Potential role of matrix metalloproteinase-2,-9 and tissue inhibitors of metalloproteinase-1,-2 in exudative pleural effusions

Purpose: To investigate diagnostic values of pleural fluid matrix metalloproteinase-2 (MMP-2), MMP-9, tissue inhibitors of metalloproteinase-1 (TIMP-1) and TIMP-2 measurements in tuberculous pleurisy(TP) and malignat pleurisy (MP). Methods: The study included 24 patients with TP, 22 patients with MP and 15 patients with pleural effusion of non-tuberculous and non-malignant origin as controls. MMP-2,-9 and TIMP-1,-2 levels in pleural fluid were measured by ELISA method. Results: Pleural fluid MMP-2 and MMP-9 levels were higher (P<0.001, P<0.001, respectively) in TP than in MP and controls. MP patients have higher pleural fluid MMP-2 and MMP-9 levels (P<0.01, P<0.05, respectively) than controls. Pleural fluid TIMP-2 levels were higher (P<0.01 and P<0.001, respectively) in MP than in TP and controls. Pleural fluid MMP-9 levels were negatively correlated with pleural fluid TIMP-2 levels (r: 0.464, P=0.029) in patients with MP. Conclusions: Determination of TIMP-2 in pleural fluid may contribute to differentiate TP from MP. These results suggest that overproduction of MMP-9 and TIMP-2 is associated with accumulation of the pleural effusion in malignancy. Further studies with a greater number of patients are needed to confirm this hypothesis.