The Effects of Corticosteroids and Gold Therapy on the Serum Concentrations of Cartilage Oligomeric Matrix Protein in Patients with Rheumatoid Arthritis

Objective: Cartilage oligomeric matrix protein (COMP) has been identified and quantified in sera and synovial fluids of patients with inflammatory arthritis and osteoarthritis and the levels may reflect processes in cartilage.We have studied the effects of drug therapy on the serum levels of COMP as well as the relationship of serum COMP levels to disease activity in patients with rheumatoid arthritis (RA).Method: COMP serum levels were measured at weeks 0, 8, 12 and 24 in patients with RA who were starting gold therapy alone (Au, n=10) and in those who received gold and intramuscular depot methyl prednisolone acetate 120 mg given at weeks 0, 4 and 8 (DMAu, n=14). Results:The addition of intermittent intramuscular depot methyl prednisolone acetate induced a rapid onset of disease remission in the DMAu patient group as well as significantly reducing the serum levels of COMP (p=0.001) by week 12.This was followed by an increase in the levels of COMP at week 24 (p=0.05).No significant changes in the levels of COMP were seen in the Au group.There was no correlation between the levels of COMP and the radiological indices or clinical and/or laboratory indices of disease activity at any time during the study.The changes in the radiological scores were similar in the two groups of patients. Conclusion:Intramuscular corticosteroid therapy decreases the levels of COMP in RA.COMP serum levels do not correlate with the indices of disease activity and radiological changes.Long term sequential measurements of serum concentrations of COMP may shed more light on whether COMP could be used for monitoring tissue effects of RA therapy.