髓过氧化物酶对急性冠状动脉综合征早期识别和急性心肌梗死诊断的价值

目的 探讨髓过氧化物酶（myeloperoxidase,MPO）在急性冠状动脉综合征（acute cornonary syndrome,ACS）发展过程中的变化规律及其在急性心肌梗死（acute myocardial infarction,AMI）诊断中的临床价值.方法 选取本院2013年4-12月健康体检、不稳定心绞痛（unstableangina pectoris,UAP）、急性心肌梗死、自身免疫性疾病和炎症疾病者肝素抗凝血浆样本.使用胶乳增强免疫比浊法测定血浆MPO的浓度,比较不同患者MPO血浆浓度的差别.结果 炎症疾病组和UAP组MPO水平高于正常对照组（P＜0.05）,AMI组同时高于正常对照组和UAP组（P＜0.05）,自身免疫性疾病组与正常对照组差异无统计学意义（P＞0.05）.血浆中MPO水平与同型半胱氨酸（homocysteine,HCY）、超敏C反应蛋白（C-reactive protein,CRP）、肌钙蛋白Ⅰ（troponin Ⅰ,CTnⅠ）、肌酸激酶（creatine kinase,CK）和乳酸脱氢酶（lactate dehydrogense,LDH）呈低度相关（r＜0.4,P＜0.05）;与缺血性修饰白蛋白（ischemia-modified albumin,IMA）无相关性（P＞0.05）.UAP组MPO的ROC曲线下面积A=0.795,P=0.000,提示MPO诊断UAP准确度为中等;AMI组MPO的ROC曲线下面积A=0.911,P=0.000,提不MPO诊断AMI准确度较高.MPO诊断临界值为149.2 ng/ml,AMI病例111例,其中MPO阳性101例,阴性10例;正常对照组161例,其中MPO阳性56例,阴性105例;MPO诊断AMI的灵敏度为91.3％,特异度为64.3％,准确度为75.7％,漏诊率为8.7％,误诊率为35.7％;阳性预测值为65.2％,阴性预测值为91.0％.本法与临床确诊结果进行Kappa 检验,P=0.000,说明MPO的检测结果与临床诊断具有一致性.采用Logistic多元回归,Wald逐步后退法筛选出MPO、LDH、HCY、IMA和年龄建立预测模型,决定系数（R2=0.922）,总正确率为96.80％,提示MPO对AMI的预测价值较高.结论 MPO可有效预测ACS的发生,有利于诊断AMI.

Clinical value of myeloperoxidase in early identification of acute coronary syndrome and in diagnosis of acute myocardial infarction

Objective To study the changing rule of myeloperoxidase （MPO） in acute coronary syndrome （ACS） and its clinical value in diagnosis of acute myocardial infarction （AMI）.Methods Heparin anticoagulant plasma samples were taken from those undergoing physical examination,and from patients with unstable angina pectoris （UAP）,AMI,autoimmune and inflammatory diseases.Their plasma MPO levels were measured by latex-enhanced turbidimetric immunoassay.Results The plasma MPO levels were significantly higher in patients with UAP,AMI and inflammatory disease than in those undergoing physical examination （P 〈 0.05）.No significant difference was found in plasma MPO level between patients with autoimmunity disease and those undergoing physical examination （P 〉 0.05）.The plasma MPO level was related with the plasma levels of HCY,CK,CRP,LDH and CTnI,r 〈 0.4,P 〈 0.05） but not with IMA （P 〉 0.05）.The area under ROC for plasma MPO was 0.795 in patients with UAP （P=0.000）,indicating that the accurate of plasma MPO level was moderate for the diagnosis of UAP.The area under ROC for plasma MPO was 0.911 in patients with AMI （P=0.000）,indicating that the accurate of plasma MPO level was high for the diagnosis of UAP.The critical value of MPO was 149.2 ng/ml for the diagnosis of AMI in 111 patients （101 with positive MPO and 10 with negative MPO） and in 161 controls undergoing physical examination （56 with positive MPO and 105 with negative MPO） with a sensitivity of 91.3%,a specificity of 64.3%,an accuracy of 75.7%,a missed diagnosis rate of 8.7%,a misdiagnosis rate of 35.7%,a positive predicting rate of 65.2%,and a negative predicting rate of 91.0%.Kappa test showed that the plasma MPO level was consistent with the clinical diagnosis of AMI （P=0.000）.Multivariate logistic regression analysis revealed that the R2 for the AMI prediction model established with MPO,LDH,HCY,IMA and age was 0.922 with a total correct rate of 96.80%.Conclusion MPO can effectively predict ACS and diagnose AMI.