SAT0031 CORRELATION BETWEEN IRREVERSIBLE PHYSICAL DISABILITY AND JOINT DAMAGE IN RHEUMATOID ARTHRITIS

Abstract

Background:In rheumatoid arthritis (RA), irreversible physical disability appears to be more clearly associated with cartilage damage rather than with bone erosions (BE) using conventional radiography (CR) imaging.Objectives:To investigate the correlation between the ultrasound (US) and CR findings indicative of joint damage and irreversible physical disability in patients with RA in sustained clinical remission.Methods:Patients in sustained clinical remission according to the Simplified Disease Activity Index (SDAI)≤3.3 for at least 6 months were enrolled. The following data were regireted: age, disease duration, anti-cyclic citrullinated peptide (ACPA) antibody and rheumatoid factor (RF) status, Health Assessment Questionnaire (HAQ), CR of hands and feet [evaluated using the Simple Erosion Narrowing Score (SENS) method]. A standardized US examination was carried out to investigate the presence of BE (lateral side of II metacarpophalangeal, V metacarpophalangeal and V metatarsophalangeal joints and ulnar styloid) and of cartilage damage (II to V metacarpal heads), bilaterally. BE and cartilage damage were assessed according to OMERACT definitions. A semiquantitative scoring system for both BE (1) and cartilage damage (2) was adopted.Results:Ninety patients were consecutively enrolled. Average time for US evaluation was 10±2 minutes. Both SENS-JSN and US score of cartilage damage (US-CD) were significantly associated with irreversible disability (R=0.39, p<0.01 and R=0.46, p<0.01). US and CR showed a moderate agreement in the evaluation of cartilage damage (kappa=0.52, 95% confidence interval: 0.44-0.61).Figure 1.shows the association between disability and structural damage (A: US-CD, B: US-BE, C: SENS-JSN and D: SENS-BE). After adjusting for confounding factors (age, disease duration, ACPA and RF status, SENS-BE and US-BE) cartilage damage was the only significant predictor of irreversible disability both using CR (R2=0.31, adjusted R2=0.26, standardized β=0.36, p<0.01) and US (R2=0.31, adjusted R2=0.26, standardized β=0.34, p<0.01).Conclusion:This study supports the hypothesis that cartilage damage is more relevant than BE in determining irreversible disability in RA. Our data provide further evidence in favor of the external validity of US in the assessment of cartilage damage.