Complement in allergy and asthma

The complement system is a vital link between innate and adaptive immunity. Recently, several investigators have implicated the complement anaphylatoxins C3a and C5a as potential effectors in Type 1 hypersensitivity reactions, including urticaria, rhinitis and asthma. Thus, complement activation may synergize with classical IgE mediated responses, and inhibition of complement may prove therapeutic.     

Corticosteroid allergy in asthma

BACKGROUND: Glucocorticosteroids form the basis of therapy for asthma and other allergic diseases. However, they frequently cause delayed contact allergy and occasionally immediate allergy. The purpose of this study was to investigate the occurrence of corticosteroid allergy among patients with asthma and with some complaints caused by inhaled corticosteroids. METHODS: Patch tests with corticosteroids were performed in 51 asthma patients with side-effects from inhalant corticosteroids and in 50 symptom-free asthma patients using the Finn Chamber system. The corticosteroids and their vehicles were: betamethasone-17-valerate 1% in petrolatum, hydrocortisone-17-butyrate (Hc-17-B) 1% in ethanol, tixocortol-21-pivalate 1% in petrolatum, budesonide 0.1% in petrolatum, beclomethasone dipropionate 0.1 and 0.5% in petrolatum and as inhalant powder 200 microg, and fluticasone propionate 0.1 and 0.5% in petrolatum and as inhalant powder 250 microg. The results were read twice, on D4-5 and again on D10. RESULTS: Two patients in the symptomatic group reacted to corticosteroids in patch tests, one to betamethasone-17-valerate, Hc-17-B and budesonide, and the other to budesonide and Hc-17-B. The first patient suffered from widespread eczematous dermatitis when using beclomethasone. Fluticasone caused oropharyngeal irritation, hoarseness and shortness of breath. The second patient experienced a severe rash after the fourth budesonide inhalation. She had used various topical corticosteroids for her atopic dermatitis without any side-effects. None of the symptom-free patients showed positive results. CONCLUSIONS: Delayed allergy to corticosteroids occurs occasionally in asthma, perhaps in the same frequency as in dermatitis. A positive patch test reaction usually means clinical allergy, i.e. the patient cannot use that particular steroid. Cross allergy between corticosteroids is common. However, such patients usually tolerate some other common corticosteroids.     

Eosinophil trafficking in allergy and asthma

Blood eosinophilia and tissue eosinophilia are characteristic features of allergic inflammation and asthma, conditions associated with prominent production of T(H)2 cytokines IL-4, IL-5, and IL-13. In this review, we will consider recent advances in our understanding of the molecular mechanisms that promote expansion and differentiation of eosinophil progenitors in bone marrow, eosinophil recruitment in response to chemokine receptor 3 agonists eosinophil transit mediated by specific ligand-receptor interactions, and prolonged survival of eosinophils in peripheral tissues. Novel rational therapies including antiselectin and antichemokine receptor modalities designed to block eosinophil development and trafficking are discussed, together with the implications of recent clinical studies that have evaluated the efficacy of humanized anti-IL-5 mAb therapy.     

Advances in asthma, allergy mechanisms, and genetics in 2006

This review discusses the main advances in animal models of allergic airway disease and genetics of asthma and allergy published in the Journal in 2006. This work highlighted and extended what has become the central dogma of allergic pathogenesis by highlighting the mechanisms involved in inducing a T(H)2 response and in determining how T(H)2 cytokines induce the allergic airway disease phenotype. By so doing, they have identified a considerable number of potential therapeutic targets. Genetic analyses, on the other hand, revealed novel, potentially important candidate genes, confirmed known ones, and refined our understanding of the putative role played by others, sometimes positively, sometimes negatively. These data reiterate allergic inflammation is a classic complex genetic disease-that is, a disorder in which multiple and distinct genetic determinants variously interact with one another and with relevant environmental exposures to result in clinical phenotypes that, although superficially similar, involve distinct genetic pathways and represent the outcome of distinct pathogenetic mechanisms.     

Genetic polymorphism in allergy and asthma

The impact of genetic factors on the pathogenesis of allergy and asthma is currently an area of intense investigation. Although epidemiological studies find more and more genes that are likely to contribute to allergic inflammation, functional studies of the mechanisms that link genetic variation with dysregulation of gene expression and function are hindered by the high frequency of natural variation. The interplay between genes and environment adds another layer of complexity to the determination of allergic phenotypes. The complexity emerging from these studies warrants novel experimental strategies and bolder conceptual paradigms.