IgE-binding Components Research Articles

Anaphylaxis caused by the new ant, Pachycondyla chinensis : Demonstration of specific IgE and IgE-binding components

Background: There have been no reports dealing with the pathogenic mechanism and IgE-binding components in patients with anaphylaxis caused by a sting from Pachycondyla chinensis . Objectives: This study was conducted to observe the clinical features of patients with P chinensis –induced anaphylaxis. The roles of specific (s) IgE and sIgG4 antibodies were evaluated, and IgE-binding components were identified. Methods: Seven patients with P chinensis –induced anaphylaxis and 15 unexposed control subjects were enrolled. P chinensis ants were collected at the patients’ homes, and venom was prepared as P chinensis extract. Five patients complained of bee venom–induced anaphylaxis and had positive sIgE levels to yellow jacket venom, wasp venom, or both as well. Serum sIgE and sIgG4 were detected by means of ELISA. To identify IgE-binding components within P chinensis extracts, 12% SDS-PAGE with immunoblot analysis was applied. Results: All patients had positive skin prick test responses to P chinensis antigen and positive sIgE levels. Five (71%) patients had positive sIgG4 levels. Eight IgE-binding components (58, 46, 3l, 29, 27, 25, 22, and 12 kd) were noted, and the component at 12 kd was the most frequently found allergen (85%). IgE ELISA inhibition tests were performed on 2 groups of sera: one from patients with anaphylaxis induced by both P chinensis and bee venom (group A) and the other from patients with anaphylaxis induced by P chinensis venom alone without bee venom allergy (group B). ELISA inhibition tests with serum from group A showed significant inhibitions with addition of P chinensis extract, partial inhibitions with yellow jacket antigen, and minimal inhibitions with wasp or imported fire ant antigens. However, ELISA inhibition tests with serum from group B showed significant inhibitions with P chinensis antigen but no inhibition with wasp, yellow jacket, or imported fire ant antigens. Conclusions: IgE-mediated reactions contributed to the development of P chinensis –induced anaphylaxis. Eight IgE-binding components and one major allergen (12 kd) were identified. Further studies will be needed to clarify the role of sIgG4 and to identify allergenic relationships with major bee and wasp allergens. (J Allergy Clin Immunol 2001;107:1095-9.)

Occupational asthma and rhinitis caused by multiple herbal agents in a pharmacist

Herb agents have been widely used for centuries in the Orient and they have been cultivated throughout Asia. There have been a few cases of occupational allergy caused by herb materials. We report a case of occupational asthma and rhinitis caused by six herb materials in a pharmacist working at a pharmacy. We sought the role of immediate hypersensitivity in herbal agent-induced asthma in a pharmacist. The patient had strong positive responses on skin prick test to extracts of six herb materials: Chunkung (Cnidii rhizoma), Banha (Pinellia ternata), Sanyak (Dioscorea radix), Kangwhal (Ostericum koreanum), Danggui (Angelica radix), and Kunkang (Zingiberis rhizoma). Bronchoprovocation tests showed an early asthmatic response to Danggui extract. Serum specific IgE antibodies to Chunkung, Banha, and Sanyak were detected by ELISA with no specific IgE bindings to Kangwhal, Danggui, and Kunkang extracts. Twelve percent sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and IgE immunoblotting revealed one IgE binding component (60 kD) within Chunkung extract, two (10, 25 kD) in Banha, and four (33, 34, 65, 98 kD) in Sanyak. Basophil histamine release test revealed that Danggui extract could release a greater amount of histamine from basophils in the patient than in a healthy control. Chunkung, Banha, and Sanyak may induce IgE-mediated bronchoconstriction in an exposed worker, and Danggui can cause bronchoconstriction by direct histamine-releasing effect from mast cells in a sensitized patient.

Identification of IgE-binding components of citrus red mite in sera of patients with citrus red mite–induced asthma

Background: Our previous investigations demonstrated that citrus red mite (CRM) antigen could cause IgE-mediated bronchoconstriction in exposed farmers working on citrus farms. Objective: This study was performed to confirm IgE-binding components and major allergens within the CRM antigens. Methods: Ten subjects who had been diagnosed as having CRM-induced asthma were enrolled. Serum-specific IgE antibodies to CRM antigens were measured by using an ELISA. To identify IgE-binding components and major allergens, SDS-PAGE, 2-dimensional PAGE, IgE-immunoblot analysis, and amino acid sequencing of major allergens were performed. Results: All the asthmatic subjects had high specific IgE antibodies to CRMs. Twelve percent SDS-PAGE analysis showed more than 10 protein bands ranging from 6 to 64 kd. SDS-PAGE and IgE-immunoblot analysis with each individual serum showed 5 IgE-binding components (11, 24, 35, 40, and 64 kd), with 2 (24 and 35 kd) of them bound in more than 50% of the study subjects. Two-dimensional PAGE and IgE-immunoblot analysis demonstrated that the major allergen at 24 kd had 2 bands with different isoelectric points of 4.75 and 5.1. Thirty-five kilodaltons had one band with an isoelectric point of 4.75. All amino acid sequencing of the 2 major allergens was performed, which was not homologous with any previously characterized allergens. Conclusion: Five IgE-binding components and 2 major allergens (24 and 35 kd) were identified within the CRM antigen. The N-terminal amino acid sequence of the 2 major allergens (24 and 35 kd) was determined. (J Allergy Clin Immunol 2001;107:244-8.)

Identification of vacuolar serine proteinase as a major allergen of Aspergillus fumigatus by immunoblotting and N-terminal amino acid sequence analysis.

Aspergillus species are common airborne fungi that have been identified as causative agents of extrinsic bronchial asthma. More than 10 allergens from A. fumigatus have been recently characterized by cDNA cloning. The objective of this study is to identify A. fumigatus allergens through immunoblot analysis using sera from asthmatic patients. IgE-binding components of A. fumigatus and IgE cross-reactivity among allergens of different prevalent airborne fungal species were analysed by immunoblot and immunoblot inhibition, respectively, using sera from asthmatic patients. The N-terminal amino acid sequences of major allergens identified were determined by Edman degradation. Among two batches (70 and 41 sera) of asthmatic sera tested, 19 (27%) and 14 (34%), respectively, have IgE immunoblot reactivity towards components of A. fumigatus. A 34-kDa protein that reacts with IgE antibodies in 15 (79%) and 11 (79%) of the 19 and 14 positive samples, respectively, may be considered a major allergen of A. fumigatus. The N-terminal amino acid sequences of the 34 kDa major allergen and the 30.5 and 30 kDa IgE-binding components of A. fumigatus showed sequence identity to that of the vacuolar serine proteinase from A. fumigatus. The results from immunoblot inhibition show IgE cross-reactivity among major allergens of A. fumigatus, P. notatum and P. oxalicum. Results obtained suggest that the 34 kDa major allergen of A. fumigatus may be a vacuolar serine proteinase. There is IgE cross-reactivity among serine proteinase allergens of A. fumigatus, P. notatum and P. oxalicum.

Assessment of IgE allergen specificity among latex-allergic health care workers: review of IgE-binding components of various latex extracts.

Allergic reactions to natural rubber latex have increased during the past 10 years, especially in many health care workers who have high exposure to latex allergens both by direct skin contact and by inhalation of latex particles from powdered gloves. Development of satisfactory diagnostic methods to verify the presence of latex allergy in health care workers requires characterization of the immunoreactive proteins in latex products and identification of specific IgE antibodies in sensitized patients. A number of different latex preparations are now available for in vitro evaluations. Utilizing different in vitro methods, this study examines IgE sensitization to components of latex in a selected population of hospital employees, employing a raw natural latex glove extract and various commercial latex extracts. Two hundred hospital employees exposed to latex were evaluated using an allergy history questionnaire. To further identify sensitized patients, two different specific IgE tests and leukocyte histamine release tests were performed using a panel of latex extracts obtained from different manufacturers. Sodium dodecylsulfate polyacrylamide electrophoresis (SDS-PAGE) profiles were obtained. Sera from 34 subjects suspected to be latex-sensitized were IgE immunoblotted to assess the presence of IgE antibodies directed toward specific latex proteins. Thirty-four participants (17%) were considered sensitized to latex by a positive clinical history in conjunction with positive specific IgE tests (18 individuals) and/or positive histamine release tests (26 individuals). Significant extract differences in both the histamine release response profile and the frequency of positive test results were noted in the histamine release test. Significant individual differences in patients' latex epitope-specificity were found by IgE immunoblotting, substantiated by sodium dodecylsulfate polyacrylamide profiles revealing differences in protein band patterns among the various extracts. The IgE immunoblots indicated that the majority of patients reacted to proteins with molecular weights of 14, 21, 30 to 35, and 42 kD; the 30 to 35 kD protein being predominant. Seven subjects (22%) of the 34 considered to be latex-sensitized did not reveal binding of specific IgE in immunoblots. One latex extract (Stallergene) with the widest IgE-reacting protein repertoire identified the majority of subjects (63%) as latex sensitive by leukocyte histamine release and also provided the best quantitative histamine release test results. Only by testing with a combination of latex extracts were all sensitized individuals identified. This study demonstrates that currently several in vitro methods may be necessary to detect IgE sensitization to latex. Latex extracts to be employed in future skin tests must contain a wide epitope repertoire of IgE-binding proteins to identify all latex-sensitized individuals.

Pine processionary caterpillar as a new cause of immunologic contact urticaria

Nowadays, caterpillars are included among the agents that elicit contact urticaria by a non-immunologic mechanism. Our objective was to find the rôle that an IgE-mediated mechanism could have among patients with suspected contact urticaria from pine processionary caterpillars. 16 patients with suspected contact urticaria from this caterpillar were studied by prick testing and specific IgE detection by immunoblotting. 87% of the patients had a positive prick test and immunoblotting for caterpillar extract. In these allergic patients, the symptoms associated with urticaria were: angioedema (79%), conjunctivitis (36%) and severe anaphylaxis (14%). The most frequent localizations of the wheals were the neck (100%) and forearms (93%). Angioedema was more frequent on the eyelids (79%). The IgE-immunoblot detected in the caterpillar extract several reactive bands, with apparent MWs from to 45 to 4kDa. A total of 5 major allergens were identified, but a band around 14kDa proved to be the dominant allergen. Sensitization to Thaumetopoea pityocampa was found to be the most important mechanism of airborne contact urticaria from this caterpillar. Low-MW proteins are the main IgE binding components of crude caterpillar extract.

Class I chitinases, the panallergens responsible for the latex-fruit syndrome, are induced by ethylene treatment and inactivated by heating

Background: Class I chitinases have been identified as the major panallergens in fruits associated with the latex-fruit syndrome, such as avocado, banana, and chestnut. However, other plant foods containing these enzymes have not been related to this syndrome. Objective: We sought out class I chitinases in the green bean, a legume that is known to express chitinases but is not associated with latex allergy, and examined whether the content or allergenic activity of chitinases can be modified by physical or chemical treatments. Methods: IgE-binding proteins in untreated bean samples, as well as in ethylene- and heat-treated samples, were detected by using a pool of sera from patients with latex-fruit allergy. Putative allergens were purified by cation-exchange chromatography and characterized by N-terminal sequencing, enzymatic activity assays, immunodetection with sera and antichitinase antibodies, and immunoblot inhibition tests. Skin prick tests with untreated and heated purified allergens were also carried out. Results: An IgE-binding protein of 32 kd that was also recognized by antichitinase antibodies was detected in green bean extracts. This reactive component was strongly induced by ethylene treatment. The protein, designated PvChI, was identified as a class I chitinase closely related to the major avocado allergen Prs a 1. Immunoblot inhibition assays demonstrated cross-reactivity between both allergens. Purified PvChI induced positive skin prick test responses in 7 of 8 patients with latex-fruit allergy. Heat treatment of both Prs a 1 and PvChI produced a full loss of their allergenic capacities both in vitro and in vivo. No IgE-binding component was detected in the white mature bean in which the main isolated 32-kd protein corresponded to a nonreactive phytohemagglutinin. Conclusions: Ethylene treatment induces the expression of plant class I chitinases. The allergenic activity of plant class I chitinases seems to be lost by heating. This fact could explain why plant foods containing these putative allergens that are consumed after cooking are not usually associated with the latex-fruit syndrome. (J Allergy Clin Immunol 2000;106:190-5.)

183 Anaphylaxis caused by new ant, Pachycondyla chinensis: determination of specific IgE and IgE binding components

183 Anaphylaxis caused by new ant, Pachycondyla chinensis: determination of specific IgE and IgE binding components

Cross-reacting IgE and IgG antibodies to Pityrosporum ovale mannan and other yeasts in atopic dermatitis.

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.

Serological characterization of allergens in poppy seeds.

Poppy seeds in food can induce immediate-type allergic reactions ranging from mild local symptoms to severe anaphylactic reactions. Previous publications showed that poppy seeds cross-react with other plant-derived allergens. The IgE-binding components have not been defined so far. We analysed sera from 11 patients with adverse reactions after ingestion of poppy seed-containing food by IgE-immunoblotting. Nine of 11 patients showed concomitant IgE binding to allergens of birch, mugwort or grass pollen in RAST-CAP, and suffered from characteristic seasonal symptoms. Ten of 11 patients showed IgE binding to a 45-kDa protein, 4/11 to a 34-kDa, 5/11 to a 17-kDa, 5/11 to a 14-kDa, and 3/11 to a 5-kDa component. Furthermore, individual IgE binding to proteins of 20, 25, 30 and 40 kDa proteins could be observed. Periodate treatment of blots markedly reduced the IgE binding capacity of the 40- and 45-kDa compounds, indicating the existence of IgE epitopes of the carbohydrate type. Inhibition studies indicated the presence of homologues of pollen allergens in extracts from poppy seeds, i.e. Bet v 1 and Bet v 2. The serological analysis showed IgE binding to protein and sugar components of poppy seeds. The 40- and 45-kDa allergens are glycoproteins and contain IgE binding carbohydrate moieties. Moreover, cross-reacting homologues of pollen allergens including Bet v 1 and profilin were detected in poppy seed extract.

Alkaline Serine Proteinase Is a Major Allergen of Aspergillus flavus, a Prevalent Airborne Aspergillus Species in the Taipei Area

Background: Aspergillus species are prevalent indoor airborne fungi and have been identified to be a causative agent of human allergic disorders. In the present study, we identified, purified and characterized the allergen(s) from Aspergillus flavus, a predominant airborne Aspergillus species in the Taipei area. Methods: The IgE–binding components of A. flavus were identified by SDS–PAGE immunoblotting with sera from asthmatic patients. The N–terminal amino acid sequences of the major allergens were determined by Edman degradation. The allergenic cross–reactivity among allergens from different fungi was analyzed by immunoblot inhibition using sera from asthmatic patients. The detected major allergen was purified from the culture medium. It was further characterized in terms of its N–terminal amino acid sequence, its IgE–binding activity and its enzymatic activity. Results: The results of the immunoblot analysis indicate that a 34–kD component that has high IgE–binding (63%) frequency is a major allergen of A. flavus. The N–terminus of this 34–kD major allergen (GLTTQKSAP) has high sequence identity with that of the 34–kD alkaline serine proteinase major allergen of A. oryzae. Results from immunoblot inhibition studies indicate that IgE cross–reactivity occurs among the 34–kD major allergens of A. flavus, A. fumigatus and Penicillium citrinum. The 34–kD major allergen of A. flavus was purified from the culture medium by ammonium sulfate precipitation and DEAE ion exchange chromatography. The N–terminal amino acid sequence of the purified allergen (Asp fl 13) is identical to that determined previously for the 34–kD major allergen in the crude extract of A. flavus. The IgE immunoblot reactivity to the 34–kD major allergen in the crude extract can be dose–dependently inhibited by the purified Asp fl 13. The degree of IgE binding to the 34–kD major allergen in the crude extract correlates with that of the purified Asp fl 13 in sera of 8 asthmatic patients. The purified Asp fl 13 has proteolytic activity with casein as substrate at pH 8.0. This enzymatic activity can be inhibited by either phenylmethylsulfonyl fluoride or diethylpyrocarbonate. Conclusion: Our results suggest that the 34–kD alkaline serine proteinase is a major allergen of A. flavus. There was IgE cross–reactivity among allergens of A. flavus, A. fumigatus and P. citrinum.

Evaluation of IgE-sensitization to fungi in HIV-positive patients with eczematous skin reactions.

Human immunodeficiency virus infection is associated with declining immune function and polyclonal B-cell activation leading to elevated IgE-levels. In selected patient categories, increased total IgE may be associated with allergic diseases. Furthermore, a significant number of patients with low CD4+ cell numbers have various skin manifestations, eg, eczema and dermatophytosis. Patients with chronic fungal infections and a tendency to produce increased levels of specific IgE may become allergic and IgE-mediated mechanism may contribute to inflammatory reactions in the skin. This study investigates IgE-sensitization of patients infected with human immunodeficiency virus to a panel of fungal extracts of Candida albicans, Fusarium moniliforme, Penicillium notatum, Pityrosporum ovale, and Trichophyton rubrum. Fifteen HIV-positive patients with eczematous skin manifestations and five non-atopic healthy controls were evaluated by basophil histamine release and skin prick test with fungal extracts. The extracts were separated by sodium dodecylsulfate-polyacrylamide gel electrophoresis under reducing conditions and analyzed by IgE-immunoblotting with sera from the patients and controls. Thirteen of 15 patients (87%) released histamine to one or more of the fungi. Skin prick test was positive to one or more fungi in 7 (47%) patients. Patient sera revealed binding to a wide range of IgE-binding components present in the fungal extracts. The IgE response was most often directed against a 46-kD main protein in the Candida albicans extract. There was no correlation between total serum IgE, CD4+ cell counts, and frequency of IgE-sensitization to fungi. The human IgE response in HIV-infected patients appears to be polyspecific and may be directed against various fungi of which Candida albicans may be an important allergen. It is possible that the sensitization is due to frequent infections with Candida albicans in this patient population. No unspecific fungal reactions were noted among control patients. These results suggest that allergen-specific IgE-mediated mechanism may contribute to the pathogenesis of the eczematous skin reaction in HIV-infected patients.

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

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. 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. 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. 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.

Molecular characterization of Dau c 1, the Bet v 1 homologous protein from carrot and its cross-reactivity with Bet v 1 and Api g 1.

Up to 70% of patients with birch pollen allergy exhibit the so-called oral allergy syndrome, an IgE-mediated food allergy. The most frequent and therefore best characterized pollen-fruit syndrome is apple allergy in patients suffering from tree pollen-induced pollinosis. The occurrence of adverse reactions to proteins present in vegetables such as celery and carrots in patients suffering from pollen allergy has also been reported. cDNAs for Bet v 1 homologous proteins have been cloned from celery, apple and cherry. Objective The aim of the study was to identify Bet v 1 homologues from carrot (Daucus carota), to isolate the respective cDNA, to compare the IgE-binding capacity of the natural protein to the recombinant allergen and determine the cross-reactivity to Api g 1 and Bet v 1. Molecular characterization of the carrot allergen was performed using IgE-immunoblotting, cross-inhibition assays, N-terminal sequencing, PCR-based cDNA cloning and expression of the recombinant protein in Escherichia coli. A 16-kDa protein from carrot was identified as a major IgE-binding component and designated Dau c 1. Sequencing corresponding cDNAs revealed three extremely similar sequences (Dau c 1.1, 1.2 and 1.3) with an open reading frame of 462 bp coding for 154 amino acid residues. Purified recombinant Dau c 1.2 was tested in immunoblots displaying IgE-binding capacity comparable to its natural counterpart. Cross-inhibition assays verified the existence of common B-cell epitopes present on Dau c 1, Api g 1 as well as on Bet v 1.

Isolation and characterization of major banana allergens: identification as fruit class I chitinases.

Banana allergy has been associated with the latex-fruit syndrome. Several IgE-binding components, the relevant ones being proteins of 30-37-kDa, have been detected in banana fruit, but none of them have been isolated and characterized yet. Objective To purify and characterize the 30-37 kDa banana allergens. Fifteen patients allergic to banana were selected on the grounds of a latex-allergic population. Prick by prick tests to this fruit were performed. Total and specific IgE to banana were determined. Banana allergens were isolated by affinity chromatography, followed by cation-exchange chromatography. Their characterization includes N-terminal sequencing, enzymatic activity assays, immunodetection with sera from allergic patients and with antichitinase antibodies, and CAP and immunoblot inhibition tests. Skin prick tests with banana extracts and with the purified allergens were also carried out. Two major IgE-binding proteins of 34 and 32 kDa, also recognized by polyclonal antibodies against chestnut chitinases, were immunodetected in crude banana extracts. Purification and characterization of both proteins have allowed their identification as class I chitinases with an hevein-like domain. Each isolated allergen reached inhibition values higher than 90% in CAP inhibition assays, and fully inhibited the IgE-binding by the crude banana extract when tested by an immunoblot inhibition method. The two purified allergens provoked positive skin prick test responses in more than 50% of the banana-allergic patients. Class I chitinases with an hevein-like domain are major allergens in banana fruit. Their presence in other fruits and nuts, such as avocado and chestnut, could explain the cross-sensitization among these foods.

Characterization of allergens from Penicillium oxalicum and P. notatum by immunoblotting and N-terminal amino acid sequence analysis.

Penicillium species are important causative agents of extrinsic bronchial asthma. However, little is known about the allergens of these ubiquitous fungal species. Objective The object was to analyse the composition, the allergenic cross-reactivity and the N-terminal sequences of allergens from two prevalent airborne Penicillium species, P. oxalicum and P. notatum. The allergenic composition and the immunoglobulin (Ig)E cross-reactivity were analysed by immunoblot and immunoblot inhibition, respectively, using sera from asthmatic patients. The N-terminal amino acid sequences of major allergens were determined by Edman degradation. Allergens identified were also characterized by immunoblotting using monoclonal antibody (MoAb) PCM39 against the alkaline serine proteinase major allergen of P. citrinum. Among the 70 asthmatic sera tested, 18 (26%) and 17 (24%) had IgE immunoblot reactivity towards components of P. oxalicum and P. notatum, respectively. Major allergens (> 80% frequency of IgE-binding) from both species are the 34 and 30 kDa proteins of P. oxalicum and the 34 and 32 kDa proteins of P. notatum. IgE cross-reactivity among these major allergens and the 33 kDa major allergen of P. citrinum can be detected by immunoblot inhibition studies. The N-terminal amino acid sequences of the 34 kDa allergen of P. oxalicum and of the 32 and the 28 kDa allergens of P. notatum share homology with sequences of the vacuolar serine proteinase from Aspergillus fumigatus. The N-terminal amino acid sequence of the 34 kDa allergen of P. notatum shows sequence homology with that of alkaline serine proteinase from P. citrinum. Results obtained from immunoblotting showed that MoAb PCM39 reacted with the 34, 30 and 16 kDa IgE-binding components of P. oxalicum, and with the 34, 32 and 28 kDa IgE-binding components of P. notatum. Results obtained suggest that the 34 kDa major allergen of P. oxalicum may be a vacuolar serine proteinase. The 34 and the 32 kDa major allergens of P. notatum may be the alkaline and the vacuolar serine proteinases of P. notatum, respectively. The 30 and 16 kDa IgE-binding components of P. oxalicum and the 28 kDa IgE-binding component of P. notatum may be breakdown products of the 34 and the 32 kDa major vacuolar serine proteinase allergens of P. oxalicum and P. notatum, respectively.

Pityrosporum species as a cause of allergy and infection.

Pityrosporum species as a cause of allergy and infection.

Identification and characterization of allergens in two species of tuna fish.

In countries where fish consumption is high, allergenic reactions to fish are common among patients diagnosed with food hypersensitivity. For tuna fish, allergenic proteins are not known. In addition, it is not known how the tuna fish extracts should be processed to obtain optimal in vitro diagnostic performance and to preserve labile antigens. The aim of this study was to characterize IgE-binding components of Yellowfin and Albacore tuna fish. Various tuna fish extract preparations were fractionated by sodium dodecylsulfate-polyacrylamide gel electrophoresis and transferred to nitrocellulose and analyzed by using tuna positive patients with different Western blot profiles. The functional activity of the extracts was evaluated by basophil histamine release. Immunoblot analysis showed the majority of patients responding to Yellowfin tuna extract. Inhibition studies using immunoblot analysis and histamine release testing showed a specific protein with a molecular weight of approximately 46 kD that is present in Yellowfin tuna, but absent in Albacore. Only defatted, lyophilized tuna fish extracts were able to induce histamine release from sensitized basophils although IgE-binding components were detected in fresh raw, fresh cooked, and canned tuna fish preparations. These studies indicate that patient sera may contain different tuna fish species IgE specific antibodies directed against unique species specific allergens present in Yellowfin and Albacore tuna fish. Possibly, extracts should contain specific allergenic components from both Albacore and Yellowfin to cover the epitope heterogeneity observed in sera from patients developing IgE antibodies against tuna fish.

Hypersensitivity of Bronchial Asthmatics to Cockroach in Taiwan

This study was performed to test the hypersensitivity of asthmatics to American and German cockroaches, which are both common in Taiwan. A total of 236 asthmatic patients received skin prick test using allergen extracts from both American and German cockroaches, and 596 sera from asthmatic patients were analyzed for their specific IgE against German cockroach extract. The results of skin test showed that 39.4 and 36.4% asthmatic patients were hypersensitive to American and German cockroaches. Fifteen among 236 patients were only allergic to American cockroaches and 8 were only allergic to German cockroaches. Using the Pharmacia CAP system, 36% of the sera were found to contain the specific IgE to German cockroach extract. Eighty–nine sera positive for German cockroach extract were then tested for their reactivity to American cockroach extract using the fluoroallergosorbent test (FAST). Sixty among 89 (68%) of their sera contained American cockroach–specific IgE. The correlation coefficient between both parameters was r = 0.45. Immunoblot and immunoblot inhibition studies were performed to analyze the IgE–binding components and the cross–reactivity between American and German cockroaches. The results showed that there are different IgE–binding components between American and German cockroaches. Sera containing specific IgE to both species of cockroach were absorbed with both species of cockroach extracts. The specific IgE to German cockroaches can be absorbed by American cockroach extract in all selected sera and the specific IgE to American cockroaches can only partially be absorbed by German cockroaches. The nonabsorbed allergens in American cockroaches had molecular weights of 33 and 50 kD. In conclusion, one–third of the asthmatic population tested was allergic to cockroaches. Although most cockroach–hypersensitive patients were allergic to both American and German cockroaches, more asthmatic patients were allergic to American cockroaches in Taiwan. The use of non–crossreacting allergen in detecting American cockroach–specific IgE might be important not only for the diagnosis and treatment of cockroach hypersensitivity in asthmatics but also for the differentiation between German and American cockroach hypersensitivity.

Identification of hevein (Hev b 6.02) in Hevea latex as a major cross-reacting allergen with avocado fruit in patients with latex allergy

Background: Recent studies demonstrated that allergy to natural rubber latex is frequently associated with hypersensitivity to avocado fruit. The responsible cross-sensitizing allergen has not been identified. Objective: The purpose of this study was to investigate the cross-reactivity of a latex major allergen, hevein, with avocado proteins. Methods: Serum samples from 118 health care workers (HCWs) allergic to latex (HCW group) and 78 patients with spina bifida (SB) allergic to latex (SB group) were included in this study. Anti-hevein and anti-avocado IgE antibodies were measured by enzyme-linked allergosorbent assay. Cross-reactivity of hevein to avocado proteins was assessed by inhibition of the IgE binding in individual patients’ sera containing IgE antibodies to both hevein and avocado. Results: The prevalence of seropositive IgE antibodies to avocado was found to be strongly associated with the presence of hevein-specific IgE antibodies in subjects of both groups ( P < .001). Sixty-seven of 91 (73%) subjects from the HCW group and all 19 subjects in the SB group with positive IgE antibodies to hevein also had elevated IgE values to avocado. Competitive RAST inhibition with 42 sera showed that IgE binding to avocado could be completely inhibited in 27 (64%) sera by preincubation with hevein. By contrast, the degrees of inhibition of IgE to hevein by avocado extract ranged from 0% to 36% ( n = 16). These results indicate that sensitization to avocado in most patients allergic to latex is caused exclusively by IgE-binding epitopes present in hevein. Results of immunoblots and immunoblot inhibition with 11 serum samples confirmed that a 30-kd protein in avocado was the major IgE-binding component; the IgE-binding reactivity to this protein could be inhibited by hevein in all sera tested. Conclusion: Hevein is the major cross-reacting allergen with avocado in subjects with latex allergy. (J Allergy Clin Immunol 1998;102:476-81.)