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The aim of this document was to provide a critical review of the current knowledge on hypersensitivity pneumonitis caused by the occupational environment and to propose practical guidance for the diagnosis and management of this condition. Occupational hypersensitivity pneumonitis ( OHP) is an immunologic lung disease resulting from lymphocytic and frequently granulomatous inflammation of the peripheral airways, alveoli, and surrounding interstitial tissue which develops as the result of a non-IgE-mediated allergic reaction to a variety of organic materials or low molecular weight agents that are present in the workplace. The offending agents can be classified into six broad categories that include bacteria, fungi, animal proteins, plant proteins, low molecular weight chemicals, and metals. The diagnosis of OHP requires a multidisciplinary approach and relies on a combination of diagnostic tests to ascertain the work relatedness of the disease. Both the clinical and the occupational history are keys to the diagnosis and often will lead to the initial suspicion. Diagnostic criteria adapted to OHP are proposed. The cornerstone of treatment is early removal from exposure to the eliciting antigen, although the disease may show an adverse outcome even after avoidance of exposure to the causal agent. [ABSTRACT FROM AUTHOR]

IgE, the key molecule in atopy has been shown to bind two receptors, FcεRI, the high‐affinity receptor, and FcεRII (CD23), binding IgE with lower affinity. Whereas cross‐linking of IgE on FcεRI expressed by mast cells and basophils triggers the allergic reaction, binding of IgE to CD23 on B cells plays an important role in both IgE regulation and presentation. Furthermore, IgE‐immune complexes (IgE‐ICs) bound by B cells enhance antibody and T cell responses in mice and humans. However, the mechanisms that regulate the targeting of the two receptors and the respective function of the two pathways in inflammation or homeostasis are still a matter of debate. Here, we focus on CD23 and discuss several mechanisms related to IgE binding, as well as the impact of the IgE/antigen‐binding on different immune cells expressing CD23. One recent paper has shown that free IgE preferentially binds to FcεRI whereas IgE‐ICs are preferentially captured by CD23. Binding of IgE‐ICs to CD23 on B cells can, on one hand, regulate serum IgE and prevent effector cell activation and on the other hand facilitate antigen presentation by delivering the antigen to dendritic cells. These data argue for a multifunctional role of CD23 for modulating IgE serum levels and immune responses. [ABSTRACT FROM AUTHOR]

Crossed line immunoelectrophoresis (CLIE) was used to show that a minor allergen present in birth pollen and another present in timothy pollen shared common epitopes with antigens in apple, carrot and celery tuber. Major pollen allergens were not involved. Structural similarities were also noticed in some mugwort pollen antigens and antigens in apple, carrot and celery, but none of these mugwort antigens acted as an allergen. In crossed immunoelectrophoresis (CIE) of samples of apple, carrot or celery extracts towards antibodies against birch pollen, grass pollen or mugwort pollen, four to 14 distinct precipitates were observed and shown to be specific. In crossed radioimmunoelectrophoresis (CRIE) none of the precipitates could be shown to act as an allergen. Using allergen detection on nitrocellulose paper, the apple, carrot and celery extracts were shown to possess IgE-binding capacity. [ABSTRACT FROM AUTHOR]

This paper is a review concerning the way in which heat treatment can modify the allergenicity of food proteins. Any food protein may be allergenic if it can be absorbed intact, or as substantial fragments, through the gut mucosa and then evoke an immune (allergic) response. The intrinsic properties of the protein, the overall composition of the food, and the past processing history (especially thermal processing) all have an effect on the allergic potential. When a protein is denatured by heat, most of the original tertiary structure is lost, so that many of the sites recognized by antibodies on the native molecule are destroyed. There are many examples of allergenicity being reduced, but not eliminated, by heating. But heat-denatured proteins can also present new antigenic sites, uncovered by the unfolding process or created by new chemical reactions with other molecules present in the food (e.g., β-lactoglobulin associating with α-lactalbumin in milk). We have found that heat-denatured β-lactoglobulin has at least one new epitope, not found in the native state. Therefore, thermal processing can be part of a procedure for making hypoallergenic food, but will rarely be sufficient on its own. Increased understanding will help in evaluating novel proteins and processes. [ABSTRACT FROM AUTHOR]

This article presents information on position statements of the European Academy of the Allergology and Clinical Immunology subcommittees. Subcommittee on Adverse Reactions to Food, will conduct a course on Atlas on Mechanisms in Adverse Reactions to Food. Subcommittee on Aerobiology and environmental aspects of inhalant allergens, will hold a course in allergenic pollens and pollinosis in Europe. Subcommittee on Immunotherapy, will hold a course in immunotherapy. Subcommittee on Skin Tests and Allergen Standardization, will conduct a meeting on skin tests used in type allergy testing.

This paper describes the identification of important allergens from the granary weevil (Sitophilus granarius) (Sg). Sera from Danish bakers whose skin prick tests were positive to extracts of Sg were screened for IgE against Sg extracts. We found that 54% (n = 66) had elevated levels of IgE (RAST classes 1-3, by luminescent immunoassay) against whole-body extracts of Sg. The specificity of patient IgE was investigated in an inhibition-dot immunoblotting assay. IgE binding was inhibited in all sera but two, thus indicating that the patients' IgE was indeed specific for the Sg extract. In crossed immunoelectrophoresis, 23 different proteins were identified. All RAST-positive sera were investigated in crossed radioimmuno-electrophoresis. At least 11 proteins in the Sg extract were capable of binding IgE. All individual sera reacted with at least four different proteins. The two most prominent allergens bound IgE from 88% and 100%, respectively, of the patients. These two are considered to be the most important allergens from Sg, and will be useful as markers in environmental immunochemical assays to detect allergens in samples from bakeries, grain stores, etc. [ABSTRACT FROM AUTHOR]

ELISA is increasingly used to measure antibodies in new circumstances. Recently, it has been applied to the measurement of IgG subclass antibodies against common antigens in early childhood. These studies have raised concerns about the specificity of some of these assays. This paper details the results of experiments which have assessed the specificity of IgG1 binding to allergens of dust mite (Dermatophagoides pteronyssinus) and ryegrass (Lolium perenne) pollen by inhibition ELISA in the sera of 2-year-old children of atopic parents. Six sera which showed binding of IgG1 to D. pteronyssinus and six to L. perenne were used. All had IgG1 antibody against ovalbumin. In the children's sera, binding to D. pteronyssinus was substantially inhibited by preincubation with the homologous antigen, but not with ovalbumin, thereby confirming the specificity of the assay. However, suppression of IgG 1 binding to L. perenne with the homologous antigen was conparatively small, and ovalbumin could cause an equivalent inhibition, indicating poor specificity. Furthermore, the level of IgG1 binding to L. perenne was closely correlated to the level of IgG1 binding to ovalbumin (r=0.98; P <0.001). When the assay was reversed, IgG1 binding to ovalbumin was only slightly inhibited by L. perenne, indicating that most antibody binding to ovalbumin was specific. Thus, binding IgG1 in both adult and child sera to D. pteronyssinus appeared to be specific, while child, but not adult, IgG1 binding to L. perenne showed poor specificity. This disparity may be due to differences in the affinities of the respective antibodies, and it illustrates the importance of determining assay specificity when making measurements in early childhood. [ABSTRACT FROM AUTHOR]

The purpose of this paper is to discuss the methodological difficulties in quantisation of human lgG subclass antibodies to allergens, to describe the subclass nature of the lgG antibody response in patients undergoing allergen-specific immunotherapy, and to discuss the possible immunological functions and clinical significance of allergen-specific lgG antibodies of different subclasses. Based on results obtained by use of assays with documented specificity it is concluded that the lgG antibody response during allergen- specific immunotherapy is lgGl and lgG4 restricted, although low levels of lgG2 and lgG3 antibodies to some allergens may occur. In most patients the early IgG antibody response is lgGl dominated and the late lgG4 dominated. A too early or too pronounced lgG4 dominated antibody response seems to indicate a poor clinical outcome of immunotherapy with inhalant allergens, whereas a pronounced early lgGl antibody production has been found to be associated with a decrease in synthesis of IgE antibodies to an insect venom. It is therefore proposed that an early lgGl dominated response is necessary to induce suppression of the ongoing lgE antibody production, which in its turn may be a prerequisite for long-lasting clinical effect. The possibility of induction of an early lgGl dominated response in every patient by use of alternative immunotherapy procedures is discussed. [ABSTRACT FROM AUTHOR]

This paper presents recommendations for standardization of allergen extract by the combined use of skin prick tests and radioallergosorbent tests. These tests provide appropriate means for quantitation of the total allergenic activity' of an extract. Advantages and limitations are discussed with reference to the literature. [ABSTRACT FROM AUTHOR]

This paper argues that with a certain allergen profile of airborne and food allergens and the use of total IgE-antibody levels, combined with the number of allergens positive at test represent a powerful tool to identify allergic disease in childhood. The allergens featured in such a profile will be dependent on the subject's age and geographical location. [ABSTRACT FROM AUTHOR]

The article focuses on purification and characterization of atopic allergens. In the past two decades, several atopic allergens, which induce IgE antibody-mediated immediate hypersensitivity in man have been purified to near homogeneity and studied for their immunochemical properties. In this paper will be reviewed some of the general findings drawn from such studies. Allergen characterization studies with extracts from these sources have confirmed the views of allergists that all extracts are multi-allergen systems and that individuals can have varying patterns of sensitivity to different allergens.

Antigen and antigen-specific IgE can activate IgE receptors and induce IL-4 production by mast cells or basophils. In allergic inflammation, the cells existing in the mucosa take up antigens and present them to produce specific immunoglobulin E (IgE). Mast cells or basophil express the IgE receptor binding to antigen-specific IgE and antigens. [Extracted from the article]

Investigates the pharmacokinetics of the sublingual/spit route of immunotherapy for the radiolabled allergen, Parietaria judaica. Background on the sublingual route of immunotherapy administration; Details on the method; Comparison with the sublingual/swallow procedure.

A new technique is presented to detect and quantify birch (Betula pendula)-pollen allergens directly on air-sampling filters. It is based on the use of specific antibodies, enzymatic reactions, and measurement by chemiluminescence or densitometry. The major pollen antigens are the most important birch allergens. The antibodies used recognize birch-pollen antigens which thus correspond to allergens. Calibration was done with a standardized extract of birch pollen for skin prick testing. The correlation coefficient for the logarithms of luminescence and the amount of birch-pollen allergen applied on filters was >0.98 in the range 0.04-200 SQ units. A similar correlation was found for the logarithms of the integrated densitometry values and the amount of birch-pollen allergen applied on filters. The number of major pollen-antigen particles or grains on filters could be estimated by counting the major stained spots produced by precipitated enzymatic products. The correlation coefficient was 0.90 for the logarithms of the number of counted major antigen spots and the calculated antigen amount obtained by luminometric measurements. Our results demonstrate that birch-pollen allergens can be determined directly on airsampling, Teflon®-based filters by luminometry, optical density, or particle counting. [ABSTRACT FROM AUTHOR]

We describe two uncommon cases of oral allergy syndrome (OAS) after eating pistachio nuts (p.n.) in subjects (a 54-year-old man and a 3-year-old girl) with exclusive skin prick test (SPT) positivity to Parietaria (P.) and pistachio nut (p.n.) allergens. Serologic P.- and p.n.-specific IgE determinations were also carried out. A double-blind, placebo-controlled food challenge (DBPCFC) was performed, for ethical reasons, only in the adult patient, but we observed a positive intraoral reaction only after slight scratching of the oral mucosa. Since this patient had put three whole p.n. with their shells into his mouth, breaking them with his teeth, before the onset of symptoms, we suggest that slight injury of the oral mucosa may enhance the local response. Preliminary results with SDS-PAGE and immunoblotting demonstrate the occurrence of a slight degree of cross-reactivity between these allergens, but further studies are necessary to obtain a definite conclusion. [ABSTRACT FROM AUTHOR]

This article presents information on the evaluation of changes in skin sensitivity by means of skin tests. Skin sensitivity to allergens and histamine can vary spontaneously, or as a consequence or specific immunotherapy, the use of antihistamines or other drugs, and other circumstances. The principle of standardization by skin tests is based on the dose-response relationship of allergen, derived by melting the wheal size produced by different concentrations of the allergen. Most authors evaluating changes in skin sensitivity reactivity.

This article presents information on standardization of allergenic preparations by in vitro and in vivo methods. There are some aspects of allergen standardization which are common for different types of extracts. The composition of an allergen extract depends on several factors, including the source material, the nature and duration of the extraction process and the storage and handling of intermediate products. During the last decades, various methods have been developed to determine the potency and composition of allergen extracts. Most often, CRIE and immunoblotting are used to study the composition of allergen extracts. These methods can also be used to define major allergens, i.e. the allergens which cause frequent and pronounced sensitization in human beings.

Two latex (Hevea brasiliensis) raw materials, one from the cytosolic fraction, the other from the total natural latex have been characterised by immunoblotting techniques. The two latex fractions A and B were studied by immunoprints using eight sera from patients who were allergic to latex. They gave different profiles though there were also allergens of common molecular weights (60, 35, 30, 25, 20, 18, 15, and 10 kD). This study confirms the importance of allergic reactions to latex, that may in some patients cause anaphylactic shock. [ABSTRACT FROM AUTHOR]

The article presents information on treatment of patients allergic to house dust mites. In the treatment of patients allergic to house dust mites two different principles can be applied; symptomatic or specific treatment. The symptomatic treatment includes medicamental treatment and the elimination of now specific irritants, while specific treatment includes elimination of allergens and immunotherapy. In case of bronchial asthma, the purpose of therapy is to keep patients free of symptoms and provide normal lung functioning. It is important neither to undertreat nor overtreat and this means variable and individual pharmacotherapy.

To assess allergen-reducing effect of dust collection from mattresses, patients were asked to vacuum clean the entire surface of their mattresses for 5 min with their household cleaners at specified intervals ranging from 1-21 days. Ten patients performed four collections, nine patients only two. Amounts of dust, concentrations and amounts of major allergens from Dermatophagoides pteronyssinus (Dp42), Dermatophagoides microceras (Dm6), and Dermatophagoides farinae (Df6) were determined. The first sampling caused a statistically significant reduction in the absolute amounts of allergens in a following sample. The same tendency was seen in dust weight but not in concentrations of allergens. At intervals of 1 or 3 weeks no consistent changes could be registered. Differences were small and good reproducibility of the sampling and analysing procedure could be assumed. Since the self-administered procedure is much cheaper and easier to handle than sampling done by technicians with special equipment, it can be recommended for sequential analysis of allergen exposure. [ABSTRACT FROM AUTHOR]

Four allergologically important fungi, viz. Aspergillus fumigatus, Penicillium notalum Alternaria altermata, and Cladosporium herbarum were cultured in a liquid synthetic me with or without addition of 0.1 % yeast extract (YE). After 10 and 28 days of cultivation, immunochemical properties of the fungal extracts, characterised by precipitation pattern and IgG- and IgE-binding capacity, were studied. In pure synthetic medium no large differences were observed in number of precipitates, as measured by DID, among the four antigenic fractions of each fungus (metabolic and mycelial antigens of both early and late phase cultures). Addition of YE to the growth medium hardly changed the number of precipitates and generally caused a decrease in lgG-binding capacity of the extracts. In contrast to these observations were the findings with the IgE-binding capacities of the fungal extracts as measured by RAST. Most allergenic fractions demonstrated an increase (sometimes strong) in lgE-binding capacity after YE was added to the growth medium. It is concluded that the time of cultivation influences the immunochemical characteristics of fungal extracts and that mycelial as well as metabolic antigens of both early and late phase cultures should be used in order to obtain a wide spectrum of allergens in extracts used for diagnostic purposes. [ABSTRACT FROM AUTHOR]

IgE and IgG antibodies (ab) and lymphocyte transformation (LT) were studied in untreated and hyposensitized birch pollen allergic subjects and in non-a topic controls using whole extract and fractions obtained by gel filtration of birch pollen extract. All the allergic subjects had positive IgE ab, IgG ab and LT responses to the whole extract. Both the untreated and the hyposensitized subjects had peak IgE ab and LT responses against the allergenic fractions of the extract, while negative responses were obtained in the non-atopic controls. Only hyposensitized subjects had developed high IgG ab responses to the allergenic fractions. Most of the treated and untreated subjects showed IgG ab and LT responses to the high molecular weight fractions with low allergenic activity. Significantly higher IgE ab responses to these fractions were observed in the treated subjects than in the untreated ones, indicating potentiation of IgE ab responses against some antigens during immunotherapy. Some of the allergic subjects also responded to the fractions of low molecular size (mol.wt. 2000-5000) with low allergenic activity. Both IgE ab, IgG ab and LT responses to these fractions were observed. [ABSTRACT FROM AUTHOR]

Monozygotic ( MZ) twins discordant for complex diseases may help to find disease mechanisms that are not due to genetic variants. Intermittent allergic rhinitis ( IAR) is an optimal disease model because it occurs at defined time points each year, owing to known external antigens. We hypothesized that MZ twins discordant for IAR could help to find gene expression differences that are not dependent on genetic variants. We collected blood outside of the season from MZ twins discordant for IAR, challenged their peripheral blood mononuclear cells ( PBMC) with pollen allergen in vitro, collected supernatants and isolated CD4+ T cells. We identified disease-relevant mRNAs and proteins that differed between the discordant MZ twins. By contrast, no differences in micro RNA expression were found. Our results indicate that MZ twins discordant for IAR is an optimal model to identify disease mechanisms that are not due to genetic variants. [ABSTRACT FROM AUTHOR]

The article focuses on the analysis and standardization of allergen extracts intended for therapeutic use. Over the past decade, many papers and international meetings have been devoted to establishing methods and requirements for analysis and standardization of allergen extracts. In fact, manufacturers and control authorities are in demand to produce procedures enabling precise and viable quantitation of allergenic activity as well as analysis of extracts. Such an approach would allow physicians to prescribe uniformly labeled extracts of known quality and guarantee therapeutic procedures.

In the article, four house dust allergen preparations of different degree of purification were examined in various institutes by means of physicochemical analysis, IgE binding, C-assay and cutaneous tests. The philosophy of this approach was that, if a chosen technique has any validity at all in standardization, potency differences among various preparations should reveal themselves in an equal manner, independent of the investigator. House dust extracts were prepared and purified according to a standard schedule and subfractions were coded as published.

The monoclonal anti-immunoglobulin E (IgE) antibody, omalizumab, was the first drug approved for use in patients with chronic idiopathic/spontaneous urticaria ( CIU/ CSU) who remain symptomatic despite H1-antihistamine treatment. Omalizumab binds to free IgE, which lowers free IgE levels and causes Fcε RI receptors on basophils and mast cells to be downregulated. It has been shown to improve symptoms of CIU/ CSU, but its mechanism of action is not currently understood. Potential mechanisms in CIU/ CSU include reducing mast cell releasability, reversing basopenia and improving basophil IgE receptor function, reducing activity of IgG autoantibodies against Fcε RI and IgE, reducing activity of IgE autoantibodies against an antigen or autoantigen that has yet to be definitively identified, reducing the activity of intrinsically 'abnormal' IgE, and decreasing in vitro coagulation abnormalities associated with disease activity. However, none of these theories alone or in combination fully account for the pattern of symptom improvement seen with omalizumab therapy, and therefore, no one mechanism is likely to be the definitive mechanism of action. Additional research is needed to further clarify the involvement of omalizumab in relieving symptoms associated with the complex, multifactorial pathogenesis of CIU/ CSU. [ABSTRACT FROM AUTHOR]

Background Allergic reactions to mosquito bites are an increasing clinical concern. Due to the lack of availability of mosquito salivary allergens, they are underdiagnosed. Here, we reported a newly cloned mosquito Aedes ( Ae.) aegypti salivary allergen. Methods A cDNA encoding a 30- kDa Ae. aegypti salivary protein, designated Aed a 3, was isolated from an expression library. The full-length cDNA was cloned into a baculovirus expression vector, and recombinant Aed a 3 ( rAed a 3) was expressed, purified, and characterized. Skin prick tests with purified rAed a 3 and Ae. aegypti bite tests were performed in 43 volunteers. Serum rAed a 3-specific IgE levels were measured in 28 volunteers. Results The primary nucleotide sequence, deduced amino acid sequence, and IgE-binding sites of Aed a 3 were identified. rAed a 3-selected antibodies recognized a 30- kDa Ae. aegypti saliva protein. rAed a 3 bound IgE in mosquito-allergic volunteers and the binding could be inhibited by the addition of natural mosquito extract dose dependently. Immediate skin test reactions to rAed a 3 correlated significantly with mosquito bite-induced reactions. Of the bite test-positive volunteers, 32% had a positive rAed a 3 skin test and 46% had specific IgE. No bite test-negative volunteers reacted to rAed a 3 in either the skin tests or the IgE assays, confirming the specificity of the assay. Conclusions Aed a 3 that corresponds to the Aegyptin protein is a major mosquito salivary allergen. Its recombinant form has biological activity and is suitable for use in skin tests and specific IgE assays in mosquito-allergic individuals. [ABSTRACT FROM AUTHOR]

The article focuses on assay of allergen preparation using direct radioallergosorbent test (RAST) titration and skin tests. The author chose the direct RAST method rather than RAST inhibition, since the inhibition method requires the availability of a good allergen reference preparation coupled to paper discs for each allergen to be assayed. Obtaining suitable reference preparations appeared difficult. Allergen concentrations in direct RAST titration units can be converted to histamine-equivalent prick units by multiplication with a factor, which is allergen specific.

Background BM4 is a novel genetically engineered variant of the major birch pollen allergen Bet v 1 that lacks the typical Bet v 1-like fold and displays negligible Ig E-binding but strong T cell-activating capacity. The aim of this study was to elucidate possible differences between BM4 and Bet v 1 in internalization, antigen processing, and presentation. Methods Proliferative responses to BM4 and Bet v 1 of peripheral blood mononuclear cells and Bet v 1-specific T-cell clones were compared. Fluorescently labeled BM4 and Bet v 1 were used to study surface binding, endocytosis, and intracellular degradation by monocyte-derived DC (md DC). Both proteins were digested by endolysosomal extracts of md DC. BM4- and Bet v 1-pulsed md DC were employed to assess the kinetics of activation of Bet v 1-specific T-cell clones and the polarization of naïve T cells. Results BM4 displayed a significantly stronger T cell-activating capacity than Bet v 1. Furthermore, BM4 showed increased surface binding and internalization as well as faster endolysosomal degradation compared with Bet v 1. BM4-pulsed md DC induced enhanced proliferative responses at earlier time-points in Bet v 1-specific T-cell clones and promoted less IL-5 production in T cells than Bet v 1-pulsed md DC. Conclusion The loss of the Bet v 1-fold changes the protein's interaction with the human immune system at the level of antigen-presenting cells resulting in altered T-cell responses. By combining low Ig E-binding with strong and modulating T cell-activating capacity, BM4 represents a highly interesting candidate for specific immunotherapy of birch pollen allergy. [ABSTRACT FROM AUTHOR]

Background Cross-reactivity between hymenoptera species varies according to the different allergenic components of the venom. The true source of sensitization must therefore be established to ensure the efficacy of venom immunotherapy. Objective In the Mediterranean region, Polistes dominulus and Vespula spp. are clinically relevant cohabitating wasps. A panel of major vespid venom allergens was used to investigate whether serum-specific IgE ( sIgE) could be used to distinguish sensitization to either vespid. Methods Fifty-nine individuals with allergic reactions to vespid stings and positive Immuno CAP and/or intradermal tests to vespid venoms were studied. sIgE against recombinant and natural venom components from each wasp species was determined using the ADVIA Centaur® system. Results sIgE against recombinant antigen 5s sensitization to be detected in 52% of the patients tested (13/25). The sensitivity increased to 80% (20/25), when using natural antigen 5s, and to 100% with the complete panel of purified natural components, because the sIgE was positive to either the antigen 5s ( Pol d 5/ Ves v 5) or to the phospholipases ( Pol d 1/ Ves v 1) of the two vespids, or to both components at the same time. In 69% of cases, it was possible to define the most probable sensitizing insect, and in the rest, possible double sensitization could not be excluded. Vespula hyaluronidase was shown to have no additional value as regards the specificity of the assay. Conclusions The major allergens of P. dominulus' and Vespula vulgaris' venom, namely phoshpholipases and antigen 5s, are required to discriminate the probable sensitizing species in vespid-allergic patients. [ABSTRACT FROM AUTHOR]

To cite this article: Lødrup Carlsen KC, Söderström L, Mowinckel P, Håland G, Pettersen M, Munthe Kaas MC, Devulapalli CS, Buchmann M, Ahlstedt S, Carlsen K-H. Asthma prediction in school children; the value of combined IgE-antibodies and obstructive airways disease severity score. Allergy 2010; 65: 1134–1140. Background: Allergic sensitisation increases the risk for asthma development. In this prospective birth cohort (Environment and Childhood Asthma) study, we hypothesized that combining quantitative measures of IgE antibodies (Σ-IgE) and Severity score of obstructive airways disease (OAD) at 2 years of age (Severity score) is superior to predict current asthma (CA) at 10 years than either measure alone. Secondarily, we assessed if gender modified the prediction of CA. Methods: A follow-up study at 10 years of age was performed in 371 2-year-old children with recurrent ( n = 219) or no ( n = 152) bronchial obstruction with available serum analysed for Σ-IgE to common food and inhalant allergens through a panel test, Phadiatop Infant® (Phadia, Uppsala, Sweden). Clinical variables included allergic sensitisation and exercise testing to characterise children with CA vs not CA at 10 years and the Severity score (0–12, 0 indicating no OAD) was used to assess risk modification. Results: Severity score alone explained 24% (Nagelkerke R2 = 0.24) of the variation in CA, whereas Σ-IgE explained only 6% ( R2 = 0.06). Combining the two increased the explanatory capacity to R2 = 0.30. Gender interacted significantly with Σ-IgE; whereas Severity score predicted CA in both genders, the predictive capacity of Σ-IgE for CA at 10 years was significant in boys only. Conclusion: Combining Σ-IgE to inhalant allergens and Severity score at 2 years was superior to predict asthma at 10 years than either alone. Severity score predicted CA in both genders, whereas Σ-IgE significantly predicted CA in boys only. [ABSTRACT FROM AUTHOR]

Background: The number of allergens to be tested in order to identify sensitized patients is important in order to have the most cost-effective approach in epidemiological studies. Objective: To define the minimal number and the type of skin prick test (SPT) allergens required to identify a patient as sensitized using results of the new Pan-European GA2LEN skin prick test study. Method: In a large Pan-European multicenter (17 centers in 14 countries) patient based study, a standardized panel of 18 allergens has been prick tested using a standardized procedure. Conditional approach allowed to determine the allergens selection. Result: Among the 3034 patients involved, 1996 (68.2%) were sensitized to at least one allergen. Overall, eight allergens (grass pollen, Dermatophagoides pteronyssinus, birch pollen, cat dander, Artemisia, olive pollen, Blatella and Alternaria) allowed to identified more than 95% of sensitized subjects. However, differences were observed between countries, two allergens being sufficient for Switzerland (grass pollen and cat dander) as opposed to nine for France (grass pollen, Dermatophagoides pteronyssinus, olive pollen, cat dander, Blatella, cypress, dog dander, alder and [Artemisia or Alternaria]). According to country, up to 13 allergens were needed to identify all sensitized subjects. Conclusion: Eight to ten allergens allowed the identification of the majority of sensitized subjects. For clinical care of individual patients, the whole battery of 18 allergens is needed to appropriately assess sensitization across Europe. [ABSTRACT FROM AUTHOR]

Background: Gliadins have been implicated in immunoglobulin E (IgE)-mediated allergy to ingested wheat and ω-5-gliadin is known to represent a major allergen in wheat-dependent exercise-induced anaphylaxis. Less known is whether ω-5-gliadin is a clinically relevant allergen in children with immediate allergy to ingested wheat. This study investigates whether specific IgE antibodies to ω-5-gliadin (sIgE-ω-5-gliadin-ab) could be used as a marker for oral wheat challenge outcome in wheat-sensitized children. A secondary objective was to study whether the level of sIgE-ω-5-gliadin was related to symptom severity in children with a positive challenge test. Methods: Serum samples from 88 children sensitized to wheat, of whom 35 underwent wheat challenge, were collected consecutively. sIgE-ω-5-gliadin-ab was related to a physician’s diagnosis of wheat allergy and challenge symptoms. Results: The mean concentration of sIgE-ω-5-gliadin-ab was 7.25 kUA/l in patients with wheat allergy and 1.08 kUA/l in patients with no wheat allergy ( P < 0.01). sIgE-ω-5-gliadin-ab was only detected in 12 of the non-wheat allergic children and 11 of them had a specific IgE to wheat below 1.30 kUA/l. Children reacting with severe symptoms upon challenge ( n = 8) had increased levels of sIgE-ω-5-gliadin-ab compared to children with moderate, mild or no symptoms ( P < 0.001). Conclusions: The presence of sIgE-ω-5-gliadin-ab is related to the reaction level to wheat challenge outcome in wheat-sensitized children. The sIgE-ω-5-gliadin-ab was found to be associated with a strong convincing history of wheat allergy also in those cases when oral food challenge was avoided. The sIgE-ω-5-gliadin-ab level may serve as a marker for clinical reactivity in wheat-sensitized individuals. [ABSTRACT FROM AUTHOR]

The major allergen in house dust comes from mites. We performed a systematic review of the randomized trials that had assessed the effects of reducing exposure to house dust mite antigens in the homes of people with mite-sensitive asthma, and had compared active interventions with placebo or no treatment. Fifty-four trials (3002 patients) were included. Thirty-six trials assessed physical methods (26 mattress covers), 10 chemical methods and eight a combination of chemical and physical methods. Despite the fact that many trials were of poor quality and would be expected to exaggerate the reported effect, we did not find an effect of the interventions. For the most frequently reported outcome, peak flow in the morning (1565 patients), the standardized mean difference was 0.00 (95% confidence interval (CI) −0.10 to 0.10). There were no statistically significant differences in number of patients improved (relative risk 1.01, 95% CI 0.80–1.27), asthma symptom scores (standardized mean difference −0.04, 95% CI −0.15 to 0.07) or in medication usage (standardized mean difference −0.06, 95% CI −0.18 to 0.07). Chemical and physical methods aimed at reducing exposure to house dust mite allergens cannot be recommended. [ABSTRACT FROM AUTHOR]

Background: Many studies have reported the prevalence of sensitization using skin prick tests. However, comparisons between studies and between regions are difficult because the number and the type of allergens tested vary widely. Using the European Community Health Respiratory Survey I data, the geographical variation of sensitization to environmental allergen as measured by skin tests was established. Methods: Adults aged 20–44 years, living in 35 centres in 15 developed countries, underwent skin tests for allergy to nine common aeroallergens: Dermatophagoides pteronyssinus, timothy grass, cat, Cladosporium herbarium, Alternaria alternata, birch, Olea europea, common ragweed and Parietaria judaica. The age–sex standardized prevalence of sensitization was determined and centres with high (95% confidence interval above and excluding study median) and low prevalence (95% confidence interval below and excluding study median) of sensitization to each allergen and to any of the nine allergens were identified. Results: There was substantial geographical variation in the prevalence of sensitization to each of the nine allergens tested and in the prevalence of sensitization to any allergen (lowest 17.1%, median 36.8% and highest 54.8%). Sensitization to D. pteronyssinus, grass pollen and cat were usually the most prevalent (median between centre 21.7%, 16.9% and 8.8%, respectively). Timothy grass sensitization was higher than that for any other pollen species. Conclusions: As expected, geographical variations of sensitization to environmental allergen were observed across centres. These findings were compatible for those observed with serum-specific IgE. Skin tests can be used to assess the geographical distribution of allergens in a multicentric epidemiological survey. [ABSTRACT FROM AUTHOR]

Background: As conventional immunotherapy is less efficacious in patients with allergic multi-sensitivities compared with mono-sensitized subjects, new intervention strategies are needed. Therefore, an allergen chimer was genetically engineered for treatment of multi-sensitization with birch and grass pollen on the basis of mucosal tolerance induction. Methods: The major birch pollen allergen Bet v 1 served as a scaffold for N- and C-terminal linkage of the immunodominant peptides of the grass pollen allergens Phl p 1 and Phl p 5 and this new construct was cloned and expressed in Escherichia coli. After purification, physicochemical and immunological characterization the chimer was used for intranasal tolerance induction prior to poly-sensitization with Bet v 1, Phl p 1 and Phl p 5. Results: The immunological characterization revealed that the conformation of Bet v 1 within the chimer was comparable to that of natural as well as recombinant Bet v 1. The chimer was immunogenic in mice for T and B cell responses to the three allergens. Intranasal application of the chimer prior to poly-sensitization significantly suppressed humoral and cellular allergen-specific Th2 responses and prevented development of airway inflammation upon allergen challenge. Moreover, local allergen-specific IgA antibodies were induced by the chimer. The mechanisms of poly-tolerance induction seemed to be mediated by regulatory cytokines, since TGF- β and IL-10 mRNA in splenocytes were upregulated and tolerance was transferable with these cells. Conclusion: The data indicate that such allergen chimers harboring several unrelated allergens or allergen peptides could serve as mucosal polyvalent vaccines for prevention of multi-sensitivities. [ABSTRACT FROM AUTHOR]

Background: In T cell-associated allergic inflammation, homing of T-helper 2 (Th2) effector cells to mucosal sites may be influenced by chemokine receptor expression. Previous studies have identified CCR3 and CCR4 as putative markers of Th2 cells and CCR5 and CXCR3 as markers of Th1 cells. The aim of this study was to assess differential chemokine receptor expression from symptomatic atopic grass pollen-sensitive subjects, compared with patients on high-dose allergen injection immunotherapy (IT) and healthy controls. Methods: We examined chemokine receptor expression (CCR1–7 and CXCR1–4) by flow cytometry of peripheral blood CD4+ and CD8+ T cells. We also depleted peripheral blood mononuclear cell (PBMC) populations of CCR3+ CD4+ cells by magnetic bead separation and cells were stimulated with grass pollen allergen for 6 days. Cytokine production was measured by enzyme-linked immunosorbent assay. Results: On freshly isolated PBMC, atopic individuals exhibited increased numbers of CCR3+ CD4+ cells compared with normal controls ( P < 0.01). CCR3 expression in IT patients was reduced compared with matched atopic rhinitic controls ( P < 0.05) and comparable with that observed in normal subjects. Depletion of CCR3+ CD4+ cells from allergen-stimulated PBMC cultures resulted in decreased interleukin (IL)-5 production compared with whole CD4+ populations ( P < 0.05). Freshly isolated CCR3+ CD4+ cells have significantly higher intracellular IL-4 and lower IFN- γ levels than CCR3− CD4+ cells. CD4+ T cells cultured from both peripheral cells and nasal biopsies demonstrated increased expression of CCR3 in the presence of IL-4 ( P < 0.05). Conclusion: CCR3+ CD4+ T cells are increased in allergic rhinitis, are reduced by allergen IT, have a Th2 phenotype and contribute to allergen-specific responses. Strategies against CCR3+ T cells may be effective in human allergic diseases. [ABSTRACT FROM AUTHOR]

Background: Quantitative relationships between immunological reactivity, non-specific bronchial responsiveness and bronchial responsiveness to allergens have scarcely been investigated in occupational asthma. Methods: We assessed the above relationships in 24 subjects with baker's asthma. The skin endpoint titration to bakery allergens as a measure of immunological reactivity, together with the methacholine PC20 and allergen PC20 during early asthmatic reaction were determined. Results: All patients had positive skin tests to some bakery allergens (wheat and rye flour, soybean flour, fungal enzymes and egg white proteins) and bronchial hyperresponsiveness to methacholine. Specific inhalation challenge (SIC) tests were performed with aqueous allergen extracts of cereal flour ( n = 14), soybean ( n = 8), baking enzymes ( n = 12), and egg white proteins ( n = 8) in sensitized workers. A positive asthmatic reaction was observed in 84% of the inhalation challenges. SIC elicited isolated early asthmatic reactions in 62%, dual reactions in 32% and isolated late reactions in 5%. Multiple linear regression analysis showed allergen PC20 as a function of skin sensitivity to allergen and methacholine PC20, yielding the following highly significant regression formula: log-allergen PC20 = 0.18 + 0.99 log(skin sensitivity) + 0.343 log(methacholine PC20) ( r = 0.89, P < 0.001). This formula predicted allergen PC20 to within one double concentration in 67%, to within two double concentrations in 85% and within three double concentrations in 97%. Conclusion: The main determinant of bronchial responsiveness to allergen in patients with baker's asthma is the degree of sensitization to occupational allergens as determined by skin reactivity, modulated to a lesser extent by non-specific bronchial hyperresponsiveness. [ABSTRACT FROM AUTHOR]

Background: Low sensitization rates to common allergens have been observed in farm children, which might be due to high exposure to microbial agents. It is not known how microbial agents modify the association between specific allergen exposure and sensitization. Objective: To examine the relations between house dust mite allergen exposure and mite sensitization in farm and nonfarm children and to assess the effects of microbial agents levels on this association. Methods: Major mite allergens of Dermatophagoides pteronyssinus (Der p 1) and Dermatophagoides farinae (Der f 1), endotoxin, β(1,3)-glucans and fungal extracellular polysaccharides were measured in mattress dust of 402 children participating in a cross-sectional study in five European countries. Mite allergen (Der p 1 + Der f 1) levels were divided into tertiles with cut-offs 1.4 and 10.4 μg/g. Sensitization was assessed by measurement of allergen-specific immunoglobulin E against house dust mite. Results: Prevalence ratios of mite sensitization for medium and high when compared with low mite allergen levels were 3.1 [1.7–5.7] and 1.4 [0.7–2.8] respectively. Highest mite sensitization rates at intermediate exposure levels were consistently observed across country (except for Sweden) and in both farm and nonfarm children. The shape of the dose–response curve was similar for above and below median mattress microbial agent levels, but the ‘sensitization peak’ appeared to be lower for above median levels. Conclusions: Our data suggest a bell-shaped dose–response relationship between mite allergen exposure and sensitization to mite allergens. In populations with high microbial agent levels and low sensitization rates, the curve is shifted down. [ABSTRACT FROM AUTHOR]

Background: Vegetable pollen is a rare source of occupational allergens. Occupational allergy has only been described in the case of paprika pollen and tomato pollen. We describe a new source of occupational pollen allergy. Aim: To study the incidence and the impact of broccoli and cauliflower pollen allergy in employees involved in classical plant breeding. Methods: Fifty-four employees of five companies working with cauliflower ( Brassica oleracea botrytis) and broccoli ( B. oleracea italica/ cymosa) pollen were eligible for complete evaluation. Allergy to cauliflower and broccoli pollen was evaluated by questionnaire and determination of sensitization by radioallergosorbent test (RAST) and skin-prick tests (SPT). SPT and RAST were performed with a panel of commercial and homemade extracts from cauliflower and broccoli pollen. Results: Work-related symptoms such as rhinitis, conjunctivitis, asthma and urticaria caused by B. oleracea pollen were reported by 44% of the participants (24/54), of whom all but one had positive SPT for cauliflower- and/or broccoli-pollen/flower extracts and 58% (14/24) had positive RAST results. Symptoms had developed within the first 2 years in 33% of the patients. Six patients had to stop or change work. Conclusions: Brassica oleracea pollen is a new source of occupational allergen with strong allergenic potential leading to symptoms in almost half of the exposed employees. [ABSTRACT FROM AUTHOR]

Background: It has been argued that the inverse association between exposure to farm animals and nasal allergies observed in children and adults might be because of self-selection. Aims: We aimed to assess the health-based selection out of farming in adults. Material and methods: A cross-sectional study was carried out in a rural region. Overall, 4053 inhabitants (63%) aged 18–44 years responded to a questionnaire on respiratory diseases, life-time exposure to farming environments and potential confounders. For 2678 of these, specific immunoglobulin E to common allergens was available. The outcome was: (i) sensitization and symptoms of nasal allergies (symptomatic sensitization); (ii) sensitization without symptoms of nasal allergies (asymptomatic sensitization). Results: Farm animal contact in childhood was associated with a decreased risk of symptomatic and asymptomatic sensitization. Continued exposure to farm animals in adulthood further decreased the odds ratio of symptomatic (odds ratio 0.2; 95% confidence interval 0.1, 0.4) but not asymptomatic sensitization (0.7; 0.4, 1.1). Starting farm animal contact in adulthood even increased the odds ratio of asymptomatic sensitization (2.4; 1.1, 5.2). Conclusions: The preventive effect of childhood contact to farm animals against sensitization continues into adulthood. However, in adulthood self-selection based on symptoms and underreporting of symptoms might also play a role. [ABSTRACT FROM AUTHOR]

Background: Fish is one of the most frequent causes of immunoglobulin E (IgE)-mediated food allergy. Although the fish dark muscle is often ingested with the white muscle, no information about its allergenicity and allergens is available. Methods: Heated extracts were prepared from both white and dark muscles of five species of fish and examined for reactivity with IgE in fish-allergic patients by enzyme-linked immunosorbent assay (ELISA) and for allergens by immunoblotting. Cloning of cDNAs encoding parvalbumins was performed by rapid amplification cDNA ends. Parvalbumin contents in both white and dark muscles were determined by ELISA using antiserum against mackerel parvalbumin. Results: Patient sera were less reactive to the heated extract from the dark muscle than to that from the white muscle. A prominent IgE-reactive protein of 12 kDa, which was detected in both white and dark muscles, was identified as parvalbumin. Molecular cloning experiments revealed that the same parvalbumin molecule is contained in both white and dark muscles of either horse mackerel or Pacific mackerel. Parvalbumin contents were four to eight times lower in the dark muscle than in the white muscle. Conclusions: The fish dark muscle is less allergenic than the white muscle, because the same allergen molecule (parvalbumin) is contained at much lower levels in the dark muscle than in the white muscle. Thus, the dark muscle is less implicated in fish allergy than the white muscle. [ABSTRACT FROM AUTHOR]

Moisture is vitally important for house dust mites and they cannot survive in cold or hot-dry climates. To investigate the influence of two extraordinarily cold and dry winters in 1995/1996 and 1996/1997 on house dust mite levels in German homes. Dust samples were collected between June 1995 and December 2001 on the mattresses of 655 adults and 454 schoolchildren living in five different areas of Germany. We compared house dust mite allergen Dermatophagoides pteronyssinus (Der p 1) levels before and during the winters of 1995/1996 and 1996/1997 with levels after these winters. D. pteronyssinus (Der p 1) levels in samples taken after the cold winters of 1995/1996 and 1996/1997 were approximately two times lower than Der p 1 levels in dust samples collected before or during these respective winters (Geometric means: Erfurt 89 vs 33 ng/g; Hamburg 333 vs 219 ng/g; Bitterfeld, Hettstedt, and Zerbst 296 vs 180 ng/g). Except for Hamburg, the decrease in Der p 1 levels was statistically significant. D. pteronyssinus levels measured in dust samples collected in 2001 (i.e. 3 years after the two cold winters) show a statistically non-significant increase (Geometric means: Erfurt 33 vs 39 ng/g; Hamburg 219 vs 317 ng/g), suggesting that it may take a long time for mite allergen levels to increase again after a sudden decrease. We conclude that Der p 1 levels in German mattress dust samples have been approximately reduced by a factor of three to four by the two consecutive cold winters of 1995/1996 and 1996/1997. [ABSTRACT FROM AUTHOR]

Sublingual-swallow immunotherapy (SLIT) is an accepted treatment for allergic rhinitis but its optimal dosage is scantly investigated. We studied the dose dependence of clinical efficacy and immunological response to SLIT by administering two different dosages of the same allergen in rhinitic children monosensitized to grass pollen.Seventy-one patients with comparable age and symptoms were randomized to receive SLIT by the same grass pollen extract from Stallergénes (Antony, France), 40 of them with the 100 IR and 31 with the 300 IR extract. All patients recorded diary cards for symptoms, medications and side-effects of the treatment, and had measurements of specific IgE and IgG4 in serum by the CAP System FEIA (Pharmacia, Uppsala, Sweden) and in nasal secretion by anin situincubation method with the same reagents of CAP System FEIA.Symptom/medication scores during the pollen season were significantly higher in patients treated with the lower dosage compared with those treated with the 300 IR dosage. Side-effects occurred with a comparable rate (25.8%vs27.5%) in the two groups. Serum-specific IgE and IgG4 had no significant changes after 3 months of SLIT in both groups, while a significant seasonal increase of nasal IgE (P = 0.015) and IgG4 (P = 0.019) was found only in patients treated with the lower dosage.A rise of specific IgG4 and a blunting of seasonal increase of specific IgE in serum was repeatedly reported during subcutaneous immunotherapy (SCIT) with pollen extracts. Our findings show such blunting of specific nasal IgE along with a low symptom/medication score in patients treated with SLIT with the higher dosage, but not a concomitant rise of specific nasal IgG4. This suggests a local immunological effect of SLIT, different from systemic mechanisms of SCIT. [ABSTRACT FROM AUTHOR]

Wood dust is known to cause allergic occupational asthma and obeche (Triplochiton scleroxylon) is a prominent exponent in this field. However, the knowledge about wood allergens is still limited. The aim of this study was to identify and characterize obeche wood allergens.Obeche extracts were prepared from freshly ground in comparison to 7 years stored wood dust and investigated by Sodium dodecyl sulfate-polyacrylamid gel electrophoresis, enzyme-linked allergosorbent test and immunoglobulin (Ig)E-immunoblot. Allergens were detected by specific IgE of seven obeche allergic patients’ sera and protein analysis was performed by mass spectrometry. Cross-reactivity was demonstrated by ImmunoCAP-inhibition with sera of seven obeche and four latex-allergic patients.Obeche extracts showed different protein pattern and IgE-binding capacities depend on the age of the wood dust. A 38 kDa protein was identified as major obeche wood allergen, detected by six of seven (85%) obeche allergic patients’ sera and was entitled as Trip s 1. Trip s 1 is homologous to plant class I chitinases and exhibited enzyme activity demonstrated by chitinolysis. Co-recognition or cross-reactivity of Trip s 1 according to structural similarity was seen in sera of latex allergic patients. IgE inhibition studies with obeche as solid phase and Trip s 1 and latex hevein as inhibitor demonstrated that Trip s 1 was a more effective inhibitor in obeche as well as in latex allergic patients’ sera.Trip s 1 is a new obeche wood allergen of the plant class I chitinase family. This finding may explain the dominant role of obeche in sensitization against wood dust. [ABSTRACT FROM AUTHOR]

Simple, inexpensive methods of sampling from allergen reservoirs are necessary for large-scale studies or low-cost householder-operated allergen measurement.We tested two commercial devices: the Indoor Biotechnologies Mitest Dust Collector and the Dräger Bio-Check Allergen Control; two devices of our own design: the Electrostatic Cloth Sampler (ECS) and the Press Tape Sampler (PTS); and a Vacuum Sampler as used in many allergen studies (our Reference Method). Devices were used to collect dust mite allergen samples from 16 domestic carpets. Results were examined for correlations between the sampling methods.With mite allergen concentration expressed asμg/g, the Mitest, the ECS and the PTS correlated with the Reference Method but not with each other. When mite allergen concentration was expressed asμg/m2 the Mitest and the ECS correlated with the Reference Method but the PTS did not. In the high allergen conditions of this study, the Dräger Bio-Check did not relate to any methods.The Mitest Dust Collector, the ECS and the PTS show performance consistent with the Reference Method. Many techniques can be used to collect dust mite allergen samples. More investigation is needed to prove any method as superior for estimating allergen exposure. [ABSTRACT FROM AUTHOR]

Numerous studies have suggested that both genetic and environmental influences are involved in the pathogenesis of allergic disease and atopy. The objective of this investigation is to elucidate the underlying mechanism of penicillins allergy and improve the diagnostic methods.Radioallergosorbent test was used to examine eight kinds of specific IgE antibodies, which included four kinds of major and minor antigenic determinants, respectively, in the sera of 448 patients with penicillins allergy and 101 healthy subjects. A restriction endonuclease fragment length polymorphism of a polymerase chain reaction product was used for analysis of the FcℇRIβ polymorphism.The positive rate of specific IgE in 448 patients was 58.26% (261), in which 37.28% (167) patients had positive IgE to major antigenic determinants and 47.09% (211) patients had positive IgE to minor antigenic determinants. Of the 179 patients with allergic history, 70.83% (17/24) patients had positive antibodies within 30 days, while 45.28% (24/53) had positive antibodies after 5 years. The positive reaction degree of skin test was absolutely correlated with specific IgE (P = 0.047). Among patients with positive specific IgE, significant differences of E237G genotype were observed between patients with positive benzylpenicillanyl (BPA)-, phenoxomethylpenicilloyl (PVO)- or ampicilloyl (APO)-IgE and control group (P = 0.015, 0.015, and 0.008, respectively). There were significant differences in E237G genotype between positive and negative BPA-, PVO- as well as APO-IgE patients (P = 0.014, 0.02, and 0.011, respectively).The patients with penicillins allergy have positive specific IgE not only to major antigenic determinants but also to minor antigenic determinants. The E237G variant of the FcℇRIβ gene is involved in the development of penicillins allergy through the process for the production of specific IgE antibodies. [ABSTRACT FROM AUTHOR]

Background: The major allergens in fish are parvalbumins. Important immunoglobulin (Ig)E cross-recognition of parvalbumins from different fish species has been shown. Recently frog parvalbumin α has been found to be responsible for a case of IgE-mediated anaphylaxis triggered by the ingestion of frog meat. The aim of this study was to investigate whether IgE antibodies of fish allergic persons cross-react with frog parvalbumin and to appreciate its clinical relevance. Methods: The sera of 15 fish allergic patients and one fish and frog allergic patient were tested by IgE-immunoblotting against frog muscle extract. Sera were tested against recombinant parvalbumin α and β from Rana esculenta. Skin prick tests were performed in selected patients with recombinant frog parvalbumin. Ca2+ depletion experiments and inhibition studies with purified cod and frog recombinant parvalbumin were done to characterize the cross-reactive pattern. Results: Fourteen of the sera tested had IgE antibodies recognizing low molecular weight components in frog muscle extract. Calcium depletion experiments or inhibition of patient sera with purified cod parvalbumin led to a significant or complete decrease in IgE binding. When tested against recombinant parvalbumins, three of 13 sera reacted with α parvalbumin and 11 of 12 reacted with β parvalbumin from R. esculenta. Skin prick tests performed with recombinant frog parvalbumin were positive in fish allergic patients. Inhibition studies showed that a fish and frog allergic patient was primarily sensitized to fish parvalbumin. Conclusions: Cod parvalbumin, a major cross-reactive allergen among different fish species, shares IgE binding epitopes with frog parvalbumin. This in vitro cross-reactivity seems to be also clinically relevant. Parvalbumins probably represent a new family of cross-reactive allergens. [ABSTRACT FROM AUTHOR]

Background: Information about the influence of housing and occupant characteristics on mite allergen concentrations is crucial to determine which methods could be used to decrease exposure of susceptible subjects. Objectives: To identify housing and occupant characteristics that are associated with mite allergen concentrations in house dust collected from living rooms and mattresses. Methods: We collected dust samples from 750 homes in the northeastern US. The influence of various characteristics on concentrations of mite allergens (Der p 1 and Der f 1) was studied using multiple linear regression analysis. Results: Some characteristics, like absence of air conditioners, the presence of mold or mildew, and a lower temperature were consistently associated with higher concentrations of both mite allergens in dust from all sampling locations. However, none of these factors changed Der p 1 or Der f 1 concentrations by more than a factor of 2. People of white ethnic background had roughly two times higher mite allergen concentrations, while family income, family size, and education level only marginally influenced mite allergen concentrations. Conclusions: Various housing characteristics have some influence on mite allergen concentrations, and could possibly be used to decrease exposure of susceptible subjects. However, only a limited percentage of the variation in mite allergen concentrations was explained by these characteristics. [ABSTRACT FROM AUTHOR]

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