Gene Pattern May Predict Osteoarthritis
For some of the more than 27 million Americans who suffer with osteoarthritis, results of a new study may help identify those who could benefit from trials of disease-modifying drugs. The answer could lie in a gene pattern that can predict who may develop severe osteoarthritis.
A Specific Pattern of Genetic Variations Indicates Increased Risk of Osteoarthritis
The large clinical study, conducted by scientists from University of North Carolina (UNC) at Chapel Hill School of Medicine and Interleukin Genetics, Inc., involved 1,154 patients with osteoarthritis who were followed for up to 11 years. This study was unique in that it included both blacks and whites and conducted genetic, radiographic, serologic, physical, and functional examinations of the subjects.
Researchers found that patients who had x-ray evidence of knee osteoarthritis and who also had a particular pattern of genetic variations in the interleukin-1 receptor antagonist (IL-1Ra) gene were nearly twice as likely to eventually develop severe osteoarthritis when compared with patients who did not have the pattern.
Interleukin-1 is one of the main chemicals associated with destruction of bone and cartilage. In this study, researchers observed that three specific genetic patterns often seen in people who have osteoarthritis are strongly predictive of risk for progression of the disease.
This finding validates earlier research indicating that the gene for IL-1Ra has a strong association with severe osteoarthritis of the knee. Although currently there are no disease-modifying drugs for osteoarthritis, the association between progressive osteoarthritis and the IL-1Ra gene variants “might suggest that this IL-1Ra genetic information could be tested as a tool to identify high-risk patients for participation in clinical trials for the development of a much-needed disease modifying OA drug,” notes Joanne Jordan, MD, MPH, who led the study, and who is Chief, Division of Rheumatology, Allergy, and Immunology at the Thurston Arthritis Research Center at UNC Chapel Hill.
The lack of disease-modifying drugs for osteoarthritis is not due to a lack of trying. Oral calcitonin has been investigated as a possible candidate, as has licofelone. Protelos® (strontium ranelate, Servier) has been shown to be effective and is available around the world but does not have approval from the Food and Drug Administration (FDA).
Ken Kornman, chief scientific officer at Interleukin Genetics, noted that developing disease-modifying drugs for osteoarthritis has been a challenge “in part due to the difficulty of enrolling patients who are likely to exhibit disease progression during the study.” This latest research showing that specific gene patterns may predict which patients with osteoarthritis will progress to more severe disease may allow investigators to select trial participants who are more likely to benefit from a test drug and greatly support ongoing research.
University of North Carolina Chapel Hill