三种检测24小时尿游离皮质醇方法的比较

Comparison of Three Methods in the Measurement of 24 Hours Urinary Free Cortisol

应用化学发光免疫测定法 (CLIA)和竞争性蛋白结合分析法 (CPBA)检测 2 4h尿游离皮质醇 (UFC)水平 ,比较方法的相关性、精密度及特异性。拟用CLIA替代CPBA检测UFC。采用CLIA提取法与CLIA未提取法和CPBA法检测 5 3名正常人 ,13例未经治疗的库欣综合征患者和 92例肥胖患者及 37例口服类固醇激素药患者的 2 4hUFC水平。对其结果进行相关性比较 ,并做重复性试验 ,同时进行了七种类固醇激素的交叉试验 ,以比较三种方法的精密度和特异性。CLIA提取法与CPBA法相比较 ,r =0 .814 ,P <0 .0 0 0 1;CLIA未提取法与CPBA法相比较 ,r =0 .70 6 ,P <0 .0 0 0 1;CLIA提取法和CLIA未提取法相比较 ,r =0 .90 1,P <0 .0 0 0 1。交叉试验显示 :除皮质醇外 ,强的松龙在CPBA法、CLIA提取法和CLIA未提取法中 ,均干扰UFC测定 ,其交叉百分率分别为 19.0 %、15 .4 %及 2 4 .9% ,高于其它五种类固醇激素 ,而后五种激素对UFC的测定干扰不大。两种CLIA法的批内和批间变异系数均小于CPBA法 ,而且均与CPBA法有很好的相关性。由于CLIA提取法的精密度和特异性均优于CPBA法和CLIA未提取法 ,本文建议用CLIA提取法代替CPBA法。

The aim is to evaluate and compare the precision and specificity of the two CLIA and CPBA in the measurement of 24 hours urinary free cortisol(UFC).Method was 1) 24h UFC were measured by three methods in 53 normal subjects, 13 Cushing′s syndrome patients, 92 cases of obesity and 37 patients under prednisone treatment;2)the specificity of the three methods was evaluated by measuring 7 different steroids cross-reactivity. 3)the precision of three methods by the intra-assay and inter-assay CV% was evaluted. Relativity for extracted CLIA vs. CPBA, direct CLIA vs. CPBA and extracted CLIA vs. direct CLIA was r = 0.814 ( P <0.0001), r =0.706( P <0.0001), r =0.901( P <0.0001) respectively; Cross reactivity of prednisolone with cortisol was 19.0%, 15.4% and 24.9% in CPBA, extracted and direct CLIA respectively. There was no significant cross reactivity with other 5 steroids. The intra-assay and inter-assay CV% of both CLIA were better than CPBA. Conclusions were: 1) Both extracted and direct CLIA has good relativity with CPBA; 2)Precicion and specificity were showed for extracted CLIA better than that for CPBA and direct CLIA. So it should be considered that the extracted CLIA may be replace of CPBA in the measurement of UFC.