A new blood test that can identify progression of osteoarthritis in the knee is more accurate than current methods, providing an important tool to advance research.
The test relies on a biomarker and fills an important void in medical research for a common disease that currently lacks effective treatments. Without a good way to identify and accurately predict the risk of osteoarthritis progression, researchers have been largely unable to include the right patients into clinical trials to test whether a therapy is beneficial.
The study was led by Virginia Byers Kraus, MD, PhD, a professor in the departments of Medicine, Pathology and Orthopedic Surgery at Duke University School of Medicine.
Kraus and colleagues isolated more than a dozen molecules in blood associated with progression of osteoarthritis, which is the most common joint disorder in the United States. It afflicts 10 per cent of men and 13 per cent of women over the age of 60 and is a major cause of disability.
With further honing, the researchers narrowed the blood test to a set of 15 markers that correspond to 13 total proteins. These markers accurately predicted 73 per cent of progressors from non-progressors among 596 people with knee osteoarthritis.
That prediction rate for the new blood biomarker was far better than current approaches. Assessing baseline structural osteoarthritis and pain severity is 59 per cent accurate, while the current biomarker testing molecules from urine is 58 per cent accurate.
The new, blood-based marker set was also successful identifying the group of patients whose joints show progression in X-ray scans, regardless of pain symptoms.
“Therapies are lacking, but it’s difficult to develop and test new therapies because we don’t have a good way to determine the right patients for the therapy,” said Professor Kraus.
“It’s a chicken-and-the-egg predicament. In the immediate future, this new test will help identify people with high risk of progressive disease — those likely to have both pain and worsening damage identified on X-rays — who should be enrolled in clinical trials. Then we can learn if a therapy is beneficial.”
Professor Kraus added: “In addition to being more accurate, this new biomarker has an additional advantage of being a blood-based test.
“Blood is a readily accessible biospecimen, making it an important way to identify people for clinical trial enrolment and those most in need of treatment.”