Increased serum levels of cartilage oligomeric matrix protein in patients with psoriasis vulgaris: a marker for unknown peripheral joint involvement?

OBJECTIVE Cartilage oligomeric matrix protein (COMP) is a parameter for the current extent of cartilage destruction. It has been shown that the release pattern of cartilage oligomeric matrix protein in serum reflects cartilage turnover. The aim of our study was to explore the utility of sCOMP as a marker for disease activity in patients with active psoriatic arthritis (PsA) in comparison to a control group only with psoriasis vulgaris (PV). METHODS Serum levels of COMP were measured in 64 patients with PsA and psoriasis vulgaris. The control group consisted of a population with PV from a dermatological outpatient clinic. ELISA-tests were used to detect sCOMP levels according to the manufacturer instructions. RESULTS In our 64 patients with PsA, we found increased sCOMP levels, which correlated significantly with inflammatory parameters and the number of swollen joints. Patients with active PsA had significantly higher sCOMP levels (p<0.0001) than the 39 patients with a low inflammatory status. In our control group with PV we also found elevated sCOMP levels, which correlated significantly with the increased C-reactive protein (CRP) levels in this group. The difference between the PsA and the PV group was not significant (p=0.092). CONCLUSION In our study, sCOMP has been demonstrated to be an indicator for disease activity in patients with PsA. Patients with active PsA showed significantly elevated sCOMP levels compared to the patients with low clinical and laboratory disease activity. The increased sCOMP levels in our control group with PV indicate that all patients with psoriatic lesions should be screened for additional joint involvement and should lead to an exact joint examination.