False-Positive Rates for the Qualitative Analysis of Urine Benzodiazepines and Metabolites with the Reformulated Abbott Multigent? Reagents

摘要

In May, 2007, Abbott notified customers of the implementation of a new polyclonal antibody pool in the Multigent? benzodiazepine reagent (supplied by Seradyn, Inc.) for use on their Architect? chemistry analyzer. The new antibody pool demonstrated an increased analytical sensitivity for this screening method, which allowed detection of lower concentrations of individual benzodiazepines and their metabolites. Unfortunately, by increasing the sensitivity, Abbott decreased the specificity of this assay, resulting in an increased number of false-positive benzodiazepine results.For the past 15 years, the clinical chemistry laboratory of the VA Boston Healthcare System has performed screening for benzodiazepines in urine by immunoassay. Before 2001 the toxicology laboratory confirmed every screen-positive benzodiazepine result by HPLC. Table 1? summarizes the historical benzodiazepine data in 2000, which shows that 94.6% of the screen-positive results were confirmed as positive. …