Component-resolved diagnosis (CRD): Is it worth it? frequency and differentiation in rhinitis patients with mite reactivity.

Component-resolved diagnosis (CRD) using microarray technology has recently been introduced with the aim to improve diagnosis of allergy. The aim of this study was to compare performance of this allergen microarray to those of an established extract-based skin prick testing (SPT).45 patients with allergic rhinitis were studied (16 children and 29 adults). SPT to Dermatophagoides pteronyssinus, Dermatophagoides farinae and Blomia tropicalis extracts and allergen microarray ImmunoCAP ISAC were carried out for all patients. Forty out of 45 patients demonstrated positive SPT to all mite extracts tested. These 40 patients were considered to be mite-allergic based on the positive SPT results. The remaining 5 patients with negative SPT to any mite extracts were classified as non-mite allergic. Comparatively, based on the microarray results, only 34 mite-allergic patients had detectable serum IgE to at least one of the mite allergen components tested whereas 6 patients with positive SPT to mite extracts showed no detectable IgE reactivity to any of the components tested. One non-mite allergic patient had a positive test- Blo t 5. Der p 10-positive patients also reacted to other cross-reactive tropomyosin from anisakis (Ani s 3) (25%), cockroach (Bla g 7) (50%) and shrimp (Pen m 1) (75%). CRD is a reliable tool for the diagnosis of allergy to mites. Der p 10 might be a useful indicator to identify a subset of mite-allergic patient that have additional sensitization due to cross-reactivity and thus allows selection of patients for immunotherapy.