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Background: β-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 β-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.

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.)

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.)

Green beans belong to the Fabaceae family, which includes widely consumed species, such as beans, peanuts, and soybeans. In the literature, few cases have described allergic reactions upon the exposure to green bean boiling steam or ingestion. Here, we describe five patients reporting documented adverse reactions upon the ingestion of cooked green beans, and we characterize the responsible allergen. Fresh and cooked green beans were tested by a prick + prick technique. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis and IgE immunoblotting were performed with boiled vegetable extract, and the N-terminal sequence of the immunoreactive protein was obtained by analyzing the excised band in a protein sequencer. Immunoblotting inhibition of cooked green bean with in-house-purified peach lipid transfer protein (LTP) Pru p 3 was performed. An interesting green bean protein was chromatographically purified, tested with a pool serum, and inhibited with Pru p 3. Moreover, its molecular mass was determined by mass spectrometry. Prick + prick tests with raw and cooked green beans were positive for all of the patients. IgE immunoblotting showed that all of the patients reacted toward a unique IgE-binding protein at about 9 kDa. The obtained N-terminal sequence revealed the following amino acids: Ala-Ile-Ser-X-Gly-Qln-Val-Thr-Ser-Ser-Leu-Ala, corresponding to an LTP. A complete inhibition of the IgE binding to this protein, in both raw and purified extract, was obtained by purified peach Pru p 3, confirming previous IgE immunoblotting results.

There is an increasing consumption of tomatoes worldwide: fresh in salads, cooked in household sauces, or industrially processed. Although many tomato allergens have been identified, there is no information in the literature on the allergenic components found in commercial tomato products. The primary aim of the study was to evaluate the allergenic profile of commercial tomato products by skin prick tests (SPTs) and IgE/immunoblotting in tomato-allergic subjects. The secondary end point was the study of the IgE-binding profile of tomato peel, pulp, and seeds. Forty tomato-allergic patients, reporting oral allergy syndrome (OAS) at different grades of severity for fresh and, in some cases, also for cooked tomato, were selected on the basis of positive tomato allergy history or open food challenge (OFC). They were evaluated by SPTs with different experimental tomato extracts. SDS-PAGE/immunoblotting was performed to detect tomato allergens, which were then identified by Edman degradation. Twenty-three patients (57.5%) presented first-grade OAS at the OFC, whereas 17 (42.5%) reported severe symptoms. Ten of these 17 patients (25%) reported allergic reactions to cooked tomatoes; in immunoblotting tests, their sera reacted only to lipid transfer protein (LTP). In commercial products, LTP was the only detectable allergen. In contrast to other LTP-containing fruits, in tomato, an IgE-binding LTP was identified not only in the peel but also in the pulp and seeds. This study demonstrates that, in fresh tomato, different LTP isoforms are present and allergenic. Industrial tomato derivatives still contain LTP, thus presenting a problem for LTP-allergic patients.