Serum cartilage oligomeric matrix protein (COMP) level is a marker of disease activity in relapsing polychondritis.

OBJECTIVES

Relapsing polychondritis (RP) is a rare and severe disease which may lead to destruction of elastic cartilages. Until now, no reliable biomarker of disease activity in RP has been available. This study was designed to measure serum levels of cartilage biomarkers during both active and inactive phases of the disease.

METHODS

Serum levels of cartilage oligomeric matrix protein (COMP), chondroitin sulfate 846 epitope (CS846) of proteoglycan aggrecan and collagen type II collagenase cleavage neoepitope (C2C) were measured retrospectively in 21 subjects with RP. The Wilcoxon matched-pairs signed-rank test was used for statistical comparisons of biomarker levels in active and inactive phases of RP.

RESULTS

Only the serum level of COMP was significantly increased during disease flares. Steroids did not alter the serum cartilage-related biomarker levels. However, during the active phase, C2C levels were significantly higher in steroid treated patients compared with non-steroid treated patients.

CONCLUSIONS

This study suggests that serum COMP level may be useful for monitoring disease activity of RP. Further prospective studies are required to confirm this result.