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Introduction: Allergy to Hymenoptera venom (HV) may lead to life-threatening anaphylaxis. Some of the factors influencing the symptom's severity are still undetermined. The aim of this study was to identify the clinical aspects associated with the most severe reactions in a population with HV allergy, by comparing clinical and immunochemical biomarkers between patients with previous local large reactions (LLRs) and systemic reactions (SRs). Methods: We selected adult patients with a history of HV allergy, with positive diagnostic tests and a correlation with one single Hymenoptera species. Age, gender, atopy, serum basal tryptase (sBT) value, total IgE, venom-specific IgE, history of hypertension, cardiovascular diseases, and hypercholesterolemia were compared between patients with previous LLRs and SRs. Results: 460 adult patients (381 SRs, 79 LLRs) were included. Age (p = 0.0097), male gender (p < 0.0001), arterial hypertension (p = 0.046), hypercholesterolemia (p = 0.009), and higher sBT levels (p = 0.0004) were significantly associated with severe reactions as independent variables. Moreover, considering the previous variables as risk factors, there was a significant and progressive increase in the odds of being Mueller III + IV as the number of positive variables increased. Patients with sBT ≥6.4 ng/mL adjusted for any of the positive variables had increased the risk of Mueller grade IV reaction (p < 0.0001). Conclusion: According to our results, older age, male gender, arterial hypertension, hypercholesterolemia, and increased levels of sBT ≥6.4 ng/mL are risk factors for severe anaphylaxis to HV in adults. Atopy and allergic asthma do not increase the risk of HV-induced SRs. [ABSTRACT FROM AUTHOR]

Background: Shrimp sensitization is common in the general population, but the presence of symptoms is only moderately related to sensitization. A point still at issue is which in vivo and/or in vitro tests (food challenge, component-resolved diagnosis, house dust mite [HDM] sensitization) can help in distinguishing shrimp-allergic subjects from subjects that are sensitized but tolerant. Methods: The aim of this study was to evaluate the role of IgE to the different shrimp and mite allergens in distinguishing shrimp challenge positive from challenge-negative patients. Subjects with suspected hypersensitivity reactions to shrimp, positive skin prick tests (SPTs), and/or anti-shrimp IgE were submitted to open and double-blind placebo-controlled food challenges (DBPCFC). Specific IgE to shrimp, mites, and the recombinants rPen a 1, rDer p 1, 2, and 10 were tested using ImmunoCAP-FEIA. IgE immunoblotting was performed to identify the patients' allergenic profiles. Results: In total, 13 out of 51 (25.5%) patients with reported reactions to shrimp were truly shrimp allergic (7 DBPCFC positive and 6 with documented severe reactions). These patients had significantly higher skin test wheal diameters than nonallergic patients, as well as higher levels of IgE to rPen a 1 and rDer p 10. HDM-induced asthma and the simultaneous presence of anti-nDer p 1, 2, and 10 IgE levels increased the risk of true shrimp allergy. Conclusion: Food challenge tests are mandatory for the diagnosis of shrimp allergy. Tropomyosin is associated with clinical reactivity. HDM-induced asthma and anti-mite IgE are risk factors for shrimp allergy. [ABSTRACT FROM AUTHOR]

Sensitisation to peach lipid transfer protein (LTP; Pru p 3) is significantly associated with severe allergic symptoms in adults, but little is known about the age at onset of peach allergy. We investigated a possible correlation between specific IgE levels to Pru p 3 and the age at onset of peach allergy. One hundred and forty-eight patients allergic to peach were divided into 6 classes according to the age at onset. Sera were analyzed for IgE antibodies to peach, rPru p 3, rPru p 1, rPru p 4, rBet v 1, rBet v 2, total IgE titre, and tryptase; all collected data were statistically analysed. A significant inverse correlation was found between the age at onset of peach allergy and anti-rPru p 3 IgE levels at diagnosis (p < 0.0005; Spearman's ρ = -0.3833). In contrast, the age at onset was directly correlated with both anti-rPru p 1 IgE levels (p = 0.0001; Spearman's ρ = 0.3197) and anti-rBet v 1 IgE levels (p = 0.0006; Spearman's ρ = 0.2914) at diagnosis. No correlations were detected between the reported age at onset and anti-peach, anti-rPru p 4, anti-rBet v 2 IgE and total IgE values and serum tryptase levels. At diagnosis, when peach allergy starts at a younger age, it is likely associated with Pru p 3 sensitisation, and the younger the onset, the higher the IgE titres. When peach allergy starts at an older age, it is more likely the result of cross-reactivity to Bet v1. Copyright © 2013 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Background: The risk factors for sensitisation to rice and the involved allergens are still partially unknown. In this study we evaluated the clinically relevant aspects of rice allergy in DBPCF-positive patients, the major rice allergens, the severity of peach- and rice-induced symptoms in respect to Pru p 3 sensitisation and the role of anti-rPru p 3 IgE levels as a risk factor for rice allergy. Methods: In 148 peach-allergic subjects, patients with allergic reactions to rice and rice-positive serum IgE were selected. Symptoms were verified by double-blind placebo-controlled food challenges (DBPCFCs), performed at a maximum dosage of 25 g. Rice allergens, identified by IgE immunoblotting, were characterised by N-terminal amino acid sequencing. The relationship between anti-rPru p 3, 1 and 4 IgE levels and rice symptoms were statistically analysed. Results: Eight out of 10 recruited rice-allergic patients had positive DBPCFCs, while 2 patients were not challenged due to their previously documented severe reactions. All patients with rice-induced symptoms were Pru p 3 positive and presented with higher anti-rPru p 3 levels than the rice-sensitised but tolerant patients. A 9-kDa lipid transfer protein, which was highly homologous to Pru p 3, was identified as the major rice allergen and elicited a positive response in all of the patients. Five patients reacted to a putative 15- to 17-kDa rice allergenic protein, and 3 patients reacted to an [alpha]-amylase/subtilisin inhibitor that was approximately 20 kDa. Conclusion: Rarely, allergic reactions to rice can arise in patients with peach allergies who are sensitised to Pru p 3, particularly in patients with high anti-rPru p 3 IgE levels. Copyright © 2013 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Background: The roles played by different peach allergens with respect to symptom severity have not been completely ascertained. We have evaluated the diagnostic efficacy of peach recombinant allergens ImmunoCAP compared to peach in the identification of subjects at an increased risk for severe reactions to peaches. Methods: 148 peach-allergic patients were divided based on their symptom severity into 2 groups: mild oral allergy syndrome (OAS) and severe OAS. Anti-rPru p 1, 3 and 4 IgE levels were measured. Statistical analyses were carried out using parametric and non-parametric tests. Results: anti-rPru p 1 and anti-rPru p 4 IgE levels were significantly higher in patients with mild OAS than in patients with severe OAS (p = 0.0001); in contrast, anti-rPru p 3 IgE levels were significantly higher in patients with severe OAS than in patients with mild OAS (p < 0.00005). Moreover, we found that any unitary increase in anti-rPru p 1 IgE values corresponded to a 2.48% reduction in the odds of having severe OAS (p = 0.048), whereas any unitary increase in anti-rPru p 3 IgE values corresponded to a 9.02% increase in the probability of having severe OAS (p = 0.001). Unexpectedly, we found that patients positive to rPru p 3 as well as rPru p 1 and 4 demonstrated a significant reduction of the odds of developing severe symptoms than those positive to rPru p 3 alone. Anti-rPru p 3 IgE levels were a significantly better indicator than anti-peach IgE values (p = 0.016) of patients with the highest risk for severe OAS. A cutoff of 2.69 kUA/l for anti-rPru p 3 IgE values better discriminated peach-allergic patients at a higher risk for symptoms. Conclusions: Italian patients with positive anti-rPru p 1, 4 and 3 IgE levels seemed less likely to experience the clinical effects of high anti-rPru p 3 IgE values. Copyright © 2011 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Background: Three main problems hamper the identification of wheat food allergens: (1) lack of a standardized procedure for extracting all of the wheat protein fractions; (2) absence of double-blind, placebo-controlled food challenge studies that compare the allergenic profile of Osborne’s three protein fractions in subjects with real wheat allergy, and (3) lack of data on the differences in IgE-binding capacity between raw and cooked wheat. Methods: Sera of 16 wheat-challenge-positive patients and 6 patients with wheat anaphylaxis, recruited from Italy, Denmark and Switzerland, were used for sodium dodecyl sulfate-polyacrylamide gel electrophoresis/immunoblotting of the three Osborne’s protein fractions (albumin/globulin, gliadins and glutenins) of raw and cooked wheat. Thermal sensitivity of wheat lipid transfer protein (LTP) was investigated by spectroscopic approaches. IgE cross-reactivity between wheat and grass pollen was studied by blot inhibition. Results: The most important wheat allergens were the α-amylase/trypsin inhibitor subunits, which were present in all three protein fractions of raw and cooked wheat. Other important allergens were a 9-kDa LTP in the albumin/globulin fraction and several low-molecular-weight (LMW) glutenin subunits in the gluten fraction. All these allergens showed heat resistance and lack of cross-reactivity to grass pollen allergens. LTP was a major allergen only in Italian patients. Conclusions: The α-amylase inhibitor was confirmed to be the most important wheat allergen in food allergy and to play a role in wheat-dependent exercise-induced anaphylaxis, too. Other important allergens were LTP and the LMW glutenin subunits. Copyright © 2007 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]