Evaluation of a particle-enhanced turbidimetric immunoassay for the measurement of immunoglobulin E in an ILab 900 analyzer

Abstract

Background: The measurement of immunoglobulin E (IgE) in serum is widely used in the diagnosis of allergic reactions and parasitic infections. We describe here a fully automated assay for human IgE suitable for routine application in a general chemistry analyzer. Methods: We used an ILab 900® analyzer. This instrument automates a particle-enhanced immunoturbidimetric assay with an analysis time of 9 min. Results: The assay was linear in the range 4-1000 kIU/L (r = 0.9998). The intra- and interassay CVs at 57, 235, and 434 kIU/L were <3.5% and <7.4%, respectively. The detection limit was 4 kIU/L. Hemoglobin (≤16 g/L), bilirubin (≤250 μmol/L), and myeloma paraproteins did not interfere with the assay. The assay showed good correlation with a microparticle enzyme immunoassay (r = 0.998) with a mean difference between methods of -6 ± 26 kIU/L. Conclusion: The new automated serum assay for IgE is an attractive alternative that avoids the need for dedicated instrumentation.