Effect of antirheumatic drugs on proteinases in synovia of patients with rheumatoid arthritis.

Synovia and synovial fluid proteinases were determined in 21 patients with rheumatoid arthritis who were using different kinds of antirheumatic medications. Significantly lower cathepsin B1-like proteinase activity (only 10% of control) was found in the synovial fluid of patients with chloroquine treatment, and significantly lower neutral trypsin-substrate hydrolysing proteinase activity (about 30% of control) was found in the synovia of patients with phenylbutazone treatment. No significant differences were found with other medications: gold, indomethacin, cortisone, acetylsalicyclic acid. No definitive correlations between disease activity parameters and proteinase activities could be found.