Duke University School of Medicine researchers are developing a blood test that they believe can detect osteoarthritis progression in the knee more accurately than currently-used methods.
They described the blood test in a National Institutes of Health (NIH)-funded study, published January 25 in Science Advances, saying that the work may advance osteoarthritis research and speed the discovery of new therapies.
Osteoarthritis is the most common joint disorder in the U.S. It afflicts 10% of men and 13% of women over the age of 60 and is a major cause of disability. However, a cure for osteoarthritis remains elusive. Its management is largely palliative, and effective new therapies are lacking.
Without a good way to identify osteoarthritis before the onset of irreversible signs and symptoms, or to accurately predict the risk of progression, researchers have been largely unable to determine the correct patients to include in clinical trials to test new therapies and find out whether they are beneficial—a situation researchers call a “chicken-and-egg” predicament.
The new test relies on blood serum biomarkers. Researchers isolated more than a dozen blood molecules associated with osteoarthritis progression among 596 people with knee osteoarthritis. Further honing enabled the researchers to narrow the blood test to a set of 15 serum proteomic markers that corresponded to 13 total proteins, which reached an area under the receiver operating characteristic curve (AUC) of 73% for accurately distinguishing disease progressors from non-progressors.
That prediction rate for the new blood biomarker was a significant improvement from other approaches. Assessing baseline structural osteoarthritis and pain severity has an accuracy rate of 59%, while another current biomarker involving testing molecules from urine has an accuracy rate of 58%. The generalizability of the marker set was confirmed in a second cohort of 86 individuals that yielded an AUC of 70% for predicting joint structural disease progression.
The new blood-based marker set was also successful in identifying a group of patients whose joints showed progression in X-ray scans, regardless of pain symptoms. Researchers say that this new test fills an important void in the medical literature for this widespread disease. In the immediate future, it could help identify people at high risk of progressive knee osteoarthritis—those likely to have both pain and worsening damage identified on x-rays, and who might benefit from enrollment in clinical trials designed to find out whether certain therapies are beneficial.
“In addition to being more accurate, this new biomarker has an additional advantage of being a blood-based test,” Duke University professor and senior author Dr. Virginia Byers Kraus said in a statement. “Blood is a readily accessible biospecimen, making it an important way to identify people for clinical trial enrollment and those most in need of treatment.”
