Measurement of IgE antibodies to shrimp tropomyosin is superior to skin prick testing with commercial extract and measurement of IgE to shrimp for predicting clinically relevant allergic reactions after shrimp ingestion

Background: Shrimp is a frequent cause of food allergy. Tropomyosin is the major allergen in shrimp, and it shares homology to tropomyosins from other crustaceans, dust mites, cockroach, and parasites. Objective: The aim of this study was to determine the value of detection of IgE to shrimp tropomyosin in the diagnosis of shrimp allergy. Methods: We have studied 35 patients with asthma, rhinitis, or both who were sensitized to Dermatophagoides pteronyssinus. All subjects underwent skin prick testing in addition to double-blind, placebo-controlled food challenges (DBPCFC); oral open challenges; or both with shrimp. Measurements of IgE to shrimp and shrimp tropomyosin were carried out by means of CAP and chimeric ELISA, respectively. Results: Oral challenges confirmed the diagnosis of shrimp allergy in 7 patients. IgE measurement to shrimp tropomyosin was positive in 71.4% of the patients with shrimp allergy. Of the 28 patients without shrimp allergy, only 7.1% (2/28) had IgE to shrimp tropomyosin compared with 25% (7/28) who had IgE to shrimp and 35.7% (10/28) who had positive skin prick test responses to shrimp. Sensitivity was similar for all 3 methods (71.4%); in contrast, specificity of IgE to shrimp tropomyosin (92.8%) was greater than that of IgE to shrimp (75%) and skin prick testing (64.2%). With regard to diagnostic efficiency, measurement of IgE to shrimp tropomyosin was superior to measurement of IgE to shrimp and skin prick testing (88.5%, 74.2%, and 65.7%, respectively). Conclusion: Use of measurements of IgE to shrimp tropomyosin provided added value to the diagnosis of shrimp allergy. (J Allergy Clin Immunol 2010;125:872-8.)

Cutaneous allergic reactions to Triatoma infestans after xenodiagnosis

We determined the frequency of cutaneous allergic reactions to bites of Triatoma infestans during xenodiagnosis in a rural community where Panstrongylus megistrus is the only domestic vector of Trypanosoma cruzi. Localized urticaria or more intense cutaneous allergic reactions at 48 and 72 hours were observed in 86.7% and 82.1% respectively of the individuals in our study. Urticaria was more severe in children and older adults and in women than in men. The high frequency of reactions suggests either cutaneous reactivity to T. infestans without prior sensitization or cross reactivity between P. megistus and T. infestans. A single application of topical corticosteroid or antihistamine medication did not reduce the cutaneous reactions.

Allergo-immunologie. 2 : Les réactions allergiques aux anti-inflammatoires non stéroïdiens [Allergic reactions to nonsteroidal anti-inflammatory drugs]

Allergy to nonsteroidal antiinflammatory drugs (NSAIDs) is a very common affliction, especially among patients with asthma and chronic urticaria. These reactions are most often of a non-immunological nature but related to pharmacologic intolerance and linked to arachidonic acid metabolism and leukotriene release. Therefore, crossed reactions implying all non-selective and semi-selective NSAIDs constitute the rule, especially during respiratory reactions to NSAIDs and for patients with chronic urticaria. In isolated acute urticaria, crossed reactions are difficult to predict so caution is necessary. Tolerance induction is possible, especially when aspirin has to be administered in small doses as antiplatelet agent. Finally, acetaminophen and selective NSAIDs as celecoxib are well tolerated by most of these patients. L'allergie aux anti-inflammatoires non stéroïdiens (AINS) est très fréquente, en particulier chez les asthmatiques ou dans l'urticaire chronique. Il s'agit en général de réactions non immunologiques, mais dues à une intolérance pharmacologique liée au métabolisme de l'acide arachidonique et à la formation de leucotriènes. Ainsi, les réactions croisées impliquant tous les AINS non sélectifs et semi-sélectifs sont la règle, surtout lors de réactions respiratoires aux AINS et dans l'urticaire chronique. Lors d'urticaire aiguë isolée, les réactions croisées sont difficiles à prédire, ainsi la prudence s'impose. Une induction de tolérance est possible, en particulier lorsque l'aspirine est nécessaire à dose faible, comme antiagrégant plaquettaire. Enfin, le paracétamol et les AINS sélectifs sont supportés par la grande majorité de ces patients.

Allergic reactions following contrast material administration: nomenclature, classification, and mechanisms

In forensic pathology routine, fatal cases of contrast agent exposure can be occasionally encountered. In such situations, beyond the difficulties inherent in establishing the cause of death due to nonspecific or absent autopsy and histology findings as well as limited laboratory investigations, pathologists may face other problems in formulating exhaustive, complete reports, and conclusions that are scientifically accurate. Indeed, terminology concerning adverse drug reactions and allergy nomenclature is confusing. Some terms, still utilized in forensic and radiological reports, are outdated and should be avoided. Additionally, not all forensic pathologists master contrast material classification and pathogenesis of contrast agent reactions. We present a review of the literature covering allergic reactions to contrast material exposure in order to update used terminology, explain the pathophysiology, and list currently available laboratory investigations for diagnosis in the forensic setting.

The role of chemokines and chemokine receptors in eosinophil activation during inflammatory allergic reactions

Chemokines are important chemotactic cytokines that play a fundamental role in the trafficking of leukocytes to sites of inflammation. They are also potent cell-activating factors, inducing cytokine and histamine release and free radical production, a fact that makes them particularly important in the pathogenesis of allergic inflammation. The action of chemokines is regulated at the level of agonist production and processing as well as at the level of receptor expression and coupling. Therefore, an analysis of the ligands must necessarily consider receptors. Eosinophils are target cells involved in the allergic inflammatory response since they are able to release a wide variety of mediators including CC and CXC chemokines and express their receptors. These mediators could damage the airway epithelial cells and might be important to stimulate other cells inducing an amplification of the allergic response. This review focuses on recently emerging data pertaining to the importance of chemokines and chemokine receptors in promoting eosinophil activation and migration during the allergic inflammatory process. The analysis of the function of eosinophils and their chemokine receptors during allergic inflammation might be a good approach to understanding the determinants of asthma severity and to developing novel therapies.

The role of chemokines and chemokine receptors in eosinophil activation during inflammatory allergic reactions

Chemokines are important chemotactic cytokines that play a fundamental role in the trafficking of leukocytes to sites of inflammation. They are also potent cell-activating factors, inducing cytokine and histamine release and free radical production, a fact that makes them particularly important in the pathogenesis of allergic inflammation. The action of chemokines is regulated at the level of agonist production and processing as well as at the level of receptor expression and coupling. Therefore, an analysis of the ligands must necessarily consider receptors. Eosinophils are target cells involved in the allergic inflammatory response since they are able to release a wide variety of mediators including CC and CXC chemokines and express their receptors. These mediators could damage the airway epithelial cells and might be important to stimulate other cells inducing an amplification of the allergic response. This review focuses on recently emerging data pertaining to the importance of chemokines and chemokine receptors in promoting eosinophil activation and migration during the allergic inflammatory process. The analysis of the function of eosinophils and their chemokine receptors during allergic inflammation might be a good approach to understanding the determinants of asthma severity and to developing novel therapies.

Influence of total and specific IgE, serum tryptase, and age on severity of allergic reactions to Hymenoptera stings

The aim of this study was to analyze the influence of total serum IgE and other potential risk factors on severity of systemic allergic Hymenoptera sting reactions.

Inhibition of ongoing allergic reactions using a novel anti-IgE DARPin-Fc fusion protein

Aggregation of the high-affinity IgE receptor (FcεRI) with the low-affinity IgG receptor (FcγRIIb) on basophils or mast cells has been shown to inhibit allergen-induced cell degranulation. Molecules cross-linking these two receptors might therefore be of interest for the treatment of allergic disorders. Here, we demonstrate the generation of a novel bispecific fusion protein efficiently aggregating FcεRI-bound IgE with FcγRIIb on the surface of basophils to prevent pro-inflammatory mediator release.