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 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%.

Variability among commercially available digoxin radioimmunoassay kits in cross reactivity to dihydrodigoxin.

1978 ◽  
Vol 24 (1) ◽  
pp. 155-157 ◽  
Author(s):  
W G Kramer ◽  
N L Kinnear ◽  
H K Morgan
Keyword(s):  
Human Serum ◽  
Therapeutic Range ◽  
Cross Reactivity ◽  
Serum Samples ◽  
Serum Digoxin ◽  
The Cross ◽  
High Degree ◽  
Free Serum ◽  
Digoxin Radioimmunoassay

Abstract We evaluated four commercially available 125I-digoxin radioimmunoassay kits with regard to their ability to cross react with the digoxin metabolite dehydrodigoxin. We prepared dihydrodigoxin serum samples in digoxin-free serum over the concentration range 0.4 to 5.0 microgram/liter and assayed them with each kit according to the manufacturer's instructions. The metabolite was able to displace the 125I-labeled digoxin derivative from the antibody supplied with all four kits. However, the extent of the cross reactivity depended on the kit, ranging from essentially zero to a high degree of interference. Dihydrodigoxin is the only metabolite of digoxin to have been quantitiated in human serum, and may comprise up to 30% of total glycosides. Over the clinical and therapeutic range of serum digoxin concentrations, enough dihydrodigoxin can be produced to interfere in the determination of serum digoxin concentrations by this method. We suggest that laboratories evaluate their specific kit with regard to cross reactivity to this metabolite.

scholarly journals Stability of oleander extract and oleandrin in sera stored in plastic serum separator tubes

2007 ◽  
Vol 44 (5) ◽  
pp. 485-487 ◽  
Author(s):  
Amitava Dasgupta ◽  
Dollett White
Keyword(s):  
The United States ◽  
Ethanolic Solution ◽  
Serum Samples ◽  
Becton Dickinson ◽  
Analytical Technique ◽  
Medicolegal Investigation ◽  
Glass Tubes ◽  
The Stability ◽  
Free Serum ◽  
Drug Free

Introduction: Oleander poisoning is common in the southern parts of the United States as well as part of Europe and South East Asia. The fluorescence polarization immunoassay (FPIA) for digoxin cross-reacts with oleandrin, the major poison of oleander extract and can be used for rapid detection of oleander poisoning. However, for medicolegal investigation, the presence of oleandrin should be confirmed by a more sophisticated analytical technique such as liquid chromatography combined with tandem mass spectrometry. We studied stability of oleander extract as well as oleandrin in serum samples stored in Becton Dickinson plastic serum separator tubes (SSTs) by comparing values obtained in parallel specimens stored in plain glass tubes and in red-topped plastic tubes. Method: Oleander leaves were extracted using absolute ethanol, and drug-free serum pools were supplemented with oleander extract or ethanolic solution of pure oleandrin. Aliquots of the supplemented pools were then stored in plain glass tubes, red-topped plastic tubes or SSTs and the stability of oleander extract or oleandrin in sera were studied by the FPIA digoxin assay for varying times up to seven days. Results: We observed no statistically significant change in apparent digoxin concentrations in specimens stored in SSTs even after seven days of storage compared to original values observed in the supplemented serum pools. Conclusions: Specimens can be stored in SSTs for up to seven days prior to analysis of oleandrin concentration.

scholarly journals Vitamin D testing: Comparison and limitations of currently employed immunoassay with a novel liquid chromatography and tandem mass spectrometry (LCMS/MS) technique.

2021 ◽  
Vol 28 (7) ◽  
pp. 1053-1057
Author(s):  
Sehrish Naz ◽  
◽  
Muhammad Aamir ◽  
Zujaja Hina Haroon ◽  
Sobia Irum ◽  
...  
Keyword(s):  
Vitamin D ◽  
Liquid Chromatography ◽  
Limit Of Detection ◽  
Tertiary Care ◽  
Method Comparison ◽  
Cross Reactivity ◽  
Serum Samples ◽  
Cross Sectional ◽  
Comparison Results ◽  
Limit Of Quantitation

Objective: To compare analytical method for 25 hydroxy vitamin D2 and D3 on LC/MS-MS and with routine vitamin D Immunoassay method. Study Design: Cross Sectional study. Setting: Department of Chemical Pathology and Endocrinology, Pakistan. Period: March 2019 to March 2020. Material & Methods: Samples were extracted and a mass spectrometer coupled to high performance liquid chromatography was adopted for quantitation of 25-hydroxyvitamin D2 and D3 in human samples (serum). After validation it was then applied to 120 serum samples from healthy individuals for method comparison. Results: The method was validated in terms of accuracy, precision, linearity on calibration curve, Limit of Detection and Limit of Quantitation. Our study showed a statistically insignificant difference in results among both the methods (p=0.715). Limit of detection (LOD) was 2.49 ng/ml and limit of quantitation (LOQ) was 3.9 ng/ml for both the metabolites. Percentage RSD was 0.8% and 1.3% for D2 and D3 respectively. This method has an advantage of minimal cross-reactivity with 24,25 hydroxy vit D and 25,26 di- hydroxy vit D metabolite than the routinely used assays. Conclusion: This methodology will be helpful in guiding patient management and assess possibility of malabsorption syndrome in patients on D2 therapy. It can give highly cost effective reliable results of Vitamin D at a tertiary care setting which has an already installed LCMS/MS with huge workload, as compared to costly Immunoassay method.

Current Trends of Liquid Chromatography Tandem Mass Spectroscopy Use in Clinical Gynecology

2019 ◽  
Vol 70 (6) ◽  
pp. 2021-2025
Author(s):  
Aida Petca ◽  
Dan Cristian Radu ◽  
Razvan Cosmin Petca ◽  
Claudia Mehedintu ◽  
Ramona Ileana Barac ◽  
...  
Keyword(s):  
Liquid Chromatography ◽  
Mass Spectroscopy ◽  
Tandem Mass ◽  
Quality Healthcare ◽  
Current Trends ◽  
Healthcare It ◽  
Liquid Chromatography Tandem Mass ◽  
Tandem Mass Spectroscopy ◽  
Technical Innovations ◽  
Hormonal Milieu

In the present environment of staggering technical innovations and increasing expectations of quality healthcare it is evident that we need to fine tune our diagnostic abilities in order to fulfil patients� demands for more efficient therapies and augmented quality of life. We are looking for current trends in clinical gynecology that make use of Liquid chromatography tandem mass spectroscopy, technology not yet employed in Romanian laboratories for the clinical practice but that is rapidly becoming the worldwide method of choice for accurate characterization of the hormonal milieu essential for the requirements of women healthcare.

scholarly journals A Label and Probe-Free Zika Virus Immunosensor Prussian Blue@carbon Nanotube-Based for Amperometric Detection of the NS2B Protein

Biosensors ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 157
Author(s):  
Bárbara V. M. Silva ◽  
Marli T. Cordeiro ◽  
Marco A. B. Rodrigues ◽  
Ernesto T. A. Marques ◽  
Rosa F. Dutra
Keyword(s):  
Carbon Nanotube ◽  
Prussian Blue ◽  
Zika Virus ◽  
Point Of Care ◽  
Amperometric Detection ◽  
Cross Reactivity ◽  
Structural Protein ◽  
Serum Samples ◽  
Polypyrrole Composite ◽  
Congenital Disabilities

Zika virus (ZIKV) is a mosquito-borne infection, predominant in tropical and subtropical regions causing international concern due to the ZIKV disease having been associated with congenital disabilities, especially microcephaly and other congenital abnormalities in the fetus and newborns. Development of strategies that minimize the devastating impact by monitoring and preventing ZIKV transmission through sexual intercourse, especially in pregnant women, since no vaccine is yet available for the prevention or treatment, is critically important. ZIKV infection is generally asymptomatic and cross-reactivity with dengue virus (DENV) is a global concern. An innovative screen-printed electrode (SPE) was developed for amperometric detection of the non-structural protein (NS2B) of ZIKV by exploring the intrinsic redox catalytic activity of Prussian blue (PB), incorporated into a carbon nanotube–polypyrrole composite. Thus, this immunosensor has the advantage of electrochemical detection without adding any redox-probe solution (probe-less detection), allowing a point-of-care diagnosis. It was responsive to serum samples of only ZIKV positive patients and non-responsive to negative ZIKV patients, even if the sample was DENV positive, indicating a possible differential diagnosis between them by NS2B. All samples used here were confirmed by CDC protocols, and immunosensor responses were also checked in the supernatant of C6/36 and in Vero cell cultures infected with ZIKV.

scholarly journals Long-Term Longitudinal Evaluation of Six Commercial Immunoassays for the Detection of IgM and IgG Antibodies against SARS CoV-2

Viruses ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1244
Author(s):  
Iulia Nedelcu ◽  
Raluca Jipa ◽  
Roxana Vasilescu ◽  
Cristian Băicuș ◽  
Costin-Ioan Popescu ◽  
...  
Keyword(s):  
Clinical Performance ◽  
Sample Selection ◽  
Early Time ◽  
Humoral Response ◽  
High Specificity ◽  
Data Interpretation ◽  
Serum Samples ◽  
Chemiluminescent Immunoassay ◽  
Chemiluminescent Microparticle Immunoassay ◽  
Antibody Levels

The number of serological assays for SARS-CoV-2 has skyrocketed in the past year. Concerns have been raised regarding their performance characteristics, depending on the disease severity and the time of the analysis post-symptom onset (PSO). Thus, independent validations using an unbiased sample selection are required for meaningful serology data interpretation. We aimed to assess the clinical performance of six commercially available assays, the seroconversion, and the dynamics of the humoral response to SARS-CoV-2 infection. The study included 528 serum samples from 156 patients with follow-up visits up to six months PSO and 161 serum samples from healthy people. The IgG/total antibodies positive percentage increased and remained above 95% after six months when chemiluminescent immunoassay (CLIA) IgG antiS1/S2 and electro-chemiluminescent assay (ECLIA) total antiNP were used. At early time points PSO, chemiluminescent microparticle immunoassay (CMIA) IgM antiS achieved the best sensitivity. IgM and IgG appear simultaneously in most circumstances, and when performed in parallel the sensitivity increases. The severe and the moderate clinical forms were significantly associated with higher seropositivity percentage and antibody levels. High specificity was found in all evaluated assays, but the sensitivity was variable depending on the time PSO, severity of disease, detection method and targeted antigen.

scholarly journals Dogs as Sentinels for Flavivirus Exposure in Urban, Peri-Urban and Rural Hanoi, Vietnam

Viruses ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 507
Author(s):  
Long Pham-Thanh ◽  
Thang Nguyen-Tien ◽  
Ulf Magnusson ◽  
Vuong Bui-Nghia ◽  
Anh Bui-Ngoc ◽  
...  
Keyword(s):  
Mosquito Control ◽  
Risk Mitigation ◽  
Significant Risk ◽  
Cross Sectional Study ◽  
Cross Reactivity ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serum Samples ◽  
Cross Sectional ◽  
Major Health ◽  
Household Level

Diseases caused by flaviviruses, including dengue fever and Japanese encephalitis, are major health problems in Vietnam. This cross-sectional study explored the feasibility of domestic dogs as sentinels to better understand risks of mosquito-borne diseases in Hanoi city. A total of 475 dogs serum samples from 221 households in six districts of Hanoi were analyzed by a competitive enzyme-linked immunosorbent assay (cELISA) for antibodies to the pr-E protein of West Nile virus and other flaviviruses due to cross-reactivity. The overall flavivirus seroprevalence in the dog population was 70.7% (95% CI = 66.4–74.8%). At the animal level, significant associations between seropositive dogs and district location, age, breed and keeping practice were determined. At the household level, the major risk factors were rural and peri-urban locations, presence of pigs, coil burning and households without mosquito-borne disease experience (p < 0.05). Mosquito control by using larvicides or electric traps could lower seropositivity, but other measures did not contribute to significant risk mitigation of flavivirus exposure in dogs. These results will support better control of mosquito-borne diseases in Hanoi, and they indicate that dogs can be used as sentinels for flavivirus exposure.

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