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Background: Allergen-specific serum immunoglobulin E detection and quantification have become an important step in allergy diagnosis and follow-up. In line with the current trend of laboratory test accreditation to international standards, we set out to design and assess an accreditation procedure for allergen-specific serum IgE., Methods: Method validation according to the accreditation procedure under the EN ISO 15189 standard was carried out for allergen-specific immunoglobulin E determination using the fluoroimmunoenzymatic method ImmunoCAP(®) (ThermoFisher). Data were produced by 25 hospital laboratories in France. A total of 29 allergen specificities including mixes, extracts, and molecular allergens were assayed. Allergen-specific serum immunoglobulin E concentrations ranged from 0.1 to 100 kUA /l., Results: Repeatability, reproducibility, and accuracy results fulfilled method validation criteria for automated laboratory tests and proved similar irrespective of the allergen specificity, allergen-specific serum immunoglobulin E concentration, or individual laboratory., Conclusion: Allergen-specific serum immunoglobulin E determination with the fluoroimmunoenzymatic method ImmunoCAP(®) is a highly repeatable, reproducible, and accurate method which may be considered as a single analyte assay in view of the EN ISO 15189 accreditation procedure., (© 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

French medical laboratories must be accredited before November 2016 according to NF/EN/ISO 15189 standard. However, technical accreditation guidelines cannot be applied literally for the determination of specific IgE for several reasons: more than 600 allergen tests, lack of international gold standard, limited external quality controls. Furthermore, the technique for determination of specific IgE is CE DM-IVD marked, common to all specificities, automatised, standardized according to a single calibration curve. Thus, we propose an efficient but reasonable solution conform to the idea of the accreditation by validating the process. We recommend: a flexible extend type A; choice of only one representative allergen (Dermatophagoides pteronyssinus) for repeatability and precision (20 tests, 2 levels 0.5-1 and 8-12 kUA/L) performed on patients sera, reproducibility (30 consecutive determinations using an Internal Quality Control/IQC), accuracy (IQC and rare External Quality Controls) compared with peers. Sensitivity, specificity, dynamic range, detection threshold are determinated by the provider. Linearity may be checked if the laboratory practices sample dilution for values higher than the upper limit guaranteed by the provider. In the absence of international gold standard, the uncertainty is not measurable. In case of change of instrument, the results obtained by the systems must be compared through 35 tests of different specificities distributed across the range of calibration and including 5 values close to the detection limit. This methodology allows a scientifically effective verification, technically and financially reasonable, to ensure the excellence of the performance of the laboratory with regard to peers and users (allergologists and patients).