Evaluation of the manufacturer-dependent differences in specific immunoglobulin E results for indoor allergens

Abstract

BackgroundEven though allergies are an important health issue, the detected amount of allergen-specific IgE (sIgE) has differed widely between manufacturers in the past, and even as recently as this year. These discrepancies hinder diagnostics and can even impact allergen immunotherapy. ObjectiveThe aim of this study was to evaluate the development and status quo of the quality of in vitro diagnostic testing for house dust mites (HDM) and cat epithelium, 2 important indoor allergen sources. MethodsWe analyzed data on the allergen sources European HDM, American HDM, and cat epithelium, which were collected by the Society for Promoting Quality Assurance in Medical Laboratories (INSTAND e.V.) during 7 years as part of External Quality Assessment schemes (EQAs). A pseudoanonymized comparison was made of the semiquantitative data and allergen-class results of the 4 main suppliers of in vitro diagnostic sIgE tests. Coefficients of variation (CV) were determined in order to evaluate interlaboratory comparability. ResultsIn vitro allergy diagnostic testing for the major allergen sources HDM and cat epithelium still reveals manufacturer-dependent differences. Despite this, a cautious trend was found towards an alignment of the results and interlaboratory comparability, with the exception of 1 supplier. ConclusionEven though these results are promising, future EQAs have to be closely monitored to ensure this positive trend is not just a snapshot.