The Experts below are selected from a list of 20406 Experts worldwide ranked by ideXlab platform
Olivie Rouxel - One of the best experts on this subject based on the ideXlab platform.
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inter calibration of a proposed new Primary Reference Standard aa eth zn for zinc isotopic analysis
Journal of Analytical Atomic Spectrometry, 2017Co-Authors: Corey Arche, Joey Nelso, Christophe Cloque, Morte Anderse, Tim M Conway, Shuofei Dong, Michael J Ellwood, Rebekah E T Moore, Mark Rehkampe, Olivie RouxelAbstract:We have prepared a large volume of pure, concentrated and homogenous zinc Standard solution. This new Standard solution is intended to be used as a Primary Reference Standard for the zinc isotope community, and to serve as a replacement for the nearly exhausted current Reference Standard, the so-called JMC-Lyon Zn. The isotopic composition of this new zinc Standard (AA-ETH Zn) has been determined through an inter-laboratory calibration exercise, calibrated against the existing JMC-Lyon Standard, as well as the certified Zn Reference Standard IRMM-3702. The data show that the new Standard is isotopically indistinguishable from the IRMM-3702 zinc Standard, with a weighted δ66/64Zn value of 0.28 ± 0.02‰ relative to JMC-Lyon. We suggest that this new Standard be assigned a δ66/64Zn value of +0.28‰ for reporting of future Zn isotope data, with the rationale that all existing published Zn isotope data are presented relative to the JMC-Lyon Standard. Therefore our proposed presentation allows for a direct comparison with all previously published data, and that are directly traceable to a certified Reference Standard, IRMM-3702 Zn. This Standard will be made freely available to all interested labs through contact with the corresponding author.
Zeno Bisoffi - One of the best experts on this subject based on the ideXlab platform.
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Diagnostic accuracy of a novel enzyme-linked immunoassay for the detection of IgG and IgG4 against Strongyloides stercoralis based on the recombinant antigens NIE/SsIR
'Springer Science and Business Media LLC', 2021Co-Authors: Francesca Tamarozzi, Silvia Stefania Longoni, Cristina Mazzi, Sofia Pettene, Antonio Montresor, Siddhartha Mahanty, Zeno Bisoffi, Dora BuonfrateAbstract:Abstract Background The diagnosis of strongyloidiasis is challenging. Serological tests are acknowledged to have high sensitivity, but issues due to cross-reactions with other parasites, native parasite antigen supply and intrinsic test variability do occur. Assays based on recombinant antigens could represent an improvement. The aim of this study was to assess the sensitivity and specificity of two novel immunoglobulin (Ig)G and IgG4 enzyme-linked immunosorbent assays (ELISAs) based on the recombinant antigens NIE/SsIR for the diagnosis of strongyloidiasis. Methods This was a retrospective diagnostic accuracy study. We included serum samples collected from immigrants from strongyloidiasis endemic areas for whom there was a matched result for Strongyloides stercoralis on agar plate culture and/or PCR assay, or a positive microscopy for S. stercoralis larvae. For the included samples, results were also available from an in-house indirect fluorescent antibody test (IFAT) and a commercial (Bordier ELISA; Bordier Affinity Products SA) ELISA. We excluded: (i) samples with insufficient serum volume; (ii) samples from patients treated with ivermectin in the previous 6 months; and (iii) sera from patients for whom only routine coproparasitology was performed after formol–ether concentration, if negative for S. stercoralis larvae. The performance of the novel assays was assessed against: (i) a Primary Reference Standard, with samples classified as negative/positive on the basis of the results of fecal tests; (ii) a composite Reference Standard (CRS), which also considered patients to be positive who had concordant positive results for the IFAT and Bordier ELISA or with a single “high titer” positive result for the IFAT or Bordier ELISA. Samples with a single positive test, either for the IFAT or Bordier ELISA, at low titer, were considered to be “indeterminate,” and analyses were carried out with and without their inclusion. Results When assessed against the Primary Reference Standard, the sensitivities of the IgG and IgG4 ELISAs were 92% (95% confidence interval [CI]: 88–97%) and 81% (95% CI: 74–87%), respectively, and the specificities were 91% (95% CI: 88–95%) and 94% (95% CI: 91–97%), respectively. When tested against the CRS, the IgG ELISA performed best, with 78% sensitivity (95% CI: 72–83%) and 98% specificity (95% CI: 96–100%), when a cut-off of 0.675 was applied and the indeterminate samples were excluded from the analysis. Conclusion The NIE-SsIR IgG ELISA demonstrated better accuracy than the IgG4 assay and was deemed promising particularly for serosurveys in endemic areas. Graphical abstrac
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diagnostic accuracy of five serologic tests for strongyloides stercoralis infection
PLOS Neglected Tropical Diseases, 2014Co-Authors: Zeno Bisoffi, Dora Buonfrate, Marco Sequi, Rojelio Mejia, Ruben O Cimino, Alejandro J Krolewiecki, Marco Albonico, Maria Gobbo, Stefania Bonafini, Andrea AnghebenAbstract:Background: The diagnosis of Strongyloides stercoralis (S. stercoralis) infection is hampered by the suboptimal sensitivity of fecal-based tests. Serological methods are believed to be more sensitive, although assessing their accuracy is difficult because of the lack of sensitivity of a fecal-based Reference (‘‘gold’’) Standard. Methods: The sensitivity and specificity of 5 serologic tests for S. stercoralis (in-house IFAT, NIE-ELISA and NIE-LIPS and the commercially available Bordier-ELISA and IVD-ELISA) were assessed on 399 cryopreserved serum samples. Accuracy was measured using fecal results as the Primary Reference Standard, but also using a composite Reference Standard (based on a combination of tests). Results: According to the latter Standard, the most sensitive test was IFAT, with 94.6% sensitivity (91.2–96.9), followed by IVD-ELISA (92.3%, 87.7–96.9). The most specific test was NIE-LIPS, with specificity 99.6% (98.9–100), followed by IVD-ELISA (97.4%, 95.5–99.3). NIE-LIPS did not cross-react with any of the specimens from subjects with other parasitic infections. NIELIPS and the two commercial ELISAs approach 100% specificity at a cut off level that maintains $70% sensitivity. Conclusions: NIE-LIPS is the most accurate serologic test for the diagnosis of S. stercoralis infection. IFAT and each of the ELISA tests are sufficiently accurate, above a given cut off, for diagnosis, prevalence studies and inclusion in clinical trials.
Corey Arche - One of the best experts on this subject based on the ideXlab platform.
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inter calibration of a proposed new Primary Reference Standard aa eth zn for zinc isotopic analysis
Journal of Analytical Atomic Spectrometry, 2017Co-Authors: Corey Arche, Joey Nelso, Christophe Cloque, Morte Anderse, Tim M Conway, Shuofei Dong, Michael J Ellwood, Rebekah E T Moore, Mark Rehkampe, Olivie RouxelAbstract:We have prepared a large volume of pure, concentrated and homogenous zinc Standard solution. This new Standard solution is intended to be used as a Primary Reference Standard for the zinc isotope community, and to serve as a replacement for the nearly exhausted current Reference Standard, the so-called JMC-Lyon Zn. The isotopic composition of this new zinc Standard (AA-ETH Zn) has been determined through an inter-laboratory calibration exercise, calibrated against the existing JMC-Lyon Standard, as well as the certified Zn Reference Standard IRMM-3702. The data show that the new Standard is isotopically indistinguishable from the IRMM-3702 zinc Standard, with a weighted δ66/64Zn value of 0.28 ± 0.02‰ relative to JMC-Lyon. We suggest that this new Standard be assigned a δ66/64Zn value of +0.28‰ for reporting of future Zn isotope data, with the rationale that all existing published Zn isotope data are presented relative to the JMC-Lyon Standard. Therefore our proposed presentation allows for a direct comparison with all previously published data, and that are directly traceable to a certified Reference Standard, IRMM-3702 Zn. This Standard will be made freely available to all interested labs through contact with the corresponding author.
Andrea Angheben - One of the best experts on this subject based on the ideXlab platform.
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diagnostic accuracy of five serologic tests for strongyloides stercoralis infection
PLOS Neglected Tropical Diseases, 2014Co-Authors: Zeno Bisoffi, Dora Buonfrate, Marco Sequi, Rojelio Mejia, Ruben O Cimino, Alejandro J Krolewiecki, Marco Albonico, Maria Gobbo, Stefania Bonafini, Andrea AnghebenAbstract:Background: The diagnosis of Strongyloides stercoralis (S. stercoralis) infection is hampered by the suboptimal sensitivity of fecal-based tests. Serological methods are believed to be more sensitive, although assessing their accuracy is difficult because of the lack of sensitivity of a fecal-based Reference (‘‘gold’’) Standard. Methods: The sensitivity and specificity of 5 serologic tests for S. stercoralis (in-house IFAT, NIE-ELISA and NIE-LIPS and the commercially available Bordier-ELISA and IVD-ELISA) were assessed on 399 cryopreserved serum samples. Accuracy was measured using fecal results as the Primary Reference Standard, but also using a composite Reference Standard (based on a combination of tests). Results: According to the latter Standard, the most sensitive test was IFAT, with 94.6% sensitivity (91.2–96.9), followed by IVD-ELISA (92.3%, 87.7–96.9). The most specific test was NIE-LIPS, with specificity 99.6% (98.9–100), followed by IVD-ELISA (97.4%, 95.5–99.3). NIE-LIPS did not cross-react with any of the specimens from subjects with other parasitic infections. NIELIPS and the two commercial ELISAs approach 100% specificity at a cut off level that maintains $70% sensitivity. Conclusions: NIE-LIPS is the most accurate serologic test for the diagnosis of S. stercoralis infection. IFAT and each of the ELISA tests are sufficiently accurate, above a given cut off, for diagnosis, prevalence studies and inclusion in clinical trials.
Dora Buonfrate - One of the best experts on this subject based on the ideXlab platform.
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Diagnostic accuracy of a novel enzyme-linked immunoassay for the detection of IgG and IgG4 against Strongyloides stercoralis based on the recombinant antigens NIE/SsIR
'Springer Science and Business Media LLC', 2021Co-Authors: Francesca Tamarozzi, Silvia Stefania Longoni, Cristina Mazzi, Sofia Pettene, Antonio Montresor, Siddhartha Mahanty, Zeno Bisoffi, Dora BuonfrateAbstract:Abstract Background The diagnosis of strongyloidiasis is challenging. Serological tests are acknowledged to have high sensitivity, but issues due to cross-reactions with other parasites, native parasite antigen supply and intrinsic test variability do occur. Assays based on recombinant antigens could represent an improvement. The aim of this study was to assess the sensitivity and specificity of two novel immunoglobulin (Ig)G and IgG4 enzyme-linked immunosorbent assays (ELISAs) based on the recombinant antigens NIE/SsIR for the diagnosis of strongyloidiasis. Methods This was a retrospective diagnostic accuracy study. We included serum samples collected from immigrants from strongyloidiasis endemic areas for whom there was a matched result for Strongyloides stercoralis on agar plate culture and/or PCR assay, or a positive microscopy for S. stercoralis larvae. For the included samples, results were also available from an in-house indirect fluorescent antibody test (IFAT) and a commercial (Bordier ELISA; Bordier Affinity Products SA) ELISA. We excluded: (i) samples with insufficient serum volume; (ii) samples from patients treated with ivermectin in the previous 6 months; and (iii) sera from patients for whom only routine coproparasitology was performed after formol–ether concentration, if negative for S. stercoralis larvae. The performance of the novel assays was assessed against: (i) a Primary Reference Standard, with samples classified as negative/positive on the basis of the results of fecal tests; (ii) a composite Reference Standard (CRS), which also considered patients to be positive who had concordant positive results for the IFAT and Bordier ELISA or with a single “high titer” positive result for the IFAT or Bordier ELISA. Samples with a single positive test, either for the IFAT or Bordier ELISA, at low titer, were considered to be “indeterminate,” and analyses were carried out with and without their inclusion. Results When assessed against the Primary Reference Standard, the sensitivities of the IgG and IgG4 ELISAs were 92% (95% confidence interval [CI]: 88–97%) and 81% (95% CI: 74–87%), respectively, and the specificities were 91% (95% CI: 88–95%) and 94% (95% CI: 91–97%), respectively. When tested against the CRS, the IgG ELISA performed best, with 78% sensitivity (95% CI: 72–83%) and 98% specificity (95% CI: 96–100%), when a cut-off of 0.675 was applied and the indeterminate samples were excluded from the analysis. Conclusion The NIE-SsIR IgG ELISA demonstrated better accuracy than the IgG4 assay and was deemed promising particularly for serosurveys in endemic areas. Graphical abstrac
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diagnostic accuracy of five serologic tests for strongyloides stercoralis infection
PLOS Neglected Tropical Diseases, 2014Co-Authors: Zeno Bisoffi, Dora Buonfrate, Marco Sequi, Rojelio Mejia, Ruben O Cimino, Alejandro J Krolewiecki, Marco Albonico, Maria Gobbo, Stefania Bonafini, Andrea AnghebenAbstract:Background: The diagnosis of Strongyloides stercoralis (S. stercoralis) infection is hampered by the suboptimal sensitivity of fecal-based tests. Serological methods are believed to be more sensitive, although assessing their accuracy is difficult because of the lack of sensitivity of a fecal-based Reference (‘‘gold’’) Standard. Methods: The sensitivity and specificity of 5 serologic tests for S. stercoralis (in-house IFAT, NIE-ELISA and NIE-LIPS and the commercially available Bordier-ELISA and IVD-ELISA) were assessed on 399 cryopreserved serum samples. Accuracy was measured using fecal results as the Primary Reference Standard, but also using a composite Reference Standard (based on a combination of tests). Results: According to the latter Standard, the most sensitive test was IFAT, with 94.6% sensitivity (91.2–96.9), followed by IVD-ELISA (92.3%, 87.7–96.9). The most specific test was NIE-LIPS, with specificity 99.6% (98.9–100), followed by IVD-ELISA (97.4%, 95.5–99.3). NIE-LIPS did not cross-react with any of the specimens from subjects with other parasitic infections. NIELIPS and the two commercial ELISAs approach 100% specificity at a cut off level that maintains $70% sensitivity. Conclusions: NIE-LIPS is the most accurate serologic test for the diagnosis of S. stercoralis infection. IFAT and each of the ELISA tests are sufficiently accurate, above a given cut off, for diagnosis, prevalence studies and inclusion in clinical trials.