Abstract:

Objective To investigate the correlation of matrix metalloproteinase ⁃ 9（MMP ⁃ 9）promoter gene⁃1562C/T mutation，MMP⁃9/TIMP⁃1 ratio and intraplaque neovessels（IPN）which were semi⁃quantitatively assessed by contrast⁃enhanced ultrasound（CEUS）. Methods A total of 180 subjects with carotid atherosclerotic plaques were selected and grouped according to IPN grading. The IPN grading was semi⁃quantitatively assessed by CEUS. The ELISA measure was utilized to examine serum MMP⁃9 and TIMP⁃1 levels. Gene sequence was detected by the Sanger measure. Correlation analysis and logistic regression were employed to analyze the effect of each parameter on IPN，and then receiver operating characteristic（ROC）curve was constructed. Results MMP⁃9 serum concentration，MMP⁃91562C/T mutation，MMP⁃9/TIMP⁃1 were positively correlated with IPN grading（r = 0.332， r =0.238，r = 0.683，P < 0.001）. Logistic regression indicated that the imbalance of MMP ⁃9/TIMP ⁃1 proportion was an independent risk factor for IPN（OR = 6.110，95%CI 1.097 ~ 34.033，P = 0.039）. If MMP⁃9/TIMP⁃1 ≥ 2.12，the area under ROC curve of IPN grading ≥ Ⅲ was 0.89，the sensitivity was 84.90% and the specificity was 85.10%. Conclusion The imbalance of MMP⁃9/TIMP⁃1 proportion may be an independent risk factor for IPN. The appropriate adjustment of IPN contrast ⁃ enhanced ultrasound visual grading combining with MMP ⁃ 9/TIMP ⁃1 was beneficial for identification of vulnerable plaques.

Key words: contrast ? enhanced ultrasound,  , matrix metalloproteinase ? 9,  , MMP ? 9C1562T polymor? phism,  , tissue inhibitor of metalloproteinase?1,  , intraplaque neovessels