AIM:Overexpression of mucosal metalloproteinases(MMP)has been demonstrated recently in inflammatory boweldisease.Their activity can be counterbalanced by the tissueinhibitor of metalloproteinases(TIMP).The aim of this studywas to evaluate the effect of ulcerative colitis(UC)on MMP-1 and TIMP-1 plasma concentrations,as two possiblebiomarkers of the disease activity.METHODS:MMP-1 and TIMP-1 plasma concentrations weremeasured with an enzyme immunoassay in 16 patients withendoscopically confirmed active UC.RESULTS:Plasma concentrations of both MMP-1(13.7±0.2ng/ml)and TIMP-1(799±140 ng/ml)were significantlyelevated in UC patients in comparison to healthy controls(11.9±0.9 ng/ml and 220±7 ng/ml respectively).There wasno correlation between TIMP-1 and MMP-1 concentrations(r=0.02).TIMP-1 levels revealed significant positivecorrelations with scored endoscopic degree of mucosal injury,disease activity index and clinical activity index values aswell as C-reactive protein concentration.There was nocorrelation between MMP-1 and laboratory,clinical orendoscopic indices of the disease activity.CONCLUSION: These results confirm the role of both MMP- 1 and TIMP-1 in the pathogenesis of ulcerative colitis. However only TIMP-1 can be useful as a biomarker of the disease activity, demonstrating association with clinical and endoscopic pictures. AIM: Overexpression of mucosal metalloproteinases (MMPs) has been demonstrated recently in inflammatory bowel disease. Their activity can be counterbalanced by the tissue inhibitor of metalloproteinases (TIMP). The aim of this study was to evaluate the effect of ulcerative colitis (UC) on MMP- 1 and TIMP-1 plasma concentrations, as two possiblebiomarkers of the disease activity. METHODS: MMP-1 and TIMP-1 plasma concentrations were quantified with an enzyme immunoassay in 16 patients withendoscopically confirmed active UC .RESULTS: Plasma concentrations of both MMP- ± 0.2 ng / ml) and TIMP-1 (799 ± 140 ng / ml) were significantly increased in UC patients in comparison to healthy controls (11.9 ± 0.9 ng / ml and 220 ± 7 ng / ml respectively). Where wasno correlation between TIMP -1 and MMP-1 concentrations (r = 0.02) .TIMP-1 levels revealed significant positivecorrelations with scored endoscopic degree of mucosal injury, disease activity index and clinical activity index values ​​aswell as C-reactive protein concentration. Where w as nocorrelation between MMP-1 and laboratory, clinical orendoscopic indices of the disease activity. CONCLUSION: These results confirm the role of both MMP-1 and TIMP-1 in the pathogenesis of ulcerative colitis. However only TIMP-1 can be useful as a biomarker of the disease activity, demonstrating association with clinical and endoscopic pictures.