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Unlabelled: Background: The role of allergens in the severity of tomato allergy symptoms has not yet been studied., Objectives: To evaluate the relationship between severe allergic reactions to peach and tomato and between tomato allergy symptoms and the pattern of IgE positivity for rPru p 1, rPru p 3, rPru p 4, rBetv 1, rBetv 2, rBetv4, rPhl p 1, and rPhl p 12 in order to identify the role of recombinant allergens in the severity of reactions to tomato., Methods: We studied peach-allergic patients with clinical reactions to tomato by performing an open food challenge, skin prick test, and determination of serum specific IgE to tomato and to recombinant peach, birch, and grass allergens. Statistical analysis was carried out to evaluate the relationship between the severity of tomato symptoms and IgE positivity to the different allergens and to peach-induced symptoms., Results: We found a significant association between severe reactions to tomato and severe reactions to peach (P = .01 7) and levels of IgE to rPru p3 (P = .029) and between mild tomato allergy symptoms and levels of IgE to rPru p1 (P = .047), anti-rBetv 1 (P = .0414), anti-rBetv 2 (P = .0457), and Phleum pratense (P = .0022)., Conclusion: We observed a significant relationship between peach and symptoms of tomato allergy. IgE positivity for rPru p3 seems to be a surrogate biochemical marker for severe tomato allergy, whereas the presence of anti-rPru p 1 IgE may be an indicator of mild tomato allergy.

Fennel allergy has been rarely reported, and the association with peach allergy has never been described. Our aim was to (i) study the correlation between symptom severity of peach and fennel and (ii) identify fennel allergens and the role of rPru p 3 antibodies in severe reactions to fennel. In 148 patients with peach allergy, we investigated 58 patients with symptoms and IgE antibodies positive to fennel. IgE to rPru p 1, 3, and 4 and rBet v 1, 2, and 4 were measured by immunoblotting, and the N-terminal amino acid sequences and relevant allergens were determined. We found significant association between severe reactions to fennel and peach (p = 0.0009). A major allergen was ~9 kDa lipid-transfer protein (LTP), cross-reactive with Pru p 3, a 15 kDa protein identified as a pathogenesis-related protein 1 of the Bet v 1 family. In conclusion, peach and fennel severe allergic symptoms are significantly related, and LTP is a major fennel allergen. Fennel should be included in the LTP syndrome.

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.)

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.)

Background: Pru p 3 is the major peach allergen recognized by more than 90% of peach-allergic individuals of the Mediterranean area. Identification of the dominant Pru p 3 T-cell epitopes can improve our understanding of the immune responses against this protein and could be helpful in the development of hypoallergenic immunotherapy. For this purpose, we examined the phenotypes, specificities and cytokine secretion profiles of proliferating T cells in response to Pru p 3 in peach-allergic individuals., Methods: Peripheral blood mononuclear cells from 15 peach-allergic patients were incubated with Pru p 3. The proliferation of antigen-specific T-cell lines (TCLs) was assessed by tritiated methylthymidine incorporation. T-cell epitopes were identified by analyzing the reactivity of TCLs against 8 overlapping peptides spanning the entire length of Pru p 3. We characterized the phenotype of Pru-p-3-specific TCLs by flow cytometry and analyzed their production of interleukin (IL) 4 and gamma-interferon (IFN-gamma) by ELISA., Results: Ninety-two Pru-p-3-specific TCLs were isolated (stimulation index > or =5). These TCLs proliferated mainly in response to Pru p 3(12-27) and Pru p 3(57-72). Pru-p-3-specific TCLs were mainly CD4+ (81%) and expressed cell surface CD30. In addition, TCLs produced high levels of IL-4 and low levels of IFN-gamma, indicating a Th2 phenotype., Conclusions: Two immunodominant T-cell-reactive regions of Pru p 3 were identified: Pru p 3(12-27) and Pru p 3(57-72). These peptides showed a differential ability to elicit a Th2 response. Taken together, our results provide a better understanding of the immunological T-cell reactivity against Pru p 3., (Copyright (c) 2010 S. Karger AG, Basel.)