Small joint synovitis in rheumatoid arthritis: should it be assessed separately?

Area of Science:

• Rheumatology
• Immunology
• Radiology

Background:

• Traditionally, rheumatoid arthritis (RA) disease activity assessment includes small joint synovitis only in joint counts.
• Radiological scores of hands and feet are primary indicators of RA disease damage and outcome.
• Current RA assessment may not fully capture disease progression in small joints.

Purpose of the Study:

• To investigate the necessity of independent assessment for small joint synovitis in rheumatoid arthritis (RA).
• To determine if small joint synovitis can occur without systemic inflammation markers.
• To explore the relationship between small joint synovitis and subsequent radiological damage.

Main Methods:

• Analysis of disease activity measures including acute phase response (erythrocyte sedimentation rate [ESR] and C-reactive protein).
• Reliability assessment of synovitis measurement in individual proximal interphalangeal (PIP) joints.
• Correlation of synovitis with subsequent X-ray changes in the same joints.

Main Results:

• Small joint synovitis in RA can be present without elevated ESR or C-reactive protein levels.
• Individual PIP joint synovitis measurement is reliable and predicts future X-ray damage.
• RA treatments may control systemic disease activity while small joint inflammation persists, leading to radiological damage and adverse outcomes.

Conclusions:

• Small joint synovitis in RA requires independent assessment due to its potential to cause damage despite controlled systemic disease activity.
• Recognizing small joint inflammation and damage as a distinct aspect of RA offers unique insights into disease progression.
• Independent assessment of small joint inflammation and damage is vital for accurate RA outcome prediction and management.