Diagnostic value of serum miR-122 in acute myocardial infarction

As one common disease that severely affects public health, myocardial infarction has been shown to be related with alternation of serum levels of various microRNAs (miR) including miR-21, miR-34a and miR-328. These molecules can thus work as biological markers for early diagnosis. MiR-122 has been shown to have up-regulation in acute coronary syndrome especially acute myocardial infarction (AMI), but leaving its potential diagnostic value unattended. This study thus investigated the value of miR-122 in AMI diagnosis. A total of 78 AMI patients were recruited along with 72 non-cardiovascular disease patients. Real-time fluorescent quantitative PCR (qRT-PCR) was employed to detect serum miR-122 levels at 0, 4, 8, 12 and 24 hours after admitting. Enzyme linked immunosorbent assay (ELISA) and immunosuppressant method were used to measure serum cardiac troponin I (cTnI) and creatine kinase isoenzyme (CK-MB) levels. Receiver operating characteristic (ROC) curve was plotted to predict the diagnostic value of miR-122 on AMI patients. Serum miR-122 level was significantly higher in AMI patients compared to control group (P<0.05), with higher level in NSTEMI patients than STEMI ones. Most significant elevation of miR-122 occurred at 8 hours after admitting. ROC analysis revealed the area under curve as 0.861, 0.895, 0.92, 0.877 and 0.859 at 0, 4, 8, 12 and 24 hours after admitting. At all time point there were statistical significance (P<0.01). MiR-122 has higher diagnostic values for AMI, especially at 8 hours after admitting. It may thus works as one biological marker for early diagnosis of AMI.