Pudek M R, Seccombe D W, Jacobson B E, Humphries K
Clin Chem. 1985 Nov;31(11):1806-10.
One or more digoxin-like immunoreactive substances (DLIS), most frequently present in serum of premature and full-term neonates. cross react to various extents with different digoxin immunoassay kit reagents. Mostly, this variation is attributed to the relative cross reactivity of DLIS with the antiserum in each kit. However, modification of standard assay procedures for digoxin can also greatly alter the relative cross reactivity of DLIS. Using sequential RIA kit methods for digoxin by 20 to 60% relative to the standard equilibrium RIA mode. Cross reactivity was decreased still more if the concentrations of antiserum (binding-site concentration) and tracer (125 l-labeled digoxin) were decreased, and conversely. Serum samples containing only digoxin, analyzed by the modified method, consistently yielded results well comparable with those obtained with the manufacturers' recommended procedures. We describe use of the different responses to digoxin and DLIS of standard and sequential radioimmunoassays and use of simultaneous equation to calculate the concentration of DLIS (in digoxin equivalents) in digoxin-containing samples.
一种或多种地高辛样免疫反应性物质（DLIS），最常见于早产儿和足月儿的血清中，与不同的地高辛免疫分析试剂盒试剂有不同程度的交叉反应。大多数情况下，这种差异归因于DLIS与每个试剂盒中抗血清的相对交叉反应性。然而，地高辛标准检测程序的改变也会极大地改变DLIS的相对交叉反应性。相对于标准平衡放射免疫分析模式，采用连续放射免疫分析试剂盒方法检测地高辛时，交叉反应性降低了20%至60%。如果抗血清（结合位点浓度）和示踪剂（125I标记的地高辛）的浓度降低，交叉反应性会进一步降低，反之亦然。用改良方法分析仅含地高辛的血清样本，其结果始终与制造商推荐程序所得结果具有良好的可比性。我们描述了标准放射免疫分析和连续放射免疫分析对地高辛和DLIS的不同反应，以及使用联立方程计算含地高辛样本中DLIS（以地高辛当量计）的浓度。
