Miller J J, Straub R W, Valdes R
Department of Pathology, University of Louisville School of Medicine, Kentucky 40292, USA.
Ther Drug Monit. 1996 Feb;18(1):65-72. doi: 10.1097/00007691-199602000-00011.
Digoxin metabolites cross-react in the Ciba Corning ACS digoxin assay in proportion to their bioactivity, but have greater (near 100%) cross-reactivity in the Abbott TDx, Baxter Stratus, and Ciba Corning Magic RIA digoxin assays. We studied the analytical performance of the ACS digoxin assay and compared it with these other assays. Coefficients of variation ranged from 5.5% at 3.11 ng/ml to 8.8% at 0.57 ng/ml. Mean analytical recovery was 96.4%. Results on dilutions were linear in the range of 0.6-5.0 ng/ml. We observed no interference by hemoglobin, bilirubin, or triglycerides. Dihydrodigoxin and digitoxin had lower cross-reactivity in the ACS and Stratus assays than in the TDx and Magic assays. Digoxin-like immunoreactive factor (DLIF) in patients' sera was not detected in the ACS assay but was in the TDx, Stratus, and Magic assays. Digibind therapy seemingly did not affect digoxin results by ACS or Stratus, but did for up to 10 days after therapy for TDx and Magic. We compared digoxin results for 121 sera from 49 patients. Deming regression analysis was performed on the first specimen from each patient: ACS = 1.08(TDx)-0.17 ng/ml (r = 0.961, Sy,x = 0.164); ACS = 1.16(Stratus)-0.46 ng/ml (r = 0.973, Sy,x = 0.123); ACS = 1.00(Magic)-0.20 ng/ml (r = 0.982, Sy,x = 0.110). Discrepant results (> 2Sy,x from the regression line) were usually lower by the ACS assay (87%). Nine of 11 patients with discrepant results had renal insufficiency or hepatic disease, conditions commonly associated with increased DLIF. These observations may be explained by the improved specificity of the ACS digoxin assay.
地高辛代谢产物在Ciba Corning ACS地高辛检测中与其生物活性成比例地发生交叉反应，但在雅培TDx、百特Stratus和Ciba Corning Magic RIA地高辛检测中具有更高（接近100%）的交叉反应性。我们研究了ACS地高辛检测的分析性能，并将其与其他检测方法进行了比较。变异系数范围为3.11 ng/ml时为5.5%至0.57 ng/ml时为8.8%。平均分析回收率为96.4%。稀释结果在0.6 - 5.0 ng/ml范围内呈线性。我们未观察到血红蛋白、胆红素或甘油三酯的干扰。双氢地高辛和洋地黄毒苷在ACS和Stratus检测中的交叉反应性低于TDx和Magic检测。患者血清中的地高辛样免疫反应因子（DLIF）在ACS检测中未被检测到，但在TDx、Stratus和Magic检测中被检测到。Digibind治疗似乎不影响ACS或Stratus的地高辛检测结果，但在TDx和Magic检测中治疗后长达10天会有影响。我们比较了49例患者的121份血清的地高辛检测结果。对每位患者的第一份标本进行Deming回归分析：ACS = 1.08(TDx) - 0.17 ng/ml（r = 0.961，Sy,x = 0.164）；ACS = 1.16(Stratus) - 0.46 ng/ml（r = 0.973，Sy,x = 0.123）；ACS = 1.00(Magic) - 0.20 ng/ml（r = 0.982，Sy,x = 0.110）。差异结果（与回归线相差> 2Sy,x）通常在ACS检测中较低（87%）。11例差异结果患者中有9例患有肾功能不全或肝病，这些情况通常与DLIF增加有关。这些观察结果可能由ACS地高辛检测提高的特异性来解释。
