Blood Test Detects Knee Osteoarthritis Years Before X-Rays Spot It

Blood tests are very telling assays. They are used to detect a vast array of health conditions, including infections, anemia, high cholesterol, vitamin deficiencies, organ failure, HIV, cancer, low hormone levels, and diabetes, among others.

Knee osteoarthritis (OA) could soon be added to that list.

A blood test has successfully predicted knee osteoarthritis at least eight years before tell-tale signs of the disease appeared on x-rays, Duke Health researchers report.
 
In a study that appearing last month in the journal Science Advances, the researchers validated the accuracy of the blood test that identifies OA’s key biomarkers. They showed the test predicted the disease’s development and progression, which was demonstrated in their earlier work. The research augers well for detecting the disease far earlier than current diagnostic tools, since these solutions only spot the disease after it has caused structural joint damage. 
 
“Currently, you’ve got to have an abnormal X-ray to show clear evidence of knee osteoarthritis, and by the time it shows up on X-ray, your disease has been progressing for some time,” said senior author Virginia Byers Kraus, M.D., Ph.D., a professor in the departments of Medicine, Pathology, and Orthopaedic Surgery at Duke University School of Medicine. “What our blood test demonstrates is that it’s possible to detect this disease much earlier than our current diagnostics permit.”
 
Osteoarthritis is the most common form of arthritis, afflicting an estimated 35 million U.S. adults and causing significant economic and societal impacts. While there are currently no cures, the success of potential new therapies could hinge on identifying the disease early and slowing its progression before it becomes debilitating.
 
Kraus and her colleagues have focused on developing molecular biomarkers that can be used for both clinical diagnostic purposes and as a research tool to aid in the development of effective drugs. In previous studies, the blood biomarker test demonstrated 74% accuracy in predicting knee OA progression and 85% accuracy in diagnosing knee OA. 
 
The current study further honed the test’s predictive capabilities. Using a large United Kingdom database, the researchers analyzed serum of 200 white women, half diagnosed with OA and the other half without the disease, matched by body mass index and age. 
 
Study results indicate a small number of biomarkers in the blood test successfully distinguished the women with knee OA from those without it, catching molecular signals of OA eight years before many of the women were diagnosed with the disease by X-ray.
 
“This is important because it provides more evidence that there are abnormalities in the joint that can be detected by blood biomarkers well before X-rays can detect OA,” Kraus said. “Early-stage osteoarthritis could provide a ‘window of opportunity’ in which to arrest the disease process and restore joint health.”
 
In addition to Kraus, study authors include Shuming Sun, Alexander Reed, Erik J. Soderblom, M Arthur Moseley, Kaile Zhou, Vaibhav Jain, Nigel Arden, and Yi-Ju Li.
 
The study received funding support from National Institutes of Health.