Pal B Szecsi1, Steen Stender. 1. Department of Clinical Biochemistry, Copenhagen University Hospital Gentofte, Hellerup, Denmark.
Abstract
BACKGROUND: Specific immunoglobulin E (IgE) antibody in vitro tests are performed on enzyme immunoassay systems. Poor agreement among systems has been reported and comparisons have been made exclusively with allergen extracts - not with recombinant allergens. Here we compare the ImmunoCAP and the IMMULITE systems. METHODS: Ten patient samples with positive IgE toward egg white, birch pollen or cat or dog dander were compared using allergen extracts or the recombinant allergens Gal d 1, Bet v 1, Fel d 1 and Can f 1 with the two assay systems. Comparisons were also performed using four monoclonal mouse-human chimeric IgE antibodies specific for the same allergenic components. RESULTS: IMMULITE estimated a higher allergen-specific IgE concentration in sera than ImmunoCAP when testing with allergen extracts as well as recombinant allergens. The chimeric antibodies gave an equivalent response in the total IgE and specific IgE (sIgE) with an average ratio of 1.08 (range 0.9-1.3) on ImmunoCAP. In contrast, IMMULITE exhibited sIgE signals that were substantially higher than the summed level of IgE for all four chimeric antibodies (average ratio 2.96 and range 1.7-4.3). CONCLUSION: Comparison using chimeric antibodies allowed the evaluation of the true performance of the systems. ImmunoCAP measured total IgE and sIgE equally, whereas IMMULITE displayed higher sIgE signals when compared to the summed level of total IgE for all four chimeric antibodies. Results obtained with the two assay systems are not interchangeable by means of mathematical conversion.
BACKGROUND: Specific immunoglobulin E (IgE) antibody in vitro tests are performed on enzyme immunoassay systems. Poor agreement among systems has been reported and comparisons have been made exclusively with allergen extracts - not with recombinant allergens. Here we compare the ImmunoCAP and the IMMULITE systems. METHODS: Ten patient samples with positive IgE toward egg white, birch pollen or cat or dog dander were compared using allergen extracts or the recombinant allergens Gal d 1, Bet v 1, Fel d 1 and Can f 1 with the two assay systems. Comparisons were also performed using four monoclonal mouse-human chimeric IgE antibodies specific for the same allergenic components. RESULTS: IMMULITE estimated a higher allergen-specific IgE concentration in sera than ImmunoCAP when testing with allergen extracts as well as recombinant allergens. The chimeric antibodies gave an equivalent response in the total IgE and specific IgE (sIgE) with an average ratio of 1.08 (range 0.9-1.3) on ImmunoCAP. In contrast, IMMULITE exhibited sIgE signals that were substantially higher than the summed level of IgE for all four chimeric antibodies (average ratio 2.96 and range 1.7-4.3). CONCLUSION: Comparison using chimeric antibodies allowed the evaluation of the true performance of the systems. ImmunoCAP measured total IgE and sIgE equally, whereas IMMULITE displayed higher sIgE signals when compared to the summed level of total IgE for all four chimeric antibodies. Results obtained with the two assay systems are not interchangeable by means of mathematical conversion.
Authors: Simon Blank; Murilo Luiz Bazon; Johannes Grosch; Carsten B Schmidt-Weber; Márcia Regina Brochetto-Braga; Maria Beatrice Bilò; Thilo Jakob Journal: Curr Allergy Asthma Rep Date: 2020-07-09 Impact factor: 4.806
Authors: Johannes Huss-Marp; Jan Gutermuth; Ina Schäffner; Ulf Darsow; Florian Pfab; Knut Brockow; Johannes Ring; Heidrun Behrendt; Thilo Jakob; Christoph Ahlgrim Journal: Allergo J Int Date: 2015-03-14