Double-stranded RNA levels were significantly higher in rheumatoid arthritis patients than osteoarthritis controls, with IFN-alpha detected in synovial fluid of 10 of 21 RA patients.
Observational
Are dsRNA levels elevated in the sera and synovial fluids of rheumatoid arthritis patients compared to osteoarthritis patients?
The presence of significantly higher levels of dsRNA in the synovial fluid of RA patients, particularly those with erosive disease, suggests a potential viral or dsRNA-mediated component in RA pathogenesis.
Viruses may be part of the pathogenesis of rheumatoid arthritis (RA). Double stranded RNA (dsRNA) is a prototypic viral conformation of nucleic acid that is highly arthritogenic in mice. Therefore, we developed an ELISA to detect dsRNA in sera and synovial fluids (SF) in RA patients and in osteoarthritic controls. The developed ELISA recognizes picogram levels of viral or synthetic dsRNA but shows no reactivity against DNA, synthetic ssRNA, or total RNA prepared from mammalian cells. Before analysis by ELISA, each sample was subjected to RNA precipitation. The RA patients had significantly higher levels of dsRNA than the osteoarthritis patients in SF and in sera. In 7 of 17 RA patients, EBV was present in SF and in all but one of these this was accompanied by the presence of dsRNA. No parvovirus, cytomegalovirus, or polyomavirus was detected. The anti-viral cytokine IFN-alpha was detected in SF in 10 of 21 RA patients, but in none of the osteoarthritis patients. Notably, RA patients with erosive disease course had significantly higher levels of dsRNA in SF than non-erosive patients, but no correlation between dsRNA levels and the presence of RF or levels of C-reactive protein, IL-6, or IFN-alpha was observed.
Bokarewa et al. (Sat,) conducted a observational in Rheumatoid arthritis. dsRNA detection vs. Osteoarthritis controls was evaluated on dsRNA levels in sera and synovial fluids. Double-stranded RNA levels were significantly higher in rheumatoid arthritis patients than osteoarthritis controls, with IFN-alpha detected in synovial fluid of 10 of 21 RA patients.