the SAA test. This technique can detect very small amounts of a protein called alpha-synuclein that is linked to Parkinson’s disease.

In individuals without a known genetic cause of the disease, the test correctly identified the disease in 96% of cases, while in those with specific gene variants, the accuracy of the test varied.

The study found that there are some differences in the results based on age and sex, especially in people with a certain genetic mutation called LRRK2.

Prof. Claudio Soto, a neurology professor and director of the George and Cynthia Mitchell Center for Research in Alzheimer’s Disease and Related Brain Disorders at UTHealth Houston, lead author of the study, explained the key findings to Medical News Today.

“This study reported the largest analysis of the diagnostic accuracy of a technology we developed in the lab, termed seed amplification assay (SAA) to detect abnormal alpha-synuclein protein in patients affected by Parkinson’s disease,” Prof. Soto said.

“The main abnormality in these patients is the accumulation in the brain of an abnormal form of the alpha-synuclein protein, which becomes toxic and destroys neurons in the brain. In this study, we showed that traces of this abnormal protein can be detected in cerebrospinal fluid of Parkinson’s disease patients with a sensitivity and specificity over 90%.”

– Prof. Claudio Soto

“This means that the disease can be diagnosed by a simple biochemical test that can be performed in a live patient,” he added.

“Importantly, we were able to detect this marker years before the patients showed the disease. This is important because at this time the brain is not yet damaged extensively and can be much more easily be healed, perhaps even with simple lifestyle changes,” Prof. Soto explained.

Dr. Elana Clar, a neurologist and Parkinson’s specialist at New Jersey Brain and Spine, not involved in this research, agreed, saying that “Parkinson’s disease is a condition where the diagnosis has been solely based on the clinical exam for over 200 years.”

“The significance of this breakthrough cannot be overstated. It is the first time we have an objective biomarker that can be identified not only in individuals with Parkinson’s disease, but younger individuals who may not be displaying any symptoms, and only carry certain risk factors,” she added.

“In essence, it can diagnose Parkinson’s disease before it becomes physically apparent, and that is a game changer. That said, the test in its current state is only done through collecting spinal fluid, and will likely pick up momentum once there is a similar test for blood, sputum, or other body fluids that are less invasive to check.”

– Dr. Elana Clar

Dr. Akil Palanisamy, a Harvard-trained physician and department chair for Integrative Medicine at the Sutter Health Institute for Health and Healing in California, also not involved in this research, had a similar perspective, telling MNT: “I found this study exciting because it could potentially be a game changer for those with Parkinson’s disease.”

“We currently do not have a test to diagnose Parkinson’s disease – the current standard of care is that diagnosis results from a doctor taking a history and performing a neurological examination, and if symptoms improve after starting Parkinson’s drugs, that may confirm that the person has Parkinson’s,” Dr. Palanisamy highlighted.

“This study describes the validation of a novel technique to accurately diagnose Parkinson’s disease using patients biological samples. For the first time, we have a way to identify the disease early on in an objective manner.”

– Prof. Claudio Soto

Prof. Soto explained how the new technique not only helps to diagnose Parkinson’s, but also distinguishes patients who have Parkinsonism symptoms but do not have typical Parkinson’s disease.

This is important for designing therapies and identifying individuals who may benefit from treatment.

Additionally, the tool can identify individuals who will develop the disease years before they have brain damage, which is crucial for early treatment and better outcomes.

Late identification of the disease can make it difficult to have an efficient treatment that can produce substantial benefits.

Dr. Clar highlighted that the test “will not change how we diagnose Parkinson’s, or change how we manage a patient’s care. It is only identifying an abnormal protein, not stating how much there is, or if it is changing over time.”

“It doesn’t tell us the extent of the disease, or help us predict the pace of progression. It is also not fool-proof; the test may not be positive in everyone who has Parkinson’s disease — let alone those who are at risk,” she clarified.

“However, the test will give us better insight into the biological changes occurring inside the body, help direct specific clinical trials, and very likely influence future drug development,” Dr. Clar noted.

The study had some limitations and the authors suggest that a larger number of samples would improve the analysis. The study is also cross-sectional, meaning it was conducted at one point in time, but future studies using samples collected over time could assess further changes.

Ultimately, the research team will continue to study SAA for research and commercialization purposes. Prof. Soto is also the co-founder, chief scientific officer, and board director of Amprion, a biotech company focusing on the commercial utilization of SAA for early diagnosis of Parkinson’s and other diseases.