[Changes in plasma content of matrix metallo proteinase-9 in acute cerebral infarction patients before and after thrombolytic therapy and its significance].

Objective: To investigate the changes in the content of plasma matrix metallo proteinase-9 (MMP-9) in patients with acute cerebral infarction before and after thrombolytic therapy and its clinical significance.

Methods: The levels of MMP-9 were determined in 34 patients with acute cerebral infarction before and after thrombolytic therapy, and 34 healthy individuals served as healthy control.

Results: Compared with the healthy controls, the levels of plasma MMP-9 before thrombolytic therapy were not significantly increased [(13.47±3.09) ng/L vs. (12.89±10.22) ng/L, P >0.05]. In contrast, MMP-9 values were significantly increased after thrombolytic therapy [(22.06±12.53) ng/L] compared with that in either before or healthy control group (both P<0.05). MMP-9 values were significantly higher in patients with hemorrhage after thrombolytic therapy (incidence rate was 26.5%, 9/34) compared with before treatment [(24.02±15.41) ng/L vs. (14.28±2.33) ng/L, P<0.05], and the values of MMP-9 were higher than those of patients without hemorrhage [(20.42±9.57) ng/L], but there was no statistically significant difference ( P >0.05). In patients with complete revascularization (revascularization rate was 58.8%, 20/34), MMP-9 level was markedly higher than before thrombolytic therapy after thrombolytic therapy [(19.26±7.94) ng/L vs. (13.63±3.02) ng/L, P<0.05], and the values of MMP-9 were higher than the no-revascularization patients [(18.97±4.23) ng/L], but there was no statistically significant difference ( P >0.05).

Conclusion: Thrombolytic therapy activated MMP-9, and MMP-9 increased the risk of hemorrhage after thrombolytic therapy, and it participated in the mechanisms of hemorrhagic tendency after thrombolysis.