The performance of a component‐based allergen‐microarray in clinical practice

Background: Currently, the diagnosis of IgE‐mediated allergy is based on allergen‐specific history and diagnostic procedures using natural allergen extracts for in vivo and in vitro tests. Objective: The aim of the study was to comparatively analyse a new component‐based allergen‐microarray and the ‘quasi‐standard’ ImmunoCAP ® for their clinical relevance in patients with allergic rhinoconjunctivitis to five aeroallergens [house dust mite (HDM), cat dander, birch, grass and mugwort pollen] in a prospective, double‐centre study. Methods: We enrolled 120 subjects at the two study centres. Allergic patients were defined as having an allergen‐specific history plus a concomitant positive skin‐prick test (SPT) to natural allergen extracts and specific serum IgE was measured by both methods. Each allergen was analysed separately. Results: The microarray performed equally well in receiver‐operating characteristic curve (ROC) analyses when compared with the CAP in cat (23 allergic vs 97 non‐allergic, ROC area under the curve microarray 0.950 vs CAP 0.894, P = 0.211), birch (31/89, 0.908 vs 0.878, P = 0.483) and grass pollen (47/73, 0.923 vs 0.915, P = 0.770). It was slightly less sensitive in HDM‐allergic subjects (26 allergic vs 94 non‐allergic, ROC area microarray 0.808 vs CAP 0.911, P = 0.053) and displayed a reduced sensitivity in the mugwort pollen‐allergic patients (17/103, 0.723 vs 0.879, P = 0.032). Conclusions: Component‐based testing and the whole‐allergen CAP are equally relevant in the diagnosis of grass‐, birch‐ and cat‐allergic patients. Although slightly less sensitive, the microarray is sufficient for the diagnosis of HDM‐allergic patients, but needs alternative and/or additional components for detecting mugwort allergy.