游离钴显色率法自动检测缺血修饰清蛋白

Automated detection of ischemia modified albumin with free-cobalt coloration rate method

目的 建立缺血修饰清蛋白（ischemia modified albumin，IMA）自动化检测方法；比较以游离钴显色率报告结果相对于吸光度单位（ABSU）的优缺点，并对112例健康对照和41例临床急性冠脉综合征（ACS）患者以及28例癫痫患者进行应用分析。方法 利用清蛋白结合重金属钴的能力随缺血修饰性清蛋白增加而下降，在480nm波长下，自动化连续监测反应体系中游离钴。结果 以游离钴显色率报告结果良好，线性范围广（回归方程：Y=0．955 2X=0．0134，r=0．9674，P〈0．01），最低生物检测限为10（ABSU：0．0635），批内及批间CV分别为0．85％和6．70％，在TG〈4．74mmol／L、Hb％15g／L时对结果无影响，与血清总胆红素（3．1～94．3μmol／L）和间接胆红素（1．6～35．0μmol／L）呈显著负相关（r=-0．8233，P〈0．01；r=-0．8504，P〈0．01），与直接胆红素（1．5～59．3μmol／L）无相关关系（r=-0．2006，P〉0．05）。以正常参考范围上限为界限（^-x＋2s），游离钴显色率：59．35；ABSU：0．3768），诊断心肌缺血的阳性率和特异性分别达87．8％和92.1％。结论 以游离钴显色率方式建立的自动化检测清蛋白结合钴实验，排除了ABSU报告结果时722分光光度计不稳定和易受人为因素的影响，简单易行，抗干扰强，重复性好，线性范围广，灵敏度高，可大样本自动化检测，应用于临床，对ACS诊断和危险分层具有重要意义，可作为心肌缺血后标志性的生化指标来监测。

Objective To establish an automated detection method of ischemia modified albumin （IMA）. The merits and demerits were compared between free-cobalt coloration rate and absorbance units, and applications of the former were analyzed in 112 normal controls, 41 patients with acute coronary syndrome （ACS） and 28 patients with epilepsy. Methods Utilizing the descent power of albumin binding cobalt along with the increase of ischemia modified albumin, free cobalt in reactive system were automatically and continuously detected under 480 nm wavelength, and results were reported in forms of absorbance unit （ABSU） and coloration rate of free cobalt. Results Free-cobalt coloration rate was reported accuracy, wide linear range （regression equation： Y = 0. 9552X - 0. 0134, r=0. 967 4,P〈0.01）, and the lowest biological detected limit was 10（ABSU：0. 063 5）. CV of intraand inter-batch was 0.85 % and 6.7 % respectively, and the results didn＇t alter markedly when TG〈4.74 mmol/L and Hb〈15 g/L, moreover it was significant negative correlative to TBil（3.1- 94.3 μmol/ L）（r=-0. 8233, P〈0.01） and IBil（1.6-35.0 μmol/L）（r=-0. 850 4, P〈0. 01）. There was no correlation of IMA and DBil（ 1.5- 59.3 μmol/L）（r= -0. 200 6, P〉0.05）. Taking upper limit of normal reference range as threshold （coloration rate of free cobalt： 59.35;ABSU：0. 376 8）, the positive rate and specificity of myocardial ischemia diagnosis was 87.80% and 92. 1% respectively. Conclusion Automated detection and results reported with coloration rate of free cobalt eliminating the influences of instable and artificial factors are simple and have stronger anti-jamming, better repeatability, wider linear range and higher sensitivity than manual method. Its clinical application is of importance in ACS diagnosis and risk demixing. IMA can be used as a potential biochemical criterion for myocardial ischemia.