Even in people without symptoms, increased levels of rheumatoid factor, an antibody, could tag an increased long-term risk of developing rheumatoid arthritis, according to results from a Danish study published in the BMJ.
The researchers screened almost 10,000 Danes between the ages of 20 and 100, measuring their levels of rheumatoid factor, and followed them for up to 28 years. They found that a doubling of rheumatoid factor levels increased the risk of developing rheumatoid arthritis threefold, with the highest levels increasing the risk twenty-sixfold. The highest risk was in women between 50 and 69 who smoked and had increased rheumatoid factor levels.
Rheumatoid arthritis is an inflammatory disease of the joints. It affects around 1 in 100 people worldwide, with three times as many cases in women as in men. There is currently no diagnostic test, and doctors look for raised rheumatoid levels and other symptoms to diagnose the disease.
With DMARDs (disease-modifying anti-rheumatic drugs), treating rheumatoid arthritis early can improve the long-term outcomes for people with rheumatoid arthritis, as well as make their day-to-day lives a lot easier.
According to the authors, these findings could suggest early referral for examination after a positive rheumatoid factor test, even with the absence of typical arthritic symptoms, like pain and swelling in the joints. However, as Julia Simard of the Karolinska Institutet in Sweden observed in an accompanying editorial, in clinical practice, people are generally not sent for rheumatoid factor testing in the absence of signs or symptoms, and future research should focus on the link between rheumatoid factor and rheumatoid arthritis, as well as on autoantibodies.