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Background: Severe side effects during venom immunotherapy (VIT) are associated with a variety of risk factors., Objective: Our aim was to evaluate the association of baseline serum tryptase concentration (BTC) and of other parameters, which are routinely recorded during patient evaluation, with the frequency of severe reactions requiring an emergency intervention during the buildup phase of VIT., Methods: In this observational prospective multicenter study, we enrolled 680 patients with established honeybee or vespid venom allergy who underwent VIT. Data were collected on tryptase concentration, age, sex, culprit insect, cardiovascular medication, degree of preceding sting reaction, preventive antiallergic medication before therapy, time between last preceding sting reaction and VIT, venom specific IgE concentration, and type of buildup procedure. Relative rates were calculated with generalized additive models., Results: Fifty-seven patients (8.4%) required an emergency intervention during buildup because of a severe systemic reaction. The frequency of interventions increased significantly with higher BTC (log-linear association; adjusted odds ratio, 1.56; 95% CI, 1.15-2.11; P < .005). The predictive power of BTC was markedly greater when VIT was performed for vespid venom allergy than for bee venom (for bee VIT, no significant association; for vespid VIT, log-linear association; adjusted odds ratio, 2.33; 95% CI, 1.28-4.26; P = .005). The most important other factor significantly associated with severe reactions during the buildup phase of VIT was bee venom allergy., Conclusion: Before vespid VIT, measurement of baseline serum tryptase concentration should be used to identify patients with a high risk for side effects. Patients with bee venom allergy require a particularly high degree of surveillance during VIT., (Copyright 2010 American Academy of Allergy, Asthma & Immunology. Published by Mosby, Inc. All rights reserved.)

Background: Severe anaphylaxis to honeybee or vespid stings is associated with a variety of risk factors, which are poorly defined., Objective: Our aim was to evaluate the association of baseline serum tryptase concentrations and other variables routinely recorded during patient evaluation with the frequency of past severe anaphylaxis after a field sting., Methods: In this observational multicenter study, we enrolled 962 patients with established bee or vespid venom allergy who had a systemic reaction after a field sting. Data were collected on tryptase concentration, age, sex, culprit insect, cardiovascular medication, and the number of preceding minor systemic reactions before the index field sting. A severe reaction was defined as anaphylactic shock, loss of consciousness, or cardiopulmonary arrest. The index sting was defined as the hitherto first, most severe systemic field-sting reaction. Relative rates were calculated with generalized additive models., Results: Two hundred six (21.4%) patients had a severe anaphylactic reaction after a field sting. The frequency of this event increased significantly with higher tryptase concentrations (nonlinear association). Other factors significantly associated with severe reactions after a field sting were vespid venom allergy, older age, male sex, angiotensin-converting enzyme inhibitor medication, and 1 or more preceding field stings with a less severe systemic reaction., Conclusion: In patients with honeybee or vespid venom allergy, baseline serum tryptase concentrations are associated with the risk for severe anaphylactic reactions. Preventive measures should include substitution of angiotensin-converting enzyme inhibitors.

Background: Autoreactivity of patients with atopic dermatitis (AD) to human proteins has been postulated as a decisive pathogenetic factor for AD., Objective: In this study, it was investigated whether the stress-inducible enzyme manganese superoxide dismutase (MnSOD) of human and fungal origin might act as an autoallergen in atopic dermatitis., Methods: Patients with AD (n = 69; mean SCORAD [SCORing Atopic Dermatitis], 27) and other inflammatory skin diseases as well as with inhalant allergies were investigated. The presence of specific IgE against recombinant MnSOD of fungal and human origin and the fungal extracts of Aspergillus fumigatus and Malassezia sympodialis was measured by CAP, ELISA, skin prick test, and in subset of patients also by atopy patch tests (APTs) and PBMC proliferation assays. Cross-reactivity between allergens was determined by CAP inhibition. The presence of MnSOD in human skin in various inflammatory skin conditions was investigated by immunohistochemistry., Results: Specific IgE antibodies against human MnSOD correlating with the disease activity were found in 29 out of 67 patients with AD. The human protein was able to induce in vitro T-cell reactivity and eczematous reactions in APT in MnSOD-sensitized patients with AD. MnSOD was upregulated in various inflammatory skin reactions and APT skin specimens. Cosensitization to structurally related and cross-reacting fungal MnSOD and the skin-colonizing yeast M sympodialis was observed in all patients sensitized against human MnSOD., Conclusion: Human MnSOD may play a role as an autoallergen in a subset of patients with AD, including nonatopic eczema. By molecular mimicry leading to cross-reactivity such sensitization might be induced primarily by exposure to environmental fungal MnSOD of M sympodialis .

Background: Allergic reactions to legumes are generally thought to be acquired by means of primary sensitization through the gastrointestinal tract. Recently, Gly m 4 (starvation-associated message 22), a Bet v 1-related pathogenesis-related protein 10 from soy, was suggested to be an allergen in patients with allergic reactions to a dietary product containing a soy protein isolate., Objective: We sought to evaluate the clinical relevance of Gly m 4 in subjects allergic to birch pollen with soy allergy and to assess the risk for subjects allergic to birch pollen to acquire soy allergy., Methods: Twenty-two patients allergic to birch pollen with soy allergy confirmed by means of positive double-blind, placebo-controlled food challenge results (n = 16) or a convincing history (n = 6) were investigated for IgE reactivity to birch pollen and soy allergens by using the Pharmacia CAP system and immunoblot analysis. Cross-reactivity was assessed by means of enzyme allergosorbent test inhibition. Ninety-four patients with birch pollen allergy were interviewed to assess soy tolerance and screened for IgE reactivity to Gly m 4 by means of immunoblotting. The Gly m 4 content in soy foods and soybean varieties was investigated by means of quantitative evaluation of immunoblots., Results: During double-blind, placebo-controlled food challenge, 10 patients experienced symptoms localized to the oral cavity, and 6 patients had a more severe reaction. CAP analysis revealed Gly m 4-specific IgE in 96% (21/22) of the patients. All patients had Bet v 1-specific IgE antibodies, and 23% (5/22) had positive Bet v 2 results. In IgE immunoblotting 25% (6/22) of the patients recognized soy profilin (Gly m 3), and 64% (14/22) recognized other soy proteins. IgE binding to soy was at least 80% inhibited by birch pollen and 60% inhibited by rGly m 4 in 9 of 11 sera tested. Seventy-one percent (67/94) of highly Bet v 1-sensitized patients with birch pollen allergy were sensitized to Gly m 4, and 9 (9.6%) of those patients reported soy allergy. The Gly m 4 content in soy products ranged between 0 and 70 ppm (milligrams per kilogram)., Conclusions: Our results confirm that soybean is another birch pollen-related allergenic food. Gly m 4 is the major soy allergen for patients allergic to birch pollen with soy allergy. The content of Gly m 4 in soy food products strongly depends on the degree of food processing.

Background: Mugwort pollen is an important allergen source in hay fever and pollen-related food allergy. Little is known about the clinical relevance of the major mugwort allergen Art v 1 and its importance in allergy., Objective: In this study we aimed to investigate the allergenicity of mugwort extract compared with the allergenicity of native (n)Art v 1 and recombinant (r)Art v 1, one major allergen of mugwort, in vivo and in vitro., Methods: Thirty-two patients allergic to mugwort and 10 control subjects were investigated by means of skin prick and nasal provocation testing with different concentrations of mugwort extract, nArt v 1, and rArt v 1. nArt v 1 was purified from aqueous mugwort extract, and rArt v 1 was cloned, expressed in Escherichia coli, and then purified. The in vitro allergenicity was measured by means of ImmunoCAP, ELISA, ELISA-inhibition experiments, and T-cell proliferation assays., Results: nArt v 1 and rArt v 1 were able to elicit positive in vivo and in vitro reactions. The IgE-binding capacity, as determined by means of ELISA, was slightly higher for nArt v 1 than for rArt v 1, and both allergens were able to induce T-cell proliferation in sensitized patients. However, rArt v 1 elicited a reduced response in skin and nasal provocation tests compared with nArt v 1. Compared with mugwort extract, both nArt v 1 and rArt v 1 showed lower sensitivity in patients with mugwort allergy in vivo., Conclusions: Art v 1, either in its native or recombinant form, is able to induce allergic reactions in patients with mugwort allergy. rArt v 1 induced comparable humoral and cell-mediated responses in vitro but showed reduced in vivo allergenicity compared with biochemically purified nArt v 1.

Background: In pollen-related food allergy, extracts for skin prick tests (SPTs) are often not standardized, and the test reliability is affected by false-negative reactions., Objective: We sought to evaluate a panel of recombinant allergens (RAs) derived from one allergenic food for use in component-resolved in vivo diagnosis, taking cherry as a model food., Methods: Seventy-nine subjects were included in the study: 24 Swiss patients (group 1) with a positive double-blind placebo-controlled food challenge result to cherries, 23 patients with birch pollen allergy but without cherry allergy (group 2), 23 nonatopic subjects (group 3), and 9 Spanish patients with a history of a cherry allergy (group 4). SPTs were performed in duplicate by using recombinant cherry allergens (Bet v 1-related allergen: recombinant (r) Pru av 1; profilin: rPru av 4; and lipid transfer protein: rPru av 3) in concentrations of 10, 50, and 100 microg/mL. Furthermore, IgE reactivity to rPru av 1, rPru av 4, and rPru av 3 was assessed by means of immunoblot analysis., Results: SPT responses with rPru av 1, rPru av 4, and rPru av 3 were positive in 92%, 17%, and 4% of the patients in group 1; in 74%, 30%, and 0% of the patients in group 2; in 0%, 22%, and 89% of the patients in group 4; and negative for all nonatopic subjects (group 3). Thus the sensitivity of a positive SPT response to at least one of the 3 RAs was 96%. The specificities, negative predictive values, and positive predictive values with the 3 RAs were 100%, 96%, and 100% if calculated in relation to the nonatopic control group but 17%, 79%, and 60% when calculated in relation to the control group with birch pollen allergy. The correlation between SPT and immunoblotting results was excellent. Sensitization to rPru av 3 was associated with more severe symptoms than sensitization to rPru av 1., Conclusions: SPTs with RAs proved to be highly sensitive for diagnosis of cherry allergy. Component-resolved in vivo diagnosis with standardized amounts of stable RAs allows us to determine sensitization patterns directly, to correlate them with severity of clinical symptoms, and to analyze geographic differences.

Background: Allergic reactions to carrot affect up to 25% of food-allergic subjects. Clinical manifestations of carrot allergy and IgE responses to carrot proteins, however, have never been studied in subjects with carrot allergy confirmed by means of double-blinded, placebo-controlled food challenge (DBPCFC)., Objective: The purposes of this investigation were to confirm clinically relevant sensitizations to carrot by means of DBPCFC, to validate current diagnostic methods, and to identify IgE-reactive carrot proteins in patients with true allergy., Methods: DBPCFCs were performed in 26 subjects with histories of allergic reactions to carrot. Patients underwent skin prick tests with carrot extract, fresh carrot, and various pollen extracts. Specific IgE to carrot, celery, birch, and mugwort pollen and to rBet v 1, rBet v 2, and rBet v 6 were measured through use of the CAP method. Carrot allergens were identified by means of immunoblotting and blotting inhibition., Results: Twenty of 26 patients had positive DBPCFC results. The sensitivity of the determination of carrot-specific IgE antibodies through use of the CAP method (> or =0.7 kU/L) was 90%, the sensitivity for skin prick testing with commercial extracts was 26%, and the sensitivity for prick-to-prick tests with raw carrot was 100%. The Bet v 1--related major carrot allergen Dau c 1 was recognized by IgE from 85% of patients; 45% were sensitized to cross-reactive carbohydrate determinants and 20% to carrot profilin. In 1 subject, a Bet v 6--related carrot allergen was recognized. In 4 patients, IgE binding to Dau c 1 was not inhibited or was weakly inhibited by rBet v 1 or birch pollen extract., Conclusion: This study confirmed the allergenicity of carrot by means of DBPCFC. DBPCFC-positive patients had exclusively specific IgE antibodies to birch pollen--related carrot allergens, Dau c 1 being the major allergen. The lack of inhibition of IgE binding to Dau c 1 by birch allergens in a subgroup of patients might indicate an secondary immune response to new epitopes on the food allergen that are not cross-reactive with Bet v 1.

Background: Allergy to persimmon (Diospyros kaki) is very rare and not yet confirmed by means of double-blind, placebo-controlled, food-challenge (DBPCFC). Thus far, specific IgE to this fruit and cross-reactivity to pollen and other foods has not been determined., Objective: The objective was to confirm allergy to persimmon in 3 patients with an according personal history and to characterize allergens and cross-reactivity of specific IgE antibodies to pollen and food allergens. One patient reacted with pruritus, penis edema, urticaria, and asthma; the second reacted with nausea and vomitus; and the third reacted with rhinoconjunctivitis, asthma, and stomachache after ingestion of persimmon., Methods: Patients underwent skin prick testing with routine allergens, latex, persimmon, and other foods. Allergy to persimmon was confirmed by means of a DBPCFC. Specific serum IgE levels were measured with CAP-FEIA and the enzyme allergosorbent test (EAST) method. EAST and immunoblot inhibitions were carried out with persimmon; birch, grass, and ragweed pollen; latex; and N-glycans as inhibitors., Results: All patients had positive skin test responses, DBPCFC and specific IgE assays to persimmon. Blot and EAST inhibition assays revealed IgE to cross-reactive profilin in one patient and IgE to cross-reacting carbohydrate determinants in all patients., Conclusions: This is the first report on 3 cases of allergy to persimmon verified by means of DBPCFC and detection of specific IgE. The sensitization is due to cross-reactive profilin and carbohydrate determinants.

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

Background: Allergy to zucchini (Cucurbita pepo), a member of the Cucurbitaceae family, has not previously been reported. We examined 4 patients complaining of allergic symptoms, such as oral allergy syndrome, nausea, diarrhea, or pruritus, after the intake of zucchini., Objective: After the confirmation of food allergy, we wanted to characterize zucchini allergens and examine possible cross-reactions to pollen and food., Methods: The patients underwent skin prick and prick-to-prick-testing with different allergens, including zucchini, latex, and birch, ragweed, and grass pollen. Moreover a double-blind, placebo-controlled, food challenge was performed to confirm food allergy. Total and specific serum IgE levels were determined by using CAP-FEIA and the enzyme allergosorbent test method (EAST), respectively. Proteins from zucchini reacting with patient IgE were detected by means of immunoblotting. To characterize cross-reacting IgE antibodies, immunoblot- and EAST-inhibition assays were carried out., Results: All patients in this study had positive reactions to zucchini both in prick-to-prick tests and double-blind, placebo-controlled, food challenges. Specific serum IgE levels to zucchini were found in all cases. In blot- and EAST-inhibition assays IgE from two patients revealed binding to zucchini profilin at about 15 kd. Furthermore, in two cases, including one of the profilin-positive patients, IgE directed against cross-reacting carbohydrate determinants was detected. For one patient, no cross-reacting IgE could be found, but IgE from this patient reacted strongly with a zucchini protein at 17 kd., Conclusions: We report the first 4 cases of food allergy to zucchini. Zucchini allergens can cause systemic reactions and are at least partially heat stable. We suggest that allergy to zucchini can occur as a result of primary sensitization to zucchini, as well as to cross-reactions to the panallergen profilin and cross-reacting carbohydrate determinants.

Background: Celery root is a frequent cause of food allergy in pollen-sensitized patients. Because of problems in blinding challenges with fresh vegetables and the risk of anaphylactic reactions, no double-blind, placebo-controlled, food challenges (DBPCFCs) with celery have been published so far., Objective: The aim of the study was to confirm the clinical relevance of celery as a food allergen by DBPCFCs and to evaluate current diagnostic procedures in patients with true allergy., Methods: DBPCFCs were performed in 32 patients with a history of an allergic reaction to celery. The patients underwent skin prick tests (SPTs) with celery extracts, crude celery, and different pollen extracts. Specific IgE for celery was determined by using the CAP method., Results: Twenty-two of 32 patients had a positive DBPCFC result. Two patients reacted to placebo, and 8 patients did not respond to the challenge. Of the nonresponders, 4 reacted to an open provocation with celery. The sensitivity of CAP determination for specific IgE (> or =0.7 kU/L) to celery in patients with a positive DBPCFC result was 73%, 48% to 86% for SPTs (> or =3 mm) with commercial extracts, and 96% for prick-to-prick tests with crude celery. The positive predictive value of the SPT and CAP tests was between 87% and 96%, whereas the specificity and negative predictive values were poor., Conclusion: This study confirms the importance of celery as a food allergen for use in DBPCFCs. The SPT and CAP methods proved to be reliable for the diagnosis of a relevant allergy to celery in regard to sensitivity and positive predictive value but not to specificity and negative predictive value.

Background: Tree nuts are a common cause of food allergy in Europe. However, few studies deal with real food allergy to hazelnuts in subjects believed to be allergic to this food., Objective: We sought to select subjects with a history of allergic reactions on ingestion of hazelnut and determine how many of these have true allergy by means of the double-blind, placebo-controlled food challenge (DBPCFC)., Methods: Eighty-six subjects with a history of symptoms after hazelnut ingestion were recruited from 3 allergy centers (Milan, Zurich, and Copenhagen). All subjects underwent skin prick tests (SPTs) with aeroallergens and hazelnut, as well as having their specific hazelnut IgE levels determined. Diagnosis of clinical relevant food allergy was made on the basis of the DBPCFC., Results: Sixty-seven (77.9%) of 86 subjects had a positive DBPCFC result; 8 were placebo responders, and 11 were nonresponders. Of the 11 nonresponders, 4 had positive open-challenge test results. Of the DBPCFC-positive subjects, 87% also had positive skin test responses to birch pollen extract. Specific IgE determination for hazelnut (positive CAP response >/=0.7 kU/L [ie, class 2]) showed a sensitivity of 0.75, a positive predictive value (PPV) of 0.92, a specificity of 0.16, and a negative predictive value (NPV) of 0.05. Skin tests with commercial hazelnut extract produced a sensitivity of 0.89, a PPV of 0.92, a specificity of 0.05, and an NPV of 0.05. Skin tests with natural food produced a sensitivity of 0.88, a PPV of 0.94, a specificity of 0.27, and an NPV of 0.15., Conclusion: This study shows that hazelnut is an allergenic source that can cause real food allergy, as confirmed by DBPCFC. Skin and IgE tests demonstrated reasonable sensitivity and PPV but a very low specificity and NPV, thus implying that these should not be used to validate the diagnosis of food allergy to hazelnut.

Background: Clinical and population studies have shown that exposure and sensitization to allergens derived from furred pets, particularly cats, represent an important risk factor of allergic respiratory disease and also a significant risk factor for asthma., Objective: In the framework of the multicenter European Community Respiratory Health Survey an analysis of the association of current and childhood exposure to cat with atopic sensitization to cat was conducted., Methods: This study included cross-sectional data from 35 centers representing 16 countries. Altogether, 18,097 subjects were included, of whom 13,509 (75%) provided a blood sample for the measurement of specific IgE. Exposure data and data for potential confounders were extracted from an interviewer-led questionnaire., Results: The prevalence of sensitization to cat (serum specific IgE >0.35 kU/L) was 9%. Among those who did not report allergic symptoms in the presence of pets or house dust, those who owned cats were significantly more likely to be sensitized to cats than were those who did not (odds ratio [95% confidence interval] 1.57 [1.20-2.06]. Childhood exposure to pets including cats was associated with lower sensitization to cats in adulthood, particularly among those with a positive family history of atopy (odds ratio [95% confidence interval] 0.68 [0.51-0.93]. Positive correlations were found between the community prevalence of cat and the prevalences of sensitization to cat, respiratory symptoms, physician-diagnosed asthma, and current asthma medication., Conclusions: Current cat ownership represents a significant risk for sensitization to cat if cats are allowed indoors. Our results support the hypothesis that childhood exposure to pets, including cats, might modulate immunologic mechanisms and reduce sensitization to cat in adulthood. The significant correlation found between the community prevalence of cat ownership and community prevalence of specific sensitization to cat represents the first documentation of such a relationship.

Background: Eosinophilic myositis/perimyositis (EM/P) are a group of rare idiopathic muscle disorders associated with eosinophilia., Objective: We describe the frequency and spectrum of cutaneous manifestations in EM/P and compare them with the idiopathic hypereosinophilic syndrome (HES)., Methods: We review the literature on EM/P and describe an additional case associated with angioedema., Results: Of a total of 26 reported patients with EM/P, cutaneous manifestations were observed in 10. These were, in order of frequency, deep subcutaneous induration, erythema, angioedema, urticaria, and papular lesions., Conclusion: Skin lesions occur less frequently in EM/P than in HES. Although erythematous papulonodular lesions and urticaria/angioedema are most commonly observed in HES, the most frequent skin manifestations of EM/P are subcutaneous induration and erythema. In HES, angioedema has been correlated with a favorable prognosis. At least some of these patients apparently have an idiopathic eosinophilic disorder distinct from HES, including EM/P. In contrast to HES, the overall prognosis of EM/P is good, particularly when muscle lesions are focal, and the principal histopathologic finding is perimysial infiltrates.

Investigations on the mechanisms of IgE regulation in vitro have been conducted thus far in systems that allow the synthesis of total rather than specific IgE. To study the regulatory prerequisites of antigen-specific IgE antibody production, we have established a culture system that allows the generation of bee venom phospholipase A2-specific IgE and IgG4 antibodies. Allergen-specific IgE was induced by simultaneously activating T cells and B cells specifically with allergen and polyclonally with anti-CD2 and soluble CD40 ligand in the presence of IL-4. Additional stimulation of T cells through the CD2 activation pathway by two different anti-CD2 monoclonal antibodies enhanced both the allergen-specific and the total IgE and IgG4 responses. An optimal amount of allergen (0.1 ng/ml) resulted in the induction of both allergen-specific IgE and IgG4 antibodies. Higher antigen doses reduced allergen-specific antibodies and enhanced total isotype production. This differential regulation of allergen-specific and total isotypes reflects different allergen dose-dependent mechanisms in specific and polyclonal activation of T and B cells. Although both isotypes require IL-4 for initial induction, opposite regulatory effects by T cells were observed for IgE and IgG4 antibody expression. In peripheral blood mononuclear cell cultures stimulated with soluble CD40 ligand, IL-4, and phospholipase A2, stimulation of T cells with higher amounts of anti-CD2 enhanced IgG4 in parallel to increased IL-2 and interferon-gamma secretion but inhibited IgE synthesis. These results provide evidence for differential regulation of allergen-specific and total IgE and IgG4 by antigen concentration and demonstrate the pivotal role of T cells controlling the synthesis of the IgE and IgG4 antibody isotypes.

Allergenic cross-reactivity between members of the Fagales family (birch, alder, hazel, and beech) and between members of the Oleaceae family (ash, olive, lilac, and privet) is well known, but little is known about possible cross-reactivity between these two groups of trees, in particular between birch and ash, both of which flower in the spring. Various immunochemical methods including RAST inhibition, Western blot, and Western blot inhibition have been used in this study to show that there is partial cross-reactivity between birch and ash pollens. Enzyme allergosorbent test measurements were performed on sera from 35 patients with hay fever in spring by using birch and ash pollen allergen disks. The major allergen of birch, Bet v 1, was readily detectable in the birch pollen extract, but a homologous allergen in the ash pollen extract was barely detectable. Common allergens could be determined in the high molecular weight region. Ash pollen should be included in diagnostic procedures for spring pollinosis and should be considered for use in specific immunotherapy.

Three patients with urticaria pigmentosa are reported who developed symptoms of anaphylaxis after Hymenoptera stings. Serum IgE antibodies to various Hymenoptera venoms could not be detected in any of the patients. Skin tests were completely negative in one patient, and borderline reactions with honeybee and yellow jacket venom, respectively, were found in the other two. Peripheral blood leukocytes of these latter two patients did not release significant amounts of histamine after exposure to the respective venoms. In patients with mastocytosis, anaphylaxis after insect stings may not be IgE-mediated but due to mediator release by the pharmacologic action of histamine liberators normally present in Hymenoptera venoms.

Bed quilts filled with silk waste were found to cause nightly attacks of asthma. The first symptoms appeared on an average after 7 mo of exposure at a mean patient age of 30 yr. About 50% of the patients could be classified as atopic. Extract of the filling material revealed positive scratch and RAST tests in most patients. The bed quilts were advertised as being filled with pure wild silk (from silk moths of the genus Antheraea feeding on oak leaves), but it was found that in most cases the filling also included waste of cultivated silk (Bombyx mori). The origin of the allergen was sought. Since textile products of silk are considered to be practically nonallergenic, some type of contaminant appeared the most likely candidate. No allergen was found in cocoons, chrysalis (pupa), or moths of Antheraea. However, some cocoons of Bombyx mori, usually in small amounts, and excretions of the silkworm did contain allergen. High concentrations of allergen were found in an extract of living insects of the genus Anthrenus that was present in one batch of Bombyx mori cocoons. Thus, the silk waste appeared to be contaminated with material from the silkworms and also with infesting insects, which together create a very potent allergen repertoire that after a short incubation time, in a considerable frequency, elicits a rise in asthmatic symptoms and high serum IgE antibody levels.