IgE-mediated shellfish allergy constitutes an important cause of food-related adverse reactions. Shellfish are classified into mollusks and crustaceans, the latter belonging to the class of arthropoda. Among crustaceans, shrimps are the most predominant cause of allergic reactions and thus more extensively studied. Several major and minor allergens have been identified and cloned. Among them, invertebrate tropomyosin, arginine kinase, myosin light chain, sarcoplasmic calciumbinding protein, and hemocyanin are the most relevant. This review summarizes our current knowledge about these allergens.IgE-mediated shellfish allergy constitutes an important and increasing health issue in both children and adults (1, 2). During the last two decades, significant progress in biochemistry and molecular biology enabled the characterization, cloning, and recombinant production of various shellfish allergen components and epitope-emulating peptides that might become available for quantification of specific IgE (sIgE) antibodies, namely molecular diagnosis. This review intends to summarize our current knowledge about shellfish allergens and their cross-reactivity as this might be the key to optimize diagnosis (3, 4). Table 1 summarizes the most relevant shellfish allergens that have currently been characterized. Tropomyosin is considered to be the major allergen in shellfish allergy. Actually, already in the early 1980s Hoffman et al. (5) identified a heat-stable IgE-binding allergen in shrimps that was later identified as tropomyosin in brown shrimp (Penaeus aztecus) reacting with 28/ 34 (82%) of shrimp-sensitive individuals (6). Moreover, tropomyosin has been identified as a panallergen of many invertebrate species including other crustaceans (lobster, crab), mollusks (mussels, oysters, scallops, octopus, squids, snails, abalones, whelk, clams, razor shell), cockroaches, and mites (7-18). Tropomyosins are present in both muscle and nonmuscle cells. In striated muscle, they mediate the interaction of troponin-actin complex to regulate contraction. Note that tropomyosins from crustaceans share a high homology (up to 98%), whereas the amino acid sequence identity between (3,(19)(20)(21)(22)(23)(24)(25). Children were once reported to recognize a greater epitope repertoire than adults and thus suggested that shrimp sensitization could decrease over age (22). However, more recent studies with challenged patients could not reproduce this observation with the same epitope mapping (3, 24). About one decade ago, a recombinant tropomyosin from Penaeus aztecus, rPen a 1, became commercially available for molecular diagnostic testing, with improved results as a diagnostic tool in comparison with the whole-shrimp extract (26,27). In addition to tropomyosin, several other allergenic components have been identified in shellfish. In 2003, Yu et al. identified a novel allergen in Penaeus monodon (black tiger shrimp) (28), designated as Pen m 2, with arginine kinase activity. Similar to tropomyosin, arginine kinase is highly abundant i...

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BACKGROUNDCannabis allergy (CA) has mainly been attributed to Can s 3, the nsLTP (non-specific lipid transfer proten) of Cannabis sativa. Nevertheless, standardized diagnostic tests are lacking and research on CA is scarce. OBJECTIVETo explore the performance of five cannabis diagnostic tests and the phenotypic profile of CA. METHODS120 CA patients were included and stratified according to the nature of their cannabis-related symptoms, 62 healthy and 189 atopic controls were included. Specific (s)IgE hemp, sIgE and BAT rCan s 3, BAT with a crude cannabis extract and a skin prick test (SPT) with a nCan s 3-rich cannabis extract were performed. Clinical information was based on patient-history and a standardized questionnaire. RESULTSFirstly, up to 72% of CA reporting likely-anaphylaxis (CA-A) are Can s 3 sensitized. Actually, the Can s 3-based diagnostic tests show the best combination of positive and negative predictive values; 80% and 60%, respectively. sIgE hemp displays 82% sensitivity but only 32% specificity. Secondly, Can s 3+CA reported significantly more cofactor mediated reactions and displayed significantly more sensitizations to other nsLTPs than Can s 3-CA. Finally, the highest prevalence of systemic reactions to plant-derived foods was seen in CA-A, namely 72%.

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Component-resolved diagnoses with the wasp-specific recombinant allergen components Ves v 1 and Ves v 5 is a reliable method to diagnose yellow jacket allergy and can help to take out the sting of difficult cases. However, as the number of patients with doubt after conventional tests is small, larger collaborative studies are needed to draw more definitive conclusions. Whether the rVes v 5 supplemented yellow jacket allergosorbent constitutes an asset in the diagnostic management of wasp venom allergy remains to be further established.

Sensitization to one or more non-specific lipid transfer proteins (nsLTPs), initially thought to exist mainly in southern Europe, is becoming accepted as a cause of allergic reactions to plant foods across Europe and beyond. The peach nsLTP allergen Pru p 3 is a dominant sensitizing allergen and peaches a common food trigger, although multiple foods can be involved. A frequent feature of reactions is the requirement for a cofactor (exercise, alcohol, non-steroidal anti-inflammatory drugs, Cannabis sativa) to be present for a food to elicit a reaction. The variability in the food and cofactor triggers makes it essential to include an allergy-focused diet and clinical history in the diagnostic workup. Testing on suspected food triggers should also establish whether sensitization to nsLTP is present, using purified or recombinant nsLTP allergens such as Pru p 3. The avoidance of known trigger foods and advice on cofactors is currently the main management for this condition. Studies on immunotherapy are promising, but it is unknown whether such treatments will be useful in populations where Pru p 3 is not the primary sensitizing allergen. Future research should focus on the mechanisms of cofactors, improving diagnostic accuracy and establishing the efficacy of immunotherapy.

Background: Immunoglubulin E antibody-mediated allergic reactions to opioids are rare and difficult to document correctly.Objective: Assessment of the basophil activation test in the diagnosis of IgE-mediated allergy to the antitussive pholcodine and associated sensitizations to neuromuscular blocking agents (NMBA).Methods: Three patients with a suspected IgE-mediated allergy to pholcodine were investigated using skin tests, quantification of specific IgE, and flow cytometric activation of basophils.Results and conclusion: Flow cytometric activation of basophils, with simultaneous analysis of CD63 appearance and median histamine content per cell, is the only technique capable to correctly document pholcodine allergy. The negative predictive value of basophil activation tests might help to elucidate on the controversial putative cross-reactivity between pholcodine and NMBA. V C 2013 International Clinical

Immediate drug hypersensitivity reactions (IDHR) to moxifloxacin constitute a pathomechanistic conundrum and a diagnostic challenge. Our objective was to study whether simultaneous phenotyping and quantification of histamine release might add to our knowledge about the basophil activation properties of moxifloxacin and constitute a reliable diagnostic aid. Fifteen patients with an IDHR to moxifloxacin and nine moxifloxacin challenged controls were selected. All had a basophil activation test (BAT) with moxifloxacin. Flow cytometric analysis of basophil responses implied labeling for CD63, CD203c, and intracellular histamine. Unlike tolerant challenged controls, basophilic upregulation of CD203c in response to moxifloxacin was observed in seven of 15 patients. Only two of these seven patients demonstrated appearance of CD63 and release of histamine. In the remainder eight patients, no basophil responses were demonstrable. In conclusion, immediate hypersensitivity to moxifloxacin might involve mechanisms difficult to capture by traditional CD63-/CD203c-based BAT. Deciphering the complexity of quinolone IDHR seems mandatory.