Determination of metalloproteinases, plasminogen-activators and their inhibitors in the synovial fluids of patients with rheumatoid arthritis during chemical synoviorthesis.

The concentrations of matrix metalloproteinase-1 (MMP-1), matrix metalloproteinase-8 (MMP-8), matrix metalloproteinase-9 (MMP-9), lactoferrin and urokinase plasminogen activator (uPA), tissue-type plasminogen activator (tPA) and the inhibitors, tissue inhibitor of metalloproteinase-1 (TIMP-1), plasminogen activator inhibitor-1 (PAI-1), plasminogen activator inhibitor (PAI-2), and alpha2-macroglobulin in the synovial fluids of patients with rheumatoid arthritis was determined before and during chemical synoviorthesis with a sodium salt of the fatty acids from cod-liver oil (Varicocid). Synovial fluids were obtained before treatment from 37 patients with rheumatoid arthritis and, in most cases, at 8 and 24 h after injection of the agent. Well-established ELISAs were used to determine the amounts of all proteins. All patients with rheumatoid arthritis revealed very high levels of metalloproteinases (about 1-15 mu g/ml) in their synovial fluids. During the inflammation inducing treatment the granulocyte enzymes increased. In contrast to this, the level of MMP-1 decreased. All granulocyte-derived enzymes were strongly correlated with each other, whereas their dependence on the granulocyte count was only weak. uPA and PAI-2 showed good correlations with the granulocytes-derived enzymes, but were also only weakly correlating with the cell counts. t-PA was not detected by the ELISA used. The proteases, MMP-8, MMP-9 and uPA were increased 8 h after the treatment, whereas the specific inhibitors TIMP-1, PAI-1 and PAI-2 showed significant changes only 24 h after the injection. Matrix metalloproteinases are important factors in the pathogenesis of rheumatoid arthritis. The inflammatory activity in the joint could be better correlated to the granulocyte enzymes than to the granulocyte counts. The levels of uPA and PAI-2 are also parallel to the granulocyte enzyme levels and might underly the same regulatory mechanism.

Comparison of in vitro and in vivo properties of rhirudin (HBW 023) and a synthetic analogous peptide.

Recombinant hirudin and a shortened synthetic analogue, with the amino acid sequence of D-Phe-Pro-Arg-Pro-(Gly)4-Asn-Gly-Asp-Phe-Glu- Glu-Ile-Pro-Glu-Glu-Tyr-Leu, are specific thrombin inhibitors which in a concentration-dependent manner inhibit thrombus formation as well as clot propagation both in vitro and in vivo. In comparison to the analogue, lower molar concentrations of rhirudin affected doubling of aPTT and TT as well as inhibition of thrombin amidolytic activity or thrombin-induced platelet aggregation in vitro. In the rat wire coil-induced thrombosis model, a 50% thromboprotective effect may be brought about with doses of 0.043 mumol/kg of rhirudin and 1.43 mumol/kg of the synthetic peptide. However, doubling of bleeding times is caused, on average, by dosages of between 0.143 and 0.43 mumol/kg rhirudin or approximately 0.143 mumol/kg of the analogue. Treatment groups included animals revealing significant prolongation of bleeding times as well as nonresponders. Despite the 10-fold longer impact on aPTT after application of rhirudin, the extent of mean bleeding time prolongation is identical to that of the analogue.