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.