The Severity and Frequency of Systemic Reactions to Hazelnut Are Significantly Higher in Hazelnut Allergic Patients Monosensitized to Cor a 8 than in Patients Polysensitized to Cor a 1, Cor a 8, and Cor a 9.

INTRODUCTION: Hazelnuts are a leading trigger of food allergy. To date, several molecular components of hazelnut are available for component-resolved diagnosis. However, little is known about how simultaneous sensitization to multiple allergens affects the severity of the hazelnut-induced reaction. In a previous study, our group demonstrated a lower risk of systemic reactions to peach in patients sensitized to both Pru p 3 and Pru p 1 than in the patient monosensitized to peach LTP. We aimed to assess whether this was also true in hazelnut allergy in a cohort of adult patients. METHODS: Patients were selected based on a history of symptoms such as urticaria, vomiting, diarrhea, asthma, and anaphylaxis indicative of hazelnut IgE-mediated food allergy and graded according to a clinical severity scale. For all patients, specific IgE was determined for Cor a 1 and Cor a 8 and, for most patients, also Cor a 9. Patients were offered an oral food challenge in open format (OFC) with a cocoa-based roasted hazelnut spread on a voluntary basis in order to prescribe an appropriate diet. RESULTS: A total of two hundred and fourteen patients were recruited. Among these, 43 patients were monosensitized to Cor a 8. One hundred and seventy-one patients were sensitized to Cor a 1 (79.9%), and, among them, 48/171 (28.1%) were also Cor a 8 positive. Cor a 9 was evaluated in 124/214 patients, testing positive in 21/124 (16.9%). Patients monosensitized to Cor a 8 experienced systemic reactions more frequently than those sensitized to Cor a 1 ± Cor a 8 (p < 0.00001), with significantly more severe reactions (p < 0.0005) and testing more frequently positive at OFC (p < 0.0001). Regarding Cor a 9, the sensitized patients were significantly younger (p = 0.0013) and showed reactions of similar severity to patients who tested Cor a 9 negative, and these reactions were milder than in patients monosensitized only to Cor a 8. DISCUSSION/CONCLUSION: Sensitization to Cor a 1 seems to protect from the development of the severe systemic reactions induced by Cor a 8 sensitization, Cor a 9 does not influence the severity of symptoms in adult patients. The OFC with roasted hazelnut may help in dietary guidance.

Clinical Features of Wheat Allergy Are Significantly Different between Tri a 14 Sensitized Patients and Tri a 19 Sensitized Ones.

INTRODUCTION: Wheat is the most important cereal for human nutrition but its high consumption is associated to an increasing complaint of wheat-related disorders, many of which are allergic in nature and different in respect to the involved allergens. In this study, we compared the clinical aspects of wheat allergy presented by patients sensitized to Tri a 19 in respect to those presented by patients sensitized to Tri a 14. METHODS: With this aim, we selected patients sensitized to 1 or both of the 2 allergens, and among these we identified those who were really wheat allergic and reactive on the basis of a standardized methodology. We evaluated the clinical features such as the kind and severity of symptoms, the coexistence of triggering factors such as physical exercise and NSAIDs and alcohol consumption, and the association with other allergens and with various immunologic parameters. Wheat allergy in Tri a 19 sensitized patients was confirmed through a questionnaire while the patients sensitized to Tri a 14 underwent wheat challenge with 100 g of pasta followed by exercise on a treadmill. RESULTS: Seventy-nine patients sensitized to Tri a 14 and 40 patients sensitized to Tri a 19 were recruited. The 2 sensitizations were independent with a significant inverse relation (p < 0.00001). The Tri a 19 sensitized patients presented, in respect to the Tri a 14 sensitized ones, an older age (p = 0.0017), a higher risk to be wheat allergic (p < 0.0001), a higher severity of the reactions (p < 0.00001) and a higher association with some cofactors, namely alcohol (p < 0.0005) and physical exercise (p = 0.003). On the contrary, Tri a 14 sensitization was associated with atopy (p < 0.0001), with a higher probability of patients being asymptomatic (p < 0.0001) and being sensitized to other foods, in particular to nuts and cereals (p < 0.00001). CONCLUSIONS: Sensitization to Tri a 19 or Tri a 14 determines different clinical pictures. In particular, sensitization to Tri a 19 implies a higher probability of severe reactions, even dependent on daily triggers, while that to Tri a 14 implies a higher cross-reactivity with other foods but it's more frequently asymptomatic, making a food challenge necessary to prevent useless food avoidance.

Basal Tryptase High Levels Associated with a History of Arterial Hypertension and Hypercholesterolemia Represent Risk Factors for Severe Anaphylaxis in Hymenoptera Venom-Allergic Subjects over 50 Years Old.

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.

Identification and molecular characterization of allergenic non-specific lipid-transfer protein from durum wheat (Triticum turgidum).

BACKGROUND: Common wheat (Triticum aestivum) and durum wheat (T. turgidum) are both involved in Baker's asthma (BA) and food allergy (FA) including wheat-dependent exercise-induced asthma (WDEIA). However, allergens in durum wheat have not been described, and the over-expression of T. turgidum non-specific lipid-transfer protein (nsLTPs) is considered to increase resistance to phytopathogens. OBJECTIVE: To identify and assess the allergenicity of nsLTP from T. turgidum. METHODS: Recombinant T. turgidum nsLTP Tri tu 14 was generated and tested for structural integrity (circular dichroism-spectroscopy) and purity (SDS-PAGE). Thirty-two wheat allergic patients were enrolled: 20 Spanish patients (BA) with positive bronchial challenge to wheat flour, and 12 Italian patients (wheat FA/WDEIA) with positive double-blind placebo-controlled food challenge/open food challenge (OFC) to pasta. IgE values to wheat, Tri tu 14, Tri a 14 (T. aestivum) and Pru p 3 (P. persica) were determined by ImmunoCAP testing. Allergenic potency (in vitro mediator release) and IgE cross-reactivity were investigated. RESULTS: Tri tu 14 was found to share 49% and 52% amino acid identity with Tri a 14 and Pru p 3, respectively. Among 25 Tri a 14 CAP positive sera, 23 (92%) were reactive to wheat extract, 22 (88%) to Tri tu 14 and 20 (80%) to Pru p 3. The correlation between Tri a 14 and Tri tu 14 specific IgE levels was r = 0.97 (BA) and r = 0.93 (FA/WDEIA), respectively. FA/WDEIA patients showed higher specific IgE values to Tri tu 14 and Pru p 3 than BA patients. Tri tu 14 displayed allergenic activity by mediator release from effector cells and IgE cross-reactivity with Pru p 3. The degree of IgE cross-reactivity between the two wheat nsLTPs varied between individual patients. CONCLUSIONS AND CLINICAL RELEVANCE: Sensitization to Tri tu 14 likely appears to be more important in wheat FA/WDEIA than in BA. Over-expression of Tri tu 14 in wheat would represent a risk for patients with nsLTP-mediated FA.

Tryptase as a marker of severity of aortic valve stenosis.

BACKGROUND: Severe aortic valve stenosis is one of the most common cause of mortality in adult patients affected with metabolic syndrome, a condition associated with an active inflammatory process involving also mast cells and their mediators, in particular tryptase. The aim of this study was to characterize the possible long-term prognostic role of tryptase in severe aortic valve stenosis. CASE PRESENTATION: The baseline serum tryptase was measured in 5 consecutive patients admitted to our Hospital to undergo aortic valve replacement for severe acquired stenosis. Within 2 years after, the patients were evaluated for the occurrence of major cardiovascular events (MACE). The tryptase measurements were higher in patients experiencing MACE (10.9, 11.7 and 9.32 ng/ml) than in non-MACE ones (5.69 and 5.58 ng/ml). CONCLUSIONS: In patients affected with severe aortic stenosis, baseline serum tryptase may predict occurence of MACE. Further studies are needed to demonstrate the long-term prognostic role of this biomarker.

Mite-Induced Asthma and IgE Levels to Shrimp, Mite, Tropomyosin, Arginine Kinase, and Der p 10 Are the Most Relevant Risk Factors for Challenge-Proven Shrimp Allergy.

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.

Anti-Amoxicillin Immunoglobulin E, Histamine-2 Receptor Antagonist Therapy and Mast Cell Activation Syndrome Are Risk Factors for Amoxicillin Anaphylaxis.

BACKGROUND: ß-Lactam antibiotics (mainly amoxicillin, AX) are the drugs that most frequently induce systemic drug allergy reactions. OBJECTIVE: We attempted to identify the risk factors associated with systemic reactions to AX. METHODS: All patients who were referred to our department for suspected hypersensitivity reactions to AX over a 6-month period were evaluated for anti-AX immunoglobulin E (IgE) levels and skin-test positivity for ß-lactams. Age, sex, concomitant diseases, therapies, total IgE, serum tryptase levels and signs and symptoms suggesting mast cell activation syndrome (MCAS) were analyzed in relation to the severity of the reaction in accordance with the Mueller classification. RESULTS: Sixty-seven patients were selected: 39 with mild reactions such as cutaneous or gastrointestinal symptoms (grades I and II) and 28 with severe systemic reactions (grades III and IV). Anti-AX IgE levels and total IgE were significantly higher in severe reactions than in mild ones (p < 0.00005, p = 0.0037). Treatment with histamine-2 receptor antagonists (anti-H2) was significantly related to severe reactions (p = 0.007). No significant correlations were found between the severity of the reactions and dyslipidemia or levels of angiotensin-converting enzyme and tryptase. CONCLUSION: Anti-AX IgE levels were the most significant immunological parameter distinguishing patients who presented with severe reactions to AX and those with mild reactions. Higher values of total IgE, the use of gastroprotective drugs and signs and symptoms suggesting an MCAS significantly increased the odds ratio of having a severe reaction. The risk of serious adverse reactions to AX increased in older patients and in males, but this trend was not significant.

Serum tryptase detected during acute coronary syndrome is significantly related to the development of major adverse cardiovascular events after 2 years.

BACKGROUND: One of the greatest challenges in cardiovascular medicine is to define the best tools for performing an accurate risk stratification for the recurrence of ischemic events in acute coronary syndrome (ACS) patients. METHODS: We followed 65 ACS patients enrolled in a previous pilot study for 2 years after being discharged, focusing on the occurrence of major adverse cardiovascular events (MACE). The relationship between serum tryptase levels on admission, SYNergy between percutaneous coronary intervention with the TAXUS drug-eluting stent and the cardiac surgery score (SX-score), cardiovascular complexity and MACE at 2 years follow-up were analyzed. RESULTS: The ACS population was divided in two groups: patients with MACE (n = 23) and patients without MACE (n = 42). The tryptase measurement at admission (T0) and at discharge (T3) and SX-score were higher in patients who experienced MACE than in those without (p = 0.0001, p < 0.0001 and p = 0.006, respectively). Conversely, we found no significant association between MACE and C-reactive protein (CRP), and between MACE and maximum level of high-sensitivity troponin (hs-Tn) values. Among all patients with MACE, 96% belonged to the group that presented with cardiovascular complexity at the beginning of ACS index admission (p < 0.0001). The predictive accuracy of serum tryptase for MACE at follow up set at the cut-off point of 4.95 ng/ml at T0 and of 5.2 ng/ml at T3. Interestingly, patients with both the above cut-off tryptase values at T0 and at T3 presented a 1320% increase in the odds of developing MACE (p < 0.0001). CONCLUSION: In ACS patients, serum tryptase measured during index admission is significantly correlated to the development of MACE up to 2 years, demonstrating a possible long-term prognostic role of this biomarker.

Identification of risk factors of severe hypersensitivity reactions in general anaesthesia.

BACKGROUND: Hypersensitivity reactions to anaesthetic agents are rare but often severe, with a mortality ranging from 4 to 9% in IgE-mediated events. Identification of the risk factors may contribute to limit the incidence of these reactions. The aim of our study was to search for possible risk factors of severe perioperative hypersensitivity reactions in our study population. METHODS: For this study we retrospectively reviewed data from 193 patients who experienced drug hypersensitivity reactions during general anaesthesia. The diagnostic protocol consisted of 1) history of the reaction, 2) measurement of serum baseline tryptase and specific IgE-assays for latex, beta-lactams and succinylcholine, 3) skin tests for the agents listed in the anaesthesia chart and for others likely to be safe for future use, latex, and others medications administered during the perioperative period (i.e. antibiotics), 4) subdivision of our patients on the basis of two criteria: a) grade of severity of clinical reactions according to the Ring and Messmer classification; b) results of skin tests and/or serum specific IgE-assays. RESULTS: One hundred of 193 patients had reactions of grade I, 32/193 patients had reactions of grade II, 55/193 patients had reactions of grade III and 6/193 patients had reactions of grade IV. A diagnosis of IgE-mediated reaction was established in 55 cases (28.50%); the most common causes were neuromuscular blocking agents, followed by latex and beta-lactams. Severe reactions were associated with older age (p = 0.025), asthma (p = 0.042), history of hypertension (p = 0.001), intake of serum angiotensin converting enzyme inhibitor medication (p = 0.012) or serum angiotensin II antagonist (p = 0.033), higher levels of basal tryptase (p = 0.0211). Cardiovascular symptoms (p = 0.006) and history of hypersensitivity to antibiotics (p = 0.029) were more frequently reported in IgE-mediated reactions. CONCLUSIONS: We confirmed the relevance of several clinical features as risk factors for anaphylactic reactions induced by anaesthetic agents: older age, asthma, hypertension and antihypertensive drugs. We observed increased levels of serum basal tryptase in severe reactions: this finding may signify that this biomarker is useful for the identification of patients at risk.

Serum tryptase: a new biomarker in patients with acute coronary syndrome?

BACKGROUND: Mast cell tryptase has recently been reported to be involved in atherosclerotic plaque destabilization. However, the results of these reports are conflicting. METHODS: The aim of this study was to characterize the role of tryptase as a prognostic marker of patient cardiovascular complexity in acute coronary syndrome (ACS). Furthermore, its association with an angiographic scoring system [defined by the SYNergy between percutaneous coronary intervention (PCI) with the TAXUS drug-eluting stent and the cardiac surgery (SYNTAX) score] was examined. The serum tryptase was measured at admission in 65 consecutive ACS patients and in 35 healthy controls. In the patients with ACS, a composite measure of clinical and angiographic patient cardiovascular complexity was indicated by two of the following: clinical adverse events at hospitalization, at least 2 epicardial coronary arteries involved in the atherosclerotic disease, more than 1 stent implanted or more than 2 coronary artery disease risk factors. RESULTS: The tryptase measurements were lower in patients without the composite measure (p < 0.0005). Linear regression showed a significant relationship between tryptase levels and the SYNTAX score (SX-score). Conversely, high-sensitivity troponin values did not correlate with either the composite outcome or the SX-score. The predictive accuracy of serum tryptase for the composite outcome was set at the cut-off point of 5.22 ng/ml (sensitivity 81% and specificity 95.7%). CONCLUSION: In ACS patients, serum tryptase levels at admission may predict patient cardiovascular complexity more reliably than currently known biomarkers. Further studies are needed to demonstrate the long-term prognostic role of this biomarker in ACS.

Anti-rPru p 3 IgE levels are inversely related to the age at onset of peach-induced severe symptoms reported by peach-allergic adults.

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.

Rice allergy demonstrated by double-blind placebo-controlled food challenge in peach-allergic patients is related to lipid transfer protein reactivity.

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.

Simulated gastrointestinal digestion of Pru ar 3 apricot allergen: assessment of allergen resistance and characterization of the peptides by ultra-performance liquid chromatography/electrospray ionisation mass spectrometry.

RATIONALE: Non-specific lipid transfer proteins (ns-LTPs) are major food allergens of the Rosaceae family. The severity of allergic reactions often relates to resistance of the allergen to digestion. Thus, it is important to evaluate the digestibility of these proteins and characterise the peptides generated in the gastrointestinal tract. METHODS: Simulated gastrointestinal digestion of purified allergen Pru ar 3 was performed using pepsin for the gastric phase in aqueous HCl at pH = 2 and chymotrypsin and trypsin for the intestinal phase in aqueous NH(4)HCO(3) at pH = 7.8. The peptide mixture obtained was analysed by ultra-performance liquid chromatography/electrospray ionisation mass spectrometry (UPLC/ESI-MS). Peptide sequences were identified by comparing their molecular mass to that obtained by in silico digestion, and were confirmed by the ions obtained by in-source fragmentation. Semi-quantification was performed for the intact protein by comparison with internal standards. RESULTS: The resistance to gastrointestinal digestion of Pru ar 3 allergen was evaluated to be 9%. This value is consistent with that found for grape LTP, but much lower than the resistance found for peach LTP (35%). All the peptides generated were identified by ESI-MS on the basis of their molecular mass and from the ions generated from in-source fragmentation. Apart from low molecular mass peptides, five high molecular mass peptides (4500-7000 Da) containing disulphide bridges were identified. ESI-MS of the intact protein indicated a less compact folded structure when compared to that of the homologous peach LTP. CONCLUSIONS: An extensive characterisation of the peptides generated from the gastrointestinal digestion of Pru ar 3 allergen was performed here for the first time via UPLC/ESI-MS analysis. The digestibility of the allergen was evaluated and compared with that of other LTPs, demonstrating that only a small amount of undigested protein remains, and that specific proteolytic action involves immunodominant epitopes. These data might explain the lower allergenicity of apricot LTP compared to peach LTP, despite their high sequence homology.

A comprehensive molecular approach in fish allergy: Usefulness in daily clinical practice.

BACKGROUND AND AIMS: Diagnosis of fish may represent an important challenge for the allergists. This study aimed to evaluate the diagnostic sensitivity of an in vitro multiplex assay using a comprehensive panel of fish allergens and the cross-reactivity patterns between different molecular components. METHODS: 56 subjects with fish allergy were enrolled. All patients underwent specific IgE measurement using the Allergy Explorer-Alex 2™ multiplex assay (Macroarray Diagnostics, Vienna, Austria) RESULTS: The single ß-parvalbumins Clu h 1, Cyp c 1, Gad m 1, Sal s 1, Sco s 1, Thu a 1 and Xyp g 1 scored positive in 75.0%, 67.8%, 62.5%, 80.3%,80.3%, 78.8% and 73,2% patients, respectively. 14.3% scored positive for the α-parvalbumin (Raj c-parvalbumin), and 16.1% for the aldolase + enolase (Gad m 2 + 3) components. 92.8% reacted to at least one ß-parvalbumin and 96.4% to at least one of the allergens tested. Overall sensitivity was higher than that obtained using commercial extracts of cod, salmon and tuna for skin prick test (75.8%) and IgE detection (92.3%). CONCLUSIONS: The Alex 2 showed high diagnostic sensitivity and it might be used as an additional assay to investigate the cross-reactivity patterns between different molecular components, looking for potentially safe fish species.

Mollusk allergy in shrimp-allergic patients: Still a complex diagnosis. An Italian real-life cross-sectional multicenter study.

Introduction: Shellfish allergy is an important cause of food allergies worldwide. Both in vivo and in vitro diagnostics failure nowadays is caused by the poor quality of the extracts associated with the scarce availability of allergenic molecules in the market. It is known that not all patients with shellfish allergies experience adverse reactions to mollusks. It is still unclear how to detect and diagnose these patients correctly. Aim: To investigate the features of shrimp-allergic patients either reactive or tolerant to mollusks, with the currently available diagnostic methods. Methods: Nineteen centers, scattered throughout Italy, participated in the real-life study, enrolling patients allergic to shrimp with or without associated reactions to mollusks. Patients underwent skin tests using commercial extracts or fresh raw and cooked shrimp and mollusks, and IgE reactivity to currently available allergenic extracts and molecules was measured in vitro. Results: Two hundred and forty-seven individuals with a self reported adverse reactions to shrimp participated in the study; of these 47.8% reported an adverse reaction to mollusks ingestion (cephalopod and/or bivalve). Neither of the tests used, in vivo nor in vitro, was able to detect all selected patients. Accordingly, a great heterogeneity of results was observed: in vivo and in vitro tests agreed in 52% and 62% of cases. Skin tests were able to identify the mollusk reactors (p < 0.001), also using fresh cooked or raw food (p < 0.001). The reactivity profile of mollusk reactors was dominated by Pen m 1, over Pen m 2 and Pen m 4 compared to tolerant subjects, but 33% of patients were not detected by any of the available molecules. Overall, a higher frequency of IgE rectivity to shrimp was recorded in northern Italy, while mollusk reactivity was more frequent in the center-south. Conclusion: The current diagnostic methods are inadequate to predict the cross-reactivity between crustaceans and mollusks. The detection of mollusks hypersensitivity should still rely on skin tests with fresh material. The exclusion of mollusks from shrimp allergic patients' diets should occur when clinical history, available diagnostic instruments, and/or tolerance tests support such a decision.

Pru p 3-sensitised Italian peach-allergic patients are less likely to develop severe symptoms when also presenting IgE antibodies to Pru p 1 and Pru p 4.

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.

Maize food allergy: lipid-transfer proteins, endochitinases, and alpha-zein precursor are relevant maize allergens in double-blind placebo-controlled maize-challenge-positive patients.

Italian patients with maize anaphylaxis have been shown to have IgE toward two major maize allergens: an alpha-amylase inhibitor and a 9-kDa LTP. A complete study on maize food allergens in patients with positive maize double-blind, placebo-controlled food challenge (DBPCFC) is lacking. The objective was to utilize the three maize protein fractions to identify and characterize the most relevant IgE-binding proteins recognized by the sera of Italian and Swiss patients with either a positive maize-DBPCFC or a history of maize-induced anaphylaxis. Osborne's protein fractions of maize were extracted to obtain water-soluble, total zein, and total protein fractions. Protein IgE-binding capacity was investigated by SDS-PAGE immunoblotting using the sera from DBPCFC-positive patients and from patients with maize-induced anaphylaxis. Purified maize LTP was used to inhibit the IgE immunoblotting of the three protein fractions. IgE immunoblotting demonstrated that the 9-kDa LTP was recognized by all the Italian patients and by none of the Swiss patients. Other allergens were: 14-kDa alpha-amylase inhibitor, 30-kDa endochitinases A and -B, 19 kDa zein-beta precursor, and 26 kDa zein-alpha precursor; a newly described allergen, the globulin-2 precursor, identified in the total protein fraction. It is noteworthy that maize LTP and endochitinase were cross-reactive with grape LTP and one grape endochitinase. LTP was found to be the only major allergen in Italian patients with either positive maize challenge or a history of maize-induced anaphylaxis. We have identified other maize allergens in subjects with maize food allergy, as grape cross-reactive endochitinase, however, the clinical significance of these proteins needs to be investigated in larger groups of patients with allergy to these food items.

Wheat IgE-mediated food allergy in European patients: alpha-amylase inhibitors, lipid transfer proteins and low-molecular-weight glutenins. Allergenic molecules recognized by double-blind, placebo-controlled food challenge.

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 alpha-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 alpha-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.