2. How are Seronegative Rheumatoid Arthritis and fibromyalgia linked?
As mentioned, seronegative RA is a less common sub-type of RA and not much study has been done on it. Researchers at the Duke University of North Carolina conducted a study to investigate medical conditions related to this form of RA. They hope that their study would spark more research on this subgroup which constitutes 20-40%, is a significant percentage, of all RA cases.
The researchers carried out the investigation with phenome-wide association study (PheWAS) analysis of electronic health records (EHRs) to identify disease related to both seropositive and seronegative RA patients. The findings suggest a strong connection between seronegative rheumatoid arthritis and fibromyalgia. According to the findings, seronegative RA patients have double the chance of having PheWAS codes for “myalgia and myositis”. These codes “myalgia and myositis” signify fibromyalgia in 80 out of 100 cases. Therefore, researchers believe that this finding indicates a strong association between seronegative rheumatoid arthritis and fibromyalgia. Furthermore, the data collected also showed that seronegative RA patients are more susceptible to back pain, a common fibromyalgia symptom.
Despite limitations of PheWAS, researchers conclude that their study indicates a connection between seronegative rheumatoid arthritis and fibromyalgia. They suggest that physicians should be mindful of the higher occurrence of fibromyalgia in seronegative RA patients.