The Experts below are selected from a list of 639 Experts worldwide ranked by ideXlab platform
Xavier Bossuyt - One of the best experts on this subject based on the ideXlab platform.
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detection of antinuclear antibodies by indirect immunofluorescence and by solid phase assay
Autoimmunity Reviews, 2011Co-Authors: Katrijn Op De Beeck, Xavier Bossuyt, Daniel Engelbert Blockmans, Pieter Vermeersch, Godelieve Marien, Patrick Verschueren, Rene WesthovensAbstract:Abstract Testing for antinuclear antibodies is useful for the diagnosis of systemic rheumatic diseases. Solid phase assays are increasingly replacing indirect immunofluorescence for detection of antinuclear antibodies. In the most recent generation of solid phase assays, manufacturers attempt to improve the performance of the assays by adding extra antigens. Solid phase assay (EliA CTD Screen, Phadia, in which antibodies to 17 antigens are detected) was compared to indirect immunofluorescence for the detection of antinuclear antibodies in diagnostic samples of 236 patients with autoimmune connective tissue diseases, in 149 healthy blood donors, 139 patients with chronic fatigue syndrome, and 134 diseased controls. The sensitivity of EliA CTD Screen for systemic lupus erythematosus, systemic sclerosis, primary Sjogren's syndrome, mixed connective tissue disease, and inflammatory myopathy was 74%, 72%, 89%, 100%, and 39%, respectively. The reactivity in blood donors, in patients with chronic fatigue syndrome, and in diseased controls was
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detection of antinuclear antibodies by indirect immunofluorescence and by solid phase assay
Autoimmunity Reviews, 2011Co-Authors: Katrijn Op De Beeck, Xavier Bossuyt, Daniel Engelbert Blockmans, Pieter Vermeersch, Godelieve Marien, Patrick Verschueren, Rene WesthovensAbstract:Testing for antinuclear antibodies is useful for the diagnosis of systemic rheumatic diseases. Solid phase assays are increasingly replacing indirect immunofluorescence for detection of antinuclear antibodies. In the most recent generation of solid phase assays, manufacturers attempt to improve the performance of the assays by adding extra antigens. Solid phase assay (EliA CTD Screen, Phadia, in which antibodies to 17 antigens are detected) was compared to indirect immunofluorescence for the detection of antinuclear antibodies in diagnostic samples of 236 patients with autoimmune connective tissue diseases, in 149 healthy blood donors, 139 patients with chronic fatigue syndrome, and 134 diseased controls. The sensitivity of EliA CTD Screen for systemic lupus erythematosus, systemic sclerosis, primary Sjogren's syndrome, mixed connective tissue disease, and inflammatory myopathy was 74%, 72%, 89%, 100%, and 39%, respectively. The reactivity in blood donors, in patients with chronic fatigue syndrome, and in diseased controls was <4%. Likelihood ratios increased with increasing antibody concentrations. Generally, a positive test result by EliA CTD Screen had a higher likelihood ratio for systemic rheumatic disease than a positive test result by indirect immunofluorescence. A negative test result by indirect immunofluorescence, however, had a lower likelihood ratio than a negative test result by EliA CTD Screen, indicating that the negative predictive value was higher for indirect immunofluorescence than for EliA CTD screen.
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diagnostic performance of igg anti deamidated gliadin peptide antibody assays is comparable to iga anti ttg in celiac disease
Clinica Chimica Acta, 2010Co-Authors: Pieter Vermeersch, Godelieve Marien, Karel Geboes, Ilse Hoffman, Martin Hiele, Xavier BossuytAbstract:Abstract Background Detection of IgG antibodies against deamidated gliadin peptides (DGP) is more sensitive and more specific for celiac disease than detection of IgG antibodies against native gliadin. Our aim was to evaluate the technical performance and diagnostic accuracy of four commercial IgG anti-DGP assays. Methods Commercial IgG anti-DGP assays from Euroimmun, Inova, Phadia and The Binding Site were evaluated and their diagnostic accuracy (sensitivity and specificity) compared to other serologic assays for celiac disease (3 IgA and 2 IgG anti-tTG assays, 1 IgA and 1 IgG anti-gliadin assay, 1 IgA anti-DGP assay). The study population consisted of 86 consecutive CD patients and 741 disease controls. Results The technical performance (linearity, interference and imprecision) of the IgG anti-DGP assays was acceptable. The sensitivity of the IgG anti-DGP assays varied between 76.7% and 86.0% at the cut-off recommended by the manufacturer and between 74.4% and 86.0% at the cut-off that corresponded to a specificity of 98%. The specificity varied between 97.3% and 99.3%. The diagnostic accuracy of the IgG anti-DGP assays was comparable to the diagnostic accuracy of the IgA anti-tTG assays. The sensitivity of the IgG anti-DGP assays was significantly better than sensitivity of the IgG anti-tTG assays (p Conclusions The overall performance of the four IgG anti-DGP assays was acceptable and the diagnostic accuracy comparable to the three IgA anti-tTG assays.
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determination of anti neutrophil cytoplasmic antibodies in small vessel vasculitis comparative analysis of different strategies
Clinica Chimica Acta, 2008Co-Authors: Pieter Vermeersch, Daniel Engelbert Blockmans, Steven Vervaeke, Lieve Van Hoovels, Godelieve Marien, Hendrik Vanmaele, Xavier BossuytAbstract:Abstract Background Anti-neutrophil cytoplasmic antibodies (ANCA) are associated with primary small vessel vasculitis (SVV). Proteinase-3 (PR3)-ANCA are primarily associated with Wegener granulomatosis, whereas myeloperoxidase (MPO)-ANCA are primarily associated with microscopic polyangiitis (MPA) and vasculitic Churg–Strauss syndrome. We evaluated whether a strategy that is based on screening with ELISA or fluoroenzymeimmunoassay (FEIA) is an accurate alternative to screening with indirect immunofluorescence (IIF). Methods C-ANCA and P-ANCA were determined by IIF and PR3-ANCA and MPO-ANCA were determined by ELISA (Inova) or FEIA (Phadia) on 326 patients (38 with newly diagnosed SVV and 288 diseased controls). Results Specificity and positive likelihood ratios were higher for ELISA and FEIA than for IIF. Post-test probability for SVV of a positive test result was higher for ELISA and FEIA than for IIF. Decision tree analysis in which several testing strategies were compared revealed that a testing strategy that is based on screening with ELISA or FEIA had an expected clinical utility that was comparable to screening with IIF and confirming with ELISA or FEIA. The highest expected clinical utility was found when both IIF and ELISA or FEIA were performed on all samples. Conclusions A strategy based on screening for ANCA with ELISA or FEIA (without prior IIF) is a valuable alternative to screening with IIF and confirming with ELISA or FEIA.
Pieter Vermeersch - One of the best experts on this subject based on the ideXlab platform.
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detection of antinuclear antibodies by indirect immunofluorescence and by solid phase assay
Autoimmunity Reviews, 2011Co-Authors: Katrijn Op De Beeck, Xavier Bossuyt, Daniel Engelbert Blockmans, Pieter Vermeersch, Godelieve Marien, Patrick Verschueren, Rene WesthovensAbstract:Abstract Testing for antinuclear antibodies is useful for the diagnosis of systemic rheumatic diseases. Solid phase assays are increasingly replacing indirect immunofluorescence for detection of antinuclear antibodies. In the most recent generation of solid phase assays, manufacturers attempt to improve the performance of the assays by adding extra antigens. Solid phase assay (EliA CTD Screen, Phadia, in which antibodies to 17 antigens are detected) was compared to indirect immunofluorescence for the detection of antinuclear antibodies in diagnostic samples of 236 patients with autoimmune connective tissue diseases, in 149 healthy blood donors, 139 patients with chronic fatigue syndrome, and 134 diseased controls. The sensitivity of EliA CTD Screen for systemic lupus erythematosus, systemic sclerosis, primary Sjogren's syndrome, mixed connective tissue disease, and inflammatory myopathy was 74%, 72%, 89%, 100%, and 39%, respectively. The reactivity in blood donors, in patients with chronic fatigue syndrome, and in diseased controls was
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detection of antinuclear antibodies by indirect immunofluorescence and by solid phase assay
Autoimmunity Reviews, 2011Co-Authors: Katrijn Op De Beeck, Xavier Bossuyt, Daniel Engelbert Blockmans, Pieter Vermeersch, Godelieve Marien, Patrick Verschueren, Rene WesthovensAbstract:Testing for antinuclear antibodies is useful for the diagnosis of systemic rheumatic diseases. Solid phase assays are increasingly replacing indirect immunofluorescence for detection of antinuclear antibodies. In the most recent generation of solid phase assays, manufacturers attempt to improve the performance of the assays by adding extra antigens. Solid phase assay (EliA CTD Screen, Phadia, in which antibodies to 17 antigens are detected) was compared to indirect immunofluorescence for the detection of antinuclear antibodies in diagnostic samples of 236 patients with autoimmune connective tissue diseases, in 149 healthy blood donors, 139 patients with chronic fatigue syndrome, and 134 diseased controls. The sensitivity of EliA CTD Screen for systemic lupus erythematosus, systemic sclerosis, primary Sjogren's syndrome, mixed connective tissue disease, and inflammatory myopathy was 74%, 72%, 89%, 100%, and 39%, respectively. The reactivity in blood donors, in patients with chronic fatigue syndrome, and in diseased controls was <4%. Likelihood ratios increased with increasing antibody concentrations. Generally, a positive test result by EliA CTD Screen had a higher likelihood ratio for systemic rheumatic disease than a positive test result by indirect immunofluorescence. A negative test result by indirect immunofluorescence, however, had a lower likelihood ratio than a negative test result by EliA CTD Screen, indicating that the negative predictive value was higher for indirect immunofluorescence than for EliA CTD screen.
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diagnostic performance of igg anti deamidated gliadin peptide antibody assays is comparable to iga anti ttg in celiac disease
Clinica Chimica Acta, 2010Co-Authors: Pieter Vermeersch, Godelieve Marien, Karel Geboes, Ilse Hoffman, Martin Hiele, Xavier BossuytAbstract:Abstract Background Detection of IgG antibodies against deamidated gliadin peptides (DGP) is more sensitive and more specific for celiac disease than detection of IgG antibodies against native gliadin. Our aim was to evaluate the technical performance and diagnostic accuracy of four commercial IgG anti-DGP assays. Methods Commercial IgG anti-DGP assays from Euroimmun, Inova, Phadia and The Binding Site were evaluated and their diagnostic accuracy (sensitivity and specificity) compared to other serologic assays for celiac disease (3 IgA and 2 IgG anti-tTG assays, 1 IgA and 1 IgG anti-gliadin assay, 1 IgA anti-DGP assay). The study population consisted of 86 consecutive CD patients and 741 disease controls. Results The technical performance (linearity, interference and imprecision) of the IgG anti-DGP assays was acceptable. The sensitivity of the IgG anti-DGP assays varied between 76.7% and 86.0% at the cut-off recommended by the manufacturer and between 74.4% and 86.0% at the cut-off that corresponded to a specificity of 98%. The specificity varied between 97.3% and 99.3%. The diagnostic accuracy of the IgG anti-DGP assays was comparable to the diagnostic accuracy of the IgA anti-tTG assays. The sensitivity of the IgG anti-DGP assays was significantly better than sensitivity of the IgG anti-tTG assays (p Conclusions The overall performance of the four IgG anti-DGP assays was acceptable and the diagnostic accuracy comparable to the three IgA anti-tTG assays.
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determination of anti neutrophil cytoplasmic antibodies in small vessel vasculitis comparative analysis of different strategies
Clinica Chimica Acta, 2008Co-Authors: Pieter Vermeersch, Daniel Engelbert Blockmans, Steven Vervaeke, Lieve Van Hoovels, Godelieve Marien, Hendrik Vanmaele, Xavier BossuytAbstract:Abstract Background Anti-neutrophil cytoplasmic antibodies (ANCA) are associated with primary small vessel vasculitis (SVV). Proteinase-3 (PR3)-ANCA are primarily associated with Wegener granulomatosis, whereas myeloperoxidase (MPO)-ANCA are primarily associated with microscopic polyangiitis (MPA) and vasculitic Churg–Strauss syndrome. We evaluated whether a strategy that is based on screening with ELISA or fluoroenzymeimmunoassay (FEIA) is an accurate alternative to screening with indirect immunofluorescence (IIF). Methods C-ANCA and P-ANCA were determined by IIF and PR3-ANCA and MPO-ANCA were determined by ELISA (Inova) or FEIA (Phadia) on 326 patients (38 with newly diagnosed SVV and 288 diseased controls). Results Specificity and positive likelihood ratios were higher for ELISA and FEIA than for IIF. Post-test probability for SVV of a positive test result was higher for ELISA and FEIA than for IIF. Decision tree analysis in which several testing strategies were compared revealed that a testing strategy that is based on screening with ELISA or FEIA had an expected clinical utility that was comparable to screening with IIF and confirming with ELISA or FEIA. The highest expected clinical utility was found when both IIF and ELISA or FEIA were performed on all samples. Conclusions A strategy based on screening for ANCA with ELISA or FEIA (without prior IIF) is a valuable alternative to screening with IIF and confirming with ELISA or FEIA.
Godelieve Marien - One of the best experts on this subject based on the ideXlab platform.
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detection of antinuclear antibodies by indirect immunofluorescence and by solid phase assay
Autoimmunity Reviews, 2011Co-Authors: Katrijn Op De Beeck, Xavier Bossuyt, Daniel Engelbert Blockmans, Pieter Vermeersch, Godelieve Marien, Patrick Verschueren, Rene WesthovensAbstract:Abstract Testing for antinuclear antibodies is useful for the diagnosis of systemic rheumatic diseases. Solid phase assays are increasingly replacing indirect immunofluorescence for detection of antinuclear antibodies. In the most recent generation of solid phase assays, manufacturers attempt to improve the performance of the assays by adding extra antigens. Solid phase assay (EliA CTD Screen, Phadia, in which antibodies to 17 antigens are detected) was compared to indirect immunofluorescence for the detection of antinuclear antibodies in diagnostic samples of 236 patients with autoimmune connective tissue diseases, in 149 healthy blood donors, 139 patients with chronic fatigue syndrome, and 134 diseased controls. The sensitivity of EliA CTD Screen for systemic lupus erythematosus, systemic sclerosis, primary Sjogren's syndrome, mixed connective tissue disease, and inflammatory myopathy was 74%, 72%, 89%, 100%, and 39%, respectively. The reactivity in blood donors, in patients with chronic fatigue syndrome, and in diseased controls was
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detection of antinuclear antibodies by indirect immunofluorescence and by solid phase assay
Autoimmunity Reviews, 2011Co-Authors: Katrijn Op De Beeck, Xavier Bossuyt, Daniel Engelbert Blockmans, Pieter Vermeersch, Godelieve Marien, Patrick Verschueren, Rene WesthovensAbstract:Testing for antinuclear antibodies is useful for the diagnosis of systemic rheumatic diseases. Solid phase assays are increasingly replacing indirect immunofluorescence for detection of antinuclear antibodies. In the most recent generation of solid phase assays, manufacturers attempt to improve the performance of the assays by adding extra antigens. Solid phase assay (EliA CTD Screen, Phadia, in which antibodies to 17 antigens are detected) was compared to indirect immunofluorescence for the detection of antinuclear antibodies in diagnostic samples of 236 patients with autoimmune connective tissue diseases, in 149 healthy blood donors, 139 patients with chronic fatigue syndrome, and 134 diseased controls. The sensitivity of EliA CTD Screen for systemic lupus erythematosus, systemic sclerosis, primary Sjogren's syndrome, mixed connective tissue disease, and inflammatory myopathy was 74%, 72%, 89%, 100%, and 39%, respectively. The reactivity in blood donors, in patients with chronic fatigue syndrome, and in diseased controls was <4%. Likelihood ratios increased with increasing antibody concentrations. Generally, a positive test result by EliA CTD Screen had a higher likelihood ratio for systemic rheumatic disease than a positive test result by indirect immunofluorescence. A negative test result by indirect immunofluorescence, however, had a lower likelihood ratio than a negative test result by EliA CTD Screen, indicating that the negative predictive value was higher for indirect immunofluorescence than for EliA CTD screen.
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diagnostic performance of igg anti deamidated gliadin peptide antibody assays is comparable to iga anti ttg in celiac disease
Clinica Chimica Acta, 2010Co-Authors: Pieter Vermeersch, Godelieve Marien, Karel Geboes, Ilse Hoffman, Martin Hiele, Xavier BossuytAbstract:Abstract Background Detection of IgG antibodies against deamidated gliadin peptides (DGP) is more sensitive and more specific for celiac disease than detection of IgG antibodies against native gliadin. Our aim was to evaluate the technical performance and diagnostic accuracy of four commercial IgG anti-DGP assays. Methods Commercial IgG anti-DGP assays from Euroimmun, Inova, Phadia and The Binding Site were evaluated and their diagnostic accuracy (sensitivity and specificity) compared to other serologic assays for celiac disease (3 IgA and 2 IgG anti-tTG assays, 1 IgA and 1 IgG anti-gliadin assay, 1 IgA anti-DGP assay). The study population consisted of 86 consecutive CD patients and 741 disease controls. Results The technical performance (linearity, interference and imprecision) of the IgG anti-DGP assays was acceptable. The sensitivity of the IgG anti-DGP assays varied between 76.7% and 86.0% at the cut-off recommended by the manufacturer and between 74.4% and 86.0% at the cut-off that corresponded to a specificity of 98%. The specificity varied between 97.3% and 99.3%. The diagnostic accuracy of the IgG anti-DGP assays was comparable to the diagnostic accuracy of the IgA anti-tTG assays. The sensitivity of the IgG anti-DGP assays was significantly better than sensitivity of the IgG anti-tTG assays (p Conclusions The overall performance of the four IgG anti-DGP assays was acceptable and the diagnostic accuracy comparable to the three IgA anti-tTG assays.
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determination of anti neutrophil cytoplasmic antibodies in small vessel vasculitis comparative analysis of different strategies
Clinica Chimica Acta, 2008Co-Authors: Pieter Vermeersch, Daniel Engelbert Blockmans, Steven Vervaeke, Lieve Van Hoovels, Godelieve Marien, Hendrik Vanmaele, Xavier BossuytAbstract:Abstract Background Anti-neutrophil cytoplasmic antibodies (ANCA) are associated with primary small vessel vasculitis (SVV). Proteinase-3 (PR3)-ANCA are primarily associated with Wegener granulomatosis, whereas myeloperoxidase (MPO)-ANCA are primarily associated with microscopic polyangiitis (MPA) and vasculitic Churg–Strauss syndrome. We evaluated whether a strategy that is based on screening with ELISA or fluoroenzymeimmunoassay (FEIA) is an accurate alternative to screening with indirect immunofluorescence (IIF). Methods C-ANCA and P-ANCA were determined by IIF and PR3-ANCA and MPO-ANCA were determined by ELISA (Inova) or FEIA (Phadia) on 326 patients (38 with newly diagnosed SVV and 288 diseased controls). Results Specificity and positive likelihood ratios were higher for ELISA and FEIA than for IIF. Post-test probability for SVV of a positive test result was higher for ELISA and FEIA than for IIF. Decision tree analysis in which several testing strategies were compared revealed that a testing strategy that is based on screening with ELISA or FEIA had an expected clinical utility that was comparable to screening with IIF and confirming with ELISA or FEIA. The highest expected clinical utility was found when both IIF and ELISA or FEIA were performed on all samples. Conclusions A strategy based on screening for ANCA with ELISA or FEIA (without prior IIF) is a valuable alternative to screening with IIF and confirming with ELISA or FEIA.
Elias Mohammed - One of the best experts on this subject based on the ideXlab platform.
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Verifiering och analys av anti-dsDNA antikroppar med instrumentet Phadia 250
Linnéuniversitetet Institutionen för kemi och biomedicin (KOB), 2017Co-Authors: Elias MohammedAbstract:Autoantikroppar är antikroppar som attackerar en individs egen vävnad. Riktas dessa mot antigener från cellkärnan kallas de för ANA. Exempel på dessa är anti-dsDNA antikroppar som associeras med sjukdomen SLE. Med hjälp av metoderna ELISA, CLIFT eller FARR-radioimmunoassay kan anti-dsDNA antikroppar analyseras och tillsammans med kliniska symptom såsom ansiktserytem kan diagnosen SLE ställas. Syftet med examensarbetet var att undersöka analys av anti-dsDNA antikroppar med hjälp av instrumentet Phadia 250 vars princip är en automatiserad ELISA, för att se om det kan användas som screeningmetod istället för CLIFT. 20 EQUALIS-serumprover (externa kontrollprover) analyserades med Phadia 250 och de Phadia 250-positiva proverna analyserades ytterligare en gång med CLIFT. Därefter analyserades 44 patienters serumprover (21 positiva och 23 negativa, tidigare analyserade med CLIFT) med Phadia 250. Patientprovernas resultat gav 70 % sensitivitet och 86 % specificitet med Phadia 250. Phadia 250-resultat som ej överensstämde med förväntade resultat på EQUALIS- och patientproverna erhölls i flera fall. Vid en noggrannare granskning av EQUALIS-proverna noterades att liknande resultat erhållits av andra laboratorier som använt likartade metoder. EQUALIS-proverna var initialt analyserade och kategoriserade enligt CLIFT, vilket innebar att hög överensstämmelse kunde förväntas med den egna CLIFT-metoden. Slutsatsen av studien är att underlaget för att införa metoden i rutindiagnostiken är inte tillräckligt utifrån de erhållna resultaten. Det krävs ytterligare studier samt granskning av inkluderade patienters journaler för att säkrare bedöma metodernas korrelation till sjukdomen
Y W Park - One of the best experts on this subject based on the ideXlab platform.
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ab1055 comparison of automated fluorescent enzyme immunoassay with enzyme linked immunosorbent assay for five anti extractable nuclear antigens specific to systemic autoimmune rheumatic diseases
Annals of the Rheumatic Diseases, 2015Co-Authors: Haksung Kim, Y W ParkAbstract:Background Autoantibodies to extractable nuclear antigens (ENAs) are important diagnostic markers for autoimmune diseases but have some limitations, since no gold standard has been established. We compared two current assays commonly used. Objectives An automated fluorescent enzyme immunoassay (FEIA), Phadia® 250 (Phadia, Sweden), is being compared with microplate ELISA assay (INOVA Diagnostics, USA) for the detection of five commonly used anti-extractable nuclear antigens. Methods A total of 100 serum samples from the patients with systemic rheumatic diseases were collected and assayed with the Phadia® 250 (Phadia, Sweden) and microplate ELISA (INOVA Diagnostics, USA) for 5 anti-extractable nuclear antigens. Five kinds of autoantibodies to SSA/Ro, SSB/La, RNP, Sm, and Scl-70 were performed using respective QUANTA Lite™ ELISA kits (INOVA Diagnostics, USA) and Phadia® 250 assays. The statistical analysis of agreement rate with kappa coefficient, sensitivity and specificity of each assays were performed with Analyse-it® for Microsoft Excel 3.90.4 (Analyse-it Software, Ltd.) Results The concordance rates between ELISA and Phadia® 250 ranged from 89% for anti-RNP to 97% for anti-Scl-70, and the kappa coefficients between the results by the two assays were from 0.44 to 0.82 (Table1). There were no significant differences in sensitivities and specificities of each anti-ENA between the two assays except for specificity of anti-RNP and sensitivity of anti-Sm. The overall sensitivities of antibodies to SS-A/Ro (0.760-0.840), SS-B/La (0.200-0.120) and RNP (0.560-0.400) in SLE group were quite similar for the two methods. Specificities of antibodies to SS-A/Ro (0.338-0.351), SS-B/La (0.689-0.730), RNP (0.824-0.919) and Sm (0.959-0.986) in SLE group also indicated similarity between the two assays. There were no significant differences in sensitivities and specificities of each antigen in Sjogren group except for sensitivity of anti-RNP. Conclusions FEIA method by automated Phadia® 250 showed comparable results with those by conventional ELISA for detecting anti-ENAs. Automated FEIA by Phadia® 250 could be a useful method in that it provides shorter protocol time, simpler use of methodology. Disclosure of Interest None declared