Evidence of cross-reactivity between olive, ash, privet, and Russian olive tree pollen allergens.

In a clinical investigation, 103 Michigan residents with symptoms suggestive of allergic rhinitis or asthma were skin tested with olive (Olea europaea) pollen extract. Nineteen had positive reactions. Since the olive tree is not native to nor grown in Michigan, this study was undertaken to determine whether the skin test reactivity was the result of cross-reactivity among tree pollen allergens. ELISAs were developed to measure olive, ash (Fraxinus americana), privet (Ligustrum vulgare), and Russian olive (Elaeagnus angustifolia) specific IgE antibodies. Inhibition studies were performed to determine whether pollen extracts from each of these tree species could inhibit IgE antibody binding to olive extracts. Eleven of the 19 skin test-positive patients were olive-ELISA positive, eight either were ELISA-positive to ash, seven to privet and ten to Russian olive. There were significant correlations between the ELISA results to olive and each of the other three pollens. The inhibition studies demonstrated that all three of the tree pollens were capable of inhibiting the binding of IgE to olive extract in a dose-response fashion. IgE-immunoblot studies demonstrated several proteins common to olive, ash, and privet. Twelve of the olive skin test-positive patients were contacted and 75% were exposed to one or more of the studied trees in their yards. Five patients had traveled to areas where olive trees are grown. We conclude that there is a high degree of cross-reactivity among allergens from native Michigan trees and from olive trees. This cross-reactivity is the most likely reason for skin test reactivity to olive pollen extract in Michigan.     

Allergenic relationship between taxonomically diverse pollens

Background Skin tests and tests for IgE antibodies show that subjects are usually sensitive to a number of different pollens, frequently from taxonomically diverse species which are assumed to be allergenically non-crossreactive. This suggests that the presence of IgE antibody-reactivity to an individual pollen may not necessarily have resulted from contact with that pollen or even with a taxonomically closely related species. Objective Since this has important consequences for allergen avoidance and desensitization of patients, we attempted to define allergenic relationships between diverse pollen species. Methods Sera from subjects were examined in direct IgE antibody binding experiments and by quantitative inhibition, protein blotting and adsorption and edition studies. Results Sera from subjects diagnosed as allergic to white cypress pine. Italian cypress. ryegrass or birch pollen were shown to have IgE antibodies that reacted with pollens from these four species and from cocksfoot, couch grass, lamb's quarter, wall pellitory. olive, plantain and ragweed. These reactions were confirmed in protein blotting and adsorption and elution studies where numerous IgE-binding bands were detected in all 11 different pollen extracts with sera from each of the different allergic categories, further evidence of allergenic (i.e. IgE-binding crossreactivity between the different pollens was provided by inhibition studies in which clear-cut inhibitions of IgE binding to the different pollen allergen discs were obtained with comparable amounts of the different pollen extracts. Conclusion We conclude that the presence of pollen reactive IgE antibodies may not necessarily be a true reflection of sensitizing pollen species.     

Cypress pollen allergy. Identification of allergens and crossreactivity between divergent species

Abstract. Studies employing sera from 34 subjects allergic to while cypress pine ( Callitris glaucophvlla ) pollen identified 18 IgE antibody-binding components in the pollen of this species, five of which (MWs∼94, 68, 64, 43 and 34 kDa) were recognized by all of the sera. Protein blotting and quantitative inhibition studies revealed clear cross-reactivity between C. glaucophylla and Cupressus sempervirens pollen proteins and striking similarities in the IgE recognition band patterns of the two pollens. Inhibition experiments with other pollen extracts revealed that sera from C. glaucophylla pollen-allergic subjects can be divided into two groups – those inhibited only by extracts from the two Cupressaceae pollens and those inhibited both by these pollen proteins and by pollen extracts from other species. Most of the crossreactions in the latter group cannot be explained on the basis of taxonomic relationships or separate sensitizations. As with previous studies on birch and olive pollens, we conclude that pollen allergenic crossreactivity is much more wide-ranging than generally believed.     

Cloning and Expression of the Olea europaea allergen Ole e 5, the pollen Cu/Zn superoxide dismutase

BACKGROUND: Recombinant DNA technology does provide pure, well-defined and reproducible products to be used for clinical purposes, by cloning and expressing the cDNA of allergens present in a specific extract. Ole e 5 is a pollen allergen of Olea europaea with an IgE-binding frequency of about 35%, which has been identified as a superoxide dismutase (SOD). The aim of this study was to clone the cDNA of Ole e 5, to express Ole e 5 in Escherichia coli and to characterize its immunoreactivity. METHODS: cDNA of Ole e 5 was amplified by nested 3'-RACE PCR and cloned in pGEX vector 6P expression vector. After sequencing of some clones and homology analysis, the rOle e 5 was produced in an E. coli strain as a fusion protein with GST and purified. Then, the protein immunoreactivity was evaluated by patients' IgE binding (ELISA, ELISA inhibition, and immunoblotting) and by rabbit anti-rOle e 5 binding (immunoblotting and immunoblotting inhibition). RESULTS: The sequence analysis of Ole e 5 cDNA confirmed that Ole e 5 is a Cu/Zn SOD, with an identity from 90 to 80% with SOD from other species. rOle e 5 was recognized by IgE from 39% of olive pollen-allergic patients tested; moreover, this binding was inhibited by the olive pollen extract. An anti-rOle e 5 antiserum raised in rabbit strongly reacted with a natural component of about 16-kDa molecular weight present in the olive pollen extract; moreover, this binding was inhibited by the recombinant protein. CONCLUSIONS: Ole e 5 is the first Cu/Zn SOD identified as an allergen in a pollen source. Due to the widespread presence of this enzyme, rOle e 5 allergen, cloned and expressed in a complete form in E. coli, could represent a good tool to investigate the allergen cross-reactivity between O. europaea pollen and other allergenic sources, such as plant foods and other pollens.     

The allergen profile of ash (Fraxinus excelsior) pollen: cross-reactivity with allergens from various plant species

BACKGROUND: Ash, a wind-pollinated tree belonging to the family Oleaceae, is distributed world-wide and has been suggested as a potent allergen source in spring time. OBJECTIVE: The aim of this study was to determine the profile of allergen components in ash pollen in order to refine diagnosis and therapy for patients with sensitivity to ash pollen METHODS: The IgE reactivity profile of 40 ash pollen-allergic patients was determined by immunoblotting. Antibodies raised to purified pollen allergens from tree and grass pollens were used to identify cross-reactive structures in ash pollen extract. IgE immunoblot inhibition studies were performed with recombinant and natural pollen allergens to characterize ash pollen allergens and to determine the degree of cross-reactivity between pollen allergens from ash, olive, birch, grasses and weeds. RESULTS: The allergen profile of ash pollen comprises Fra e 1, a major allergen related to the major olive allergen, Ole e 1, and to group 11 grass pollen allergens, the panallergen profilin, a two EF-hand calcium-binding protein, a pectinesterase-like molecule and an allergen sharing epitopes with group 4 grass pollen allergens. Thus, the relevant allergens of ash are primarily allergens that share epitopes with pollen allergens from other tree, grass and weed species. CONCLUSIONS: Allergic symptoms to ash pollen can be the consequence of sensitization to cross-reactive allergens from other sources. The fact that ash pollen-allergic patients can be discriminated on the basis of their specific IgE reactivity profile to highly or moderately cross-reactive allergens has implications for the selection of appropriate forms of treatment.     

Identification of a 36‐kDa olive‐pollen allergen by in vitro and in vivo studies

BACKGROUND: Ole e 1 has been considered the major allergen of olive (Olea europaea) pollen. Some other relevant allergens (Ole e 2, 3, 4, and 6) have been recently described. This work aimed to study the IgE-binding frequency of a 36-kDa protein from O. europaea pollen in a large population of olive-allergic patients, its allergenic reactivity in vivo, and its presence in olive pollens of different origin, as well as in other relevant allergenic pollens. METHODS: Identification of IgE-binding components from O. europaea pollen extracts was elucidated by inhibition of SDS-PAGE immunoblotting using recombinant profilin (Ole e 2) and Ole e 1 molecules. The IgE-binding frequency of the 36-kDa protein was estimated by Western blot in a sample of 120 sera from olive-allergic patients. The cutaneous test with the 36-kDa protein was performed by intradermoreaction in allergic patients and control subjects. RESULTS: Exactly 83% of the sera from O. europaea-allergic patients recognized a protein with an apparent molecular weight of 36 kDa, under reducing conditions. It was detected by sera from monosensitized and polysensitized patients, showing a higher IgE frequency than the major allergen Ole e 1 (59%) and the minor profilin (Ole e 2) allergen (27%). Similar reactivity rates (79%) was found by intradermal test. Extracts from olive pollens collected in California presented a much higher amount (around 16-fold on average) of the 36-kDa protein than those from pollens of Spanish origin. The presence of similar allergens was detected only in closely related species (Syringa, Fraxinus, Ligustrum), and not in other common allergenic pollens. CONCLUSIONS: The 36-kDa protein constitutes a major allergen for olive-sensitized patients, but it is not equally represented in O. europaea pollens of different origins.     

Allergenicity and cross-reactivity of pine pollen

Background Pine pollen has long been considered a non-allergenic pollen. The large size of the grain and its low levels of proteins are the main reasons invoked to explain this low allergenicity. The aim of this study was to describe the main allergenic bands of Pinus radiata ( PR ) and its cross-reactivity with other pine species, other conifers and grass pollen.
Methods Sixty-five pine-pollen-allergic patients (51% also sensitized to grass pollen) were studied. Skin prick tests (SPT) to a battery of allergens including PR, Pinus pinea, Pinus sylvestris, Pinus nigra and Cupressus sempervirens pollens and specific IgE determination to PR and Pinus strobus were performed. IgE-immunoblotting to a PR extract and other pine pollens was also carried out. UniCAP inhibition and immunoblotting inhibition studies were performed to assess the cross-reactivity between different pollens.
Results The SPTs were positive with all the pine pollen extracts tested in 69% of the patients. Specific IgE was positive to PR or P. strobus in 77% of the patients, and to Lolium perenne in 51%. Nine different allergenic bands were detected. The two main allergens were a 42 kDa band recognized by 85% of the patients and a band of approximately 6–8 kDa recognized by 40%. A high degree of cross-reactivity was observed between different pine pollen species, but not between pines and C. sempervirens pollen. A partial cross-reactivity could be seen between pine and grass pollens only in patients also sensitized to L. perenne .
Conclusions Pine pollen should be considered as a potential allergenic pollen especially where this pollen is abundant. The detection of a high number of patients that were monosensitized to pine pollen suggests the possibility of treating these patients with specific immunotherapy.     

The major allergen of olive pollen Ole e 1 is a diagnostic marker for sensitization to Oleaceae

BACKGROUND: Trees of the family Oleaceae are important allergen sources, with a strongly varying geographic distribution. For example, olive pollen is an important allergen source in Mediterranean countries, whereas ash pollen dominates in Northern and Central Europe and North America. The aim of this study was to compare the profiles of olive and ash pollen allergens and to study the degree of cross-reactivity using populations of allergic patients selectively exposed to olive or ash pollen. METHODS: Olive and ash pollen extracts were analyzed by IgE immunoblotting using sera from Spanish patients highly exposed to olive pollen and Austrian patients without olive but ash pollen exposure. IgE cross-reactivity was studied by qualitative immunoblot inhibition assays and semiquantitative ELISA inhibitions using olive, ash, birch, mugwort, timothy grass pollen extracts and the major olive pollen allergen, Ole e 1. RESULTS: Spanish and Austrian patients exhibited an almost identical IgE-binding profile to olive and ash pollen allergens, with major reactivity directed against Ole e 1, and its homologous ash counterpart, Fra e 1. IgE inhibition experiments demonstrated extensive cross-reactivity between olive and ash pollen allergens. However, whereas cross-reactions between profilins and calcium-binding allergens also occurred between unrelated plant species, cross-reactivity to Ole e 1 was confined to plants belonging to the Oleaceae. CONCLUSIONS: Ole e 1 is a marker allergen for the diagnosis of olive and ash pollen allergy.     

Allergic conjunctivitis to chamomile tea

Eye washing with chamomile tea is a folk remedy used by the general public to treat conjunctivitis and other ocular reactions. Chamomile is also found in many cosmetic products. Some cases of contact dermatitis (but not reactions of type I) were reported following its topical applications. We present seven hay fever patients that suffered from conjunctivitis; two of them also had lid angioedema after eye washing with chamomile tea. All seven patients had positive skin prick tests to the chamomile tea extract, Matricaria chamomilla pollen and Artemisia vulgaris pollen extracts. Positive conjunctival provocations were also observed in all the patients with the chamomile tea extract. In contrast, no symptoms were observed after oral challenges with this infusion. IgE activity against chamomile tea and Matricaria and Artemisia extracts (composite pollens) was detected by ELISA in the seven patients' sera. A cross reactivity among the above extracts was observed by an ELISA inhibition study. In all cases, the IgE activity to chamomile tea could fully be absorbed by Matricaria pollen extract. Skin prick tests and conjunctival provocation tests also performed in 100 hay fever controls revealed a positive immediate skin response to Artemisia in 15 patients, eight of them also to Matricaria pollen and five of them to Chamomile tea as well. Only two of the last patients had a positive conjunctival response. The results were negative in the rest of the controls. We conclude that the chamomile tea eye washing can induce allergic conjunctivitis. Matricaria chamomilla pollens contained in these infusions are the allergens responsible for these reactions.     

Allergenic and antigenic cross-reactivities of group IX grass pollen allergens.

The allergenic and antigenic cross-reactivities between a major recombinant Poa pratensis (Poa p) IX allergen, rKBG8.3, and its corresponding proteins of different grass pollens were examined. Immunoblotting of the proteins of thirteen different grass pollens using anti-rKBG8.3 antibodies indicated that Poa p IX-like proteins are present in ten other grass pollens, albeit in variable amounts and polymorphic forms. These proteins ranged in size from 20 to 88 kDa in different grass pollens. The percent relative binding determined for each grass pollen extract using allergic human sera showed a significant correlation (r = 0.891) with that of anti-rKBG8.3 antiserum. Moreover, there was a strong association (r = 0.901) between the Kentucky bluegrass extract and rKBG8.3 with respect to their inhibition of the binding of human IgE antibodies to allergens in grass pollen extracts. Taken together, these results suggest that the allergenic and antigenic epitopes of the Poa p IX-related proteins in some but not all grass pollens are similar in structure and specificities. It is concluded that the group IX allergens constitute a major family of homologous proteins in several grass pollens.     

Sensitization to Lolium multiflorum grass pollen in pollinosis patients: evaluation of allergenic fractions recognized by specific IgE antibodies

BACKGROUND: Lolium multiflorum (Lm) pollen allergens are the major causative agents for rhinoconjunctivitis in Southern Brazil. There have been no studies about the sensitization and allergenic cross-reactivity between Lm and other grass pollens. We evaluated the sensitization of Brazilian pollinosis patients to Lm pollen allergens through skin prick test (SPT) and immunoassays (ELISA and immunoblot). METHODS: Serum samples from 60 patients with pollinosis and positive SPT to grass pollen extracts (Lm+ group), 30 patients with negative SPT to grass pollen, but positive SPT to mite extracts (Lm- group), and 30 nonatopic subjects (NA group) were tested by SPT, ELISA, and immunoblot using Lm extract. Inhibition immunoassays with Lolium perenne (Lp), mixed grass (Gmix) and Lm extracts were also performed. RESULTS: A high concordance was found between the Gmix and Lm extracts in SPT. Positivity rates in SPT were also highly concordant with IgE-ELISA results. The assay was able to detect Lm-specific IgE in >95% of Lm+ patients. A significant self- and cross-inhibition was observed in IgE-ELISA, reflecting a high cross-reactivity between the grass pollen allergens. Immunoblot revealed 13 IgE-binding Lm fractions, from which the bands 28-30 kDa and 31-34 kDa were recognized by >90% of Lm+ patients. CONCLUSION: Lm-specific IgE antibodies are highly cross-reactive with pollen proteins from other grass species. The results indicate that Lm extracts could be used in both SPT and ELISA for a more specific evaluation of IgE responses to Lm grass pollen in Brazilian pollinosis patients.     

IgE immune response to Ginkgo biloba pollen.

BACKGROUND: The ginkgo (Ginkgo biloba L.) continues to be planted as a shade tree in preference to other species in Seoul, Korea. The proportion of ginkgo to total shade trees was 43.2% in 1998, but the allergenic characteristics of ginkgo pollen has not been elucidated. OBJECTIVES: This study was undertaken to obtain information regarding the skin reactivity rate to ginkgo pollen in a population of Korean subjects with respiratory allergy. Possible ginkgo pollen allergens and the cross-reactivity of ginkgo pollen with other prevalent pollens were also examined. METHODS: Four hundred and forty-seven patients with asthma and/or allergic rhinitis were skin prick tested with extract of ginkgo pollen (1:20 wt/vol). Of these patients, positive skin responders (A/H ratio > or =2+) were selected for ELISA and immunoblot experiments. RESULTS: A total of 21 patients (4.7%) showed skin reactivity (A/H ratio > or =2+) to ginkgo pollen in the skin prick test. They were also cosensitized to many other tree, grass, and weed pollens. Sixteen (76%) of the 21 positive skin responders showed specific IgE responses to ginkgo pollen in ELISA. In inhibitory ELISA, IgE binding to ginkgo pollen was inhibited by more than 80% by oak, ryegrass, mugwort, and ragweed; and 34% by hop Japanese; and 10% by rBet v 2 at 10 microg/mL. In immunoblot, 10 out of 21 sera (48%) reacted to the 15-kD protein of ginkgo pollen, 9 (43%) to 33-35 kD, and 8 (38%) to 36-38 kD. In inhibitory immunoblot, IgE binding to ginkgo pollen proteins was almost completely inhibited by oak, ryegrass, mugwort and ragweed, but only partially by hop Japanese and rBet v 2. CONCLUSION: The skin reactivity rate to ginkgo pollen is approximately 4.7% in a population of Korean subjects with respiratory allergy. Since ginkgo pollen has a high cross-reactivity with other prevalent pollens, it could cause clinical symptoms during its pollen season by cross-reacting with the IgE produced in response to other pollens in patients sensitized to multiple pollens.     

The role of major olive pollen allergens Ole e 1, Ole e 9, and Ole e 10 on mice sensitization.

BACKGROUND: Olive pollen is an important cause of allergy in Mediterranean countries. To date, 10 allergens (Ole e 1 to Ole e 10) have been isolated and characterized. Animal models of olive pollen allergy are suitable tools for testing the efficacy and safety of new forms of immunotherapy. OBJECTIVES: To characterize the immune response in mice sensitized with olive pollen extract and to compare it with that of allergic patients. METHODS: BALB/c mice were sensitized by 4 intraperitoneal injections of olive pollen extract in aluminum hydroxide. The allergic state was proved by measuring serum specific IgG1 and total IgE antibody levels. The IgG1 responses to olive pollen allergens were assayed by immunoblotting and enzyme-linked immunosorbent assay. Competition experiments between human IgE and mouse IgG1 binding to olive pollen allergens were performed. RESULTS: Sensitization with olive pollen extract induced high levels of specific IgG1 and total IgE in all tested animals. Immunoblotting experiments showed that the mouse IgG1 binding pattern to pollen extract was complex and heterogeneous, as occurs with human IgE. High IgG1 antibody levels to the major olive pollen allergens described for humans were detected in serum samples from sensitized mice, whereas minor olive pollen allergens induced no significant IgG1 response. Coincubation of mouse serum samples with a cocktail of Ole e 1, Ole e 9, and Ole e 10 resulted in a significant decrease (60%) in IgG1 binding to olive pollen extract. Specific mouse IgG1 strongly inhibited human IgE binding to olive pollen allergens. CONCLUSIONS: This mouse model of olive pollen sensitization mimics immunologic features of human pollinosis and could be a useful tool for designing novel forms of immunotherapy for olive pollen allergy based on allergen cocktails.     

Immunoglobulin E (IgE)-mediated cross-reactivity between mesquite pollen proteins and lima bean, an edible legume

Immunoglobulin E (IgE)-mediated food allergy often develops as a consequence of allergic sensitization to pollen proteins. Mesquite (Prosopis juliflora) tree pollen is reported to be cross-reactive with other pollen species, but little has been reported on its cross-reactivity with plant-derived foods belonging to the same/different families. The present study investigates the in vitro cross-reactivity of mesquite pollen and lima bean (Phaseolus lunatus), an edible seed belonging to the Leguminosae family. Of 110 patients (asthma, rhinitis or both) tested intradermally, 20 showed marked positive reactions with Prosopis pollen extract. Of these, 12 patients showed elevated specific IgE to Prosopis pollen extract alone and four to both Phaseolus and pollen extract. In vitro cross-reactivity was investigated using inhibition assays [enzyme-linked immunosorbent assay (ELISA) inhibition, immunoblot inhibition], histamine release and lymphoproliferation. P. lunatus extract could inhibit IgE binding to P. juliflora in a dose-dependent manner, requiring 400 ng of protein for 50% inhibition in ELISA assay. Immunoblot and immunoblot inhibition demonstrated the presence of 20, 26, 35, 66 and 72 kDa as shared IgE binding components between the two extracts. Histamine release, peripheral blood mononuclear cells proliferation and interleukin (IL)-4 levels also suggested allergenic cross-reactivity. In conclusion, there is humoral and cellular cross-reactivity between Prosopis pollen and Phaseolus seed allergens.     

Allergy in the Mediterranean area III: cross reactivity among Oleaceae pollens

Pollens of closely related species often share common antigens and allergens although this is not always the case. Four species of Oleaceae pollens commonly found in the Mediterranean area were investigated For cross-reactivity: olive (Olea europaea), ash (Fraxinus exselsior), privet (Ligustrum vulagare) and Phillyreu augustifolia, a common bush. Twenty individual sera of patients allergic to Oleaceae were investigated for specific IgE antibodies against the four species of Oleaceae pollens. The results indicated a high degree of correlation between RAST titres of Oleaceae pollens but three gave a particular emphasis on one species only. Cross-reactivity among these four pollen species was sought by means of RAST inhibition, iso-electric focusing and tandem cross-immunoelectrophoresis. All tests revealed a high degree of cross reactivity although there is no total identity among these four pollen species.     

Profilin (Che a 2) and polcalcin (Che a 3) are relevant allergens of Chenopodium album pollen: isolation, amino acid sequences, and immunologic properties

BACKGROUND: Little is known about the molecular properties of chenopod allergens. Recently, profilin and 2 EF-hand calcium-binding protein (polcalcin) have been shown to play a role in chenopod pollinosis. OBJECTIVE: We sought to analyze these panallergens in chenopod pollen and to evaluate their involvement in the allergy to this biologic source. METHODS: Profilin and polcalcin were purified to homogeneity and characterized by using spectrometric and chemical methods. Immunologic analyses were performed by means of immunoblotting, ELISA, and competitive inhibition assays with olive profilin- and polcalcin-specific rabbit polyclonal antibodies and sera from patients with chenopod allergy. cDNAs encoding these proteins were cloned by means of PCR and sequenced. RESULTS: Purified Che a 2 (profilin) and Che a 3 (polcalcin) exhibited prevalences of 55% and 46%, respectively, in patients (n=104) hypersensitive to chenopod pollen. Both purified allergens individually inhibited the IgE binding to the whole pollen extract and showed strong cross-reactivity with the corresponding olive pollen profilin (Ole e 2) and polcalcin (Ole e 3). Chenopod profilin consists of a 131-amino-acid chain that displays identities of approximately 75% and 82% with pollen and food profilins, respectively. Che a 3 (86 amino acids) displays similarity (65% to 82% identity) with polcalcins from pollens of olive, birch, alder, rapeseed, and timothy. CONCLUSION: Profilin and polcalcin are relevant panallergens in chenopod pollen and good candidates to be involved in IgE cross-reactivity with other pollen sources, thus explaining the highly frequent polysensitization of patients allergic to chenopod.     

Immunoblot analysis of IgE-binding antigens in paprika and tomato pollen

BACKGROUND: The high incidence of occupational allergy in horticulture has only recently been recognized. We determined IgE against pollen and fruit from paprika and tomato plants in sera from 3 greenhouse workers and in 3 sera from food-allergic patients. METHODS: Proteins in extracts of paprika and tomato pollen were incubated with patients' sera after covalent coupling of these proteins to agarose beads, or in immunoblots. RESULTS: IgE against paprika pollen, but no IgE against tomato pollen, was found in serum from 2 greenhouse workers who worked with paprika plants only. IgE binding of these 2 sera to agarose-bound paprika pollen extract could be inhibited by paprika pollen but not by tomato pollen extract. A greenhouse worker, who cultivated tomato plants, had IgE against both tomato and paprika pollen. IgE binding of this serum to agarose-bound paprika pollen extract could be inhibited by both paprika pollen and tomato pollen extract. Three food-allergic patients also had IgE against tomato and paprika pollen. IgE from 2 food-allergic patients recognized IgE-binding structures in paprika or tomato pollen that were also present in fruit from the corresponding plant. In contrast, no substantial cross-reactivity was observed between paprika pollen and fruit towards IgE from 3 greenhouse workers. In 4 of 5 sera that were positive in the paprika pollen immunoblot major IgE binding to allergens of about 30 and 64 kD occurred. CONCLUSION: The presence of IgE against paprika or tomato pollen is not restricted to workers in horticulture; IgE against these pollen can also be present in food-allergic patients who have serum IgE against paprika and/or tomato fruit.     

Currant allergy and the Rosaceae-grass pollen allergy syndrome: a case report.

BACKGROUND: Despite the increasing use of currants in culinary recipes, currant allergy has rarely been reported. OBJECTIVES: To study a case of currant allergy and to explore cross-reactivity between grass pollen and Rosaceae family fruit allergens. METHODS: Skin prick tests to pollen and skin prick-to-prick tests with currants and peach were performed. Specific IgE levels were determined using the CAP method. We prepared a protein extract of 0.1 mg/mL in phosphate-buffered saline using red currant in the presence of protease inhibitors. Immunoblot inhibition studies were performed to explore cross-reactivity between grass pollen and currant allergens. RESULTS: Skin prick test results were positive to Dactylis, arizonic, and olive pollens. Results of skin prick-to-prick tests with fresh red and black currants were negative and positive, respectively, to peach. The specific IgE level was 5.7 KU/L to red currant and 2.92 KU/L to peach (CAP). Western blot analysis with red currant extract revealed specific IgE protein bands of 37 and 26 kDa. Preincubation of sera with extracts from red currant and peach inhibited both IgE bands, and preincubation with Dactylis pollen inhibited the 37-kDa band only. CONCLUSIONS: We report a case of allergy to grass pollen with an oral allergy syndrome involving several fruits from 2 different families of the Rosidae subclass confirmed by in vitro tests. Inhibition studies demonstrated cross-reactivity between different fruits (currant and raspberry) from the Rosidae subclass and were incomplete with grass pollen allergens.     

A clinical study of two cases with immediate hypersensitivity to apple-pulp and an investigation of cross-allergenicity between apple-pulp allergen and some other pollen allergens

In Japan there are no case reports of immediate hypersensitivity to apple-pulp. Here, we report on two patients: a 23-year-old woman and a 14-year-old girl with 3-year and 7-year histories, respectively, of anaphylactic reactions to apple-pulp. In the first patient, eating raw apples immediately elicited itching and tingling of the lips and mouth with severe edema of the lips and tongue, irritation of the throat and slight colic in the upper abdomen. In the second, nausea and vomiting occurred after ingestion of apples. In skin prick tests, they showed positive reactions to apple-pulp extract prepared by the method of Bj?rkstén et al. and to fresh apple juice. In addition, IgE antibody to the apple-pulp extract was detected in the sera of both patients. They also possessed IgE antibodies to some other species of both pollens and fruits/vegetables in their sera. In the present study, cross-allergenicity between apple-pulp and five pollen species, which consisted of birch, Japanese cedar, orchard grass, mugwort and ragweed pollen, was investigated by RAST inhibition. The apple-pulp extract effectively inhibited RASTs to all the pollens except Japanese cedar pollen. These results suggested that the four pollens might have shared allergen with the apple-pulp extract.     

Celery allergens in patients with positive double-blind placebo-controlled food challenge

BACKGROUND: Recently, for the first time, allergy to celery was confirmed by double-blind placebo-controlled food challenge (DBPCFC). Api g 1, Api g 4, cross-reactive carbohydrate determinants (CCD), and a 60 kDa allergen have been described as celery allergens. OBJECTIVE: To get insights in IgE responses of patients with a positive DBPCFC to celery tuber (celeriac) compared with patients with a negative challenge test. METHODS: Specific IgE to native and heated celery tuber and to recombinant Api g 1, the major celery allergen, were determined by enzyme allergosorbent test and immunoblotting. IgE binding to Api g 1, Api g 4, and CCD was confirmed by inhibition experiments that used recombinant Api g 1, recombinant Api g 4, pure N-glycans, and extracts of celeriac, lychee fruit, and pollens of birch, mugwort, and timothy grass as inhibitors. RESULTS: Immunoblotting with sera from 22 patients with a positive DBPCFC to celeriac confirmed the presence of known allergenic structures: The major allergen Api g 1 (16 kDa) was recognized by IgE from 13 of 22 patients (59%). Another major allergen was CCD, determined by IgE reactivity in 12 of 22 patients (55%). Celery profilin, Api g 4, was recognized by IgE from 5 of 22 patients (23%). CONCLUSION: Our DBPCFC-positive patients exclusively presented IgE to known celery allergens, although the prevalences were slightly different than were previously reported. No obvious differences were found in patients with positive IgE antibody but negative challenge test. IgE binding to all 3 structures in celeriac extract was inhibited by birch pollen extract, whereas mugwort pollen extract could only inhibit IgE reactivity to Api g 4 and CCD. Inhibition experiments with a purified carbohydrate moiety clearly showed that the IgE epitope mannose-xylose-fucose-glycan (Manalpha1-6[Xylbeta1-2]Manbeta1-4GlcNAcbeta1-4[ Fucalpha1-3]GlcNAc) or a closely related structure is present in celeriac extract and is important in patients with clinical allergy to celery.