Dasgupta A, Wells A, Datta P
Department of Pathology and Laboratory Medicine, University of Texas-Houston Medical School, 77030, USA.
Ther Drug Monit. 1999 Apr;21(2):251-5. doi: 10.1097/00007691-199904000-00018.
Digoxin fab antibody (Digibind; Burroughs Wellcome, Research Triangle Park, NC, USA) is used in the treatment of digoxin overdose. The effect of digibind on the measurement of total and free digoxin has been extensively studied. However, the effect of digibind on digitoxin measurements has not been studied thoroughly. The authors studied the effect of digibind on the measurement of total and free digitoxin in vitro using the fluorescence polarization immunoassay and a new chemiluminescent immunoassay. We also studied the capability of digibind to bind digitoxigenin, the major aglycon metabolite of digitoxin. Digibind neutralized both digitoxin and digitoxigenin in vitro, as evidenced by significant reductions in free digitoxin and digitoxigenin (measured as digitoxin equivalent) concentrations. Digibind caused negative interference in the measurement of total digitoxin concentrations by both fluorescence polarization and chemiluminescent assays. However, the magnitude of negative interference was significantly higher with the chemiluminescent assay. For example, in a serum pool supplemented with 80 ng/mL of digitoxin, the concentrations of total and free digitoxin measured by the fluorescence polarization immunoassay were 82.1 ng/mL and 3.3 ng/mL respectively. In the presence of 5 microg/mL of Digibind, the corresponding total and free digitoxin concentrations were 73.9 ng/mL and none detected, respectively. In another serum pool supplemented with 70 ng/mL of digitoxin, the concentrations of total and free digitoxin as measured by the chemiluminescent assay were 69.1 ng/mL and 3.8 ng/mL, respectively. In the presence of 5 microg/mL of Digibind, the corresponding total and free digitoxin concentrations were 29.0 ng/mL and none detected, respectively. Because this effect may also occur in vivo, the progress of Digibind therapy in treating a patient with digitoxin overdose may be monitored by measuring the free digitoxin concentrations.
地高辛Fab抗体（Digibind；美国北卡罗来纳州三角研究园的百时美施贵宝公司）用于治疗地高辛过量。Digibind对总地高辛和游离地高辛测量的影响已得到广泛研究。然而，Digibind对洋地黄毒苷测量的影响尚未得到充分研究。作者使用荧光偏振免疫分析法和一种新的化学发光免疫分析法，在体外研究了Digibind对总洋地黄毒苷和游离洋地黄毒苷测量的影响。我们还研究了Digibind结合洋地黄毒苷元（洋地黄毒苷的主要苷元代谢物）的能力。Digibind在体外中和了洋地黄毒苷和洋地黄毒苷元，游离洋地黄毒苷和洋地黄毒苷元（以洋地黄毒苷当量测量）浓度显著降低证明了这一点。Digibind在荧光偏振和化学发光分析中对总洋地黄毒苷浓度的测量产生负干扰。然而，化学发光分析的负干扰程度明显更高。例如，在添加了80 ng/mL洋地黄毒苷的血清混合液中，荧光偏振免疫分析法测得的总洋地黄毒苷和游离洋地黄毒苷浓度分别为82.1 ng/mL和3.3 ng/mL。在存在5 μg/mL Digibind的情况下，相应的总洋地黄毒苷和游离洋地黄毒苷浓度分别为73.9 ng/mL和未检测到。在另一个添加了70 ng/mL洋地黄毒苷的血清混合液中，化学发光分析法测得的总洋地黄毒苷和游离洋地黄毒苷浓度分别为69.1 ng/mL和3.8 ng/mL。在存在5 μg/mL Digibind的情况下，相应的总洋地黄毒苷和游离洋地黄毒苷浓度分别为29.0 ng/mL和未检测到。由于这种影响在体内也可能发生，因此在治疗洋地黄毒苷过量患者时，可通过测量游离洋地黄毒苷浓度来监测Digibind治疗的进展。
