Increased tenosynovitis and synovitis scores at clinically suspect arthralgia (CSA) onset and the increase in synovitis and osteitis during progression to rheumatoid arthritis (RA) suggest an “outside-in” temporal relationship of arthritis development, in particular for anti-citrullinated protein antibody (ACPA)-negative RA. This according to a longitudinal study that assessed the course of MRI-detected subclinical joint inflammation during progression to RA. Patients that progressed from CSA to RA underwent 1.5-T MRI of the metacarpophalangeal (MCP), wrist, and metatarsophalangeal (MTP) joints at presentation with arthralgia and at first identification of synovitis assessed through physical examination (n=31). MRIs were evaluated for osteitis, synovitis, tenosynovitis, and erosions by 2 readers, blinded for clinical data and order in time. Researchers found:
- At presentation with CSA, synovitis and tenosynovitis scores were higher than scores from age-matched symptom-free persons.
- ACPA-positive arthralgia patients also had increased osteitis scores.
- Median duration between presentation with arthralgia and RA development was 17 weeks.
- During progression to RA, synovitis and osteitis increased significantly in contrast to tenosynovitis and erosion scores.
ten Brinck RM, van Steenbergen HW, van der Helm-van Mil AHM. Sequence of joint tissue inflammation during rheumatoid arthritis development. [Published online ahead of print November 21, 2018]. Arthritis Res Ther. doi:10.1186/s13075-018-1756-z.