Allergy
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Comparative Study
Skin test reactivity to natural and recombinant Blomia and Dermatophagoides spp. allergens among mite allergic patients in the UK.
Many asthmatics in tropical and subtropical areas have positive skin prick tests to both Dermatophagoides spp. and to the mite Blomia tropicalis. This may be due to recognition by IgE of cross-reactive allergens between the different mite species or because of sensitization to species-specific allergens. A 14-kDa Blomia tropicalis allergen, Blo t 5, has been cloned and shows 40% sequence homology with Der p 5. The aim of this study was to investigate reactivity to B. tropicalis in patients known to be sensitized to D. pteronyssinus and to assess allergenic activity and cross-reactivity of recombinant (r) Group 5 allergens amongst these patients, who live in the UK and who are not exposed to B. tropicalis in their homes. ⋯ This study of patients naturally exposed to D. pteronyssinus but not to Blomia tropicalis, provides evidence for IgE mediated cross-reactivity between allergens produced by both mite species. The results suggest that the Group 5 allergens of D. pteronyssinus and B. tropicalis are species-specific.
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Comparative Study
Urinary metabolites of histamine and leukotrienes before and after placebo-controlled challenge with ASA and food additives in chronic urticaria patients.
The recovery of mediator metabolites from urine has the potential to provide a rapid, safe, and easily available index of release of mediators. We aimed to determine urinary metabolites of both histamine and leukotrienes (LTs) in patients affected by chronic urticaria (CU). ⋯ Our results show that urinary excretion of N-MH and LTE4 is different for CU patients without ASA or food hypersensitivity, compared to those with CU with ASA or food additive hypersensitivity after specific challenge.
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Comparative Study
Cytokine production from sputum cells after allergenic challenge in IgE-mediated asthma.
Th2 cytokine production from airway cells is thought to govern the eosinophilic airways inflammation in allergic asthma. Induced sputum has become a widely used technique to assess airways inflammation. ⋯ Sputum cell culture is a useful model to assess cytokine production in allergic asthmatics who show a marked up-regulation of Th2 cytokines following acute allergen exposure. The rise in sputum eosinophil count following allergen challenge strongly correlates with the rise in IL-4 generation from sputum cells.
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A new technique, cutaneous field stimulation (CFS), which activates electrically unmyelinated C-fibers, is used to treat localized itch. Its action is similar to that of capsaicin, the pungent agent in hot peppers, which enhances delayed allergic reactions. The aim of the study was to investigate how experimental contact dermatitis responds to CFS. ⋯ Repeated use of CFS to reduce itch has no adverse effects on contact dermatitis.