Gene pattern may predict osteoarthritis

Researchers have identified genetic patterns that may predict osteoarthritis.

Scientists from the University of North Carolina and Interleukin Genetics, Inc. revealed the findings from a large clinical study to evaluate the role played by genetic factors in the worsening of osteoarthritis (OA).

The study, which was part of the Johnston County Osteoarthritis Project, showed patients with X-ray evidence of knee osteoarthritis who inherited a specific pattern of genetic variations in the interleukin-1 receptor antagonist (IL-1Ra) gene were almost twice as likely to progress to severe disease as other patients.

The study followed patients for up to 11 years.

The study, led by Joanne Jordan of the University of North Carolina, is the first of its kind to include both  African-Americans and Caucasians. It included genetic, radiographic, serologic, physical and functional examinations of its participants.

"The strong association shown in this study between progressive OA and the IL-1Ra gene variations, as well as the body of previous related published research, 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," said Jordan.

Ken Kornman of Interleukin Genetics said: "There appears to be strong potential to use the IL-1Ra genetic patterns to select for clinical trials patients who are more likely to benefit from an effective drug.

"A genetic test also would have strong clinical utility for physicians to better manage patients who will more likely progress to a severe form of the disease and require surgery."

The 1,154 subjects in the Johnston County Osteoarthritis Projected, which is directed by Jordan, were monitored for a period between four and 11 years to study initiation or progression of osteoarthritis.

Subjects at the start of the study were analysed for genetic markers that predicted those subjects who remained stable and those who progressed to severe osteoarthritis, as measured radiographically.

Nine genes were found to be associated with osteoarthritis progression, with the strongest prediction of progression from combinations of gene variations in the gene for IL-1Ra.

The findings were presented at the World Congress on Osteoarthritis in Brussels, Belgium.