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• Posted April 29, 2024

Blood Test Might Predict Knee Osteoarthritis Years Early

A blood test could help doctors spot the signs of knee osteoarthritis at least eight years before it shows up on X-rays, a new study claims.

After analyzing the blood of 200 white British women, half diagnosed with knee osteoarthritis and half without, researchers discovered a small number of biomarkers distinguished the women with osteoarthritis from those without it.

"We found we were able to identify people who are at risk for knee osteoarthritis, but what was exciting was that we were able to identify it eight years before they had any X-ray changes," said senior study author Dr. Virginia Byers Kraus, a professor in the departments of Medicine, Pathology and Orthopedic Surgery at Duke University School of Medicine, in Durham, N.C.

The study, published April 26 in the journal Science Advances, builds on previous research where the blood test demonstrated 74% accuracy in predicting knee arthritis progression and 85% accuracy in diagnosing knee arthritis.

Knee arthritis strikes approximately 35 million adults in the United States. While there are no cures, the success of new therapies could hinge on identifying the disease early and slowing its progression.

The researchers emphasized that just like heart disease, osteoporosis or Alzheimer's disease, knee osteoarthritis is a chronic disorder that is typically diagnosed late in the game. By identifying it earlier, doctors could potentially stop the disease before it becomes debilitating, the researchers said.

"The reason that this is really important is that until now, we have been thinking about osteoarthritis as a disease with X-ray changes. But it turns out that, in fact, there are a lot of things going on prior to that and by actually identifying it much earlier, we can prevent disability, pain and the deterioration of quality of life that people who develop the X-ray changes usually get," Kraus said.

According to Kraus, if patients discover through a blood test that they are at a high risk for knee osteoarthritis, they could make lifestyle changes that include weight loss, exercise, eating healthy or even getting steroid injections.

Researchers also emphasized that knee osteoarthritis is more than just painful for patients: It also leads to the majority of all joint replacements, creating a massive economic burden.

These concerns were echoed by Stephen Messier, a professor of health and exercise science at Wake Forest University and an Arthritis Foundation-funded investigator.

"The burden of osteoarthritis [OA] continues to rise, driving higher healthcare costs and poorer patient outcomes,"Messier said. "Early detection of knee OA could help clinicians intervene sooner and reduce the pain and loss of function of patients before joint replacement surgery is necessitated."

However, more research is needed to validate the test before it can be deployed in the general population. This test was also performed only in white women, and future studies should broaden the patient population.

According to Kraus, there are also about 100 different types of arthritis including OA, rheumatoid arthritis and gout, and they can affect multiple joints besides the knee.

Future studies will include examining the hips, hands and spine of patients, to see whether they are similarly affected.

Overall, the researchers noted that adoption of a blood test could aid in the development of early and targeted intervention for patients who previously would not be identified as having knee osteoarthritis.

"I think that one of the take-home messages is that osteoarthritis is not just the disease of older people, it's the disease of younger people as well, especially if they've had a major joint injury," Kraus said. "The second message would be that it truly is very, very important, whether you have chronic disease risk or not, to try to do the important lifestyle management."

More information

The Arthritis Foundation has more on knee osteoarthritis.

SOURCES: Virginia Byers Kraus, MD, professor, departments of Medicine, Pathology and Orthopedic Surgery, Duke University School of Medicine, Durham, N.C.; Stephen Messier, professor, health and exercise science, Wake Forest University, Winston-Salem, N.C.; Science Advances, April 26, 2024