The effects of pulse methylprednisolone on matrix metalloproteinase and tissue inhibitor of metalloproteinase-1 expression in rheumatoid arthritis

Objective. To investigate the effects of a 1000 mg i.v. pulse of methylpred nisolone succinate (pulse therapy) on the expression of matrix metalloprote inases (MMPs) and tissue inhibitor of metalloproteinases-1 (TIMP-1) in the synovial membrane of the knee in patients with rheumatoid arthritis (RA). Methods. Sequential arthroscopic biopsies of the knee were taken before and 24 h after pulse therapy (11 patients), at disease relapse (three patients ) and after retreatment with pulse therapy (one patient). Immunoperoxidase staining for MMP-1 (interstitial collagenase), MMP-3 (stromelysin-1) and TI MP-1 was performed and the immunoreactive staining quantified by colour vid eo image analysis. Results. In the synovial lining layer, MMP-1 and TIMP-1 immunostaining was reduced by a mean of 47% (P = 0.02) and 72% (P = 0.05), respectively, 24 h after pulse methylprednisolone therapy. In the synovial sublining layer, MM P-1 was reduced by a mean of 51% (P = 0.08) and TIMP-1 by a mean of 73% (P = 0.02) 24 h after pulse methylprednisolone therapy. There was no change in MMP-3 staining in the synovial lining or sublining layer. Conclusions. High-dose pulse methylprednisolone therapy is associated with a rapid (within 24 h) and substantial decrease in the expression of MMP-1 a nd TIMP-1 but not MMP-3 in the synovial membrane in RA.