Revue francaise d'allergologie et d'immunologie clinique最新文献

This review intends to summarise on the application of the basophil activation test (BAT) in the diagnostic management of anaesthesia-related allergy. The BAT relies upon flow cytometric quantification of alterations of particular basophilic activation markers. In the context of anaesthesia-related allergy the technique has been applied and proven reliable to diagnose IgE-mediated allergy from drugs (e.g., neuromuscular blocking agents, β-lactam antibiotics), natural rubber latex, chlorhexidine, plasma expanders and dyes. Moreover, the technique has proven to be complementary to skin tests in the assessment of cross-reactivity and tailoring safe alternative regimens for future anaesthesia.

Among the six members of the IL-17 family, three are clearly implicated in the regulation of the allergic response: IL-17A (also called IL-17), IL-17E (or IL-25) and IL-17F. IL-17A expresses strong homology with IL-17F and shares the same receptor. IL-17A is produced by various cells, mainly Th17 and iNKT17. IL-17A is a potent pro-inflammatory cytokine that induces the production of numerous other cytokines and chemokines and controls the recruitment and activation of neutrophils. However, in an experimental allergic asthma mouse model, IL-17A can induce either harmful or beneficial effect depending on the status of the allergic response. IL-17E, which is produced mainly by basophils and eosinophils in humans, acts mainly on Th2 cell differentiation either by polarizing naive CD4+ cells towards the Th2 pathway in an IL-4- dependent fashion, or by amplifying expansion and activation of memory Th2 cells in an IL-4-independent manner.

Sublingual immunotherapy (SLIT) is a non-invasive and efficacious treatment for type I respiratory allergies. To identify candidate adjuvants and galenic formulations capable of inducing tolerance by the sublingual route, an initial screening was carried out using in vitro cocultures of human monocyte-derived dendritic cells and naïve CD4⁺ T cells. Selected molecules were subsequently tested in a murine asthma model of sublingual immunotherapy in BALB/c mice sensitized to ovalbumin. In this model, we evaluated bronchial hyperreactivity (measured by whole-body plethysmography), pulmonary inflammation (evaluated histologically), and type 2 humoral and cellular immune responses monitored by Elisa and Elispot techniques in mice sensitized with either soluble or with adjuvant-formulated ovalbumin. Four categories of adjuvant known to increase IL-10 +/− IFNγ production by naïve CD4⁺ T cells (Treg/Th1) were found to enhance SLIT efficacy in vivo in these mice. These adjuvants were: vitamin D3/dexamethasone, Lactobacillus plantarum, the TLR2 agonist Pam3CSK4, and the TLR4 synthetic ligand OM-294-BA-MP. In addition, sublingual administration of ovalbumin combined with mucoadhesive maize-derived maltodextrin increased sublingual tolerance induction by targeting oral dendritic cells and ovalbumin-specific T cells in cervical and submaxillary lymph nodes. In conclusion, better understanding of specific immune responses to allergen at the level of the sublingual mucosa may lead to the development of new sublingual vaccines. In the future, such vaccines would incorporate Th1/Treg adjuvants, as well as mucoadhesive galenic formulations that target dendritic cells in the sublingual mucosa.

Quaternary ammonium compounds are widely used in many occupations (conservation, cleaning and disinfection) and all the workers in these occupations are exposed to the potentially irritant or allergenic effects to these products. The clinical manifestations are usually dermatological but respiratory symptoms such as rhinitis or respiratory symptoms are more and more often seen by occupational disease. The nature of the product used, its concentration, and how it is used are important factors to consider, even though the pathophysiological mechanisms involved have not yet been established.

A certain number of new potential therapies for hereditary angioedema (HAE) are currently being studied. They include new inhibitors of the contact system, such as ecallantide, a kallikrein inhibitor, Icatibant, a bradykinin receptor B2 antagonist, as well as a recombinant C1-INH secreted in the milk of transgenic rabbits. Publication of the data concerning these state-of-the-art therapies could be the beginning of new therapeutic advances in the treatment of HAE and, hopefully, lead to reduction in the burden that this condition represents.

Immediate hypersensitivity reactions occurring during anaesthesia, whether IgE-mediated or non IgE-mediated, remain a major cause of concern. The authors report results from an eight-year survey conducted by the GERAP. From 1 January 1997 to 31 December 2004, 2516 patients who had experienced an immediate hypersensitivity reaction were included in this survey. A non-IgE mediated reaction was diagnosed in 700 cases (27.82%) and an IgE mediated reaction in 1816 cases (72.18%). The most common causes were neuromuscular blocking agents (n = 1067, 58.08%), latex (n = 361, 19.65%) and antibiotics (n = 236, 12.85%). The results were significantly different in children: latex was incriminated in more than 50% of the cases, followed by neuromuscular blocking agents (39%) and antibiotics (10.2%). The data showed a female predominance in adults but not in children, whatever the mechanism of the reaction. These results emphasize the need for systematic screening in case of an immediate hypersensitivity reaction during anaesthesia and for the development of centres specializing in perioperative allergies capable of providing expert advice to anaesthesiologists and allergists.

The innate immune system provides a quick response to infection, notably by using sensor receptors such as Toll-like receptors (TLR), but it also informs and directs the adaptive immune response through dendritic cells (DC). In the allergic reaction, DC play a fundamental role by transporting allergen to lymph nodes and by inducing allergen-specific T cell responses. The polarized Th2 response induced in allergic patients by DC can be modified by the participation of certain TLR, thereby inhibiting the development of the allergic reaction. Therapeutic approaches using allergens combined with TLR ligands are being evaluated to increase the efficacy of specific immunotherapy.

Allergens can be classified into different families of proteins with common structural features, but there are not structures and functions in common to all allergens. High degree of amino acid sequence identity between homologous proteins reflects on common molecular surface patches that are the basis of allergenic cross-reactivity. Allergens need to be available for exposure (dose) to individuals susceptible (genetic predisposition) to develop allergies.

The epidemiology of food allergy normally relies on surveys using questionnaire in general populations and studies on cohorts and through professionals in allergy clinics, sometimes completed by prick-tests, specific IgE assays and/or oral challenges. Complementary data are supplied by specialized medical networks. In European countries, the prevalence of food allergy in the pediatric population is about 4.7%, and in adults it is about 3.2%. Striking disparities characterize the response to questionnaires in EU countries. Life-threatening anaphylaxis occurs in 1/10,000 inhabitants, fatal anaphylaxis in 1/1 million inhabitants. A drastic increase of life-threatening and lethal anaphylaxis has been noted in the UK and Australia over the past ten years. In France, there has been an increase of 28% between 2001 and 2006. The Allergy Vigilance Network, which includes 400 allergists, reports that this increase has occurred in the pediatric population. The prevalence of food allergies depends on age and consuming habits. Milk, egg, peanut and tree-nuts are at the top of the list in children. Prunoïdeae, latex-group fruits, Apiaceae, wheat and tree-nuts are the most important food allergens in adults. Peanut and tree nuts are the main offending allergens in severe anaphylactic cases. Since 2002 the Allergy Vigilance Network in France and Belgium has been identifying newly-appearing dangerous allergens. Molluscs, lupine flour and cashew nuts are the most common on this list and labelling these foods is now compulsory. Goat and sheep milk proteins (14 cases), buckwheat (25 cases) and wheat isolates are not yet required to be labelled. The danger of anaphylaxis to goat and sheep proteins (two deaths out of 14 cases) is due to the likelihood of their being masked allergens, for which reason the EU Scientific Agency should be made aware of the necessity of required labelling of foods containing these substances.