scholarly journals Effect of antibody specificity on results of selected digoxin immunoassays among various clinical groups

1996 ◽  
Vol 42 (3) ◽  
pp. 373-379 ◽  
Author(s):  
P Datta ◽  
L Xu ◽  
S Malik ◽  
D Landicho ◽  
L Ferreri ◽  
...  
Keyword(s):  
Cardiac Surgery ◽  
Liver Failure ◽  
Cross Reactivity ◽  
Antibody Specificity ◽  
Significant Interference ◽  
Free Serum ◽  
Drug Free ◽  
Digitoxin Metabolites ◽  
Positive Results ◽  
Digoxin Metabolites

Abstract We examined the specificity of three automated digoxin immunoassays (Abbott TDxFLx Digoxin II assay, Baxter-Dade Stratus II Digoxin assay, and Ciba Corning ACS Digoxin assay) applied without modification to (a) sera from 229 digoxin-free patients in 12 cohorts associated with nonspecific or endogenous digoxin-like immunoreactive factor (DLIF) interference, and (b) drug-free serum supplemented with the major metabolites and analogs of digoxin. We observed three patterns of apparent digoxin results among the DLIF samples: one common to kidney and liver failure patients, where TDx and Stratus assays showed significant positive results; one common to newborns and cord blood, where only the TDx assay had significant interference; and one from cardiac surgery patients, where the Stratus assay alone showed interference. Of the three assays, the ACS had the least interference from DLIF. The assays also behaved differently with respect to cross-reactivity with digoxin metabolites, digitoxin, and digitoxin metabolites. The ACS assay again had the least analog or metabolite cross-reactivity. The three methods agreed well on digoxin-positive specimens, with a mean bias of <0.15 microgram/L digoxin for each and discrepancies (defined as >3 SD between the assay pairs compared) of only 3-5%.

scholarly journals Variability in Telavancin Cross-Reactivity among Vancomycin Immunoassays

2014 ◽  
Vol 58 (12) ◽  
pp. 7093-7097 ◽  
Author(s):  
Kevin W. McConeghy ◽  
Siyun Liao ◽  
Douglas Clark ◽  
Philip Worboys ◽  
Steven L. Barriere ◽  
...  
Keyword(s):  
Liquid Chromatography ◽  
Mass Spectroscopy ◽  
Cross Reactivity ◽  
Serum Samples ◽  
Chemiluminescent Immunoassay ◽  
Dual Mechanism ◽  
Free Serum ◽  
Drug Free ◽  
Sample Set ◽  
Duplicate Sample

ABSTRACTTelavancin is a semisynthetic lipoglycopeptide with a dual mechanism of action against Gram-positive pathogens. Two brief reports have suggested potential cross-reactivity of telavancin with the vancomycin particle-enhanced turbidometric immunoassay (PETIA). The purpose of this study was to evaluate several commercially available vancomycin immunoassays (fluorescence polarization [FPIA], enzyme-multiplied immunoassays [EMIT], PETIA, and chemiluminescent immunoassay [CMIA]) for cross-reactivity with telavancin. Seven sites were selected to analyze serum samples for vancomycin. Each site received a set of samples (n= 18) which combined drug-free serum with telavancin, 7-OH telavancin metabolite, or vancomycin. Immunoassays demonstrating potential cross-reactivity were further evaluated by sending a duplicate sample set to multiple laboratories. Cross-reactivity was defined as the percent theoretical concentration (reported concentration/theoretical concentration × 100). No cross-reactivity was seen with FPIA or EMIT. Within the theoretical concentration range of 5 to 120 μg/ml of telavancin, the Synchron PETIA system reported vancomycin concentrations ranging from 4.7 to 54.2 μg/ml compared to vancomycin concentrations from 1.1 to 5.6 μg/ml for the Vista PETIA system. The Architect CMIA system reported vancomycin concentrations in the range of 0.27 to 0.97 μg/ml, whereas Advia Centaur XP CMIA reported vancomycin concentrations between 1.6 and 31.6 μg/ml. The Architect CMIA immunoassay had the lowest percent cross-reactivity (0.8 to 5.4%), while the Synchron PETIA immunoassay demonstrated the highest percent cross-reactivity (45.2 to 53.8%). Telavancin samples measured by liquid chromatography-mass spectroscopy were within 93.9 to 122% of theoretical concentrations. Vancomycin concentrations were not measured in any 7-OH telavancin-spiked sample. Vancomycin concentrations measured by liquid chromatography-mass spectroscopy were within 57.2 to 113% of theoretical concentrations. PETIA and CMIA measured vancomycin concentrations in telavancin-spiked samples. Significant variability in percent cross-reactivity was observed for each platform regardless of immunoassay method.

scholarly journals Cross-Reactivity Between Heparin and Danaparoid Antibodies in Cardiac Surgery

2017 ◽  
Vol 103 (1) ◽  
pp. e9-e10 ◽  
Author(s):  
Thibault Ronchard ◽  
Erwan Salaun ◽  
Alexis Theron ◽  
Dominique Grisoli ◽  
Nicolas Jaussaud ◽  
...  
Keyword(s):  
Cardiac Surgery ◽  
Cross Reactivity

Evaluation of an alternative S100b assay for use in cardiac surgery: relationship with microemboli and neuropsychological outcome

Perfusion ◽  
2007 ◽  
Vol 22 (4) ◽  
pp. 267-272 ◽  
Author(s):  
D.C. Whitaker ◽  
A.J.E. Green ◽  
J. Stygall ◽  
M.J.G. Harrison ◽  
S.P. Newman
Keyword(s):  
Cardiac Surgery ◽  
Limit Of Detection ◽  
Artery Bypass ◽  
Sandwich Elisa ◽  
High Sensitivity ◽  
Cross Reactivity ◽  
Cell Protein ◽  
Skin Closure ◽  
Neuropsychological Outcome ◽  
The Right

Introduction. The aim of the study was to investigate the relationship between S100b release, neuropsychological outcome and cerebral microemboli. Peri-operative assay of the astroglial cell protein S100b has been used as a marker of cerebral damage after cardiac surgery but potential assay cross-reactivity has limited its specificity. The present study uses an alternative enzyme-linked immunoabsorbant assay (ELISA) for serum S100b that has documented sensitivity and specificity data in patients undergoing coronary artery bypass grafting (CABG). Methods. Fifty-five consecutive patients undergoing routine CABG surgery received serial venous S100b sampling at five time points: i) Pre-operative, ii) At the end of cardiopulmonary bypass (CPB), iii) 6 hrs, iv) 24 hrs and v) 48 hrs post skin closure. A previously described sandwich ELISA with monoclonal anti- S100b was used. This assay has a lower limit of detection of 0.04 μ g/L and < 0.006% reactivity with S100a at a concentration of 100 μg/L S100a. Cerebral microemboli during surgery were recorded by transcranial Doppler monitor over the right middle cerebral artery. Evidence of cerebral impairment was obtained by comparing patients' performance in a neuropsychological battery of 9 tests administered 6—8 weeks post-operatively with their pre-operative scores. Results. There was a significant increase in S100b only at the end of bypass (mean 0.30 μg/L, SD ± 0.33 and range .00 to 1.57). S100b levels at the end of bypass did not correlate with neuropsychological outcome or microemboli counts. Conclusions. The low levels of S100b detected using the present assay, despite its high sensitivity and despite the routine use of cardiotomy suction, suggest that the assay may have higher specificity for cerebral S100b than previously used assays. There was no evidence that this assay is related to neuropsychological change or cerebral microemboli in cardiac surgery. Perfusion (2007) 22, 267—272.

scholarly journals Inhibition of Na,K-ATPase by oleandrin and oleandrigenin, and their detection by digoxin immunoassays

1996 ◽  
Vol 42 (10) ◽  
pp. 1654-1658 ◽  
Author(s):  
S A Jortani ◽  
R A Helm ◽  
R Valdes
Keyword(s):  
Sodium Pump ◽  
Serum Proteins ◽  
Cross Reactivity ◽  
Pump Activity ◽  
Ic50 Values ◽  
On Line ◽  
Atpase Inhibition ◽  
Free Serum ◽  
Derivatives Of ◽  
Rule Out

Abstract Ingestion of oleander plant, containing the cardiac glycoside oleandrin, has been reported to induce fatal poisonings. Derivatives of oleandrin are structurally similar to digoxin. We investigated the cross-reactivities of oleandrin and its aglycone metabolite, oleandrigenin, in several commercially available digoxin immunoassays; assessed their ability to inhibit Na,K-ATPase catalytic activity; and measured their binding to proteins in serum. As assayed with ACS:180, Stratus, RIA, On-Line, and TDx digoxin assays, oleandrin at 100 micromol/L in digoxin-free serum gave apparent digoxin values of 0, 0.83, 2.24, 2.37, and 5.34 nmol/L, respectively, whereas oleandrigenin at that concentration gave results of 0, 0.52, 0.77, 4.94, and 1.40 nmol/L. Study of Na,K-ATPase inhibition showed IC50 values (micromol/L) of 0.22 for ouabain, 0.62 for oleandrin, 1.23 for oleandrigenin, and 2.69 for digoxin. At 25 degrees C, 96% of oleandrin and 48% of oleandrigenin were bound to serum proteins. Because detection of oleandrin and oleandrigenin by digoxin immunoassays is variable between assays as well as between congeners, assessment of cross-reactivity is warranted for each assay. The inhibition of Na,K-ATPase by oleandrin and oleandrigenin confirms that they likely exert their toxic effects through inhibition of sodium pump activity. In cases of digitalis-like poisoning with suspicion of oleander ingestion, a combination of digoxin immunoassays may be useful to effectively rule out the presence of oleander.

Serum Propylthiouracil: Determination by a Direct Colorimetric Procedure

1972 ◽  
Vol 18 (11) ◽  
pp. 1373-1375 ◽  
Author(s):  
Charles R Ratliff ◽  
Paul F Gilliland ◽  
Frank F Hall
Keyword(s):  
Filter Paper ◽  
Colorimetric Method ◽  
Control Sample ◽  
Chloroform Solution ◽  
Soluble Compound ◽  
Aqueous Layer ◽  
Free Serum ◽  
Drug Free ◽  
Colorimetric Procedure

Abstract A direct colorimetric method is described for the determination of propylthiouracil in serum, which is based on reaction of the drug at pH 8.0 with 2,6-dichloroquinone-chloroimide to produce a colored chloroform-soluble compound. After isolation from the aqueous layer with phase-separating filter paper, the chloroform solution is read against a chloroform blank at 435 nm. Propylthiouracil added to drug-free serum serves as a control sample. The method obeys Beer's law up to a concentration of at least 10 mg/liter.

Quetiapine Cross-Reactivity with Plasma Tricyclic Antidepressant Immunoassays

2005 ◽  
Vol 39 (9) ◽  
pp. 1446-1449 ◽  
Author(s):  
E Martin Caravati ◽  
JoEtta M Juenke ◽  
Barbara I Crouch ◽  
Kathleen T Anderson
Keyword(s):  
Tricyclic Antidepressants ◽  
Antipsychotic Agent ◽  
Structural Similarity ◽  
Cross Reactivity ◽  
Tricyclic Antidepressant ◽  
Spiked Plasma ◽  
Screening Assays ◽  
Drug Free ◽  
Spiked Plasma Sample

BACKGROUND: Toxicology screens obtained on patients who have overdosed on drugs frequently include tricyclic antidepressants (TCAs) as part of the evaluation. Quetiapine is an antipsychotic agent with structural similarity to the TCAs. OBJECTIVE: To determine whether quetiapine may cross-react with plasma TCA immunoassays in vitro using commonly available autoanalyzers. METHODS: Quetiapine stock solution was added to 9 separate samples of pooled drug-free human plasma to produce concentrations ranging from 1 to 640 ng/mL that were verified by gas chromatography. No quetiapine metabolites were present. Each spiked plasma sample was tested in a blinded fashion using the Abbott Tricyclic Antidepressant TDx Assay on the TDxFLx autoanalyzer in 2 separate laboratories, the Syva Emit tox Serum Tricyclic Antidepressant Assay on the AU400 autoanalyzer and the S TAD Serum Tricyclic Antidepressant Screen on the ACA-Star 300 autoanalyzer. The TDx assay is quantitative, while Emit and S TAD are qualitative screening assays with a threshold of 300 ng/mL for TCA positivity. The outcome of interest was a positive TCA result. RESULTS: The quantitative assay showed concentration-related TCA cross-reactivity beginning at quetiapine concentrations of 5 ng/mL. The 640-ng/mL spiked sample produced TCA results of 379 and 385 ng/mL in labs 1 and 2, respectively. The qualitative assays were screened as TCA positive at quetiapine concentrations of 160 and 320 ng/mL for the S TAD and Emit assays, respectively. CONCLUSIONS: Quetiapine cross-reacts with quantitative and qualitative plasma TCA immunoassays in a concentration-dependent fashion. Therapeutic use or overdose of quetiapine may result in a false-positive TCA immunoassay result.

Combined liquid chromatography/radioimmunoassay with improved specificity for serum digoxin.

1985 ◽  
Vol 31 (8) ◽  
pp. 1272-1277 ◽  
Author(s):  
M H Gault ◽  
L Longerich ◽  
M Dawe ◽  
S C Vasdev
Keyword(s):  
Renal Failure ◽  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Present Method ◽  
High Performance ◽  
Cross Reactivity ◽  
Small Column ◽  
Polar Metabolites ◽  
Column Extraction ◽  
Digoxin Metabolites

Abstract This method for assaying digoxin in serum with improved specificity combines small-column extraction of serum, "high-performance" liquid chromatography, and RIA of the eluted fractions. Analytical recoveries of 1.0, 0.5, and 0.1 microgram/L standards were 95%, 93%, and 84%, respectively. The CVs for duplicates and replicates of sera with values of 0.5 to 1 microgram/L were 4 to 6%. Fifty-nine sera from 50 patients receiving digoxin were so studied. All digoxin metabolites appear to cross react with antibody to digoxin to various degrees. The most polar metabolites were quantitatively the most important, their average cross reactivity being 33%. For eight patients the value for digoxin by the present method was less than 60% of the RIA value. Sera from nine patients not taking digoxin but with falsely high digoxin values were also studied by the present method. The digoxin peak was well resolved from those for (a) digoxin metabolites (except dihydrodigoxin), (b) digitalis-like factors in neonates and in patients with renal failure or combined hepatic and renal failure, and (c) two cross reacting drugs and their metabolites.

scholarly journals Poor specificity and recovery of urinary free cortisol as determined by the Bayer ADVIA Centaur extraction method

2003 ◽  
Vol 40 (5) ◽  
pp. 563-565 ◽  
Author(s):  
G Gray ◽  
L Shakerdi ◽  
AM Wallace
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Solvent Extraction ◽  
Extraction Method ◽  
Urinary Free Cortisol ◽  
Cross Reactivity ◽  
Gas Chromatography Mass Spectrometry ◽  
Sample Matrix ◽  
Free Cortisol ◽  
Free Serum

Background: Immunoassay methods for urinary free cortisol (UFC) lack specificity, and many procedures have not been fully evaluated for routine use. In the current study we evaluated the Bayer ADVIA Centaur extraction UFC immunoassay and compared results to those obtained by a specific gas chromatography-mass spectrometry (GC-MS) method. Results: The Bayer ADVIA Centaur cortisol assay lacked specificity. Cortisone, a steroid present in urine at concentrations similar to those of cortisol, demonstrated a cross-reactivity of 44%. In addition, the choice of matrix used to resuspend steroids after solvent extraction from urine affected recovery. Recovery was improved if the recommended urine reconstruction buffer was replaced by steroid-free serum. Conclusion: Irrespective of the sample matrix used, the Centaur method overestimates UFC, giving results up to twice those obtained by a specific GC-MS method.

scholarly journals Prometheus therapy for the treatment of acute liver failure in patients after cardiac surgery

2017 ◽  
Vol 4 ◽  
pp. 230-235 ◽  
Author(s):  
Ekaterina Komardina ◽  
Michael Yaroustovsky ◽  
Marina Abramyan ◽  
Marina Plyushch
Keyword(s):  
Cardiac Surgery ◽  
Liver Failure ◽  
Acute Liver Failure

scholarly journals Cross-reactivity of antibodies in human infections by the kinetoplastid protozoa Trypanosoma cruzi, Leishmania chagasi and Leishmania (Viannia) braziliensis

1996 ◽  
Vol 38 (3) ◽  
pp. 177-185 ◽  
Author(s):  
Ana de Cássia Vexenat ◽  
Jaime M. Santana ◽  
Antonio R.L. Teixeira
Keyword(s):  
Trypanosoma Cruzi ◽  
Chagas Disease ◽  
Cross Reactivity ◽  
Antigenic Determinants ◽  
Leishmania Braziliensis ◽  
Leishmania Chagasi ◽  
Mucocutaneous Leishmaniasis ◽  
Kala Azar ◽  
Homologous Antigen ◽  
Positive Results

We have detected antibodies, in the sera of Chagas disease, Kala-azar and Mucocutaneous leishmaniasis patients, that bind multiple antigens shared between the three causative agents. The Chagas disease sera showed 98 to 100% positive results by ELISA when the Leishmania braziliensis and Leishmania chagasi antigens were used, respectively. The Kala-azar sera showed 100% positive results with Trypanosoma cruzi or L. braziliensis antigens by immunofluorescence assays. The antibodies in the sera of Mucocutaneous leishmaniasis patients showed 100% positive results by ELISA assays with T. cruzi or L. chagasi antigens. Furthermore, the direct agglutination of L. chagasi promastigotes showed that 95% of Kala-azar and 35% of Mucocutaneous leishmaniasis sera agglutinated the parasite in dilutions above 1:512. In contrast, 15% of Chagas sera agglutinated the parasite in dilutions 1:16 and below. Western blot analysis showed that the Chagas sera that formed at least 24 bands with the T. cruzi also formed 13 bands with the L. chagasi and 17 bands with the L. braziliensis. The Kala-azar sera that recognized at least 29 bands with the homologous antigen also formed 14 bands with the T. cruzi and 10 bands with the L. braziliensis antigens. Finally, the Mucocutaneous leishmaniasis sera that formed at least 17 bands with the homologous antigen also formed 10 bands with the T. cruzi and four bands with the L. chagasi antigens. These results indicate the presence of common antigenic determinants in several protozoal proteins and, therefore, explain the serologic cross-reactions reported here.

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