Researchers have identified three different synovial subtypes of rheumatoid arthritis that exhibit different mechanisms of pain and correlate with specific clinical phenotypes.
The findings could be clinically meaningful and may help guide optimal treatment strategies for patients, as well as provide a better understanding of the cause of pain in patients with high tender and swollen joint counts but little tissue inflammation, according to the research team led by Dana E. Orange, MD, of the Hospital for Special Surgery and Rockefeller University in New York.
The report was published in Arthritis & Rheumatology.
The assessment of the synovium in rheumatoid arthritis (RA) has the potential to provide guidance on optimal treatment strategies, they noted, but its classification has not yet factored into current diagnosis or treatment guidelines of RA.
In the study, the researchers analyzed clinical, histologic, and gene expression data from a cohort of 123 RA patients (106 of whom were women) who underwent arthroplasty at the Hospital for Special Surgery, and 6 osteoarthritis patients. About half of the RA patients were seropositive for rheumatoid factor and cyclic citrullinated peptides. The patients had a moderate Disease Activity Score in 28 joints (DAS28) of 3.8 on average despite their mean disease duration of 14 years.In total, the research team analyzed 20 histologic features on 129 synovial tissue samples.