title: Diagnostic performance of the EMIT-tox benzodiazepine immunoassay, FPIA serum benzodiazepine immunoassay, and radioreceptor assay in suspected acute poisoning.
abstract: We evaluated the diagnostic performance of the EMIT-tox serum benzodiazepine assay adapted to a Hitachi 717 analyzer (EMIT), the Abbott ADx serum benzodiazepine fluorescence polarization immunoassay (FPIA), and a radioreceptor assay (RRA) in 113 patients with suspected acute poisoning. The reference method was high-performance liquid chromatography with ultraviolet detection after solid-phase extraction. For the discrimination between negative and positive samples, the areas under the receiver-operating characteristic (ROC) curves were 0.976, 0.991, and 0.991 for EMIT (cutoff, 50-ng/mL diazepam), FPIA (cutoff, 12-ng/mL nordiazepam), and RRA (cutoff, 50-ng/mL diazepam), respectively. For the discrimination between non-toxic and toxic concentrations, the areas under the ROC curves were 0.896, 0.893, and 0.933, respectively. EMIT (with the cutoff lowered to 50 ng/mL), FPIA, and RRA can be reliably used to screen for the presence of benzodiazepines in serum, but in many cases they cannot discriminate between toxic and nontoxic concentrations.
authors.affiliation: Laboratory of Clinical Chemistry, University Hospital, Gent, Belgium.
authors.forename: A G
authors.initials: AG
authors.lastname: Verstraete
authors.forename: F M
authors.initials: FM
authors.lastname: Belpaire
authors.forename: G G
authors.initials: GG
authors.lastname: Leroux-Roels
mesh_terms: D014151:Anti-Anxiety Agents / Q000097:blood* / Q000506:poisoning*; D002851:Chromatography, High Pressure Liquid; D003975:Diazepam / Q000097:blood* / Q000506:poisoning; D062787:Drug Overdose / Q000175:diagnosis; D017248:Enzyme Multiplied Immunoassay Technique; D005188:False Negative Reactions; D005189:False Positive Reactions; D016231:Fluorescence Polarization Immunoassay; D006801:Humans; D007118:Immunoassay / Q000379:methods*; D003708:Nordazepam / Q000097:blood* / Q000506:poisoning; D011041:Poisoning / Q000175:diagnosis*; D012372:ROC Curve; D011869:Radioligand Assay; D013056:Spectrophotometry, Ultraviolet; D013329:Structure-Activity Relationship
chemical_list: D014151:Anti-Anxiety Agents; D003708:Nordazepam; D003975:Diazepam