Association of rheumatoid factors and anti-filaggrin antibodies with severity of erosions in rheumatoid arthritis

Objectives. To evaluate and to compare the association of two types of auto antibodies-rheumatoid factors (RF) and anti-filaggrin antibodies (AFA)-with clinical severity and joint damage progression in rheumatoid arthritis (RA ) patients. Methods. In a cross-sectional study. we determined RP and AFA titres in 199 RA patients and 65 controls. Erosions apparent on X-rays were quantified u sing the Larsen score in 143 patients, and the distribution of these scores was studied according to disease duration in patients who were positive an d negative for RF and AFA. Results. RF were detected in 72% and AFA in 47% of RA patients. AFA were hi ghly specific for RA (100%). RF positivity was correlated with the presence of subcutaneous nodules. sicca syndrome and the severity of erosions for a given disease duration. AFA positivity was correlated only with the presen ce of the HLA-DRB1 shared epitope. Conclusions. Since no significant correlation was observed between joint da mage progression and AFA positivity, the determination of AFA does not appe ar to be useful in assessing the prognosis of RA. However, AFA, which appea r early in RA, could be helpful for the diagnosis of RA in patients who do not fulfil four American College of Rheumatology criteria.