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BACKGROUND Polyethylene glycol (PEG) may elicit anaphylaxis to COVID-19 mRNA vaccines, and guidance for patients at risk is needed. METHODS In retrospective patients with PEG allergy collected from 2006 till 2019, clinical, skin, and basophil activation test (BAT) characteristics discriminative for PEG allergy were analyzed and compared with the literature. In 421 prospective real-life patients asking for allergy workup for COVID-19 vaccine hypersensitivity in 2020/2021, risk assessment was performed and tolerance of the recommended vaccination approach was assessed. RESULTS Ten patients with PEG allergy were found in the retrospective cohort. Patients reacted with immediate anaphylaxis (100%) not only to PEG-based laxatives/bowel preparations or injections, but also to cold medication, antiseptics, analgetics, or antibiotics. Skin tests ± BAT with PEG ± elicitors were positive in 10/10. Provocation tests were positive in 7/9 patients. From the prospective cohort, 370/421 patients self-reporting increased risk for vaccine allergy lacked criteria necessitating allergy workup and were recommended for routine vaccination. A total of 51/421 patients were tested, and three (6%) with PEG allergy were identified, whereas 48 patients remained negative in skin tests. Vaccination was recommended in all those patients. No hypersensitivity reactions were reported to vaccination including six PEG-allergic patients tolerating COVID-19 vaccination. CONCLUSIONS Taking a detailed history excluded PEG allergy in most referred patients and enabled direct safe vaccination. Immediate urticaria/anaphylaxis to typical elicitors identified patients requiring PEG allergy workup. Skin tests ± BAT identified PEG allergy and helped to select the vaccine and the vaccination approach. Even PEG-allergic patients can tolerate COVID-19 vaccines.

Alergia; Anafilaxia; Asma Allergy; Anaphylaxis; Asthma Al·lèrgia; Anafilaxi; Asma Since the discovery of immunoglobulin E (IgE) as a mediator of allergic diseases in 1967, our knowledge about the immunological mechanisms of IgE-mediated allergies has remarkably increased. In addition to understanding the immune response and clinical symptoms, allergy diagnosis and management depend strongly on the precise identification of the elicitors of the IgE-mediated allergic reaction. In the past four decades, innovations in bioscience and technology have facilitated the identification and production of well-defined, highly pure molecules for component-resolved diagnosis (CRD), allowing a personalized diagnosis and management of the allergic disease for individual patients. The first edition of the “EAACI Molecular Allergology User's Guide” (MAUG) in 2016 rapidly became a key reference for clinicians, scientists, and interested readers with a background in allergology, immunology, biology, and medicine. Nevertheless, the field of molecular allergology is moving fast, and after 6 years, a new EAACI Taskforce was established to provide an updated document. The Molecular Allergology User's Guide 2.0 summarizes state-of-the-art information on allergen molecules, their clinical relevance, and their application in diagnostic algorithms for clinical practice. It is designed for both, clinicians and scientists, guiding health care professionals through the overwhelming list of different allergen molecules available for testing. Further, it provides diagnostic algorithms on the clinical relevance of allergenic molecules and gives an overview of their biology, the basic mechanisms of test formats, and the application of tests to measure allergen exposure.

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Background: The alpha-gal syndrome (AGS) describes a new type I allergy entity to the carbohydrate epitope galactose-α-1,3-galactose (alpha-gal), which is mainly found in mammalian food products (e.g., beef, pork, and venison). Apart from meat products, alpha-gal can also be found in products containing gelatin of bovine or porcine origin. Recent case reports pointed to severe anaphylaxis in patients suffering from AGS after vaccination with vaccines containing hydrolyzed gelatin. It was the objective of this study to evaluate if basophil activation tests (BATs) performed with such vaccines were positive in patients with AGS. Methods: BAT was performed with different dilutions of a gelatin-containing measles, mumps, and rubella (MMR) live vaccine; an attenuated varicella (V) vaccine; an attenuated V-zoster (VZ) vaccine; a MMR live vaccine not containing gelatin (non-gelatin MMR vaccine) in 2 patients with confirmed AGS, 2 patients highly suspicious for AGS, and 2 healthy individuals without any previous medical history for allergies. Results: All patients showed strongly positive results for all gelatin-containing vaccines (MMR vaccine, V vaccine, and VZ vaccine). Non-gelatin MMR vaccine was negative. The 2 healthy controls did not show any basophil activation. Conclusions: Gelatin-containing vaccines should be administered with caution or avoided in patients with AGS because of their high potential to activate basophils indicating a risk for anaphylaxis. Also, BAT is a useful additional tool when it comes to screening for potentially high-risk alpha-gal-containing drugs.

The worldwide use of COVID-19 vaccines has shown that immediate allergic reactions to the ingredients are rare but should be clarified by means of an allergological work-up. This review aims to highlight the current state of knowledge and possible pathogenesis based on the literature published to date. In addition to recording a detailed history and performing skin tests, cellular tests (basophil activation or basophil histamine release test) by using the vaccines or modified compounds containing polyethylene glycol (PEG), rather than unmodified PEGs, have proven to be particularly helpful. Negative results with vaccines seem to indicate tolerance. Details of the performance of these cellular tests with different vaccines, PEGs of different molecular weights, other ingredients of the vaccines, as well as other PEGylated drugs, and the results in the context of COVID-19 vaccination of various working groups worldwide are summarized.

Discriminating Polistes dominula and Vespula spp. venom allergy is of growing importance worldwide, as systemic reactions to either species’ sting can lead to severe outcomes. Administering the correct allergen-specific immunotherapy is therefore a prerequisite to ensure the safety and health of venom-allergic patients. Component-resolved diagnostics of Hymenoptera venom allergy might be improved by adding additional allergens to the diagnostic allergen panel. Therefore, three potential new allergens from P. dominula venom—immune responsive protein 30 (IRP30), vascular endothelial growth factor C (VEGF C) and phospholipase A2 (PLA2)—were cloned, recombinantly produced and biochemically characterized. Sera sIgE titers of Hymenoptera venom-allergic patients were measured in vitro to assess the allergenicity and potential cross-reactivity of the venom proteins. IRP30 and VEGF C were classified as minor allergens, as sensitization rates lay around 20–40%. About 50% of P. dominula venom-allergic patients had measurable sIgE titers directed against PLA2 from P. dominula venom. Interestingly, PLA2 was unable to activate basophils of allergic patients, questioning its role in the context of clinically relevant sensitization. Although the obtained results hint to a questionable benefit of the characterized P. dominula venom proteins for improved diagnosis of venom-allergic patients, they can contribute to a deeper understanding of the molecular mechanisms of Hymenoptera venoms and to the identification of factors that determine the allergenic potential of proteins.

For some years now the basophil activation test (BAT) using flow cytometry has emerged as a powerful tool and sensitive marker that can be used to detect clinically relevant allergies, provide information on the severity of an allergic reaction, and monitor therapies. Compared to other in vitro diagnostic tests, BAT seems to have a better informative value in terms of clinical relevance. In general, the BAT can be used for the diagnosis of the most common forms of IgE-mediated allergy such as hymenoptera venom allergy, inhalant allergy, food allergy, and drug allergy. Various basophil markers and parameters have been established which, depending on the trigger of the respective allergy, can provide information on the clinical relevance of sensitization, on the development of natural tolerance, on trigger thresholds, and on the severity of the allergic reaction. The BAT also serves as a suitable follow-up instrument for various therapeutic approaches such as specific immunotherapy, desensitization protocols, or use of anti-IgE-antibodies for the various diseases. Quality controls for routine use, standardization, and automatization are expected to expand the range of applications for the above-mentioned indications.

Background: Galactose-alpha-1,3-galactose (alpha-gal) syndrome is characterized by the presence of serum specific IgE antibodies to alpha-gal and delayed type I allergic reactions to the carbohydrate alpha-gal after consumption of mammalian (red) meat products and drugs of mammalian origin. Diagnostics currently rely on patient history, skin tests, determination of serum specific IgE antibodies, and oral food or drug challenges.Objective: We sought to assess the utility of different basophil parameters (basophil reactivity and sensitivity, the ratio of the percentage of CD63(+) basophils induced by the alpha-gal-containing allergen to the percentage of CD63(+) basophils after stimulation with anti-Fc epsilon RI antibody [%CD63(+)/anti-Fc epsilon RI], and area under the dose-response curve [AUC]) as biomarkers for the clinical outcome of patients with alpha-gal syndrome compared with subjects with asymptomatic alpha-gal sensitization.Methods: In addition to routine diagnostics, a basophil activation test (Flow CAST) with different concentrations of alpha-gal-containing allergens (eg, commercially available alpha-gal-carrying proteins and pork kidney extracts) was performed in 21 patients with alpha-gal syndrome, 12 alphagal-sensitized subjects, and 18 control subjects.Results: Alpha-gal-containing allergens induced strong basophil activation in a dose-dependent manner in patients. Basophil reactivity at distinct allergen concentrations, the % CD63(+)/anti-FceRI ratio across most allergen concentrations, the AUC of dose-response curves, and basophil allergen threshold sensitivity (CD-sens) with pork kidney extract were significantly higher in patients with alpha-gal syndrome compared with those in sensitized subjects. All parameters were negative in control subjects.Conclusion: The basophil activation test should be considered as an additional diagnostic test before performing time-consuming and potentially risky oral provocation tests. The % CD63(+)/anti-Fc epsilon RI ratio for all allergens and AUCs for pork kidney were the best parameters for distinguishing patients with alpha-gal syndrome from subjects with asymptomatic alpha-gal sensitization.

Allergen-specific immunotherapy is the only curative treatment of honeybee venom (HBV) allergy, which is able to protect against further anaphylactic sting reactions. Recent analyses on a molecular level have demonstrated that HBV represents a complex allergen source that contains more relevant major allergens than formerly anticipated. Moreover, allergic patients show very diverse sensitization profiles with the different allergens. HBV-specific immunotherapy is conducted with HBV extracts which are derived from pure venom. The allergen content of these therapeutic extracts might differ due to natural variations of the source material or different down-stream processing strategies of the manufacturers. Since variations of the allergen content of therapeutic HBV extracts might be associated with therapeutic failure, we adressed the component-resolved allergen composition of different therapeutic grade HBV extracts which are approved for immunotherapy in numerous countries. The extracts were analyzed for their content of the major allergens Api m 1, Api m 2, Api m 3, Api m 5 and Api m 10. Using allergen-specific antibodies we were able to demonstrate the underrepresentation of relevant major allergens such as Api m 3, Api m 5 and Api m 10 in particular therapeutic extracts. Taken together, standardization of therapeutic extracts by determination of the total allergenic potency might imply the intrinsic pitfall of losing information about particular major allergens. Moreover, the variable allergen composition of different therapeutic HBV extracts might have an impact on therapy outcome and the clinical management of HBV-allergic patients with specific IgE to particular allergens.

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 ImmunoCAP, 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 ImmunoCAP 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.

The nature of basophil activation as an ex vivo challenge makes it a multifaceted and promising tool for the allergist. Through the development of flow cytometry, discovery of activation markers such as CD63 and markers identifying basophil granulocytes, the basophil activation test ( BAT) has become a pervasive test. BAT measures basophil response to allergen crosslinking IgE on between 150 and 2,000 basophil granulocytes with remarkable analytical sensitivity in < 0.1 ml fresh blood. Dichotomous activation is assessed as the fraction of reacting basophils. In patients with food-, insect venom-, and drug allergy and patients with chronic urticaria BAT can be part of the diagnostic evaluation in addition to history, skin prick testing, and specific IgE determination. BAT may also be helpful in determining the clinically relevant allergen. Basophil sensitivity may be used to monitor patients on allergen immunotherapy, anti-IgE treatment, or in the natural resolution of allergy. The test may use fewer resources and be more reproducible than oral, sting, nasal or bronchial challenge testing. BAT may be useful before challenge testing as it is less stressful for the patient and avoids severe allergic reactions. It may be useful before challenge testing. An important next step is to standardize BAT and make it available in diagnostic laboratories. This article provides an overview of the practical and technical details as well as the utility of BAT in diagnosis and management of allergic diseases.

The strawberry fruit proteins Fra a 1.01E-1.08 are homologues of the major birch pollen allergen Bet v 1. Three of the proteins are known to have essential biological functions in pigment formation during fruit ripening and seem to be responsible for allergic reactions to strawberry fruit. We evaluated the cross-reactive allergenic potential of these putative strawberry allergens in patients allergic to birch pollen. Activation of basophils of eight atopic patients was studied using different concentrations of Fra a 1 isoforms. Bet v 1a was used as control and as atopic patient selection criterion. Although Fra a 1.01E-1.08 have amino acid sequence identities of 74.5-97.5% with Fra a 1.02, the basophil activation mediated by the eight Fra a 1 proteins differed substantially. Fra a 1.03 and Fra a 1.02 showed the highest activation of basophils, 73 and 66% of total basophils, respectively. On the basis of the high relative expression of the gene Fra a 1.02 in ripe strawberry fruits of allergenic varieties, Fra a 1.02 was identified as the main strawberry allergen of the Bet v 1 superfamily. Knowledge of the allergenic potential of Fra a 1.02/1.03 will help to improve food safety and can serve as a valuable marker for the development of red-fruited hypoallergenic strawberry cultivars.

Background The phenomenon of allergy transfer from an allergic donor to a non-allergic recipient via hematopoietic cell transplantation has been described by several reports. However, it could not yet been conclusively shown that allergic reaction of the recipient is elicited by the donor's cells. Objectives In the case of a 46-year-old male patient who – for the first time in his life – had two episodes of oral allergic syndrome upon kiwi consumption after having received myeloablative hematopoietic stem cell transplantation (HCT) from his kiwi-allergic sister, we aimed to clarify the origin of allergen reactive cells in the donor. We not only intended to demonstrate if allergy was transferred by HCT but also to present an experimental workup for the analysis of allergy transfer by HCT. Methods Allergic sensitization to kiwi in recipient and donor was proven by ImmunoCAP. Furthermore, origin of peripheral blood mononuclear cells (PBMCs) was analyzed by chromosomal fluorescence in situ hybridization (FISH). To confirm allergic reaction and activation of hematopoietic cells by customized kiwi extract, we performed basophil activation test from whole blood as well as T cell proliferation assays from purified PBMCs of both recipient and donor. Results Basophil activation upon kiwi extract was demonstrated in both recipient and donor. Besides, we showed proliferation of CD4+ T cells after incubation with kiwi extract. FISH analysis proved that hematopoietic cells of the male recipient completely originated from the female donor. Conclusion Exemplified in this patient, we show for the first time that allergy transfer is mediated by the donor's cells. Moreover, our experimental approach using customized kiwi extract to prove contribution of kiwi-specific T and B cells in both kiwi-allergic recipient and donor could serve as a model approach for future studies.

Honeybee (Apis mellifera) venom (HBV) represents an ideal model to study the role of particular venom components in allergic reactions in sensitized individuals as well as in the eusociality of Hymenoptera species. The aim of this study was to further characterize the HBV components C1q-like protein (C1q) and PDGF/VEGF-like factor 1 (PVF1). C1q and PVF1 were produced as recombinant proteins in insect cells. Their allergenic properties were examined by determining the level of specific IgE antibodies in the sera of HBV-allergic patients (n = 26) as well as by their capacity to activate patients' basophils (n = 11). Moreover, the transcript heterogeneity of PVF1 was analyzed. It could be demonstrated that at least three PVF1 variants are present in the venom gland, which all result from alternative splicing of one transcript. Additionally, recombinant C1q and PVF1 from Spodoptera frugiperda insect cells exhibited specific IgE reactivity with approximately 38.5% of sera of HBV-allergic patients. Interestingly, both proteins were unable to activate basophils of the patients, questioning their role in the context of clinically relevant sensitization. Recombinant C1q and PVF1 can build the basis for a deeper understanding of the molecular mechanisms of Hymenoptera venoms. Moreover, the conflicting results between IgE sensitization and lack of basophil activation, might in the future contribute to the identification of factors that determine the allergenic potential of proteins.

Hymenoptera venom allergy can cause severe anaphylaxis in untreated patients. Polistes dominula is an important elicitor of venom allergy in Southern Europe as well as in the United States. Due to its increased spreading to more moderate climate zones, Polistes venom allergy is likely to gain importance also in these areas. So far, only few allergens of Polistes dominula venom were identified as basis for component-resolved diagnostics. Therefore, this study aimed to broaden the available panel of important Polistes venom allergens. The 100 kDa allergen Pol d 3 was identified by mass spectrometry and found to be a dipeptidyl peptidase IV. Recombinantly produced Pol d 3 exhibited sIgE-reactivity with approximately 66% of Polistes venom-sensitized patients. Moreover, its clinical relevance was supported by the potent activation of basophils from allergic patients. Cross-reactivity with the dipeptidyl peptidases IV from honeybee and yellow jacket venom suggests the presence of exclusive as well as conserved IgE epitopes. The obtained data suggest a pivotal role of Pol d 3 as sensitizing component of Polistes venom, thus supporting its status as a major allergen of clinical relevance. Therefore, Pol d 3 might become a key element for proper diagnosis of Polistes venom allergy.

Purpose of Review: We review basophil testing by flow cytometry with an emphasis on advantages and disadvantages. Recent Findings: There are many tools available to assess the presence and severity of allergic diseases in patients. For 50 years, peripheral blood basophils have been used as tools to study these diseases. It is a very accessible cell that binds IgE antibody and secretes the classical mediators responsible for the symptoms of allergic reactions. In the last decade, an even more accessible methodology, using flow cytometry, has been developed to enhance the ability to use basophils for both mechanistic and clinical diagnostics. Basophil testing has been included in diagnostics for different forms of allergies as well as to monitor disease status. Summary: A variety of studies have begun to establish both precise methods and their clinical relevance for disease diagnosis, but there remain some important questions on how to take optimal advantage of the behaviours of basophils.

Background: Hymenoptera venom sensitization in highly exposed individuals frequently requires risk assessment for future severe sting reactions. In this study, we determined the prevalence of Hymenoptera venom sensitization in individuals who hunt and fish and analyzed possible correlations between the severity of sting reactions and the IgE sensitization profile. Methods: In this cross-sectional study, paper-based, self-filled questionnaires about previous insect stings and sting reactions were obtained from individuals who hunt and fish in Bavaria, Germany. Blood samples were taken and analyzed for the levels of tryptase, total IgE and IgE to honey bee (i1) and wasp (13) venom, the recombinant allergens rApi m 1, rApi m 2, rApi m 3, rApi m 5, rApi m 10, rVes v 1, rVes v 5, and the CCD marker molecule MUXF3. Odd ratios (ORs) for sensitization and anaphylaxis and Pearson's correlations for the different allergens were calculated. Results: Of 257 participants, 50.2% showed a sensitization to honey bee venom (i1), and 58.4% showed sensitization to wasp venom (i3). A total of 98.4% of participants claimed to have been stung at least once. Anaphylaxis was reported in 18.7%, and a local sting reaction was reported in 18.3%. The highest sensitization rates were found for whole venom extracts, sensitization to any of the available recombinant allergens exceeded sIgE levels to honeybee venom (i1) in 28.5% and to wasp venom (i3) in 52.9% of participants. Participants with a history of more than 5 stings showed a higher risk for anaphylaxis. Conclusions: Sensitization to Hymenoptera venom and their recombinant allergens are present in the majority of individuals who hunt and fish. Sensitization to distinct recombinant allergens does not necessarily affect the severity of sting reactions including anaphylaxis. A meticulous medical history of the number of previous stings as well as systemic reactions remains essential. Keywords: Anaphylaxis, Hymenoptera venom sensitization, Outdoor population, Recombinant allergens, Sting reaction

Andre Franke and colleagues report a genome-wide association study for psoriasis vulgaris in a German cohort with replication in German and North American psoriasis cohorts. They identify variants in TRAF3IP2, encoding a protein involved in IL-17 mediated T-cell immune response, associated with psoriasis. Psoriasis is a multifactorial skin disease characterized by epidermal hyperproliferation and chronic inflammation, the most common form of which is psoriasis vulgaris (PsV). We present a genome-wide association analysis of 2,339,118 SNPs in 472 PsV cases and 1,146 controls from Germany, with follow-up of the 147 most significant SNPs in 2,746 PsV cases and 4,140 controls from three independent replication panels. We identified an association at TRAF3IP2 on 6q21 and genotyped two SNPs at this locus in two additional replication panels (the combined discovery and replication panels consisted of 6,487 cases and 8,037 controls; combined P = 2.36 × 10−10 for rs13210247 and combined P = 1.24 × 10−16 for rs33980500). About 15% of psoriasis cases develop psoriatic arthritis (PsA). A stratified analysis of our datasets including only PsA cases (1,922 cases compared to 8,037 controls, P = 4.57 × 10−12 for rs33980500) suggested that TRAF3IP2 represents a shared susceptibility for PsV and PsA. TRAF3IP2 encodes a protein involved in IL-17 signaling and which interacts with members of the Rel/NF-κB transcription factor family.

Summary Background Flow cytometric basophil activation tests (BAT) have been developed as cellular tests for in vitro diagnosis of IgE-mediated reactions. Different markers and techniques have been used after stimulation with various allergens. Objective It was the aim of the present study to compare an established BAT (Flow-CAST®) with a newly developed basophil activation protocol using CD63 and CCR3 (Flow2 CAST®) in patients with type-I allergy to antibiotics. Materials and methods Twenty-four patients with a history of type-I allergy to antibiotics were examined. A careful allergy history was taken, and skin tests and determination of specific IgE antibodies were performed. Two different BAT using CD63 expression but different protocols were carried out after stimulation with different concentrations of antibiotics. Fifteen healthy subjects without a history of antibiotic allergy were studied as controls. Results The Flow2 CAST® showed a higher sensitivity than the Flow-CAST® (55% vs. 53%) with regard to patients' history. Specificity was 80% both for the Flow2 CAST® and for the Flow-CAST® with regard to controls with negative history and negative RAST. Conclusion These results show the value of two different BAT as cellular tests in the in vitro diagnosis of patients with antibiotic allergy with equal specificity and a slightly higher sensitivity for the Flow2 CAST®. Cite this as: B. Eberlein, I. Leon Suarez, U. Darsow, F. Rueff, H. Behrendt and J. Ring, Clinical & Experimental Allergy, 2010 (40) 411–418.

Endotoxins and allergens represent the major relevant contents of the atmospheric bioaerosol with regard to the triggering and exacerbation of allergic diseases. In this study, mattress concentrations of endotoxin and indoor allergens were measured in three hospitals in the alpine climate of Bavaria and in adjacent homes. Dust was collected from each of 10 mattresses according to a standardized protocol, and endotoxin was analyzed with the Limulus Amebocyte Lysate (LAL) test, indoor allergens Der p 1, Der f 1 and Fel d 1 were analyzed by ELISAs. The concentration of endotoxin in the mattresses did not differ significantly between different cities. The percentiles of endotoxin were significantly higher in hospitals than in homes. The concentrations of mite allergens (Der p 1 and Der f 1) in the dust were significantly lower in all hospitals than in homes. There was no significant difference of mite allergens between different time points. The concentrations of Fel d 1 were significantly higher in the autumn than in the summer (median: 1376 vs. 478ng/g). No significant differences of Fel d 1 were found between hospitals and homes or between different hospitals. As Fel d 1 concentrations reached levels at which cat allergic patients can experience symptoms, efforts had to be made to reduce the concentrations of Fel d 1 especially in hospitals. In contrast, mite allergens were low in hospitals, which can be clinically beneficial for patients with mite allergies.

Objective: Investigation of the efficacy of ultraviolet (UV) A1 phototherapy on atopic eczema, scleroderma, granuloma annulare, urticaria pigmentosa, prurigo nodularis, lichen sclerosus et atrophicus, T-cell lymphoma, keratosis lichenoides chronica, chronic urticaria and some rare, sclerosing skin diseases. Methods: The data of 230 patients treated with low-dose, medium-dose and high-dose UVA1 therapy during 6 years were retrospectively analysed. The mean single dose (J/cm 2 ), the mean number of irradiations and the mean total dose (J/cm 2 ) were evaluated. The efficacy of phototherapy was assessed by a grading scale and the number of patients was given in percentage for each group. Results: Good therapeutic effects of UVA1 therapy were shown in patients with atopic eczema, scleroderma, lichen sclerosus et atrophicus, keratosis lichenoides chronica, prurigo nodularis and with cutaneous T-cell lymphoma. Positive effects in some patients were seen in the urticaria pigmentosa and granuloma annulare group, no change to slight improvement was seen in most of the patients with rare, sclerosing skin diseases and no effect was seen in the chronic urticaria group. Conclusion: Besides topical and systemic therapy, UVA1 radiation is a good option of treatment in various skin diseases. It is one of the first-line treatments for several sclerotic diseases and it often improves pruritus considerably.

In vitro allergy diagnostics is rapidly advancing. This is primarily due to the development of component-based diagnostic tools. The availability of allergen components now allows a more precise and patient-tailored diagnostics, which has implications for therapeutic strategies including decision about specific immunotherapy. Furthermore, differential diagnostics of food intolerances and food allergies is also advancing because of this novel test. Another area of advancement is cellular diagnostics, which is primarily based on basophile activation tests. These recent developments will be discussed in this article.

BACKGROUND: Serum IgE-antibodies directed at galactose-α-1,3-galactose (α-Gal) are associated with a novel form of delayed anaphylaxis occuring upon consumption of red meat or innards. Pork kidney is known as the most potent trigger of this syndrome, but the culprit allergens have not yet been identified. The aim of this study was the identification and characterization of pork kidney proteins mediating delayed anaphylactic reactions through specific IgE to α-Gal.METHODS: A cohort of 59 patients with specific IgE to α-Gal was screened by immunoblot for IgE-reactive proteins in pork kidney. Proteins were identified by peptide mass fingerprinting. Isolated proteins were assayed in ELISA and ELISA inhibition, basophil activation and skin prick test.RESULTS: Several IgE-binding proteins of high molecular weight (100 - >200 kDa) were detected in pork kidney extracts by immunoblot using patient sera and an anti-α-Gal antibody. Two major IgE-binding proteins were identified as porcine angiotensin I converting enzyme (ACE I) and aminopeptidase N (AP-N). Reactivity of patient sera and anti-α-Gal antibody to both proteins was abolished by carbohydrate oxidation. The α-Gal IgE epitopes were resistent to heat denaturation. Pork kidney extract, isolated ACE I and AP-N were able to activate patient basophils and elicit positive responses in skin prick tests.CONCLUSION: Two cell-membrane proteins carrying α-Gal epitopes were identified in pork kidney. For the first time, isolated meat proteins were shown to induce basophil activation in patients with delayed anaphylaxis to red meat providing further confirmation for the clinical relevance of these α-Gal-carrying proteins. This article is protected by copyright. All rights reserved.

BACKGROUND: Antivenoms are mammalian immunoglobulins with the ability to neutralize snake venom components and to mitigate the progression of toxic effects. Immediate hypersensitivity to antivenoms often occurs during the first administration of these heterologous antibodies. A comparable clinical situation occurred after introduction of cetuximab, a chimeric mouse-human antibody, for cancer treatment. The carbohydrate epitope galactose-alpha-1,3-galactose, located on the Fab region of cetuximab, was identified as the target responsible for IgE reactivity. OBJECTIVE: To investigate whether serum IgE antibodies directed to the α-gal epitope are associated with hypersensitivity to equine antivenoms. METHODS: Antivenoms were screened for α-gal epitopes via immunoblot and in comparison with cetuximab and pork kidney by IgE reactivity assays. Basophil activation tests were used to investigate reactivity to antivenoms in samples from 20 patients with specific IgE antibodies to α-gal and 10 controls. Additional IgE detection, IgE inhibition, ImmunoCAP inhibition, and skin prick tests were performed using samples from selected patients. RESULTS: Both antivenoms and cetuximab induced positive skin prick test results in patients with sIgE to α-gal. Alpha-gal epitopes were detected by immunoblotting on antivenoms. Measurements of IgE reactivity and ImmunoCAP inhibition indicated that the antivenoms contained lower α-gal contents than cetuximab. Deglycosylation assays and IgE inhibition tests confirmed that IgE-mediated reactivity to antivenom is associated with α-gal. Antivenoms, pork kidney, and cetuximab activated basophils from patients with IgE to α-gal. CONCLUSION: Alpha-gal is a potential target of IgE-mediated reactivity to equine antivenom and a possible cause of the high incidence of hypersensitivity reactions during the first application of equine antivenom.

UV irradiation is widely used for the treatment of atopic eczema. In recent years, UVA1 phototherapy has gained increasing attention. This study analyzed the influence of different UV wavelengths--especially UVA1--on histamine release from human basophils and mast cells. The modulation of this parameter might be responsible for some of the therapeutic effects of UV irradiation. Enriched human basophils and human mast cells (HMC1 cell line) were irradiated with increasing doses of UVB, UVA and UVA1 in vitro. After irradiation, different stimulants were added to induce histamine release. In additional experiments, basophils were preincubated with superoxide dismutase, ascorbate or trolox to study the role of antioxidants in the modulation of histamine release after UV irradiation. UVA and UVA1 significantly inhibited histamine release from basophils and mast cells. UVB only had an inhibitory effect on mast cells. Preincubation with superoxide dismutase and ascorbate did not influence the inhibitory effect of UVA1 on basophil histamine release, whereas trolox decreased significantly the histamine release from nonirradiated basophils.

Background: Regulatory T cells (T-reg cells) have been described as an important cell population in the UV treatment of inflammatory skin diseases. Methods: We have treated five patients with generalized atopic eczema (AE) using medium-dose (15 cycles of 50 J/cm2, total dose of 750 J/cm2) UVA1 therapy and have analyzed the skin-infiltrating T-cellular subsets before and after therapy. Skin biopsies were split for immunohistochemistry and Real-time PCR and analyzed for CD4, Fox-P3, GATA-3, and IL-10 transcription as well as for CD3, CD4, CD152, Fox-P3, and GITR staining. Results: In all the investigated patients, we observed a good clinical response to UVA1. As described previously, the number of epidermal T cells slightly declined after irradiation. However, we did not observe a general decrease in T cell numbers. Within the population of T cells, no specific difference in the kinetics of Fox-P3-positive cells and Fox-P3-specific mRNA was noted as compared with GATA-3 positive T cells. These results were paralleled by RT-PCR for IL-10 and staining for CD152, a surface molecule that has been described for T-reg cells. Conclusion: In our hands, the clinical benefit of UVA1 treatment in AE patients does not seem to be due to a preferential survival/proliferation of T-reg cells.

Epidemiological studies have linked the high prevalence rates of IgE-mediated allergic diseases to an increase in exposure to traffic-related air pollutants such as diesel exhaust particles (DEPs). There is growing experimental evidence that organic compounds of DEPs, predominantly polycyclic aromatic hydrocarbons (PAHs), participate in the development and maintenance of allergic airway diseases. In this study we investigated the impact of organic extracts of urban aerosol (AERex) containing various PAH concentrations on the activation of human basophils. Whole blood samples from six birch pollen-allergic and five control subjects were repeatedly incubated in the presence of AERex with or without recombinant Bet v 1 (rBet v 1). Basophils were analyzed for CD63 expression as a measure of basophil activation by using multiparameter flow cytometry. Basophils, when exposed in vitro to AERex and rBet v 1, expressed CD63 significantly more than with antigen activation alone. AERex synergized with rBet v 1 in a dose-dependent manner, but did not activate basophils from nonallergic donors. AERex effect on CD63 upregulation was found in blood samples of all patients and did not occur in the absence of rBet v 1. Strongest basophil activation was monitored upon stimulation with AERex comprising the highest PAH content. The capability of AERex to increase activation of basophils from birch pollen-allergic subjects at ambient concentrations suggests an important role of organic compounds of airborne particles in the aggravation of IgE-mediated allergic diseases. This could be a new aspect of regulation of unspecific promoting stimuli in clinical manifestation of allergic inflammation.

The basophil activation test (BAT) has become a pervasive test for allergic response through the development of flow cytometry, discovery of activation markers such as CD63 and unique markers identifying basophil granulocytes. Basophil activation test measures basophil response to allergen cross-linking IgE on between 150 and 2000 basophil granulocytes in

Flowcytometric identification of basophils is a prerequisite for measuring activation of basophils with IgE-dependent or IgE-independent stimuli. Aim of this study was to compare different marker combinations in a simultaneous multicolor flowcytometric measurement.Ten patients with a grass pollen allergy and three controls were included in the study. Basophilic cells were gated by using anti-CCR3, anti-IgE, anti-CRTH2, anti-CD203c, and anti-CD3. Cells were activated by a monoclonal anti-Fc?RI antibody, N-formyl-methionyl-leucyl-phenylalanine (fMLP), and the allergen extract Phleum pratense. The activation marker anti-CD63 was used.The highest relative number of basophils was found with anti-CCR3+ cells, anti-IgE+ and anti-IgE+ /anti-CD203c+ cells, the lowest with CRTH2+/CD203c+/CD3- cells. A very good and good concordance of CCR3+ cells was seen with CCR3+/CD3- cells and CRTH2+/CD203c+/CD3- cells in all experiments. The contamination of the CCR3+ population with CD3+ cells and the contamination of the IgE+-population with CCR3- cells and CD203- cells were the lowest compared to all other marker combinations.As the highest relative number of basophils was identified by anti-CCR3 followed by the anti-IgE and anti-IgE/antiCD203c positive population in most cases, these markers can generally be recommended for identification of basophils. If a basophil population with very high purity is needed, anti-IgE should be chosen.

Background Reduction in the size of the allergen-induced late-phase reaction (LPR) is seen as a consequence of successful allergen specific immunotherapy. Objective It was the aim of this study to characterize the cellular infiltrate at the sites of cutaneous LPR that may occur following injection of a depot pollen allergoid (Allergovit®) during immunotherapy and thereby determine the immunological nature of the response. Methods Punch biopsies were taken 24 h after subcutaneous injection of a depot pollen allergoid from eight patients that showed LPR and a further five patients that did not. Additional biopsies taken 24 h after injection of allergoid-free depot in the same patients served as controls. Immunoenzymatic labelling of the cryostat sections with different antibodies was performed with the APAAP technique. Results were expressed as cells/field (400 × magnification). Results Similar dermal cellular infiltrations were seen following depot allergoid injections in patients both with and without LPR. Patients with LPR showed statistically significant increases in total cells, CD4+ cells, CD11c+ cells, CD45RO+ cells, CD45RB+ cells and activated eosinophils at the reactions sites as compared with control sites. In patients without LPR CD11c+ cells, HLA-DR+ cells and CD45RA+ T cells increased significantly. CD8+, CD1a+, NP57+, CD23+ and CD25+ cells did not differ significantly in either group. Conclusion These results indicate that activation of T cells, monocytes/macrophages and eosinophils at the sites of LPR following injection of depot allergoid are comparable with those following injection of allergen. Even in the absence of a cutaneous LPR, subsets of T cells and monocytes/macrophages increased. These cell activations may reflect events associated with the mechanisms of allergoid-based specific immunotherapy, and suggest that at least part of the late-phase reaction may be independent of IgE.

Ultraviolet (UV) radiation causes hemolysis of human erythrocytes in the presence of photosensitizers. This can be used as an in vitro model for evaluating photosensitizing properties of substances. Antioxidants such as ascorbic acid (vitamin C) and d-alpha-tocopherol (vitamin E) have been found to be photoprotective in such test systems. We assessed the effect of combined systemic intake of both ascorbic acid and d-alpha-tocopherol by human volunteers on phototoxic in vitro lysis of their erythrocytes. In a double-blind placebo-controlled study, 10 subjects took daily 2 g ascorbic acid combined with 1000 IU d-alpha-tocopherol, and 10 took a placebo. Blood was taken before and after 7 days of treatment, erythrocytes were prepared and then incubated with 10(-3) mol/l fenofibrate, a photosensitizer acting in the UVA and UVB region. The suspensions were exposed to radiation rich in UVA (up to 40 J/cm2 UVA) or to radiation rich in UVB (up to 1.6 J/cm2). Photohemolysis of the samples was calculated as a percentage of complete hemolysis. At the end of the treatment phase, in the placebo group photohemolysis was not significantly reduced compared with the initial values at all irradiation doses except for 1.6 J/cm2 UVB (96% vs 79%; P < 0.01). In the group taking vitamins, photohemolysis was significantly reduced at nearly all UV doses, most impressively after moderate UVA irradiation (20 J/cm2 UVA: 86.5% vs 14.5%; P < 0.01). It is concluded that the results of the photohemolysis test are influenced by the antioxidative status of the cell donor and that ascorbic acid and d-alpha-tocopherol also may protect against phototoxic damage in vivo.

Background Specific IgE (sIgE) antibodies to both bee and wasp venom can be due to a sensitivity to both insect venoms or due to cross-reactive carbohydrate determinants (CCDs). Objective Investigating whether a basophil activation test (BAT) with both venoms as well as with bromelain and horseradish peroxidase (HRP) or recombinant allergen–based IgE testing can improve the diagnostic procedure. Methods Twenty-two Hymenoptera-venom allergic patients with sIgE antibodies to both bee and wasp venom were studied. sIgE antibodies to MUXF3 CCD, bromelain, HRP, rApi m 1, and rVes v 5 were determined, and a BAT (Flow2 CAST) with venom extracts, bromelain, and HRP was performed. Further recombinant allergen–based IgE testing was done by using an ELISA, if required. The reactivity of basophils was calculated from the insect venom concentration at half-maximum stimulation. Results Double positivity/double negativity/single positivity to rApi m 1 and rVes v 5 was seen in 12/1/9 patients. Further recombinant allergen–based IgE testing in the last ones revealed positive results to the other venom in all cases except one. BAT was double positive/double negative/single positive in 6/2/14 patients. Four patients with negative results in sIgE antibodies to CCDs had positive results in BAT. BAT with bromelain/HRP showed a sensitivity of 50%/81% and a specificity of 91%/90%. Conclusion Component-resolved IgE testing elucidates the pattern of double positivity, showing a majority of true double sensitizations independent of CCD sensitization. BAT seems to add more information about the culprit insect even if the true clinical relevance of BAT is not completely determined because of ethical limitations on diagnostic sting challenges. BAT with HRP is a good method to determine sensitivity to CCDs.

The association between viral activity and antibody profiles was investigated in 202 individuals infected by the human immunodeficiency virus (HIV) grouped according to their Walter Reed clinical stage. Each study group was subdivided into subjects positive or negative for markers of active viral replication: presence of serum p24 antigen and viral culture. In Western blots using recombinant antigens, sera of HIV-positive individuals with positive viral markers had a significantly lower antibody reactivity to several viral proteins than did individuals without viral markers. Noticeably, proteins of the gag (p24, p17) and env (gp120, COOH-terminal part of gp41) open-reading frames revealed a decreased reactivity. The antibody response to the regulatory proteins revealed no or poor association with viral activity in the host. The results suggest that seroreactivity is mainly influenced by factors reflecting the viral activity of an HIV-infected individual, while the clinical stage of the patient is less important. Especially, reductions in antibodies against gp120 and p17 were useful markers associated with increased viral activity.

The possible influence of oxidative stress is discussed in the pathogenesis of polymorphous light eruption (PLE). A double-blind, placebo-controlled study of prophylactic treatment with systemic administration of vitamin C (3 g/d) and E (1500 IU/d) for 8 days was undertaken in 9 patients with PLE (verum, n=4; placebo, n=5). Evaluation of the maximal effects after photoprovocation before and after intake of the antioxidants revealed a reduction of most skin reactions (overall skin reaction, papules/vesicles) in both groups with marked differences in the placebo group. The antioxidants in the doses given and over the time period used did not influence the development of PLE, but might interfere with immunosuppressive effects of repeated photoprovocation tests.

Background The allergen-induced release of mediators from basophils is known to be decreased after rush venom immunotherapy (VIT) compared with pretreatment values. A rise in the intracellular cyclic adenosine monophosphate (cAMP) level is known to inhibit mediator release. Objectives To determine changes in cAMP levels in peripheral blood leukocytes (PBLs) during rush VIT and to evaluate their relation to allergen-specific reactivity of basophils. Methods Ten patients allergic to vespid venom (VV) were investigated before rush VIT and after reaching the maintenance dose. Five VV-allergic patients not undergoing VIT served as controls. Patients' PBLs were incubated with VV, and allergen-induced histamine and leukotriene release from basophils was measured. Levels of cAMP were determined in PBLs and in plasma. Results Immediately after rush VIT, VV-induced histamine release ( P = .04) and VV-induced leukotriene release ( P = .01) were significantly reduced. Intracellular cAMP levels increased significantly ( P = .047). However, 6 months after VIT, mediator responses in basophils were comparable with pre-VIT values. No significant changes were found in the control group. Conclusions An increase in intracellular cAMP levels might account for the decreased reactivity of basophils to allergen after 1 week of VIT. However, similar to the decreased mediator release after 1 week of VIT, this is not a long-term effect as values returned to baseline after 6 months.

Objectives Among the theories supporting the increase of allergic diseases in modern western countries during the last several decades is the concept that environmental pollutants may play a vital role. Reading this article will enable the reader to recognize the effect of different types of environmental pollution on the development, modulation, and persistence of allergic reactions. Data Sources Data sources include references to relevant articles and texts. To characterize the influence of environmental pollutants on allergic reactions (allergotoxicology), epidemiologic, clinical, and experimental data are considered. Results The investigations show that air pollution patterns differ with respect to their effect upon allergies. Classical air pollution (type I) with high sulfur dioxide and dust particles seems not to be associated with allergic disease in humans. However, type II pollution characterized by elevation of oxides of nitrogen (NOx), ozone (O 3 ), tobacco smoke, fine and ultrafine particulate matter, and diesel exhaust particles seems to enhance allergic disease. Conclusions The data suggest that environmental pollution can act at different levels and by complex interactions both outside and inside the individual and influence allergic diseases.

Background: Flow cytometric basophil activation tests have been developed as cellular tests for in vitro diagnosis of IgE-mediated reactions. Different activation markers (CD63 or CD203c) with distinct ways of regulation have been used after stimulation with various allergens. Objective: It was the aim of the present study to compare basophil activation tests by measuring both CD63 and CD203c upregulation in patients with insect venom allergy. Materials and methods: 43 patients with a history of insect venom anaphylaxis were examined. A careful allergy history was taken, and skin tests and determination of specific IgE-antibodies were performed. Basophil activation tests (BAT) using CD63 or CD203c expression were done after stimulation with different concentrations of bee and wasp venom extracts. 25 healthy subjects with negative history of insect venom allergy were studied as controls. Results: The CD203c protocol showed a slightly higher sensitivity than the CD63 protocol (97% vs. 89%) with regard to patients’ history. The magnitude of basophil response was higher with CD203c in comparison to CD63 for both insect venoms. Specificity was 100% for the CD63 protocol and 89% for the CD203c protocol with regard to controls with negative history and negative RAST. Conclusion: These results support the reliability of basophil activation tests using either CD63 or CD203c as cellular tests in the in vitro diagnosis of patients with bee or wasp venom allergy with a slightly higher sensitivity for the CD203c protocol.