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

Asthma is a chronic condition which is seen frequently in pediatrics. Development of predictors of occurrence, eventual worsening and of the evolution of the condition could improve the overall prognosis. This literature review covers recent advances on this subject. Among the risk factors, perinatal conditions such as prematurity play an important role. The occurrence of respiratory infections in the infant constitutes a key step in the initiation of the bronchial inflammatory process. The social milieu and the environment are clearly contributing factors. Atopy is an essential element in the development of chronic asthma. It worsens the prognosis in certain cases and can be responsible for fatal outcomes. Progress in genetics, especially concerning single nucleotide polymorphisms, which is to say localized amino acid mutations, sheds light on the major role of a genetic factor in certain special cases.

We report a case of allergic asthma induced by professional exposure to shrimp cooking vapors in a 19-year-old patient. The patient's medical history revealed an anaphylactic shock seven years ago caused by ingestion of fish food. The diagnosis of asthma induced by seafood cooking vapors is based on clinical history and the positivity of the allergy work-up. Complete eviction of shrimps and redeployment resulted in clinical improvement.

Respiratory manifestations represent one of the most prevalent and difficult to manage extra-esophageal syndromes of GORD. However, the relationship between reflux and respiratory symptoms such as chronic cough is frequently difficult to establish with a high degree of certainty. The causality of reflux in cough can be supported by several different pieces of evidence, including (1) a significant epidemiological association between GORD and respiratory symptoms, (2) a temporal relationship between cough occurrence and reflux episodes (as shown by pH or pH-impedance monitoring). The diagnosis of GORD is easily made if the patient complains of typical symptoms, such as heartburn and regurgitation, or if endoscopy shows unequivocal signs of esophagitis (i.e. mucosal breaks). However, in the case of GORD-related cough, the typical digestive syndrome is frequently absent, a situation corresponding to the so-called “silent GORD”. Reflux can induce chronic cough through different mechanisms including micro-aspiration and both local and central reflexes. Cough and reflux may precipitate each other. A meta-analysis found no significant difference between placebo and Proton Pump Inhibitors (PPI) in the resolution of cough. Encouraging results have been reported, following antireflux surgery in patients selected on the basis of pH-impedance monitoring. Future trials should concentrate on patient selection and the control of efficacy using recently developed technologies, such as pH-impedance monitoring.

Specific oral tolerance induction (SOTI) to food is a new topical-therapeutic approach of food allergy. When successful, it improves significantly the patients’ quality of life. SOTI’s practical aspects for child are discussed from our recent experience concerning cow milk, hen’s egg and wheat. Family’s motivation and education are crucial questions to achieve SOTI correctly. A detailed information of possible side effects is essential.

The allergens responsible for wheat food allergy are beginning to be characterized. Nevertheless, animal models that produce highly-specific IgE and clinical symptoms comparable to those observed in allergic patients are of great interest for precise studies of allergens and of the mechanisms involved in wheat allergy. The aim of our research was to develop, in the first instance, a mouse model of allergy to a total extract of gliadins, then to use this model to study two major wheat allergens involved in wheat food allergy on children and adults, namely, the lipid-transfer protein (LTP) and the omega-5 gliadins.

Methods

First, we determined the mouse strain and the allergen dose required to induce an optimal allergic reaction to wheat. Three strains of mice (Balb/cJ, B 10.A ND c3 h/hEj) received four successive intraperitoneal injections of a total-gliadin extract (10 or 20 μg) adsorbed on alum. The level of sensitization was determined by assay of gliadin-specific IgE and IgG1 and by the level of cytokines secreted by splenocytes activated in vivo by the gliadins; in vitro basophil (RBL) degranulation tests were also done. In addition, the intensity of the allergic reaction was evaluated in vivo by analysis of the production of type Th2 cytokines and the influx of eosinophils in bronchoalveolar fluid (BAF) after intranasal gliadin extract provocation. Sensitization assays and provocation tests with LTP and omega-5 gliadins were done subsequently.

Results

The highest level of sensitization was observed in the Balb/cJ mice, whatever the dose of gliadins used. After the provocation test, these mice developed an intense-allergic reaction, as demonstrated by the strong production of type Th2 cytokines and the influx of eosinophils in the BAF. In contrast, a weak or no reaction was observed in the other two mouse strains. While sensitization of Balb/cJ mice by omega-5 gliadins was not very effective, administration of LTP induced significant production of specific IgE and IgG1 as well as specific degranulation of RBL cells, but little or no secretion of type Th2 cytokines by activated splenocytes. Induction of an allergic response after intranasal introduction of LTP was not very effective, in spite of the cellular influx in the BAF.

Conclusion

Balb/cJ mice, sensitized by intraperitoneal injection of a total-gliadin extract, appeared to produce some of the markers of wheat allergy, but the results of the sensitization studies with the purified allergens appear to be more complex.

Anesthesia is a situation during which patients are exposed to a large number of drugs in a very short period of time. Almost all of such products may be incriminated as the cause of a hypersensitivity reaction. We conducted a retrospective analysis that included 171 patients who had had an allergy workup in the General Allergy Unit at the Angers CHU following a reaction which occurred during the course of a general or locoregional anesthesia between January 2000 and January 2007. The results of this analysis led us to raise some questions related to the interpretation in a number of these cases, i.e., the results suggesting polysensitization on the one hand, whereas, on the other hand, the tests were negative when done during the course of severe grade III reactions. These two points, which have not been considered up to the present in multicentric studies on the prevalence and the risk of peri-anesthesic allergic reactions, are the subject of the present article.

Here is the translation for the French society of study of allergies of the reference document stemming from the World Organization of the Allergy (WAO) defining the doctor allergist.