Allergy to stings and bites from rare or locally important arthropods: Worldwide distribution, available diagnostics and treatment.

Insect venom allergy is the most frequent cause of anaphylaxis in Europe and possibly worldwide. The majority of systemic allergic reactions after insect stings are caused by Hymenoptera, and among these, vespid genera induce most of the systemic sting reactions (SSR). Honey bees are the second leading cause of SSR. Depending on the global region, other Hymenoptera such as different ant genera are responsible for SSR. Widely distributed hornets and bumblebees or local vespid or bee genera rarely induce SSR. Hematophagous insects such as mosquitoes and horse flies usually cause (large) local reactions while SSR occasionally occur. This position paper aimed to identify either rare or locally important insects causing SSR as well as rarely occurring SSR after stings or bites of widely distributed insects. We summarized relevant venom or saliva allergens and intended to identify possible cross-reactivities between the insect allergens. Moreover, we aimed to locate diagnostic tests for research and routine diagnosis, which are sometimes only regionally available. Finally, we gathered information on available immunotherapies. Major allergens of most insects were identified, and cross-reactivity between insects was frequently observed. While some diagnostics and immunotherapies are locally available, standardized skin tests and immunotherapies are generally lacking in rare insect allergy.

Early and midterm results of frozen elephant trunk operation with Evita open stent-graft in patients with Marfan syndrome: results of a multicentre study.

BACKGROUND: Endovascular treatment of patients with Marfan syndrome (MFS) is not recommended. Hybrid procedures such as frozen elephant trunk (FET), which combines stent-graft deployment with an integrated non-stented fabric graft for proximal grafting and suturing, have not been previously evaluated. The aim of this study was to assess the safety and feasibility of FET operation in patients with MFS. METHODS: Patients enrolled in the International E-vita Open Registry (IEOR) who underwent FET procedure between January 2001 and February 2020 meeting Ghent criteria for MFS were included in the study. Early and midterm results were retrospectively analyzed. Preoperative, postoperative and follow-up computed tomography angiography scans were analysed. RESULTS: We analyzed 37 patients [mean age 38 ± 11 years, 65% men]. Acute or chronic aortic dissection was present in 35 (95%) patients (14 and 21 patients respectively). Two (5%) patients had an aneurysm without dissection. Malperfusion syndrome was present in 4 patients. Twenty-nine (78%) patients had history of aortic surgical interventions. The 30-day and in-hospital mortality amounted to 8 and 14% respectively. False lumen exclusion was present in 73% in stented segment in last postoperative CT. The overall 5-year survival was 71% and freedom from reintervention downstream was 58% at 5 years. Of the nine patients who required reintervention for distal aortic disease, one patient died. CONCLUSIONS: FET operation for patients with MFS can be performed with acceptable mortality and morbidity. In long-term follow-up no reinterventions on the aortic arch were required. FET allows for easier second stage operations providing platform for surgical and endovascular reinterventions.

Molecular sensitization patterns in animal allergy: Relationship with clinical relevance and pet ownership.

BACKGROUND: In vitro diagnosis using single molecules is increasingly complementing conventional extract-based diagnosis. We explored in routine patients with animal allergy to what extent molecules can explain polysensitization and identify primary sensitizers and how individual IgE patterns correlate with previous pet ownership and clinical relevance. METHODS: Serum samples from 294 children and adults with suspect allergic rhino-conjunctivitis or asthma and a positive skin prick test to cat, dog and/or horse were tested by ImmunoCAP for IgE antibodies against eleven different allergens from cat (Fel d 1,2,4,7), dog (Can f 1,2,3,4,5,6) and horse (Equ c 1). RESULTS: Patients monosensitized to cat (40.8%) or dog (6.1%) showed simple IgE patterns dominated by Fel d 1 (93%) and Can f 5 (67%), respectively. Double-sensitization to cat+dog (25.9%), cat+horse (5.4%) and polysensitization (20.7%) was associated with an increasing prevalence of the cross-reactive lipocalins Fel d 4/Can f 6/Equ c 1 and Fel d 7/Can f 1. While these lipocalins were not reliable markers for genuine sensitization per se, comparison of sIgE levels may give a clue on the primary sensitizer. Sensitizations to dog appeared to result from cross-reactivity with cat in 48%, with half of these sensitizations lacking clinical relevance. Individual sensitization patterns strongly mirrored current or previous pet ownership with the exception of Fel d 1 which regularly caused sensitization also in non-owners. CONCLUSIONS: Allergen components can reasonably illuminate the molecular basis of animal (poly)sensitization in the majority of patients and are helpful in distinguishing between primary sensitization and sometimes less relevant cross-reactivity.

Gal d 7-a major allergen in primary chicken meat allergy.

BACKGROUND: Poultry meat can induce severe allergic reactions. So far, the molecules causing poultry meat allergy are largely unknown. OBJECTIVE: Our aim was to identify and characterize poultry meat allergens. METHODS: Profiles of patients' IgE reactivity to chicken muscle were analyzed in immunoblots, and proteins recognized by the majority of patients were subjected to peptide mass fingerprinting. A 23-kDa IgE-reactive protein was identified as myosin light chain 1, designated Gallus domesticus 7 (Gal d 7). Recombinant Gal d 7 was produced in Escherichia coli. The protein's IgE reactivity was analyzed in ELISA experiments, and cross-reactivity with allergens of other poultry species was assessed in inhibition immunoblots. Fold and thermal stability were evaluated by circular dichroism analysis, and enzymatic stability was investigated using in vitro gastrointestinal digestion assays. RESULTS: Recombinant Gal d 7 represents a properly folded, predominantly α-helical protein and displays IgE-binding activity comparable to that of its natural counterpart. IgE reactivity analysis in 28 patients allergic to chicken meat revealed that Gal d 7 is a major allergen for patients primarily sensitized to chicken meat. Furthermore, Gal d 7-cross-reactive allergens were also detected in other poultry species, suggesting that recombinant Gal d 7 can be used as a diagnostic marker allergen for poultry meat allergy. The high thermal stability, refolding capacity, and resistance to gastrointestinal enzymes might explain why Gal d 7 can act as a potent sensitizing agent. CONCLUSION: Gal d 7 represents a novel major chicken meat allergen. Recombinant Gal d 7 could be used for diagnosis of genuine poultry meat sensitization.

Development of a novel Ara h 2 hypoallergen with no IgE binding or anaphylactogenic activity.

BACKGROUND: To date, no safe allergen-specific immunotherapy for patients with peanut allergy is available. Previous trials were associated with severe side effects. OBJECTIVE: We sought to determine the relative importance of conformational and linear IgE-binding epitopes of the major peanut allergen Ara h 2 and to produce a hypoallergenic variant with abolished anaphylactogenic activity. METHODS: Wild-type Ara h 2 and a mutant lacking the loops containing linear IgE epitopes were produced in insect cells. Conformational IgE epitopes were removed by unfolding these proteins through reduction and alkylation. IgE binding was tested by means of ELISA with sera from 48 Ara h 2-sensitized patients with peanut allergy. Basophil activation and T-cell proliferation were tested with blood samples from selected patients. Anaphylactogenic potency was tested by using intraperitoneal challenge of mice sensitized intragastrically to peanut extract. RESULTS: Patients' IgE recognized conformational and linear epitopes in a patient-specific manner. The unfolded mutant lacking both types of epitopes displayed significantly lower IgE binding (median ELISA OD, 0.03; interquartile range, 0.01-0.06) than natural Ara h 2 (median ELISA OD, 0.99; interquartile range, 0.90-1.03; P < .01). Basophil activation by unfolded mutant Ara h 2 was low (median area under the curve, 72 vs 138 for native wild-type Ara h 2; P < .05), but its ability to induce T-cell proliferation was retained. Unfolded mutants without conformational epitopes did not induce anaphylaxis in peanut-sensitized mice. CONCLUSIONS: By removing conformational and linear IgE epitopes, a hypoallergenic Ara h 2 mutant with abolished IgE binding and anaphylactogenic potency but retained T-cell activation was generated.

Drug-specific history, skin and in vitro tests can reduce the need for drug provocation tests in betalactam-hypersensitivity.

BACKGROUND: Many patients report questionable drug hypersensitivity reactions (DHR) to betalactam antibiotics. A workup is required for objectivation. Direct drug provocation tests (DPTs) omitting a prior allergy workup are increasingly recommended as the primary diagnostic approach. However, apart from the risk of severe side effects, DPTs often are a scarce resource in overloaded healthcare-systems. We investigated how many cases can be solved by drug-specific history, drug-specific IgE, and skin tests obviating the need for DPT. METHODS: We conducted a chart review in a retrospective cohort of 932 patients in an allergy outpatient centre from 2016 to 2017. Patients had been submitted to drug-specific history and specific IgE-, skin prick-, intradermal- and patch-tests with early and late readings with a series of penicillins and cephalosporins but DPTs were no option. RESULTS: Overall, positive in vitro and/or skin tests were found in 96/932 (10.3%) patients. Drug-specific IgE was detected in 40/932 (4.3%) patients, 61/787 (7.8%) patients had positive skin tests. In vitro tests to Pencillin V showed the highest rate of positivity 24/479 (5.0%) and early readings of ampicillin the highest amongst the skin tests (3/49, 6.1%). Immediate skin tests were more often positive than delayed ones (75:45). The combination of all parameters including drug-specific history solved 346/932 (37.1%) cases while 586/932 (62.9%) remained unresolved. Self-reported DHR could be less often confirmed in females and young children (p < 0.05). CONCLUSIONS: Testing with betalactams applying simple, cheap, and safe skin and blood tests can solve a third of DHR-cases on a high throughput scale.

Only α-Gal bound to lipids, but not to proteins, is transported across enterocytes as an IgE-reactive molecule that can induce effector cell activation.

BACKGROUND: The oligosaccharide galactose-α-1,3-galactose (α-Gal), present in mammalian proteins and lipids, causes an unusual delayed allergic reaction 3 to 6 hours after ingestion of mammalian meat in individuals with IgE antibodies against α-Gal. To better understand the delayed onset of allergic symptoms and investigate whether protein-bound or lipid-bound α-Gal causes these symptoms, we analyzed the capacity of α-Gal conjugated proteins and lipids to cross a monolayer of intestinal cells. METHODS: Extracts of proteins and lipids from beef were prepared, subjected to in vitro digestions, and added to Caco-2 cells grown on permeable supports. The presence of α-Gal in the basolateral medium was investigated by immunoblotting, thin-layer chromatography with immunostaining and ELISA, and its allergenic activity was analyzed in a basophil activation test. RESULTS: After addition of beef proteins to the apical side of Caco-2 cells, α-Gal containing peptides were not detected in the basolateral medium. Those peptides that crossed the Caco-2 monolayer did not activate basophils from an α-Gal allergic patient. Instead, when Caco-2 cells were incubated with lipids extracted from beef, α-Gal was detected in the basolateral medium. Furthermore, these α-Gal lipids were able to activate the basophils of an α-Gal allergic patient in a dose-dependent manner. CONCLUSION: Only α-Gal bound to lipids, but not to proteins, is able to cross the intestinal monolayer and trigger an allergic reaction. This suggests that the slower digestion and absorption of lipids might be responsible for the unusual delayed allergic reactions in α-Gal allergic patients and identifies glycolipids as potential allergenic molecules.

ImmunoCAP cellulose displays cross-reactive carbohydrate determinant (CCD) epitopes and can cause false-positive test results in patients with high anti-CCD IgE antibody levels.

BACKGROUND: Cross-reactive carbohydrate determinants (CCDs) in plants and insect venoms are a common cause of irrelevant positive test results during in vitro allergy diagnosis. We observed that some CCD-positive sera show nonspecific IgE binding even with CCD-free recombinant allergens when using the Phadia ImmunoCAP platform. OBJECTIVE: We investigated whether cellulose used as an allergen carrier in ImmunoCAP harbors residual N-glycans, causing nonspecific background binding in CCD-positive sera. METHODS: IgE binding to 6 samples of blank ImmunoCAPs coupled to either streptavidin (SA-CAP-1 or 2) or nonallergenic maltose-binding protein (MBP; MBP-CAP-1 to 4) and binding to a panel of 4 recombinant allergens were compared in CCD-positive sera before and after inhibition with a CCD inhibitor (MUXF3-human serum albumin). RESULTS: Of 52 CCD-positive sera (bromelain, 1.01-59.6 kilounits of antigen per liter [kUA/L]) tested on SA-CAP-1, 35 (67%) showed IgE binding of greater than 0.35 kUA/L (0.41-4.22 kUA/L). Among those with anti-CCD IgE levels of greater than 7.0 kUA/L, 90% (26/29) were positive. IgE binding to SA-CAP-1 correlated with IgE binding to bromelain (r = 0.68) and was completely abolished by serum preincubation with the CCD inhibitor (n = 15). Binding scores with SA-CAP-2 and MBP-CAP-1 to MBP-CAP-4 were generally lower but strongly correlated with those of SA-CAP-1 and bromelain. IgE reactivity of 10 CCD-positive sera (14.0-52.5 kUA/L) with the recombinant allergens rPhl p 12, rFel d 1, rAra h 2, and rPru p 3 was positive to at least 1 allergen in 8 of 10 (0.36-1.63 kUA/L) and borderline in 2 of 10 (0.21-0.25 kUA/L). Binding correlated with antibody binding to bromelain (r = 0.61) and to all blank ImmunoCAPs (r > 0.90) and could be completely blocked by the CCD inhibitor. Overall, mean background binding to cellulose CCDs corresponded to 2% to 3% of the reactivity seen with bromelain. CONCLUSIONS: Cellulose used as a solid-phase allergen carrier can contain varying amounts of CCDs sufficient to cause false-positive test results up to 2 kUA/L with nonglycosylated recombinant allergens in patients with high levels of anti-CCD IgE antibodies.

A Novel Designed Valved Conduit for RVOT Reconstruction in Grown-up Congenital Heart Patients: a Glimpse Down the Road.

BACKGROUND: A plethora of valves and valve conduits are available for reconstruction of the right ventricular outflow tract (RVOT) for grown-up congenital heart patients. However, for several reasons, the ideal pulmonary valve substitute still remains the subject of debate. In this study, we investigated the preliminary clinical and echocardiographic results after implantation of the RVOT Elan (Vascutek, Renfrewshire, United Kingdom) conduit in adolescents and adults. MATERIAL AND METHODS: Between October 2012 and December 2014, a total of 27 patients (19 males, mean age: 23.7 ± 22.5; range: 9-74 years) received a RVOT Elan conduit for RVOT reconstruction and were prospectively followed up clinically and echocardiographically. Twenty-five patients had previous cardiac surgery. The median number of prior operations per patient was 2 (range: 1-4). Tetralogy of Fallot was the most common diagnosis (n = 7). RESULTS: At a mean follow-up time of 0.9 ± 0.61 years (100% complete), all patients (27 of 27) were alive and in New York Heart Association Class I. Adverse events defined as valve failure, thrombosis, embolism, bleeding, or endocarditis did not occur. Freedom from reoperation in general was 100%. At 1-year follow-up, median peak pressure gradients (Δ Pmax) across the RVOT Elan conduit were 15 ± 3.2; 15.3 ± 2.1Δ, 16 ± 4.8, and 16.3 ± 5.1 mm Hg for the 19 (n = 3), 21 (n = 3), 23 (n = 6), and 25 mm (n = 15) conduit size, respectively. CONCLUSION: The RVOT Elan conduit revealed excellent preliminary clinical and hemodynamic performances independent from the underlying cardiac pathology with insignificant transvalvular gradients and nonturbulent flow characteristics.

Age-related reoperation rate after the Ross procedure: a report from the German Ross Registry.

BACKGROUND AND AIM OF THE STUDY: An increasing number of young adult patients are choosing bioprostheses for aortic valve replacement (AVR). In this context, the Ross operation deserves renewed consideration as an alternative biological substitute. After both the Ross procedure and bioprosthetic AVR, reoperation rates remain a concern and may be related to age at surgery. Herein are reported details of freedom from reoperation after the Ross procedure for different age groups. METHODS: The reoperation rates of 1,925 patients (1,444 males, 481 females; mean age 41.2 ± 15.3 years) from the German Ross registry with a mean follow up of 7.4 ± 4.7 years (range: 0.00-18.51 years; total 12,866.6 patient-years) were allocated to three age groups: group I < 40 years; group II 40-60 years; and group III > 60 years. RESULTS: At 10 years (respectively 15 years) of follow up, freedom from reoperation was 86% (76%) in group I, 93% (85%) in group II, and 89% (83%) in group III. CONCLUSION: There is some evidence that, at least during the first 10 and 15 years after AVR, the Ross procedure provides a significantly lower reoperation rate in young adult and middle-aged patients aged < 60 years. This information may be of interest to the patients' or physicians' decision-making for aortic valve surgery.

Chimeras of Bet v 1 and Api g 1 reveal heterogeneous IgE responses in patients with birch pollen allergy.

BACKGROUND: Characterization of IgE-binding epitopes of allergens and determination of their patient-specific relevance is crucial for the diagnosis and treatment of allergy. OBJECTIVE: We sought to assess the contribution of specific surface areas of the major birch pollen allergen Bet v 1.0101 to binding IgE of individual patients. METHODS: Four distinct areas of Bet v 1 representing in total 81% of its surface were grafted onto the scaffold of its homolog, Api g 1.0101, to yield the chimeras Api-Bet-1 to Api-Bet-4. The chimeras were expressed in Escherichia coli and purified. IgE binding of 64 sera from Bet v 1-sensitized subjects with birch pollen allergy was determined by using direct ELISA. Specificity was assessed by means of inhibition ELISA. RESULTS: rApi g 1.0101, Api-Bet-1, Api-Bet-2, Api-Bet-3, and Api-Bet-4 bound IgE from 44%, 89%, 80%, 78%, and 48% of the patients, respectively. By comparing the amount of IgE binding to the chimeras and to rApi g 1.0101, 81%, 70%, 75%, and 45% of the patients showed significantly enhanced IgE binding to Api-Bet-1, Api-Bet-2, Api-Bet-3, and Api-Bet-4, respectively. The minority (8%) of the sera revealed enhanced IgE binding exclusively to a single chimera, whereas 31% showed increased IgE binding to all 4 chimeras compared with rApi g 1.0101. The chimeras inhibited up to 70% of IgE binding to rBet v 1.0101, confirming the specific IgE recognition of the grafted regions. CONCLUSION: The Bet v 1-specific IgE response is polyclonal, and epitopes are spread across the entire Bet v 1 surface. Furthermore, the IgE recognition profile of Bet v 1 is highly patient specific.

Sensitization to Hymenoptera venoms is common, but systemic sting reactions are rare.

BACKGROUND: Sensitization to Hymenoptera venom without systemic sting reactions (SSRs) is commonly observed in the general population. Clinical relevance for a future sting has not yet been investigated. OBJECTIVE: We aimed to evaluate the effect of these debatable sensitizations with deliberate sting challenges and to monitor serologic changes for up to 2 years. METHODS: One hundred thirty-one challenges with bees and wasps were performed in 94 subjects with a hitherto irrelevant sensitization. The clinical outcome was recorded, and results of specific IgE (sIgE) determinations, skin tests, and basophil activation tests were correlated to the sting reaction. sIgE levels were monitored in reactors and nonreactors after 3 hours, 1 week, 4 weeks, and 1 year. RESULTS: Only 5 (5.3%) patients had SSRs, but 41 (43.6%) had large local reactions (LLRs) after the sting. Compared with the general population, there was a 9.5-fold higher risk for LLRs but not for SSRs. Three hours after the sting, sIgE levels slightly decreased, but none of the 94 subjects' results turned negative. After 1 week, sIgE levels already increased, increasing up to 3.5-fold (range, 0.2- to 34.0-fold) baseline levels after 4 weeks. To assess the clinical relevance of this increase, we randomly selected 18 patients for a re-sting. Again, 50% had an LLR, but none had an SSR. CONCLUSION: Although sensitization to Hymenoptera venoms was common, the risk of SSRs in sensitized subjects was low in our study. The sIgE level increase after the sting was not an indicator for conversion into symptomatic sensitization. Currently available tests were not able to distinguish between asymptomatic sensitization, LLRs, and SSRs.

Allergy screening with extract-based skin prick tests demonstrates higher sensitivity over in vitro molecular allergy testing.

BACKGROUND: As extract-based skin testing as well as in vitro tests for major allergens have their own advantages, both procedures are usually performed in routine settings. In times of shortages in medical staff and supplies, we asked ourselves, how many patients would be underdiagnosed, if only one test could be used. METHODS: In a retrospective analysis, we investigated a cohort of 2646 patients seen by a single physician in a large Austrian outpatient allergy clinic in 2018. Only patients with an allergen source-specific history and pairs of extract-based skin prick (SPT) and in vitro molecular allergy tests to major allergens were included. RESULTS: For all tested allergen sources, sensitivity was higher for SPT than for sIgE-based molecular allergy testing. Concerning 1006 birch pollen-allergic patients, 791 (78.6%) had positive results with both tests, while 153 (15.2%) only with the SPT and 62 (6.2%) only with the sIgE to Bet v1. The other allergen sources showed similar results: For house dust mite 816/1120 (72.9%), grass pollen 1077/1416 (76.1%) and cat 433/622 (69.6%) remained test-positive with both procedures, whereas in 276 (24.6%), 224 (15.8%) and 173 (27.8%) times only the SPT and 28 (2.5%), 115 (8.1%) and 16 (2.6%) times only the sIgE to Der p1/2/23, Phl p1/5 and Fel d1 showed a positive result. Each comparison was statistically significant (each p < 0.0001, Chi-squared test). CONCLUSIONS: Screening for allergy with major molecular allergens has lower sensitivity when compared with extract-based skin tests. A combination of both is required for an optimal sensitivity.

Molecular allergy diagnosis is sensitive and avoids misdiagnosis in patients sensitized to seasonal allergens.

BACKGROUND: The specificity of extract-based pollen allergy diagnosis is decreased due to cross-reactivity via cross-reactive carbohydrate determinants (CCDs) or panallergens such as profilins or polcalcins. This study aimed to explore the prevalence of sensitization to seasonal extracts, CCDs, profilin and polcalcin and investigate the sensitivity and specificity of seasonal molecular allergy diagnosis (MAD) using commercially available test methods. METHODS: 2948 patients were screened for specific immunoglobulin E to ash, birch, mugwort, ragweed and timothy grass pollen extracts and grouped according to the number of positive tests (1-5). 100 patients from each group and a control group were randomly selected to calculate the prevalence of CCD and panallergen sensitization. With 742 patients, sensitivity and specificity of MAD (Alt a 1, Fra/Ole e 1, Bet v 1, Phl p 1, Art v 1, and Amb a 1) was determined. RESULTS: 1627 patients (55.2%) were positive to at least one, and 1002 patients (34.0%) were positive to multiple of the five pollen allergens investigated; 18.5% of the pollen-sensitized patients had sensitization to CCDs or panallergens. Specifically, sensitization to CCDs, profilins, and polcalcins was observed in 8.7%, 10.9%, and 2.9% of these patients, respectively. The sensitivity of MAD was high, with sensitivities between 96.2% and 100% using ImmunoCAP and 91.5% and 100% using ALEX2 . Specificity was 100% for both assays. CONCLUSIONS: Due to cross-reactivity, about one-fifth of pollen-sensitized patients is at risk of misdiagnosis. However, MAD is sensitive, specific and helps to avoid misdiagnosis and select primary allergen sources for immunotherapy.

Peanut lipids influence the response of bronchial epithelial cells to the peanut allergens Ara h 1 and Ara h 2 by decreasing barrier permeability.

Background: Peanut-allergic individuals react upon their first known ingestion of peanuts, suggesting sensitization occurs through non-oral exposure. Increasing evidence suggests that the respiratory tract is a probable site for sensitization to environmental peanuts. However, the response of the bronchial epithelium to peanut allergens has never been explored. Furthermore, food matrix-derived lipids play an important role in allergic sensitization. Objective: To contribute to a better understanding of the mechanisms of allergic sensitization to peanuts via inhalation, by exploring the direct effect of the major peanut allergens Ara h 1 and Ara h 2 and peanut lipids on bronchial epithelial cells. Methods: Polarized monolayers of the bronchial epithelial cell line 16HBE14o- were stimulated apically with peanut allergens and/or peanut lipids (PNL). Barrier integrity, transport of allergens across the monolayers, and release of mediators were monitored. Results: Ara h 1 and Ara h 2 impacted the barrier integrity of the 16HBE14o- bronchial epithelial cells and crossed the epithelial barrier. Ara h 1 also induced the release of pro-inflammatory mediators. PNL improved the barrier function of the cell monolayers, decreased paracellular permeability and reduced the amount of allergens crossing the epithelial layer. Conclusion: Our study provides evidence of the transport of Ara h 1 and Ara h 2 across the airway epithelium, of the induction of a pro-inflammatory milieu, and identifies an important role for PNL in controlling the amount of allergens that can cross the epithelial barrier. These, all together, contribute to a better understanding of the effects of peanuts exposure on the respiratory tract.

Bos d 13, A Novel Heat-Stable Beef Allergen.

SCOPE: Red meat, a staple food of Western diets, can also induce IgE-mediated allergic reactions. Yet, apart from the heat-labile protein serum albumin and the carbohydrate α-Gal, the molecules causing allergic reactions to red meat remain unknown. METHODS AND RESULTS: IgE reactivity profiles of beef-sensitized individuals are analyzed by IgE-immunoblotting with protein extracts from raw and cooked beef. Two IgE-reactive proteins are identified by peptide mass fingerprinting as myosinlight chain 1 (MYL1) and myosin light chain 3 (MYL3) in cooked beef extract and are designated Bos d 13 isoallergens. MYL1 and MYL3 are produced recombinantly in Escherichia coli. ELISAs proved their IgE reactivity and circular dichroism analysis showed that they represent folded molecules with remarkable thermal stability. In vitro gastrointestinal digestion experiments showed the higher stability of rMYL1 as compared to rMYL3. Exposure of a monolayer of Caco-2 cells to rMYL1 indicated that the molecule is able to cross intestinal epithelial cells without disturbing the integrity of the tight junctions, suggesting the sensitizing capacity of MYL1. CONCLUSION: MYLs are identified as novel heat-stable bovine meat allergens.

Identification of Potentially Tolerated Fish Species by Multiplex IgE Testing of a Multinational Fish-Allergic Patient Cohort.

BACKGROUND: Although recent studies indicated that many fish-allergic patients may safely consume certain fish species, no clinical guidelines are available for identification of the exact species tolerated by specific patients. OBJECTIVE: To investigate whether multiplex immunoglobulin E (IgE) testing reveals potentially tolerated fish through absence of IgE to parvalbumin (PV) and extracts from specific species. METHODS: Sera from 263 clinically well-defined fish-allergic patients from Austria, China, Denmark, Luxembourg, Norway, and Spain were used in a research version of the ALEX2 multiplex IgE quantification assay. Specific IgE to PVs from 10 fish species (9 bony and 1 cartilaginous), and to extracts from 7 species was quantified. The IgE signatures of individual patients and patient groups were analyzed using SPSS and R. RESULTS: Up to 38% of the patients were negative to cod PV, the most commonly used molecule in fish allergy diagnosis. Forty-five patients (17%) tested negative to PVs but positive to the respective fish extracts, underlining the requirement for extracts for accurate diagnosis. Between 60% (Spain) and 90% (Luxembourg) of the patients were negative to PV and extracts from ray, a cartilaginous fish, indicating its potential tolerance. Up to 21% of the patients were negative to at least 1 bony fish species. Of the species analyzed, negativity to mackerel emerged as the best predictive marker of negativity to additional bony fish, such as herring and swordfish. CONCLUSIONS: Parvalbumins and extracts from multiple fish species relevant for consumption should be used in fish-allergy diagnosis, which may help identify potentially tolerated species for individual patients.