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Background Hymenoptera stings can cause severe anaphylaxis in untreated venom-allergic patients. A correct diagnosis regarding the relevant species for immunotherapy is often hampered by clinically irrelevant cross-reactivity. In vespid venom allergy, cross-reactivity between venoms of different species can be a diagnostic challenge. To address immunological IgE cross-reactivity on molecular level, seven recombinant antigens 5 of the most important Vespoidea groups were assessed by different diagnostic setups. Methods The antigens 5 of yellow jackets, hornets, European and American paper wasps, fire ants, white-faced hornets, and Polybia wasps were recombinantly produced in insect cells, immunologically and structurally characterized, and their sIgE reactivity assessed by Immuno CAP, ELISA, cross-inhibition, and basophil activation test ( BAT) in patients with yellow jacket or Polistes venom allergy of two European geographical areas. Results All recombinant allergens were correctly folded and structural models and patient reactivity profiles suggested the presence of conserved and unique B-cell epitopes. All antigens 5 showed extensive cross-reactivity in sIgE analyses, inhibition assays, and BAT. This cross-reactivity was more pronounced in Immuno CAP measurements with venom extracts than in sIgE analyses with recombinant antigens 5. Dose-response curves with the allergens in BAT allowed a differentiated individual dissection of relevant sensitization. Conclusions Due to extensive cross-reactivity in various diagnostic settings, antigens 5 are inappropriate markers for differential sIgE diagnostics in vespid venom allergy. However, the newly available antigens 5 from further vespid species and the combination of recombinant allergen-based sIgE measurements with BAT represents a practicable way to diagnose clinically relevant sensitization in vespid venom allergy. [ABSTRACT FROM AUTHOR]

Background: Although avian coronavirus infectious bronchitis virus (IBV) and SARS‐CoV‐2 belong to different genera of the Coronaviridae family, exposure to IBV may result in the development of cross‐reactive antibodies to SARS‐CoV‐2 due to homologous epitopes. We aimed to investigate whether antibody responses to IBV cross‐react with SARS‐CoV‐2 in poultry farm personnel who are occupationally exposed to aerosolized IBV vaccines. Methods: We analyzed sera from poultry farm personnel, COVID‐19 patients, and pre‐pandemic controls. IgG levels against the SARS‐CoV‐2 antigens S1, RBD, S2, and N and peptides corresponding to the SARS‐CoV‐2 ORF3a, N, and S proteins as well as whole virus antigens of the four major S1‐genotypes 4/91, IS/1494/06, M41, and D274 of IBV were investigated by in‐house ELISAs. Moreover, live‐virus neutralization test (VNT) was performed. Results: A subgroup of poultry farm personnel showed elevated levels of specific IgG for all tested SARS‐CoV‐2 antigens compared with pre‐pandemic controls. Moreover, poultry farm personnel, COVID‐19 patients, and pre‐pandemic controls showed specific IgG antibodies against IBV strains. These antibody titers were higher in long‐term vaccine implementers. We observed a strong correlation between IBV‐specific IgG and SARS‐CoV‐2 S1‐, RBD‐, S2‐, and N‐specific IgG in poultry farm personnel compared with pre‐pandemic controls and COVID‐19 patients. However, no neutralization was observed for these cross‐reactive antibodies from poultry farm personnel using the VNT. Conclusion: We report here for the first time the detection of cross‐reactive IgG antibodies against SARS‐CoV‐2 antigens in humans exposed to IBV vaccines. These findings may be useful for further studies on the adaptive immunity against COVID‐19. [ABSTRACT FROM AUTHOR]

Background: Oral immunotherapy (OIT) is a treatment option for patients with milk, egg, and peanut allergy, but data on the efficacy and safety of cashew OIT are limited. Methods: A cohort of 50 cashew‐allergic patients aged ≥4 years, who were consecutively enrolled into cashew OIT (target dose 4000 mg protein) between 4/2016 and 12/2019. Fifteen cashew‐allergic patients who continued cashew elimination served as observational controls. Co‐allergy to pistachio and walnut was determined. Full desensitization rate and associated immunological changes in both groups were compared. Patients fully desensitized to cashew were instructed to consume a dose of 1200 mg cashew protein for 6 months and were then challenged to a full dose. Patients with co‐allergy to pistachio or walnut were challenged to the respective nut. Results: Forty‐four of 50 OIT‐treated patients (88%) compared to 0% in controls tolerated a dose of 4000 mg cashew protein at the end of the study (odds ratio 8.3, 95% CI 3.9–17.7, p < 0.001). An additional three patients were desensitized to 1200 mg cashew protein, and three patients stopped treatment. Three patients (6%) were treated with injectable epinephrine for home reactions. Desensitized patients had decreased SPT, sIgE, basophil reactivity, and increased sIgG4, following treatment. Following cashew desensitization, all pistachio (n = 35) and four of eight walnut co‐allergic patients were cross‐desensitized to the respective nut. All (n = 44) patients consuming a low cashew dose for ≥6 months following desensitization passed a full‐dose cashew OFC. Conclusions: Cashew OIT desensitizes most cashew‐allergic patients and cross‐desensitizes to pistachio. Safety is similar to OIT for other foods. [ABSTRACT FROM AUTHOR]

The American Polistes species venom mixture – that of P. annularis, P. fuscatus, P. metricus and P. exclamans– was the only commercially available mixture for diagnosis and therapy until 1996. However, these species of Polistes are not present in Europe, where P. dominulus and P. gallicus and to a lesser extent P. nimphus are widespread. The aim of this study was to assess the allergenic differences among the commercial American mix, P. dominulus and P. gallicus venom in European patients and therefore to verify if this mixture is suitable for diagnosis in these patients. We carried out skin tests, radioallergosorbent tests (RAST) and RAST inhibition in Italian patients with adverse reactions to Polistes stings. RAST inhibition results demonstrated that cross-reactivity between the American and European species is only partial and that P. dominulus and P. gallicus venoms have exclusive allergens. Skin tests and direct RAST confirmed these results and also showed that European Polistes venom is more suitable than the American mix in Italian patients. Moreover, we found a high rate of cross-reactivity between P. dominulus and P. gallicus. To conclude, P. dominulus and/or P. gallicus venoms are necessary for diagnosis and therefore in the therapy of European patients. [ABSTRACT FROM AUTHOR]

Background: Ole e 7 is a nonspecific lipid transfer protein (nsLTP) from olive pollen, one of the main allergenic pollens worldwide. This allergenic nsLTP is responsible for severe symptoms in regions with high olive pollen exposure, where many Ole e 7‐sensitized patients exhibit a co‐sensitization to the peach nsLTP, Pru p 3. However, there is no evidence of cross‐reactivity, which explains this observed co‐sensitization. Therefore, the purpose of this study was to explore the relationship between Ole e 7 and Pru p 3. Methods: A total of 48 patients sensitized to Ole e 7 and/or Pru p 3 were included in the study. Specific IgE serum levels were measured by ImmunoCAP 250 and ELISA. Inhibition assays were performed to determine the existence of cross‐reactivity between both nsLTPs. Allergic response was analyzed ex vivo (basophil activation test) and in vitro (RBL‐2H3 mast cell model). Results: Common IgG and IgE epitopes were identified between both allergens. IgE‐binding inhibition was detected in Ole e 7–monosensitized patients using rPru p 3 as inhibitor, reaching inhibition values of 25 and 100%. Ex vivo and in vitro assays revealed a response against rPru p 3 in four (31%) Ole e 7–monosensitized patients. Conclusions: Our results suggest that Ole e 7 could play a new role as primary sensitizer in regions with high olive pollen exposure, leading to the peach nsLTP sensitization. This co‐sensitization process would occur because of the cross‐reactivity between Ole e 7 and Pru p 3 observed in some allergic patients. [ABSTRACT FROM AUTHOR]

Abstract: Background: Profilins are dominant pan‐allergens known to cause cross‐sensitization, leading to clinical symptoms such as pollen‐food syndrome. This study aimed to determine the T‐cell response to Phl p 12 in profilin‐sensitized patients, by measuring the prevalence, strength and cross‐reactivity to clinically relevant profilins. Methods: The release of Phl p allergens from pollen was determined by mass spectrometry and immunochemistry. T‐cell responses, epitope mapping and cross‐reactivity to profilins (Phl p 12, Ole e 2, Bet v 2 and Mal d 4) were measured in vitro using PBMCs from 26 Spanish grass‐allergic donors IgE‐sensitized to profilin. Cross‐reactivity was addressed in vivo using 2 different mouse strains (BALB/c and C3H). Results: Phl p 12 and Phl p 1 are released from pollen simultaneously and in similar amounts. Both T‐cell response frequency (17/26 donors) and strength were comparable between Phl p 12 and Phl p 1. T‐cell cross‐reactivity to other profilins correlated with overall sequence homology, and 2 immunodominant epitope regions of Phl p 12 were identified. Data from mice immunized with Phl p 12 showed that cross‐reactivity to Bet v 2 was mediated by conserved epitopes and further influenced by additional genetic factors, likely to be MHC II. Conclusion: The strength, prevalence and cross‐reactivity of T‐cell responses towards Phl p 12 are comparable to the major allergen Phl p 1, which supports the hypothesis that T cells to Phl p 12 can play an important role in development of allergic symptoms, such as those associated with pollen‐food syndrome. [ABSTRACT FROM AUTHOR]

Abstract: Background: Little is known about the prevalence of food allergy (FA) in China. The aim of this study was to investigate the disparity of FA between urban and rural areas in southern China. Methods: EuroPrevall questionnaire responses were obtained from 5542 school‐age children in urban Guangzhou and 5319 in rural Shaoguan. A case‐control study enrolled 190 children with adverse reactions (ARs) after food intake as cases and 212 controls in Guangzhou, whereas 116 cases and 233 controls in Shaoguan. These subjects underwent skin prick test (SPT) and serum IgE measurements to food and inhalant allergens. Allergen extracts from shrimp, house dust mite (HDM), and cockroach were prepared for IgE cross‐reactivity testing in 23 Guangzhou and 20 Shaoguan shrimp‐sensitized subjects. Results: The prevalence of ARs to shrimp was higher in Guangzhou than in Shaoguan children (3.5% vs 1.4%, P < .001). However, sensitization rate to shrimp (SPT: 3.7% vs 11.2%, P = .015; IgE: 12.6% vs 36.2%, P < .001) and cockroach (SPT: 5.3% vs 33.5%; IgE: 2.6% vs 27.6%, P < .001) was lower in Guangzhou. A significant correlation between shrimp and HDM/cockroach IgE was found in Shaoguan children. The proportions of positive IgE to tropomyosin (Pen a 1, Der p 10) were lower than 7.4% in both areas. Cockroach allergen has a significantly higher inhibition rate of binding to IgE to house dust mite allergens in Shaoguan sera. Conclusion: Shrimp is a common allergic food in southern China. Higher proportion of shrimp sensitization in rural subjects could be explained by cross‐reactivity to cockroach. Tropomyosin was not a major allergen responding to the cross‐reactivity. [ABSTRACT FROM AUTHOR]

EoE patients show variable sensitization patterns to food and aeroallergens. The value of allergy testing in adult EoE patients is unclear. Component-resolved diagnosis ( CRD) may offer additional insights into sensitization patterns. The aim of this study was to characterize sensitization patterns in adult EoE patients using CRD. Serum from 76 patients (17 female), age 38.6 ± 1.5 years, was analyzed for reactivity to 112 different allergen components using an immuno-solid-phase allergen chip ( ISAC). We observed any sensitization in 59 patients (78%), of which 54 patients were polysensitized. Aeroallergen sensitization, mostly against components of grass or tree pollen, or house dust mite, was observed in 74% of the patients. Birch pollen ( rBet v 1) sensitization with cross-reactivity to food allergen components was observed in 30 patients (39%). In conclusion, food sensitizations in EoE patients are mainly caused by cross-reactivity to food allergens after primary birch pollen sensitization. Pollen and food sensitizations may cause or maintain esophageal inflammation in EoE patients. CRD provides more insight into sensitization patterns, identifies additional food allergen sensitizations and might be useful to direct dietary therapy in EoE. [ABSTRACT FROM AUTHOR]

To cite this article: Aalberse RC, Crameri R. IgE-binding epitopes: a reappraisal. Allergy 2011; 66: 1261-1274. Abstract Here, we discuss various questions related to IgE epitopes: What are the technical possibilities and pitfalls, what is currently known, how can we put this information into hypothetical frameworks and the unavoidable question: how useful is this information for patient care or allergenicity prediction? We discuss the information obtained by (i) 3D structures of allergen-antibody complexes; (ii) analysis of allergen analogues; (iii) mimics without obvious structural similarity; (iv) mAbs competing with IgE; (v) repertoire analysis of cloned IgEs, and other developments. Based on limited data, four suggestions are presented in the literature: (i) IgE might be more cross-reactive than IgG; (ii) IgE might be more often directed to immunologically 'uninviting' surfaces; (iii) IgE epitopes may tend to cluster and (iv) IgE paratopes might have a higher intrinsic flexibility. While these are not proven facts, they still can generate hypotheses for future research. The hypothesis is put forward that the IgE repertoire of switched B-cells is less influenced by positive selection, because positive selection might not be able to rescue IgE-switched B cells. While this might be of interest for the discussion about mechanisms leading to allergen-sensitization, we need to be modest in answering the 'clinical relevance' question. Current evidence indicates the IgE-epitope repertoire is too big to make specific IgE epitopes a realistic target for diagnosis, treatment or allergenicity prediction. In-depth analysis of a few selected IgE epitope-peptides or mimitopes derived from allergen-sequences and from random peptide libraries, respectively, might well prove rewarding in relation to diagnosis and prognosis of allergy, particularly food allergy. [ABSTRACT FROM AUTHOR]

To cite this article: Gámez C, Sánchez-García S, Ibáñez MD, López R, Aguado E, López E, Sastre B, Sastre J, del Pozo V. Tropomyosin IgE-positive results are a good predictor of shrimp allergy. Allergy 2011; 66: 1375-1383. Abstract Background: Shrimp is a common cause of food allergy. Our aims were to determine the value of IgE antibodies in the diagnosis of shrimp allergy and to study red shrimp ( Solenocera melantho) tropomyosin both as a new allergen and as a cross-reactive IgE-binding protein. Methods: We have studied 45 subjects. Skin prick test (SPT) was carried out in all subjects, and specific IgE (sIgE) to shrimp, recombinant and natural shrimp tropomyosins rPen a 1 and nPen m 1, recombinant Der p 10, and Dermatophagoides pteronyssinus was assessed by fluoroimmunoassay and/or immunoblotting. Double-blind, placebo-controlled food challenges were carried out to confirm diagnosis of shrimp allergy. Also, in vitro inhibition tests were performed to evaluate cross-reactivity. Results: Shrimp allergy was confirmed in 18 shrimp-allergic patients. Skin prick test and IgE antibodies to shrimp were positive in all shrimp-allergic patients; sIgE to rPen a 1 was detected in 98% of these patients. Of the 18 shrimp-tolerant patients, 61% had positive SPT to shrimp, 55% were IgE-positive to shrimp, and 33% showed IgE antibodies to rPen a 1. Determination of IgE to rPen a 1 yielded a positive predictive value of 0.72 and a negative predictive value of 0.91. Conclusion: IgE levels to rPen a 1 provided additional value to the diagnosis of shrimp allergy. Some allergens in mite extract are recognized by patients who are allergic to shrimp, though their clinical relevance remains unknown. [ABSTRACT FROM AUTHOR]

Background: Administration of imipenem-cilastatin to patients with IgE-mediated hypersensitivity to β-lactams has always been considered potentially harmful. Recent studies have demonstrated the tolerability of carbapenems (imipenem-cilastatin and meropenem) in patients with IgE-mediated hypersensitivity to β-lactams; there are no studies on this topic regarding patients with cell-mediated allergy to β-lactams. The aim of this study is to assess cross-reactivity and tolerability of imipenem in patients with cell-mediated allergy to β-lactams. Methods: From our database we selected 73 patients with cell-mediated allergy to β-lactams, diagnosed by means of immediate-type skin tests, delayed reading intradermal tests, patch tests and detection of specific IgE. Patients with negative patch tests with imipenem-cilastatin underwent an intramuscular test dosing. Results: Our patients had a total of 94 nonimmediate reactions to penicillins. All patients had positive patch tests and/or delayed reading intradermal tests for at least one of the penicillin reagent tested and negative immediate-type skin tests and specific IgE. Four patients out of 73 had a positive patch tests to at least one penicillin reagent and imipenem-cilastatin showing cross-reactivity. Sixty-four patients underwent the imipenem-cilastatin intramuscular test dosing and none of them had a clinical reaction. Conclusions: Our rate of cross-reactivity between imipenem-cilastatin and other β-lactams was 5.5%. This result is different from previous findings and this may be explained by the fact that we investigated patients with cell-mediated allergy to β-lactams. Patients with cell-mediated allergy to β-lactams should undergo patch tests and a tolerance challenge test before treatment with imipenem-cilastatin. [ABSTRACT FROM AUTHOR]

Background: Sensitization to rats and mice can develop in laboratory animal workers exposed to only one species. Reasons for this dual sensitization are unclear but may reflect a genetic predisposition to developing allergy (atopy) or alternatively cross-reactivity between rat and mouse urinary allergens. We examined cross-reactivity between rat and mouse urine and the effect atopy has on dual sensitization in laboratory animal workers. Methods: In a cross-sectional study the frequency of sensitization to rat and/or mouse was analysed in 498 employees exposed to both rat and mouse at work and 220 to rat only. RAST inhibitions, western blots and blot inhibitions were carried out on a subset of five individuals to assess cross-reactivity. Results: Fourteen per cent of workers were sensitized to rats and 9% to mouse. Over half (62%) of rat sensitized individuals were also mouse sensitized and the majority (91%) of mouse sensitized individuals were also rat sensitized. IgE cross-reactivity was demonstrated between rat and mouse urine using RAST inhibitions. Rates of atopy did not differ between rat only sensitized individuals compared with those sensitized to both species. Sensitization to cats and rabbits was more common amongst those with dual sensitization. Conclusions: Dual sensitization to rat and mouse reflects IgE cross-reactivity rather than atopy. Individuals with dual sensitization are more likely to be sensitized to other animal allergens. These findings will have implications for individuals working with only one rodent species who develop sensitization and symptoms to be aware of the potential for allergy to other species. [ABSTRACT FROM AUTHOR]

Background: Hymenoptera venom allergy can be effectively cured with specific immunotherapy, thus the correct identification of the allergen is essential. In the case of multiple skin and serum positivities it is important to know if a cross-reaction among venoms is present. We studied by CAP-inhibition assays the degree of cross-reactivity between Vespula vulgaris and Polistes dominulus. Methods: Serum samples were obtained from consecutive patients with a clinical history of grade III–IV reactions to hymenoptera sting and with nondiscriminative skin/CAP positivity to both Vespula and Polistes. Inhibition assays were carried out with a CAP method, incubating the sera separately with both venoms and subsequently measuring the specific immunoglobulin E (IgE) to venoms themselves. Results: Forty-five patients (33 male, mean age 40 years, age range 12–74, total serum IgE 242 ± 168 kU/l) were included. Their specific IgE to Vespula and Polistes were 12.03 ± 5.70 kU/l and 10.7 ± 2.0 kU/l ( P = NS), respectively. At the CAP-inhibition assays, in 25 patients a >75% heterologous inhibition by P. dominulus venom against V. vulgaris-specific IgE was found. In six subjects V. vulgaris venom effectively inhibited the P. dominulus-specific IgE. In the remaining 14 cases the CAP-inhibition test provided intermediate and not discriminative results. Conclusion: In 31/45 patients, the double sensitizations to venoms were probably the result of cross-reactions and the CAP-inhibition allowed identifying the true double sensitizations. This approach may be helpful for the correct prescription of immunotherapy in the case of V. vulgaris and P. dominulus double positivity. [ABSTRACT FROM AUTHOR]

Mustard IgE-mediated allergy is supposed to be a rare cause of food allergy, and its clinical features and cross-reactivities have not been fully elucidated.A prospective study was carried out, recruiting mustard allergic patients, and paired control subjects. A clinical questionnaire was administered, and skin-prick tests (SPT) with panels of aeroallergens and foods, serum extraction forin vitrotests and double-blind placebo-controlled food challenges (DBPCFC) were performed.Thirty-eight mainly adult patients, with 10.5% reporting systemic anaphylaxis, were included in the study [age (mean ± SD): 21.9 ± 8.6 years]. DBPCFC were performed in 24 patients, being positive in 14 cases (58.3%). Patients with positive outcome showed significantly greater mustard SPT than those with negative outcome (8.2 ± 3.7vs5.3 ± 2.4 mm,P < 0.05), and the receiver-operating characteristic (ROC) curve analysis yielded a cut-off value for mustard commercial SPT of 8 mm, with a specificity of 90% (95% CI, 55.5–98.3), and a sensitivity of 50% (95% CI, 23.1–76.9). A significant association between mustard hypersensitivity and mugwort pollen sensitization was found (97.4% of patients), with partial cross-reactivity demonstrated by UniCAP System inhibition assays. All patients showed sensitization to other members of Brassicaceae family, and cross-reactivity among them was also confirmed. Moreover, significant associations with nut (97.4%), leguminous (94.7%), corn (78.9%), and Rosaceae fruit (89.5%) sensitizations were also shown. Around 40% of these food sensitizations were symptomatic, including food-dependent exercise-induced anaphylaxis in six patients.Mustard allergy is a not-uncommon disorder that can induce severe reactions. Significant associations with mugwort pollinosis and several plant-derived food allergies are demonstrated, suggesting a new mustard–mugwort allergy syndrome. A relationship between this syndrome and food-dependent exercise-induced anaphylaxis is also reported. [ABSTRACT FROM AUTHOR]

Jackfruit allergy has been reported just once. It is unknown whether this food allergy is caused by direct sensitization or cross-sensitization to pollen allergens.Establish whether jackfruit allergy is linked to birchpollen allergy.Two jackfruit allergic patients and five patients with birchpollen-related apple allergy were recruited. Sensitization to pollen and plant foods was assessed by skin prick test (SPT), radio-allergosorbent test (RAST) and immunoblot. RAST analysis was performed for Bet v 1 and Mal d 1. Cross-reactivity was evaluated by RAST and immunoblot-inhibition. Biological activity of immunoglobulin E (IgE) was measured by basophil histamine release. Allergy to jackfruit was evaluated by double-blind placebo-controlled food challenge (DBPCFC) or open challenge (OC).In both patients DBPCFC confirmed the reported jackfruit allergy. SPT was 41 and 27 mm2 and specific IgE to jackfruit was 5.9 and 0.8 IU/ml, respectively. Immunoblot analysis revealed IgE reactivity at Mr of approximately 17 kDa. The Bet v 1-related nature of this allergen in jackfruit was demonstrated by RAST and immunoblot inhibition. To assess whether jackfruit allergy might be common in patients with combined birchpollen-fruit allergy, five such patients underwent an OC with jackfruit. All five had OA-like symptoms.Jackfruit allergy can be added to the list of birchpollen-related food allergies. Increased consumption of this fruit will result in a rise in allergic reactions. [ABSTRACT FROM AUTHOR]

Background: Guinea pigs are important sources of inhalant allergens in home and working environments. However, little is known about the molecular characteristics and the relevant epitopes of guinea pig allergens. Recently, several allergens have been identified in hair extract and urine, and the major allergen Cav p 1 (20 kDa) has been characterized. Objective: The aim of the present study was to isolate and to characterize a further major allergen from guinea pig hair with 17 kDa. Methods: Guinea pig hair extract was fractionated using anion exchange chromatography and reverse-phase high performance liquid chromatography. Analyses were carried out by sodium dodecyl sulphate–polyacrylamide gel electrophoresis, 2D-PAGE, immunoblotting, immunoblot inhibition, glycoprotein detection, and N-terminal amino acid sequencing. Results: The nonglycosylated 17 kDa allergen, which was named Cav p 2, was purified to homogeneity. On the basis its 15 N-terminal residues, there was 69% identity with a sequence of Bos d 2, an allergenic protein from cow dander belonging to the lipocalin family. The 2D-immunoblotting analyses of guinea pig hair extract demonstrated that Cav p 2 and Cav p 1, contained several isoforms with pI values ranging from 3.6 to 5.3. The 2D-immunoblot inhibition disclosed cross-reactive IgE epitopes on the allergens Cav p 2 and Cav p 1. Furthermore, Cav p 1 can form both monomers (20 kDa) and dimers (40–42 kDa). Conclusion: These studies provide important information on the isoallergen character of two relevant guinea pig allergens Cav p 1 and Cav p 2 as well as on their cross-reactive properties. [ABSTRACT FROM AUTHOR]

Background: The present study investigates immunological cross-reactivity between Par o 1, the major pollen allergen of Parietaria , and the VP4 protein of rotavirus, a microorganism that is world-wide the main etiological agent of gastroenteritis in children. Methods: IgG and IgE cross-reactivity was assessed by direct binding and competitive inhibition assays (ELISA and DARIA), using recombinant VP4 from rhesus infectious rotavirus (RR), synthetic peptides and Par o 1-specific antibodies affinity purified from pooled and individual human sera. Results: Antibodies specifically binding Par o 1, affinity purified from the sera of 35 individuals with skin test positivity to Parietaria and from 14 pools, were extensively cross-reactive with RRVP4. Cross-reactive binding was specifically inhibited by synthetic peptides derived from the C-terminal sequences of the VP4 proteins from human and rhesus infectious rotavirus. Conclusions: This study reports the first evidence of cross-reactivity between an allergen and a viral antigen. [ABSTRACT FROM AUTHOR]

Background: Limpet is a mollusc that is frequently found along the shores of warm seas. Few allergic reactions to limpet have been described, and cross-reactivity with house-dust mites has not been established. Methods: We report five patients with anaphylactic reactions due to limpet ingestion. A limpet extract was prepared and skin prick tests (SPT), radioallergosorbent assays (RAST), sodium dodecylsulfate polyacrylamide gel electrophoresis (SDS-PAGE), and IgE-immunoblotting were performed. In order to evaluate cross-reactivity, an immunoblotting inhibition assay with Dermatophagoides pteronyssinus was also done. Results: All patients were asthmatics sensitized to house-dust mites. In each case, severe bronchospasm was evidenced, and three required mechanical ventilation. Positive SPT with limpet extract was found in the four patients tested. RAST showed specific IgE on each patient's sera. Immunoblotting showed several allergenic fractions with a wide molecular weight range (15–250 kDa). D. pteronyssinus inhibited IgE-binding molecules above 50 kDa in the limpet extract, particularly one molecule of 75 kDa. Conclusions: We describe five patients with IgE-mediated limpet allergy. Severe bronchospasm was the most important symptom. Cross-reactivity with D. pteronyssinus was demonstrated. [ABSTRACT FROM AUTHOR]

Background: Allergic contact sensitization to ‘para amino’ compounds is frequent and the spectrum of cross-reactivity between members of this chemical group is variable. Methods: A retrospective analysis of clinical patch test data obtained with a special test series in the centres of the Information Network of Departments of Dermatology (IVDK) between 1995 and 1999. Results: In the 638 patients tested with the above test panel positive reactions were observed most often to p- aminoazobenzene (16.2%), p- phenylenediamine (14.1%), p- toluylenediamine (10.0%), followed by 4,4′-diaminodiphenylmethane (8.5%), Disperse Orange 3 (8.4%) and p- aminophenol (3.1%). Among the 544 patients tested with p- phenylenediamine and all seven additional ‘para amino’ compounds, concordance between reactions varied greatly. The stronger the positive test reaction to p- phenylenediamine, p- toluylenediamine or p- aminoazobenzene, the more frequently additional positive reactions to the other compounds were observed. Conclusions: A screening employing several ‘para amino’ compounds is necessary to describe the individual spectrum of allergic contact sensitization, as there is no reliable marker substance. Further research should aim at (i) establishing the mechanism of cross-reactivity to ‘para amino’ compounds and (ii) identifying exposures in the environment. Background: Allergic contact sensitization to ‘para amino’ compounds is frequent and the spectrum of cross-reactivity between members of this chemical group is variable. Methods: A retrospective analysis of clinical patch test data obtained with a special test series in the centres of the Information Network of Departments of Dermatology (IVDK) between 1995 and 1999. Results: In the 638 patients tested with the above test panel positive reactions were observed most often to p- aminoazobenzene (16.2%), p- phenylenediamine (14.1%), p- toluylenediamine... [ABSTRACT FROM AUTHOR]

Background: Thiomucase® is a mucopolysaccharidase obtained from ovine tissues mainly used to facilitate the diffusion of local anaesthetics and in the treatment of cellulitis. A patient with an anaphylaxis in relation to the intramuscular administration of Thiomucase® is reported. Objective: To investigate Thiomucase® allergens and their possible relationship with dander allergens and animal albumins. Material and methods: Skin prick tests (SPT) and serum-specific IgE were performed with Thiomucase® and danders. Thiomucase® SDS-PAGE immunoblotting was performed in order to study allergens. RAST/CAP inhibition and SDS-PAGE immunoblotting inhibition were carried out to study the cross-reactivity. Results: Skin prick tests (SPT) were positive to Thiomucase®, animal dander (cat, dog, sheep, other), bovine serum albumin (BSA), and echinococcus. Specific IgE was also positive to Thiomucase®, animal dander (cat, dog, sheep, other), BSA and echinococcus. In the RAST-CAP inhibition assays BSA was nearly completely inhibited by Thiomucase®, Thiomucase® was partially inhibited by BSA and cat and Echinococcus granulosus was partially inhibited by sheep and Thiomucase®. In the Thiomucase® SDS-PAGE immunoblotting several proteins fixed IgE, ranging from 20 kDa to > 94 kDa, the strongest with 43 kDa. The IgE fixation to BSA, cat and sheep in the SDS-PAGE immunoblotting was completely inhibited by the preincubation of the serum with Thiomucase®. Conclusions: An IgE-mediated anaphylaxis to Thiomucase® is documented. Multiple allergens are recognized in Thiomucase® by the patient serum, the main with 43 kDa. Partial cross-reactivity with BSA, cat dander and sheep dander is documented. [ABSTRACT FROM AUTHOR]

Background: Several associations have been described between tree and plant pollens and certain foods. The objective of this study is to verify whether there is cross-reactivity between Platanus pollen and vegetable origin foods. Methods: We selected 56 patients allergic to vegetable foods and subjected them to cutaneous tests with aeroallergens and vegetable foods. A statistical analysis was performed to evaluate the association of Platanus pollen with foods and with other aeroallergens. Later, a specific IgE determination was performed as well as a RAST (radioallergosorbent) inhibition experiment, to verify the existence of cross-reactivity in vitro. Results: In the cutaneous tests we found a positive correlation between Platanus pollen and hazelnut, peanut, banana and celery. The results of the RAST inhibition experiment indicate an important cross-reactivity between the pollen of Platanus acerifolia and hazelnut and banana fruit, and an intermediate cross-reactivity with celery and peanut. Conclusion: We have described an association between the pollen of the Platanus tree and some vegetable foods such as hazelnut, banana, peanut and celery. This association could be explained by the in vitro IgE cross-reactivity detected. [ABSTRACT FROM AUTHOR]

Background: Diplotaxis erucoides is a common weed of the Brassicaceae family widespread in southern and central Europe. Methods: A total of 410 consecutive patients referred for allergy study of rhinoconjunctivitis and/or asthma were skin tested with D. erucoides pollen, 14 proving positive. A purified D. erucoides pollen extract was prepared to perform quantitative skin tests, provocation tests, immunoblotting, and EIA inhibition in the 14 sensitized patients. Results: Three patients, directly involved in viniculture, had rhinoconjunctivitis related to D. erucoides pollen. No D. erucoides -related symptoms were observed in most patients, who were also sensitized to Artemisia pollen. RAST was positive in 12/14 patients and nasal provocation tests in 9/12. The molecular masses of the most prevalent IgE-binding proteins ranged from 26 to 27.5 and from 31 to 34 kDa. D. erucoides pollen inhibited the IgE-binding of other sensitizing pollens in the three viniculture workers, whereas both Artemisia and D. erucoides pollen produced similar heterologous inhibition in the pooled serum of the remaining, nonclinically affected, D. erucoides -sensitized patients. Conclusions: D. erucoides pollen may be an important prevalent aeroallergen, particularly in rural areas. It may act as an occupational allergen in vineyard workers, in whom it seems to be the primary sensitizing agent, playing a secondary cross-reactive role in other sensitized patients. [ABSTRACT FROM AUTHOR]

Background: Allergens in Plantago lanceolata have not been characterized yet. The objective was to characterize some plantain-pollen allergens and to investigate the cross-reactivity between plantain and grass pollens. Methods: Sera from four patients monosensitive to plantain pollen and from eight grass-pollen-allergic patients showing strong skin reactivity to plantain pollen in the skin prick test (SPT) underwent immunoblot analysis with both Plantago and grass mix extract. Moreover, immunoblot inhibition experiments were done with grass mix extract as inhibitor. Results: All four sera from plantain-allergic patients reacted to two distinct bands at 17 and 19 kDa, and 2/4 sera showed further reactivity to a 40-kDa protein, which in one case represented the most prominent IgE-binding allergen. Plantain-monosensitive subjects did not show any reactivity to grass-pollen extract, and preabsorption of their sera with grass-pollen extract did not cause any loss of reactivity to plantain pollen. Sera from all eight grass-pollen-allergic controls reacted to a 30-kDa protein in plantain pollen, and some sera showed cross-reactivity to higher and lower molecular-weight structures as well. In all cases, plantain reactivity was totally abolished by preabsorption of sera with grass-pollen extract. A preliminary investigation by immunoblot showed that polyclonal IgG anti-Phl p 5 (but not polyclonal Phl p 1) from rabbit reacted to a 30-kDa protein in plantain pollen. Conclusions: Three specific allergens (of 17, 19, and 40 kDa, respectively) have been detected in plantain pollen. Further studies on a larger number of patients will determine whether these proteins may be considered major allergens. Cross-reactivity between grass and plantain pollen is mainly caused by a 30-kDa protein in plantain pollen. Group 5 grass-pollen allergen is probably responsible for most grass/plantain cross-reactivity. [ABSTRACT FROM AUTHOR]

Background: Although beef is a main source of protein in Western diets, very little has been published on allergic reactions to beef or the main allergens implicated in these reactions. The aim was to evaluate the IgE antibody response to beef in suspected meat-allergic subjects and assess cross-reactivity of beef with other vertebrate meats. Methods: Fifty-seven sera from suspected meat-allergic subjects were tested by grid blot for specific IgE antibodies to vertebrate meats (beef, lamb, pork, venison, and chicken), and the patterns of recognition of meat proteins were assessed by immunoblot studies. Results: A 160-kDa band, identified as bovine IgG, was detected in raw beef in 83% (10/12) of beef-allergic subjects but in only 24% of the beef-tolerant subjects. IgE reactivity to a band of similar mol. mass was detected also in lamb and venison, but rarely in pork or chicken. Complete inhibition of the IgE reactivity to the bovine IgG was obtained with lamb, venison, and milk. IgE reactivity to this band also completely disappeared when beef or lamb extracts were separated under reducing conditions, indicating conformational epitopes. Conclusions: Bovine IgG appears to be a major cross-reacting meat allergen that could predict beef allergy. Further studies with oral IgG challenges should be performed to document the conclusion that in vitro reactivity correlates with clinical hypersensitivity. The role of bovine IgG in other bovine products such as milk, dander, or hair must also be studied, and the hypothesis that it is a cross-reacting allergen with other mammalian products validated. [ABSTRACT FROM AUTHOR]

Atopic dermatitis (AD) patients often demonstrate positive skin prick test results and serum IgE antibodies to a range of different yeasts. This has been thought to be due to cross‐reactivity. In this study, the cross‐reactivity of IgE and IgG antibodies between mannan and crude antigens of Pityrosporum ovale, Candida albicans, and Saccharomyces cerevisiae and crude antigens of Cryptococcus albidus and Rhodotorula rubra was examined by RAST and ELISA inhibition with two serum pools of AD patients. We found cross‐reacting IgE and IgG antibodies. In the IgE response, the main cross‐reacting pattern was the mannan region, although inhibition could be achieved also with crude antigens of C. albicans, S. cerevisiae, and, to some extent, C. albidus. P. ovale was the most potent inhibitor of IgE‐binding components, and against it the highest IgE antibody levels were detected in AD serum pools. In contrast, C. albicans was found to be the most important inducer of IgG antibodies, since the IgG level against P. ovale mannan in both AD serum pools was very low. Cross‐reacting antibodies were also seen in ELISA inhibition with both crude and mannan antigens, but since the IgG antibody level of P. ovale mannan in AD serum pools was low, further studies are needed to confirm the IgG results. [ABSTRACT FROM AUTHOR]

The present study deals with the detailed investigation of the IgE antibody response of a gum arabic-allergic patient. The patient showed multiple serologic and skin test sensitizations to a range of pollen, other inhalants and foods, and bee venom, and to the recombinant allergens Bet v 1 and Bet v 2. Moreover, the patient's serum reacted strongly to gum-arabic extract. The NaIO4-treated and thus deglycosylated extract showed no binding to IgE. In contrast, removal of the protein backbone by basic hydrolysis did not deplete the IgE reactivity. Therefore, it is concluded that the gum arabic-specific IgE antibodies of this patient were mainly directed against the carbohydrate fraction of this material. In IgE-inhibition assays, cross-reactions occurred in the range of 60% between gum arabic and known immunogenic N-glycans containing α1-3-linked fucose. Since the inhibition graphs were not parallel and the inhibition was not complete with heterologue antigens, the cross-reacting epitopes of gum arabic appeared to be different from the latter well-known cross-reactive carbohydrate determinants (CCD). Inhibition may have been caused by a partial immunologic identity of the investigated carbohydrate moieties. A strong IgE response to the fucose-containing glycan from bromelain was measured in a glycan ELISA that utilizes purified glycopeptides at the solid phase. This response, which may explain the multiple sensitizations without clinical significance diagnosed in the patient, could originate from inhalation of pollen, which is known to contain similar glycans, or from occupational sensitization during work as a baker and confectioner. Since the gum-arabic protein showed only very weak participation in the IgE reactivity, the clinical symptoms of the patient caused by gum arabic may be attributed to carbohydrate epitopes. Due to the repetitive polysaccharide sequence of gum arabic, several epitopes for the cross-linking of IgE should exist. [ABSTRACT FROM AUTHOR]

The article discusses the general rule concerning the interactions between allergen and cell-bound immunoglobulin E (IgE) antibody. It highlights the differences between carbohydrate epitopes and peptide epitopes in terms of structures and immunologic recognition. It also discusses the modifying effects of IgE antibodies and its structural variability in glycosylation patterns through chemical analysis of myeloma proteins and of reactivity to lectins.

To obtain more information on IgE cross-reactivity between bumblebee venom and honeybee venom, we tested sera from venom-sensitized patients for specific IgE against venoms from the European bumblebee (Bombus terrestris), the North American bumblebee (Megabombus pennsylvanicus), and the honeybee (Apis mellifera). RAST, RAST-inhibition, and immunoblotting experiments indicate that bumblebee venom and honeybee venom contain venom-specific IgE-binding epitopes. These results suggest that immunotherapy using honeybee venom may not be effective in all bumblebee venom-allergic patients. Our experiments also revealed differences in IgE binding for venom from European and American bumblebees. [ABSTRACT FROM AUTHOR]

Species of the Cupressaceae family are a worldwide cause of respiratory allergies. We used monoclonal antibodies (mAbs) to investigate the presence and the nature of cross-reacting epitopes shared by various components within Cupressus arizonica pollen extract (CaE) or by CaE and pollen extract from C. Sempervirens (CsE). mAbs were produced in mice immunized with whole CaE (4A6 and 5E6) or with the major allergen components (2D5). Their reactivity was investigated by ELISA and immunoblotting before and after CaE periodate treatment. Cross-reactivity was evaluated by ELISA inhibition and immunoblotting. mAbs 2D5 and 4A6 recognized periodate-resistant epitopes, whereas the mAb 5E6 reacted with a periodate-sensitive determinant. The former mAbs recognized epitopes present on CaE major allergen and also shared by other components. mAb 5E6 showed a spread reactivity on CaE, with exclusion of the major allergen. When the three mAbs were tested with CsE, a restricted pattern of reactivity to mAbs 2D5 and 4A6 was obtained, whereas mAb 5E6 maintained a spread reactivity. The CaE major allergen is represented by two components recognized by human IgE and sharing common epitopes, as proven by mAbs reactivity. The use of these mAbs demonstrates that cross-reactivity within CaE components and between CaE and CsE is due to the presence of periodate-sensitive as well as -resistant epitopes. [ABSTRACT FROM AUTHOR]

The prevalence of sensitization to the storage mites Acarus siro (AS), Tyrophagus putrescentiae (TP), and Lepidoglyphus destructor (LD) was studied in 250 sera of patients with different degrees of sensitization to the house-dust mite Dermatophagoides pteronyssinus (DP) by measuring IgE binding to extracts of the storage mites. Additionally, allergenic crossreactivity between DP and the storage mite species was studied by RAST inhibition with five individual sera (and a pool of these sera) with moderate IgE levels to all three storage mites and to DP. Increased serum IgE to storage mites was found in 46% of the 200 patients sensitized to DP. Increased prevalence rates of IgE titers to storage mites were associated with higher IgE levels to DP In 50 sera without sensitization to DP, only five sera showed increased IgE to one of the storage mites. Extracts of TP almost completely inhibited the IgE binding to AS, and vice versa. DP inhibited IgE binding to all storage mites up to 60%, whereas IgE binding to DP was only minimally inhibited by extracts of storage mites. In conclusion, cosensitization to storage mites is a frequent finding in patients sensitized to DP. Although this is largely the result of cross-reactivity between different mite species, it may nevertheless be of clinical significance in patients exposed to storage mites. [ABSTRACT FROM AUTHOR]

The article presents information on a survey that was undertaken to describe what characterizes in vitro the clinically relevant cross-reactivities in birch-pollen-sensitized patients and the severity of symptoms. The survey also probed whether there is a correlation between the magnitude of the IgE response to basic proteins, apple, hazelnut, celery and carrot and the clinical situation. Results of the survey revealed that Birch-pollen-allergic patients with symptoms after eating apple, hazelnut and carrot showed significantly higher IgE levels to the respective food items than asymptomatic patients. There were no significant differences in the IgE level between patients with localized or systemic symptoms.

Anisakis simplex larvae parasitize animals used as seafood and can produce a specific immune response in man. The ingestion of seafood contaminated with stage three of A. simplex larvae can induce a specific IgE response with clinical symptoms, usually urticaria, even if the fish is cooked before ingestion and the invasive infestation power destroyed by heating. Our preliminary studies showed a strong association of A. simplex sensitization with Ascaris lumbricoides, Daphnia, chironomid spp., Atlantic shrimp (Pandalus borealis), and German cockroach (Blattella germanica). We conducted the cross-reactivity study with cockroach, a ubiquitous insect, and Chironomidae (red mosquito larvae), a work-related allergen, without any possibility of Anisakis contamination. Serum samples were collected from 60 pediatric patients, with serum specific IgE to A. simplex. Both specific-IgE and immunoblot-inhibition studies, with a serum pool from 18 patients, were performed to determine whether the association of sensitizations to nematodes and arthropods was due to immunologic cross-reactivity. In addition, serum samples from 21 of 60 patients who showed also sensitization to German cockroach were used for individual immunoblot studies. In the serum pool, dose-dependent inhibition of B. germanica and Chironomus spp, was observed after preincubation with the A. simplex extract. Immunoblot of Anisakis, inhibited with Chironomus and German cockroach, yielded a partial blot inhibition but mainly on bands below 41 kDa. Blot inhibition of German cockroach and Chironomus with Anisakis was dose related. The band patterns in individual blots were heterogeneous, but most of them had bands of 30-43 kDa. None of these sera recognized allergens in the 14-kDa area. In our study, CAP-inhibition and immunoblot-inhibition analysis of Anisakis showed that several IgE-binding components could be shared by the three allergens. [ABSTRACT FROM AUTHOR]

Our investigation aimed to produce and characterize a kiwi extract and to use this extract to investigate a possible cross-reactivity with birch pollen. Kiwi was extracted in two buffers: phosphate-buffered saline (PBS) and borate-buffered saline (BBS). Extraction in BBS produced a double amount of protein, and a more stabile extract. Tandem crossed-immunoelectrophoresis showed that the BBS and PBS extracts had several common, but also a few individual, proteins. The mixture of both extracts was assumed to represent the most complete allergen extract. The allergenic properties of the kiwi extract were investigated by immunoblotting (IB), RAST, and histamine-release (HR) test in 15 birch-pollen-allergic patients (eight of them with clinical kiwi allergy) and one with clinical monoallergy to kiwi. All eight birch-pollen-allergic patients with kiwi allergy and the kiwi-monoallergic patient were positive in kiwi IB binding most frequently to proteins of 10-12 and 20-25 kDa. With our extract, RAST was positive in four kiwi-allergic and one non-kiwi-allergic patient, whereas the HR test was positive in five kiwi-allergic patients and negative in all non-kiwi-allergic patients. RAST and IB inhibition demonstrated cross-reactivity between birch-pollen and kiwi allergens due to a 10-12 kDa protein. In conclusion, a kiwi extract with allergenic properties was produced, and, by the methods used, cross-reactivity was demonstrated between birch-pollen and kiwi allergens. [ABSTRACT FROM AUTHOR]

In recent years, patients allergic to amoxicillin (AX) but with good tolerance of penicillin G (PG) have been described. It has been suggested that the epitope implicated in this type of sensitization might be located on the side-chain of the AX molecule. Thus, cross-reactivity between AX and cephadroxil (CEPH), a cephalosporin which shares an identical side-chain with AX, is suspected. This study aimed to demonstrate clinical cross-reactivity between AX and CEPH in patients allergic to AX and showing good tolerance of PG. in 76 of 576 subjects with suspected allergic reaction to PG and/or AX. the diagnosis of allergy was confirmed. All of these had specific IgE to PG, penicillin V, or AX, and/or positive skin tests to PPL (penicilloyl-polylysine), or MDM (minor determinant mixture), or PG. or AX, and/or positive challenge tests with PG and/or AX. Sixteen subjects (21%) allergic to AX (11 with positive skin test and five with positive challenge test to AX) and good tolerance of PG (all with negative parenteral challenge test) were selected. These 16 patients were subsequently challenged with CEPH (up to 500 mg). Fourteen patients tolerated CEPH, and two (12%) had an immediate allergic reaction. Our study indicates that allergy to the side-chain of aminopenicillins seems to have little clinical relevance in patients with allergic reactions to aminopenicillins but with good tolerance of PG, as 88% of patients with this clinical characteristic tolerate a cephalosporin which shares an identical side-chain. It seems that IgE from most of these patients recognizes an epitope different from the side-chain and the β-lactam ring. [ABSTRACT FROM AUTHOR]

Sera of 17 patients receiving immunotherapy for house-dust mite allergy were tested for IgE antibodies against snail and shrimp. Serum samples were taken at the start of immunotherapy and 14-20 months later. While the average IgE response to mite, Der p 1, and Der p 2 did not alter significantly, the average response to snail showed a significant increase. This included two conversions from negative to strongly positive. These novel IgE antibodies against snail were shown to be cross-reactive with mite. Three patients had a positive RAST for shrimp. For one of them, a strong increase of IgE against shrimp (and snail) was observed, in 2/3 snail/shrimp-positive sera, IgE antibodies against the cross-reactive allergen tropomyosin from mite, snail, and shrimp were demonstrated. A clear IgE response to snail (>10% binding in a snail RAST) was confirmed by a positive skin prick test (SPT) for 6/10 patients. The two patients with antitropomyosin IgE also had a positive SPT or shrimp, and demonstrated the oral allergy syndrome (OAS) after eating shrimp. The observations in this study indicate that house-dust mite immunotherapy is accompanied by the induction of IgE against foods, including tropomyosin-reactive IgE. Food allergy (OAS) was observed in patients that had IgE antibodies against this cross-reactive allergen. In conclusion, induction of IgE during mite immunotherapy might occasionally cause allergy to foods of invertebrate animal origin. [ABSTRACT FROM AUTHOR]

Ampicillin and benzylpenicillin conjugated to human serum albumin were used as immunogens in order to obtain antihaptenic IgG responses in outbred guinea pigs according to different schedules, all involving complete Freund's adjuvant. The individual responses were characterized by ELISA and by ELISA inhibition using ampicillin, benzylpenicillin, and carbenicillin peptidic conjugates for coating and for inhibition. In several instances, drastically reduced cross-reactivity and even its absence were observed, although the penicillin antigens differ only in the side-chain. The notion that the invariantly present thiazolidine ring will always provide significant binding to antibodies against all penicillins differing only in the side-chain has to be dropped. The experiments were performed in relation to newer findings of clinical penicillin-allergy skin testing which suggest that benzylpenicillin-based reagents alone are not able to detect or predict all reactions against semisynthetic penicillins. The experimental evidence here obtained corroborates this conclusion. [ABSTRACT FROM AUTHOR]

We have purified four allergens from Helianthus annuus (sunflower) pollen, hereafter named as allergens a, b, c, and d. Under native conditions, allergen a has a mol. mass of 32, allergen b has one of 24, and allergens c and d each have one of 55 kDa. At the least, allergens b, c, and d demonstrate charge heterogeneity, and the electrophoretic mobility of allergens c and d increases when these allergens are deglycosylated with trifluoromethanesulfonic acid. Cross-reactivity among the four allergens and with the whole extract is very high, and each allergen recognizes IgE in a high proportion of patients sensitized to sunflower pollen. [ABSTRACT FROM AUTHOR]

The avocado (Av) is a fruit that belongs to the Lauraceae family. We report 17 patients with immediate hypersensitivity to avocado. Clinical manifestations in relation to avocado ingestion were as follows: systemic anaphylaxis in seven patients, angioedema/urticaria in six, vomiting in two, bronchial asthma in one, and rhinoconjunctivitis in one Skin prick test (SFT) with fresh avocado was positive in all patients with the Strong avocado variety (SAy) and in 14 patients with the Hass avocado variety (HAy). Our patient-associated sensitizations were as follows: 10 to latex, eight to chestnut, eight to banana four to kiwi, and four to walnut. Avocado sensitizations patients with latex allergy' were typically middle-aged women, professionally exposed to latex, who also exhibited frequent associated sensitizations to chestnut. banana; and other fruits. Specific IgE against avocado was demonstrated in 11 of our patients by both commercial CAP and RAST with avocado extract coupled to nitrocellulose disks. Despite its lower protein content. SAv seems to be more allergenic than HAv both in vivo and in vitro. On incubating a pool of sera from our patients with avocado, latex , chestnut and banana extracts, a progressive RAST inhibition was obtained with SAv- and chestnut-marked disks. This suggests the existence of common antigenic determinants among these allergens. [ABSTRACT FROM AUTHOR]

In this study, the homologous C-termini of Lol p I, Lol p II, and Lol p III were shown to contain cross-reactive B-cell epitopes. This was demonstrated by inhibition studies with purified Lol p I, II, and III and synthetic peptides of their C-termini. It was ruled out that the observed cross-reactivity was caused by cross-contamination of the purified allergens. Both human IgE and IgG bound to the C-terminus of Lol p I. These antibodies were cross-reactive with Lol p II and, more specifically, with its C-terminus. Within a small panel of allergic patients, no cross-reactivity with Lol p III was found. A hyperimmune polyclonal rabbit antiserum against Lol p I also recognized the Lol p I C-terminus. As for human antibodies, cross-reactivity with Lol p II and its C-terminus was demonstrated. Cross-reactivity with Lol p III was demonstrated with C-terminal peptides, but not with native Lol p III. A polyclonal rabbit antiserum against Lol p II bound to the C-terminal peptides of both Lol p II and III. This binding was inhibited with Lol p I, confirming that cross-reactive structures exist not only on the C-termini of Lol p II and Lol p I, but also of Lol p III and Lol p I. The existence of cross-reactivity between Lol p I and Lol p II and III possibly contributes to the frequently observed cosensitization for these allergens in grass-pollen-allergic patients. [ABSTRACT FROM AUTHOR]

Low-temperature, acetone powder extracts were prepared from mature fruit of 16 apple strains. SDS--PAGE and immunoblot analysis revealed great variation in the relative amounts of the 18-kDa apple allergen in these extracts. EAST (RAST) scores, measured with individual and pool sera from patients allergic to birch pollen and apples, ranged from 0.2 to 4.0 and were related to the relative amount of the 18-kDa protein. These findings were confirmed by ELISA-inhibition assays, dose-related histamine release, semiquantitative evaluation of immunoblots by absorption/reflection densitometry, and skin prick tests with extracts of Golden Delicious, Boskoop, and Jamba apples (corresponding to a high, low, and very low 18-kDa allergen content). Additional open oral challenge tests were performed with two apple-allergic patients and 15 and 16 apple strains. With all methods, the deduced allergenic potency decreased in the following order: Golden Delicious > Boskoop > Jamba. Therefore, we concluded that the IgE-binding potency of apple strains depends on the occurrence of the 18-kDa allergen. [ABSTRACT FROM AUTHOR]

Hemoglobins of the Diptera (insect) family Chironomidae have been identified as causative allergens in asthmatic patients. In this study, 229 Japanese, 17 Taiwanese, and 92 Swedish sera from atopic patients were tested for antibodies against Chi tI, the hemoglobin from the European midge species Chironomus thummi, and against crude extracts from the Japanese midges Tokunagayusurika akamusi (T. akamusi) and Cricotopus sylvestris (Cr. Sylvestris). Nearly 40% of patients showed a positive reaction to Cr. Sylvestris extract, which contains no hemoglobin. This result is probably due to the presence of other partially cross-reacting allergens than hemoglobin. Nearly all tested Japanese serum samples showed cross-reactivity between Chi t I and Cr. Sylvestris, a finding which is evidence for common epitopes in both midge species. Furthermore, an overall good correlation between the amounts of IgE antibodies against Chi t I and Chi t I component III was found in sera from Swedish, Japanese, and German patients. [ABSTRACT FROM AUTHOR]

Ornamental plants have long been used for indoor decoration. An example is the India rubber tree (Ficus elastica). With the increased popularity of green plants, both in private homes and public premises, small-leaf species, such as sweeping fig or Ficus benjamina (Fb), have become widely used. Exposure to dust from Fb may cause sensitization and allergic airway symptoms, which among occupationally exposed plant keepers occur both in atopics and non-atopics. The serum reactivity to sap extracts from Fb and seven other indoor plants of the genus Ficus were investigated with RAST and a RAST inhibition technique, using sera from 12 atopic subjects and 12 plant keepers, sensitized to Fb. The allergenic similarity between the different extracts was found to be extensive. The specific IgE antibodies with the highest concentrations in serum were those against Fb and its variegate form, ‘star light’, with decreasing values for the other species, especially those with larger leaves. The binding of IgE antibodies to the other Ficus RAST discs could be completely inhibited by extract of Fb. These reactions were probably due to cross-reactivity. Sensitization is believed to occur by inhalation of allergen-enriched dust, emanating from the leaves of the plants. The high allergenic potency of the species with many small leaves may be due to their large total leaf area. [ABSTRACT FROM AUTHOR]

Sera of patients suffering from birch pollinosis were studied in the radio-allergo-sorbent test (RAST) for the presence of IgE antibodies to various allergens of vegetable origin. The sera selected were positive in the RAST for both birch pollen and fruits. IgE antibodies directed against at least three different cross-reacting determinants in birch pollen were detected. In addition to periodate-susceptible cross-reacting determinants, which are found on a number of glycoproteins, two non-related periodate-resistent determinants were found in birch pollen, with molecular weights of 20 and 18 kD, respectively. The 20-kD component appears to be responsible for the co-occurrence of the binding of IgE to allergens of fresh fruits, whereas the 18-kD component appears to cause the cross-reactivity among grass pollen, potato and fruits. [ABSTRACT FROM AUTHOR]

The occurrence of proteins cross-reacting with allergens in hen's egg white was studied in turkey duck, goose and seagull egg whites, in hen egg yolk, and in hen and chicken sera and flesh. The study was based upon quantitative immunoelectrophoretic techniques. The different egg whites were all found to contain proteins cross-reacting with most of the allergens in hen's egg white, but the degree of cross-reactivity varied considerably among the various egg whites;. All egg whits contained proteins able to bind human IgE-antibody in the sera of patient with allergy to hen's egg white. Several proteins cross-reacting with allergens in hen's egg white were, also detected in egg yolk and in hen and chicken sera and flesh. Clinical implications of the results are discussed. [ABSTRACT FROM AUTHOR]

Radioallergosorbent testing (RAST) of sera from subjects sensitized to wheat and rye flour indicated that there is significant reaction with seed extracts of 12 cereals (wheat, durum wheat, triticale, cereal rye, barley, rye grass, oats, canary grass, rice, maize, sorghum and Johnson grass). Results were evaluated in terms of taxonomic relationships and of the electrophoretically determined protein composition of the cereal extracts. RAST uptakes were uniformly low in sera from four rhinitic bakers, yet were significantly above the levels for non-allergic and cord sera. Much higher RAST uptakes were obtained with sera from four asthmatic bakers when tested with wheat and its close relatives, but there was still reasonably high reactivity with more distantly related cereals. RAST inhibition experiments indicated in a more direct way the extent of cross-reactivity between grain extracts of wheat, rye, barley and oats. One baker had a history of more severe attacks of breathlessness following inhalation of rye flour compared with wheat flour. This was confirmed by bronchial challenge testing, but the comparison was not obviously consistent with the results of prick testing or estimation of histamine released from his leucocytes. The results as a whole suggested that the bran layers of cereal grains are at least as allergenic as flour. [ABSTRACT FROM AUTHOR]

Studies a delayed-type allergy to systemic corticosteroids. Case study of a patient; Results of a patch testing.