Effects of infliximab therapy on biological markers of synovium activity and cartilage breakdown in patients with rheumatoid arthritis

Background: Defining the remission criteria of rheumatoid arthritis ( RA) remains a critical issue. Markers of synovium activity, urinary glucosyl-galactosyl-pyridinoline (Glc-Gal-PYD) and of cartilage destruction, urinary C-terminal crosslinking telopeptide of type II collagen (CTX-II) have been shown to reflect disease activity and joint damage progression in RA. Methods: The prospective study cohort comprised 66 RA patients treated with infliximab and methotrexate and 76 healthy controls. Measurements of urinary Glc-Gal-PYD and CTX-II were performed at baseline and at 1 year of infliximab therapy. Results: At baseline, urinary Glc-Gal-PYD and CTX-II levels were increased in patients with RA and correlated with modified Sharp scores and progression of joint damage. Patients with more progressive joint destruction had higher Glc-Gly-PYD and CTX-II baseline levels. Conclusion: These markers reflected bone erosion evolution and might be useful for treatment monitoring and evaluation of RA. Markers remained high even in clinical responders after infliximab, suggesting persistence of synovitis.