Background Food allergy to hazelnut occurs both with and without concomitant pollen allergy. Objective We sought to evaluate a panel of hazelnut allergens for diagnosis of hazelnut allergy in Spain, ...Switzerland, and Denmark. Methods Fifty-two patients with a positive double-blind, placebo-controlled food challenge result with hazelnuts; 5 patients with a history of anaphylaxis; 62 patients with pollen allergy but hazelnut tolerance; and 63 nonatopic control subjects were included. Serum IgE levels to hazelnut extract, recombinant hazelnut allergens (rCor a 1.04, rCor a 2, rCor a 8, rCor a 11), and native allergens (nCor a 9, nCor a Bd8K, nCor a Bd11K) were analyzed by means of ImmunoCAP. Results Among patients with hazelnut allergy, 91% (Switzerland/Spain, 100%; Denmark, 75%) had IgE to hazelnut extract, 75% to rCor a 1.04, 42% to rCor a 2, 28% to rCor a 8, and 2% to rCor a 11. The highest rate of sensitization to Cor a 1.04 was found in the northern regions (Switzerland/Denmark, 100%; Spain, 18%), whereas IgE to the lipid transfer protein rCor a 8 prevailed in Spain (Spain, 71%; Switzerland, 15%; Denmark, 5%). IgE to profilin rCor a 2 was equally distributed (40% to 45%). Among control subjects with pollen allergy, 61% had IgE to hazelnut extract, 69% to rCor a 1.04, 34% to rCor a 2, 10% to rCor a 8, and 6% to rCor a 11. Conclusion Component-resolved in vitro analyses revealed substantial differences in IgE profiles of hazelnut allergic and hazelnut tolerant patients across Europe.
Background Isolated Ara h 8 sensitization is suggested to be associated with no or mild symptoms among peanut-sensitized subjects. Objective We sought to investigate the occurrence of systemic ...reactions in children with isolated sensitization to Ara h 8. Methods Participants were 144 children sensitized to Ara h 8 (≥0.35 kUA /L) but not to Ara h 1, Ara h 2, or Ara h 3 (<0.35 kUA /L). An open oral challenge with peanut was performed in those subjects who did not consume peanut regularly, and an extended IgE reactivity profile was obtained. If the child had a documented history of systemic reactions up to grade I anaphylaxis, double-blind, placebo-controlled food challenges were performed. Results One hundred twenty-nine (89.5%) children were either peanut consumers or did not react to peanut challenge. Another 14 (9.7%) children experienced oral cavity symptoms at the first 2 but not subsequent challenge doses. At the time of the double-blind, placebo-controlled food challenge, 1 boy with a previous mild systemic reaction to peanut experienced lip swelling, stomach cramping, and objective tiredness. Reanalysis of IgE levels showed an increase in peanut IgE levels from 1.5 to 8.8 kUA /L, but IgE levels to Ara h 8 remained stable and IgE levels to Ara h 1, Ara h 2, and Ara h 3 were all still less than 0.35 kUA /L. The IgE level to Ara h 6 was 0.45 kUA /L. Conclusion Isolated Ara h 8 sensitization indicates tolerance to peanuts in almost all cases. However, sensitization against thus far unidentified determinants in peanut might cause symptoms in rare cases.
Background Detection of IgE to recombinant Hymenoptera venom allergens has been suggested to improve the diagnostic precision in Hymenoptera venom allergy. However, the frequency of sensitization to ...the only available recombinant honeybee venom (HBV) allergen, rApi m 1, in patients with HBV allergy is limited, suggesting that additional HBV allergens might be of relevance. Objective We performed an analysis of sensitization profiles of patients with HBV allergy to a panel of HBV allergens. Methods Diagnosis of HBV allergy (n = 144) was based on history, skin test results, and allergen-specific IgE levels to HBV. IgE reactivity to 6 HBV allergens devoid of cross-reactive carbohydrate determinants (CCD) was analyzed by ImmunoCAP. Results IgE reactivity to rApi m 1, rApi m 2, rApi m 3, nApi m 4, rApi m 5, and rApi m 10 was detected in 72.2%, 47.9%, 50.0%, 22.9%, 58.3%, and 61.8% of the patients with HBV allergy, respectively. Positive results to at least 1 HBV allergen were detected in 94.4%. IgE reactivity to Api m 3, Api m 10, or both was detected in 68.0% and represented the only HBV allergen–specific IgE in 5% of the patients. Limited inhibition of IgE binding by therapeutic HBV and limited induction of Api m 3– and Api m 10–specific IgG4 in patients obtaining immunotherapy supports recent reports on the underrepresentation of these allergens in therapeutic HBV preparations. Conclusion Analysis of a panel of CCD-free HBV allergens improved diagnostic sensitivity compared with use of rApi m 1 alone, identified additional major allergens, and revealed sensitizations to allergens that have been reported to be absent or underrepresented in therapeutic HBV preparations.
Background Patients with birch pollen allergy often develop allergic reactions to plant foods. Objective To evaluate the prevalence, main symptoms, and triggers of birch pollen–related food allergy ...and the role of food-specific IgG4 antibodies in food tolerance. Methods Food-induced symptoms were evaluated in 225 individuals with birch pollen allergy by using a standardized questionnaire. IgE and IgG4 levels specific for the major birch pollen allergen Bet v 1 and birch profilin Bet v 2 and the Bet v 1 homologs in apple (Mal d 1) and hazelnut (Cor a 1) were quantified by ImmunoCAP. Mock-treated and IgG-depleted sera from patients tolerating hazelnuts in food challenges were compared for their inhibitory activity for binding of Cor a 1–IgE complexes to B cells. Results In total, 73% of the study population experienced food allergy, which was perennial in 86% of the affected individuals. The oral allergy syndrome was the main clinical manifestation. However, more than 58% of the patients also experienced food-induced rhinoconjunctivitis. Apples and hazelnuts were identified as the most frequent triggers. Food allergy correlated with IgE reactivity to Bet v 1 but not to Bet v 2. Mal d 1–specific and Cor a 1–specific IgG4 /IgE ratios were significantly higher in food-tolerant individuals than individuals with food allergy. Sera from IgG4 -positive food-tolerant patients possessed IgG-dependent IgE-inhibitory activity. Conclusion Birch pollen–related food allergy is highly prevalent and often perennial. High food allergen–specific IgG4 /IgE ratios seem associated with food tolerance, potentially because specific IgG4 blocks IgE binding to food allergens. Thus, the presence of food allergen–specific IgG4 antibodies is no diagnostic marker for birch pollen–related food allergy.
Background Component resolution recently identified distinct sensitization profiles in honey bee venom (HBV) allergy, some of which were dominated by specific IgE to Api m 3 and/or Api m 10, which ...have been reported to be underrepresented in therapeutic HBV preparations. Objective We performed a retrospective analysis of component-resolved sensitization profiles in HBV-allergic patients and association with treatment outcome. Methods HBV-allergic patients who had undergone controlled honey bee sting challenge after at least 6 months of HBV immunotherapy (n = 115) were included and classified as responder (n = 79) or treatment failure (n = 36) on the basis of absence or presence of systemic allergic reactions upon sting challenge. IgE reactivity to a panel of HBV allergens was analyzed in sera obtained before immunotherapy and before sting challenge. Results No differences were observed between responders and nonresponders regarding levels of IgE sensitization to Api m 1, Api m 2, Api m 3, and Api m 5. In contrast, Api m 10 specific IgE was moderately but significantly increased in nonresponders. Predominant Api m 10 sensitization (>50% of specific IgE to HBV) was the best discriminator (specificity, 95%; sensitivity, 25%) with an odds ratio of 8.444 (2.127-33.53; P = .0013) for treatment failure. Some but not all therapeutic HBV preparations displayed a lack of Api m 10, whereas Api m 1 and Api m 3 immunoreactivity was comparable to that of crude HBV. In line with this, significant Api m 10 sIgG4 induction was observed only in those patients who were treated with HBV in which Api m 10 was detectable. Conclusions Component-resolved sensitization profiles in HBV allergy suggest predominant IgE sensitization to Api m 10 as a risk factor for treatment failure in HBV immunotherapy.
A very high correlation between cashew- and pistachio-specific IgE levels (Spearman correlation coefficient rs = 0.95) has been previously reported, suggesting significant serologic ...cross-reactivity.5 Conventional IgE assays have been shown to be suboptimally specific for either cashew nut or pistachio allergy, thus leaving a "gray area" with positive results of uncertain clinical significance.5,6 The aim of the present study was to investigate the utility of recombinant cashew 2S albumin Ana o 3 in the diagnosis of cashew nut allergy and to explore its relevance in the diagnosis of associated pistachio allergy. ...in our population, 13 of 15 patients falsely labeled as allergic to cashew by detection of cashew-specific IgE would have been correctly classified by subsequent measurement of IgE levels to rAna o 3.
Prostatic kallikrein: A new major dog allergen Mattsson, Lars, PhD; Lundgren, Thomas, BSc; Everberg, Henrik, PhD ...
Journal of allergy and clinical immunology,
02/2009, Letnik:
123, Številka:
2
Journal Article
Recenzirano
Background Dog dander is an important cause of respiratory allergy, but the spectrum of known dog allergens appears incomplete. Two lipocalins, Can f 1 and Can f 2, and serum albumin, Can f 3, have ...been characterized in detail but do not fully account for the IgE antibody-binding activity of dog dander extract. Allergen activity has previously been detected in dog urine but not further characterized. Objective We sought to identify, characterize, and assess the importance of allergen components in dog urine. Methods Dog urine was fractionated by means of size exclusion chromatography and examined for IgE antibody binding. A protein present in one fraction displaying IgE antibody-binding activity was identified by means of N-terminal sequencing and mass spectrometry. A recombinant form of the protein was produced in Pichia pastoris . IgE antibody binding to dog allergen components among sera of 37 subjects with dog allergy was determined by means of ImmunoCAP analysis. Results An IgE antibody-binding protein was isolated from dog urine and identified as prostatic kallikrein. A closely related or identical protein was detected in dog dander. The recombinant prostatic kallikrein displayed immunologic and biochemical properties similar to those of the natural protein and bound IgE antibodies from 26 (70%) of 37 sera of subjects with dog allergy, 14 of which reacted to none of Can f 1, Can f 2, or Can f 3. The dog allergen identified here was found to cross-react with human prostate-specific antigen, a key culprit in IgE-mediated vaginal reactions to semen. Conclusion Prostatic kallikrein is a new major dog allergen.
Background Hazelnut allergy is birch pollen–driven in Northern/Western Europe and lipid transfer protein–driven in Spain and Italy. Little is known about other regions and other allergens. Objective ...Establishing a molecular map of hazelnut allergy across Europe. Methods In 12 European cities, subjects reporting reactions to hazelnut (n = 731) were evaluated and sensitization to 24 foods, 12 respiratory allergen sources, and latex was tested by using skin prick test and ImmunoCAP. A subset (124 of 731) underwent a double-blind placebo-controlled food challenge to hazelnut. Sera of 423 of 731 subjects were analyzed for IgE against 7 hazelnut allergens and cross-reactive carbohydrate determinants by ImmunoCAP. Results Hazelnut allergy was confirmed in 70% of those undergoing double-blind placebo-controlled food challenges. Birch pollen–driven hazelnut sensitization (Cor a 1) dominated in most cities, except in Reykjavik, Sofia, Athens, and Madrid, where reporting of hazelnut allergy was less frequent anyhow. In Athens, IgE against Cor a 8 dominated and strongly correlated with IgE against walnut, peach, and apple and against Chenopodium , plane tree, and mugwort pollen. Sensitization to seed storage proteins was observed in less than 10%, mainly in children, and correlated with IgE to nuts, seeds, and legumes. IgE to Cor a 12, observed in all cities (10% to 25%), correlated with IgE to nuts, seeds, and pollen. Conclusions In adulthood, the importance of hazelnut sensitization to storage proteins, oleosin (Cor a 12), and Cor a 8 is diluted by the increased role of birch pollen cross-reactivity with Cor a 1. Cor a 8 sensitization in the Mediterranean is probably driven by diet in combination with pollen exposure. Hazelnut oleosin sensitization is prevalent across Europe; however, the clinical relevance remains to be established.
Background The prevalence of peanut allergy has increased in developed countries, but little is known about developing countries with high peanut consumption and widespread parasitic infections. ...Objective We sought to investigate peanut allergy in Ghana. Methods In a cross-sectional survey among Ghanaian schoolchildren (n = 1604), data were collected on reported adverse reactions to peanut, peanut sensitization (serum specific IgE and skin reactivity), consumption patterns, and parasitic infections. In a subset (n = 43) IgE against Ara h 1, 2, 3, and 9 as well as cross-reactive carbohydrate determinants (CCDs) was measured by using ImmunoCAP. Cross-reactivity and biological activity were investigated by means of ImmunoCAP inhibition and basophil histamine release, respectively. Results Adverse reactions to peanut were reported in 1.5%, skin prick test reactivity in 2.0%, and IgE sensitization (≥0.35 kU/L) in 17.5% of participants. Moreover, 92.4% of those IgE sensitized to peanut (≥0.35 kU/L) had negative peanut skin prick test responses. Schistosoma haematobium infection was positively associated with IgE sensitization (adjusted odds ratio, 2.29; 95% CI, 1.37-3.86). In the subset IgE titers to Ara h 1, 2, 3, and 9 were low (<1.3 kU/L), except for 6 moderately strong reactions to Ara h 9. IgE against peanut was strongly correlated with IgE against CCDs ( r = 0.89, P < .0001) and could be almost completely inhibited by CCDs, as well as S haematobium soluble egg antigen. Moreover, IgE to peanut showed poor biological activity. Conclusions Parasite-induced IgE against CCDs might account largely for high IgE levels to peanut in our study population of Ghanaian schoolchildren. No evidence of IgE-mediated peanut allergy was found.
Background Kiwifruit is one of the most common causes of food allergic reactions. Component-resolved diagnostics may enable significantly improved detection of sensitization to kiwifruit. Objective ...To evaluate the use of individual allergens for component-resolved in vitro diagnosis of kiwifruit allergy. Methods Thirty patients with a positive double-blind placebo-controlled food challenge to kiwifruit, 10 atopic subjects with negative open provocation to kiwifruit, and 5 nonatopic subjects were enrolled in the study. Specific IgE to 7 individual allergens (nAct d 1-5 and rAct d 8-9) and allergen extracts was measured by ImmunoCAP. Results The diagnostic sensitivities of the commercial extract and of the sum of single allergens were 17% and 77%, respectively, whereas diagnostic specificities were 100% and 30%. A combination of the kiwi allergens Act d 1, Act d 2, Act d 4, and Act d 5 gave a diagnostic sensitivity of 40%, whereas diagnostic specificity remained high (90%). Exclusion of the Bet v 1 homolog recombinant (r) Act d 8 and profilin rAct d 9 from this allergen panel reduced sensitivity to 50% but increased specificity to 40%. Kiwifruit-monosensitized patients reacted more frequently ( P < .001) with Act d 1 than polysensitized patients, whereas the latter group reacted more frequently with rAct d 8 ( P = .004). Conclusion Use of single kiwifruit allergen ImmunoCAP increases the quantitative test performance and diagnostic sensitivity compared with the commercial extract. Bet v 1 homolog and profilin are important allergens in pollen-related kiwifruit allergy, whereas actinidin is important in monoallergy to kiwifruit, in which symptoms are often more severe.
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