Identification by serological proteome analysis of paramyosin as prominent allergen in dust mite allergy.

Component-resolved diagnosis (CRD) of IgE-mediated hypersensitivities is challenged by the possibility that single patients are sensitized to components not commercially available to the clinical lab. Here, we studied a patient with positive extract-based diagnosis of house dust mite (HDM) allergy based on routine in vivo (prick test) and in vitro (serum specific IgE) tests, whose serum scored negative for IgE to the three recombinant allergens routinely used in CRD (group 1 allergens, group 2 allergens and tropomyosin). By means of serological proteome analysis via two-dimensional gel electrophoresis combined with immunoblotting and mass spectrometry, paramyosin (group 11 allergen: Der f 11 and Der p 11) was identified as the allergen component recognized by serum IgE from this patient in a raw allergen extract. Nine patients (64%) had IgE to Der p 11 in a group of 14 HDM allergic patients. BIOLOGICAL SIGNIFICANCE: Our results add up to previous reports indicating that paramyosin is a clinically relevant HDM allergen and highlight that it can represent, in some patients, the first sensitizing component of this allergen source. This suggests that, at the moment, the use of allergen extract for the purpose of measuring IgE reactivity cannot be replaced by component resolved diagnosis and that group 11 allergens should be included among allergen components routinely tested in the clinical laboratory.

Diagnosis of latex hypersensitivity: comparison of different methods.

A standardized diagnostic protocol for latex allergy is still lacking, although latex-related manifestations are a common health problem especially among health-care workers and patients with spina bifida. The present study was aimed to compare different in vivo (skin prick test, patch test, use test) and in vitro (specific IgE determination by CAP-Rast, basophil histamine release assay, immunoblot) methods to diagnose latex sensitization in 47 health care workers reporting latex-related manifestations. According to the established criteria, 20 subjects (42.5%) were considered as truly sensitized to latex, 18 with type I and 2 with type IV hypersensitivity. Skin prick test displayed the highest diagnostic efficiency, having higher sensitivity and specificity than specific IgE determination and use test. Patch test with rubber chemicals had a low sensitivity, but a good specificity. Basophil histamine release and immunoblot showed low sensitivity and specificity. A combination of clinical history and skin prick test should be used in order to diagnose latex allergy, except in those subjects reporting life-threatening reactions, in which in vitro specific IgE determination must be preferred. Patch testing with rubber chemicals should be reserved to selected cases. Basophil histamine release and immunoblotting can be performed for research purpose, but cannot be recommended for routine diagnostic use.