Patterns of IgE sensitization in house dust mite-allergic patients: implications for allergen immunotherapy.

BACKGROUND: Understanding patterns of IgE sensitization in Dermatophagoides-allergic patients living in various geographical areas is necessary to design a product suitable for worldwide allergen immunotherapy (AIT). METHODS: Using a HIFI Allergy customized microarray assay, IgEs specific for 12 purified allergens from Dermatophagoides pteronyssinus or D. farinae were assessed in sera from 1302 house dust mite (HDM)-allergic patients living in various areas. Comprehensive mass spectrometric (MS) analyses were conducted to characterize HDM extracts, as well as purified bodies and feces. RESULTS: Patterns of IgE reactivity to HDM allergens are comparable in all cohorts of patients analyzed, encompassing adults and 5- to 17-year-old children, as well as American, Canadian, European, and Japanese patients. Overall, >70% and >80% of HDM-allergic patients are sensitized to group 1 and group 2 allergens, respectively, from D. pteronyssinus and/or D. farinae species. Furthermore, 20-47% of patients also have IgEs to allergens from groups 4, 5, 7, 13, 15, 21, and 23. All patients have IgEs to allergens present in mite bodies and feces. MS-based analyses confirmed the presence of mite allergens recorded by IUIS in D. pteronyssinus and D. farinae extracts, with groups 2, 8, 10, 11, 14, and 20 prominent in bodies and groups 1, 6, 18, and 23 well represented in feces. CONCLUSIONS: Mite-specific AIT should rely upon a mixture of D. pteronyssinus and D. farinae extracts, manufactured from both feces and bodies. Such a combination is appropriate to treat children and adult Dermatophagoides-allergic patients from Asia, Europe, and North America.

Disposable screen-printed chemiluminescent biochips for the simultaneous determination of four point-of-care relevant proteins.

A screen-printed (SP) microarray is presented as a platform for the achievement of multiparametric biochips. The SP platform is composed of eight (0.28-mm(2)) working electrodes modified with electroaddressed protein A-aryl diazonium adducts. The electrode surfaces are then used as an affinity immobilisation support for the orientated binding of capture monoclonal antibodies, having specificity against four different point-of-care related proteins (myoglobin, cardiac troponin I, C-reactive protein and brain natriuretic peptide). The immobilised capture antibodies are involved in sandwich assays of the four proteins together with biotinylated detection antibodies and peroxidase-labelled streptavidin in order to permit a chemiluminescent imaging of the SP platform and a sensitive detection of the assayed proteins. The performances of the system in pure buffered solutions, using a 25-min assay duration, were characterised by dynamic ranges of 0.5-50, 0.1-120, 0.2-20 and 0.67-67 microg/L for C-reactive protein, myoglobin, cardiac troponin I and brain natriuretic peptide, respectively. The four different assays were also validated in spiked 40-times-diluted human sera, using LowCross buffer, and were shown to work simultaneously in this complex medium.