Inter-Laboratory Comparison of Multi-Allergen-Specific Immunoglobulin E Screening Assay Using Polycheck Allergy Diagnostic

Young Ae Lim Department of Laboratory Medicine, Ajou University School of Medicine, Suwon, Korea Background: Currently there is no external proficiency testing program for allergen-specific immunoglobulin E assays (sIgE) in Korea. The aim of this study was to evaluate the accuracy of sIgE performed in different laboratories in Korea using Polycheck Allergy Diagnostic (Biocheck GmbH, Germany) or simply ‘Polycheck’ and to further perform an inter-laboratory comparison of sIgE. Methods: Three inter-laboratory trials were undertaken from June 2016 to December 2017 at nine institutions. Serum samples obtained from three patients who had a history of positive Polycheck results were used in each trial. A total of 59 allergens were evaluated from the standard panel, inhalation panel, and food panel. The acceptable rates (%) of classes 0–6 of the results were calculated using three different criteria, including the consensus of 80% participants of the College of American Pathologists (CAP), the most frequent value (MFV), and the Overall Misclassification Index Score (OMIS). Results: The proportion of laboratories that showed acceptable results for CAP criteria, MFV, and OMIS were around 93.0%–97.7%, 66.3%–76.0%, and 0.1–1.3, respectively, in each trial. Under-performing institutes showed consistently higher (49/68, 72.1%) or lower (19/68, 27.9%) than acceptable results for all criteria. Conclusions: This is the first study evaluating the inter-laboratory variation of sIgE in Korea using various criteria. It was found that the acceptable rate could be altered based on changes in these criteria. These findings might be useful for the inter-laboratory comparison of sIgE in Korea in the future as well. (J Lab Med Qual Assur 2019;41:39-46)