LAUSR

OBJECTIVES To evaluate the relevance of serum immunoglobulin G (IgG) titers against periodontopathic bacteria to predict the clinical response to one-year treatment with biological disease-modifying antirheumatic drugs (bDMARDs) in rheumatoid arthritis (RA) patients. METHODS Data were collected from 50 RA patients who had received conventional synthetic DMARDs, corticosteroids, or non-steroidal anti-inflammatory drugs before (baseline) and after one-year treatment with bDMARDs in a retrospective cohort study. Changes in rheumatologic conditions were compared between the two groups for low and high baseline IgG titers against Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans according to their median measurements. RESULTS Twenty-five patients with low anti-P. gingivalis IgG titers showed significantly greater decreases in changes in the clinical disease activity index (CDAI) and swollen joint count than 25 patients with high anti-P. gingivalis IgG titers (p=0.04 for both). Bivariate and multivariate analyses revealed a significantly positive association of baseline anti-P. gingivalis IgG titers with CDAI changes (p=0.02 and p=0.002). However, post-treatment rheumatologic conditions were comparable between 25 patients each in the low and high baseline anti-A. actinomycetemcomitans IgG titer groups. CONCLUSIONS Baseline serum anti-P. gingivalis IgG titers are predictive of the clinical response to one-year treatment with bDMARDs in RA patients.