Third-party verification of total and specific immunoglobulin E on analyzer Immulite® 2000XPi

•Stability as well as transferability of reference intervals for both tIgE and sIgE CLEIA assays (Immulite ®2000XPi, Siemens) have not yet been demonstrated by a third-party.•We report very good analytical performance of Immulite® 2000XPi analyzer implemented in our laboratory.•We were able to confirm manufacturer’s declarations for stability of serum tIgE and sIgE (7 days at 2–8 °C).•We verified manufacturer’s declarations for method precision and reference intervals for adults and children.•Close agreement between two Immulite analyzers was observed for most frequent sIgEs.•Our study has provided evidence of poor comparability of tIgE results measured by FEIA and CLEIA. Although Immulite®2000XPi (Siemens) allergy testing is routinely used in laboratories worldwide; a well-designed comprehensive third-party verification of its analytical performance has not yet been published. Our aim was to verify stability, precision and reference intervals for total and some frequent specific IgEs, test trueness for several most common allergens and assess the comparability of fluorescent- and chemiluminescent-enzyme immunoassay for total IgE. Verification was based on EP15-A3, EP9-A3 and EP28-A3c CLSI guidelines. Stability was tested on serum pools stored at 2–8 °C, during 7 days. Manufacturer’s reference intervals were verified for children and adults. Acceptance criteria were based on manufacturer specifications and national External Quality Assessment provider data. Samples for total IgE analysis were stable at 2–8 °C for 7 days. Precision was within manufacturer’s specifications for most of tested allergens, except for total IgE (92.5 kIU/L, CVs 5.6% and 7.6%) and w1 (9.3 kU/L, CV = 5.9%). Bland-Altman plot revealed statistically significant constant (−32.4 kIU/L) and proportional bias (−20.2%) for total IgE between two methods. Passing Bablok showed statistically but not clinically significant biases between two Immulite analyzers for betula verrucosa (constant and proportional), house dust mite and egg white allergens (proportional). For adults and children, total IgE results were within reference intervals declared by Siemens. Immulite®2000XPi assay has acceptable precision and trueness. Samples for total IgE are stable even longer than declared by the manufacturer. Declared reference intervals can safely be adopted for both adult and children population in our laboratory. Fluorescent- and chemiluminescent-enzyme immunoassay results of total IgE are not compara