Development of Indirect Competitive Enzyme-Linked Immunosorbent Assay and Lateral-Flow Immunochromatographic Strip for the Detection of Digoxin in Human Blood.

Fanqian Ling,Chuanlai Xu,Liqiang Liu,Gang Cui,Hua Kuang

doi:10.1021/acsomega.9b02254

Abstract

Mouse–mouse hybridoma cell lines producing stable, highly specific monoclonal antibodies with good affinity for the cardiac glycoside digoxin (DIG) were established to construct an indirect enzyme-linked immunosorbent assay and lateral-flow immunochromatographic strip to detect DIG in human blood. The hapten DIG was coupled to bovine serum albumin or chicken ovalbumin by sodium periodate oxidation. The highest sensitivity and specificity antibody had a median inhibitory concentration (IC50) of 0.45 ng/mL, a linear range of detection of 0.293–0.7 ng/mL, and low cross-reactivity with several DIG analogues. The cut-off value of the lateral-flow immunochromatographic strip was 5 ng/mL when the strip was tested with human blood. The immunochromatographic lateral flow strip test provides a quick and convenient method for determining DIG in plasma which can be visually observed in only 5 min to promote rational drug use.

Highlights

Digoxin (DIG) is a cardiac glycoside extracted from the leaf of the Digitalis lanata plant that binds Na+/K+-ATPase and inhibits its activity
DIG has a relative molecular mass of about 781 and is not immunogenic, so it is a hapten. This small-molecule hapten must be coupled to a macromolecular protein to prepare an artificial DIG antigen
The hapten DIG was conjugated to bovine serum albumin (BSA) or OVA by sodium periodate oxidation in this experiment

Summary

Introduction

Digoxin (DIG) is a cardiac glycoside extracted from the leaf of the Digitalis lanata plant that binds Na+/K+-ATPase and inhibits its activity. It is the most frequently used digitalisbased cardiac-active drug for the treatment of congestive heart failure (HF) and supraventricular arrhythmias.[1,2] HF remains a huge medical problem, with unacceptably high morbidity and mortality rates, despite optimal medical and mechanical treatment. DIG significantly reduced the risk of all-cause hospital admission in patients with HF during a mean followup period of 37 months and reduced the left ventricular ejection fraction.[3,4] its mechanism of action is complex, its therapeutic index is low, and its effective therapeutic range is narrow (only 0.8−2.0 ng mL−1), so any small increase in plasma levels can have serious adverse effects, and the optimal blood concentration is 0.5−0.8 ng mL−1. The incidence of poisoning during its clinical application is high.[7,8]

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