Effect of chloroquine phosphate treatment on serum MMP-9 and TIMP-1 levels in patients with systemic lupus erythematosus.

Antimalarials are widely used for the treatment of systemic lupus erythematosus. However, their mechanisms of action have not been fully elucidated. Literature data indicate that matrix metalloproteinases may play a role in the immune response and tissue damage that occur in autoimmune skin diseases. The aim of this study was to determine the effect of 3 months of chloroquine treatment on serum levels of MMP-9 and TIMP-1 in patients with systemic lupus erythematosus. The study group consisted of 25 patients with systemic lupus erythematosus and 25 sex- and age-matched healthy volunteers. Before drug administration, serum levels of MMP-9 and TIMP-1 were determined by enzyme-linked immunosorbent assay. The same procedure was performed after chloroquine treatment. We found significantly higher median serum levels of MMP-9 in patients with systemic lupus erythematosus before therapy (57.20 ng/ml) when compared with controls (44.50 ng/ml) (p < 0.001). After chloroquine therapy the median MMP-9 serum level of systemic lupus erythematosus patients decreased significantly (43 ng/ml; p < 0.001). Before treatment the median TIMP-1 serum level in the patients with systemic lupus erythematosus was significantly higher than in the control group (500 vs. 200 ng/ml; p < 0.001), and after therapy it increased significantly (750 ng/ml TIMP-1; p < 0.001). The results suggest that chloroquine treatment may affect the matrix metalloproteinase network, and this effect may contribute to the immunoregulatory and anti-inflammatory properties of antimalarials.