Significant elevation of plasma matrix metalloproteinase-9 level and its ratio to matrix metalloproteinase-2 in patients with pelvic inflammatory disease

Objective: To detect the expression of plasma matrix metalloproteinase-2 (MMP-2) and MMP-9, and MMP-9:MMP-2 ratio in patients with pelvic inflammatory disease (PID). Design: A consecutive study with approximate 1:2 case-to-control ratio. Setting: University hospital. Patient(s): Forty-seven patients with PID and 80 healthy women. Intervention(s): Collected blood specimens of patients with PID before and after treatment. Main Outcome Measure(s): ELISA and gelatin zymography were used to measure the expression of plasma MMP-2 and MMP-9. Result(s): The level of plasma MMP-9 or MMP-9:MMP-2 ratio was elevated in patients with PID compared with healthy controls and decreased significantly after treatment. The activity of MMP-9, but not MMP-2, tended to be higher in 47 patients with PID before the treatment compared with that after the treatment. Pretreatment plasma MMP-9 or MMP-9:MMP-2 ratio was significantly correlated with white blood cell (WBC) and neutrophil counts. As prediction markers for PID, the sensitivities of MMP-9 and MMP-9:MMP-2 ratio were 76.6% and 76.6%, whereas the negative predictive values were 82.5% and 83.3%. Conclusion(s): Level of plasma MMP-9 and MMP-9:MMP-2 ratio may act as prediction markers for PID. In patients with PID, 80% have a plasma MMP-9 level higher than 115 ng/mL or a MMP-9:MMP-2 ratio higher than 2.15.