A cooperative study between Interleukin Genetics and the Thurston Arthritis Research Center at the University of North Carolina has found that individuals with radiographic knee osteoarthritis (OA) with a specific pattern of gene variations in the interleukin-1 receptor antagonist gene (IL1RN) were more likely to progress to severe disease than those without the gene variations. The effect of these gene variations was particularly important in those with a high body mass index. It did not have a strong effect in those with a lower body mass index. The IL1RN gene is involved in controlling inflammation.
Joanne Jordan, M.D., Director of the Thurston Arthritis Research Center conducted the study: “Progression of knee osteoarthritis often leads to severe disability and total knee replacement in many patients.” She stated: “The factors determining progression are poorly understood and the genetic markers we reported appear to substantially improve our ability to identify which knee OA patients are more likely to progress. Our goal is to use such information to improve drug development and medical management for our OA patients.”
The study evaluated radiographic progression of knee OA using the Johnston County Osteoarthritis Project, with a population in North Carolina of 1, 153 subjects. Initially 154 had radiographic signs of knee OA. If they had the specific pattern of IL1RN gene variations that is found in approximately 40% of Caucasians they were more than twice as likely to have radiographic progression of the disease during the 4 to 11 year monitoring period than did all of the other individuals with knee OA.
“This study was a critical validation of the importance of IL-1 receptor antagonist genetic variations in knee osteoarthritis that we and others have seen in other cohorts, ” said Kenneth Kornman, M.D., Chief Executive Officer of Interleukin Genetics. “We hope to start using this genetic information in partnerships to help guide therapeutic development to improve the management of knee OA.”
