Int J Med Sci 2016; 13(8):638-645. doi:10.7150/ijms.16187 This issue Cite
1. Institute of Medicine, Chung Shan Medical University, Taichung, Taiwan;
2. Division of Respiratory Therapy, Department of Internal Medicine, Chung Shan Medical University Hospital, Taichung, Taiwan;
3. Division of Pulmonary Medicine, Department of Internal Medicine, Chung Shan Medical University Hospital, Taichung, Taiwan;
4. School of Medicine, Chung Shan Medical University, Taichung, Taiwan;
5. Division of Gastroenterology, Department of Surgery, Chung Shan Medical University Hospital, Taichung, Taiwan;
6. Division of Infectious Diseases, Department of Internal Medicine, China Medical University Hospital, Taichung, Taiwan;
7. Department of Microbiology and Immunology, School of Medicine, China Medical University, Taichung, Taiwan;
8. Department of Medical Research, Chung Shan Medical University Hospital, Taichung, Taiwan.
*These authors contributed equally to the work.
Ventilator-associated pneumonia (VAP) increases patient mortality and medical expenditure, and a real-time and reliable method for the rapid diagnosis of VAP may help reduce fatal complications. Matrix metalloproteinases-9 (MMP-9) is considered significant in the pathogenesis of lung inflammation and infection. Therefore, we examined its relationship with the clinical course of VAP. This retrospective observational study recruited 30 healthy volunteers, 12 patients who used mechanical ventilation without the development of VAP (hereafter, patients without VAP), and 30 patients with a clinical diagnosis of VAP (hereafter, patients with VAP). The activity and level of plasma MMP-9 were determined through a gelatin zymography assay and ELISA. Our results report that both plasma MMP-9 activity and concentration were significantly elevated in the acute stage of patients with VAP when compared with control group and patients without VAP (p < 0.001). Subsequently, the plasma MMP-9 of patients with VAP decreased significantly after antibiotic treatment. Furthermore, plasma MMP-9 concentration was positively correlated with the clinical pulmonary infection score (r = 0.409, p = 0.007), WBCs (r = 0.620, p < 0.001), and neutrophils counts (r = 0.335, p = 0.035). In addition, plasma MMP-9 is an excellent tool for recognizing VAP when the cutoff level is set to 92.62 ng/mL (AUC = 0.863, 95% CI = 0.761 to 0.932). In conclusions, we concluded that MMP-9 levels play a role in the development of VAP and might have the potential to be applied in the development of VAP therapies.
Keywords: Ventilator-associated pneumonia, MMP-9, pulmonary infection score.