Gault M H, Longerich L, Dawe M, Vasdev S C
Clin Chem. 1985 Aug;31(8):1272-7.
This method for assaying digoxin in serum with improved specificity combines small-column extraction of serum, "high-performance" liquid chromatography, and RIA of the eluted fractions. Analytical recoveries of 1.0, 0.5, and 0.1 microgram/L standards were 95%, 93%, and 84%, respectively. The CVs for duplicates and replicates of sera with values of 0.5 to 1 microgram/L were 4 to 6%. Fifty-nine sera from 50 patients receiving digoxin were so studied. All digoxin metabolites appear to cross react with antibody to digoxin to various degrees. The most polar metabolites were quantitatively the most important, their average cross reactivity being 33%. For eight patients the value for digoxin by the present method was less than 60% of the RIA value. Sera from nine patients not taking digoxin but with falsely high digoxin values were also studied by the present method. The digoxin peak was well resolved from those for (a) digoxin metabolites (except dihydrodigoxin), (b) digitalis-like factors in neonates and in patients with renal failure or combined hepatic and renal failure, and (c) two cross reacting drugs and their metabolites.
这种具有更高特异性的血清地高辛检测方法结合了血清小柱萃取、“高效”液相色谱法以及对洗脱组分的放射免疫分析。1.0、0.5和0.1微克/升标准品的分析回收率分别为95%、93%和84%。浓度为0.5至1微克/升的血清重复检测和多次检测的变异系数为4%至6%。对50名接受地高辛治疗的患者的59份血清进行了此项研究。所有地高辛代谢物似乎都与地高辛抗体有不同程度的交叉反应。极性最强的代谢物在数量上最为重要，其平均交叉反应率为33%。对于8名患者，用本方法测得的地高辛值低于放射免疫分析值的60%。还对9名未服用地高辛但地高辛值假性升高的患者的血清采用本方法进行了研究。地高辛峰与以下物质的峰得到了很好的分离：(a) 地高辛代谢物（除二氢地高辛外）；(b) 新生儿以及肾衰竭或肝肾联合衰竭患者体内的洋地黄样因子；(c) 两种交叉反应药物及其代谢物。
