The Differential Effect of Antibodies on Radiographic Progression in Rheumatoid Arthritis

Area of Science:

• Rheumatology
• Immunology
• Radiology

Background:

• Rheumatoid arthritis (RA) is characterized by bony erosions, a marker of disease severity.
• These erosions are often irreversible once present.
• Previous research indicates an association between rheumatoid factor (RF) and anti-cyclic citrullinated peptide (ACPA) antibodies and erosive burden.

Purpose of the Study:

• To determine the strength of the relationship between antibody status and the presence of radiographic erosions at the time of diagnosis in RA patients.

Main Methods:

• Retrospective study of 774 RA patients diagnosed between 1981 and 2018.
• Review of clinical records for antibody status (RF and ACPA), diagnosis date, and other clinical factors.
• Analysis of plain film radiographs for the presence of erosions at diagnosis using Chi Square and Mann Whitney U tests.

Main Results:

• 127 patients (16.4%) had erosions at diagnosis.
• Patients positive for both RF and ACPA (RF+/ACPA+) showed a significantly higher erosion burden (21.5%) compared to antibody-negative patients (RF-/ACPA-, 11.0%; p=0.003).
• Erosion burdens were 13.7% for RF+/ACPA- and 12.1% for RF-/ACPA+ groups.

Conclusions:

• Patients with RA who are positive for both RF and ACPA antibodies have a nearly two-fold higher incidence of radiographic erosions at diagnosis.
• Antibody status is a significant factor associated with early erosive disease in RA.