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Background: The European Academy of Allergy and Clinical Immunology (EAACI) is developing Guidelines for Allergen Immunotherapy (AIT) for IgE-mediated Food Allergy. To inform the development of clinical recommendations, we sought to critically assess evidence on the effectiveness, safety and cost-effectiveness of AIT in the management of food allergy., Methods: We undertook a systematic review and meta-analysis that involved searching nine international electronic databases for randomized controlled trials (RCTs) and nonrandomized studies (NRS). Eligible studies were independently assessed by two reviewers against predefined eligibility criteria. The quality of studies was assessed using the Cochrane Risk of Bias tool for RCTs and the Cochrane ACROBAT-NRS tool for quasi-RCTs. Random-effects meta-analyses were undertaken, with planned subgroup and sensitivity analyses., Results: We identified 1814 potentially relevant papers from which we selected 31 eligible studies, comprising of 25 RCTs and six NRS, studying a total of 1259 patients. Twenty-five trials evaluated oral immunotherapy (OIT), five studies investigated sublingual immunotherapy, and one study evaluated epicutaneous immunotherapy. The majority of these studies were in children. Twenty-seven studies assessed desensitization, and eight studies investigated sustained unresponsiveness postdiscontinuation of AIT. Meta-analyses demonstrated a substantial benefit in terms of desensitization (risk ratio (RR) = 0.16, 95% CI 0.10, 0.26) and suggested, but did not confirm sustained unresponsiveness (RR = 0.29, 95% CI 0.08, 1.13). Only one study reported on disease-specific quality of life (QoL), which reported no comparative results between OIT and control group. Meta-analyses revealed that the risk of experiencing a systemic adverse reaction was higher in those receiving AIT, with a more marked increase in the risk of local adverse reactions. Sensitivity analysis excluding those studies judged to be at high risk of bias demonstrated the robustness of summary estimates of effectiveness and safety of AIT for food allergy. None of the studies reported data on health economic analyses., Conclusions: AIT may be effective in raising the threshold of reactivity to a range of foods in children with IgE-mediated food allergy whilst receiving (i.e. desensitization) and post-discontinuation of AIT. It is, however, associated with a modest increased risk in serious systemic adverse reactions and a substantial increase in minor local adverse reactions. More data are needed in relation to adults, long term effects, the impact on QoL and the cost-effectiveness of AIT., (© 2017 The Authors. Allergy Published by John Wiley & Sons Ltd.)

Background: Chlorhexidine is an effective disinfectant, which may cause severe allergic reactions. Plasma level of specific IgE to chlorhexidine (ImmunoCAP(®) ) has high estimated sensitivity and specificity when measured within 6 months of allergic reaction, but knowledge of the dynamics over longer time periods is lacking and it is unknown whether levels fall below <0.35 kUA/L in patients with previously elevated levels. It is also unclear whether re-exposure influences levels of specific IgE., Objective: To investigate the dynamics of specific IgE in chlorhexidine allergic patients with and without re-exposure., Methods: All patients diagnosed with chlorhexidine allergy in the Danish Anaesthesia Allergy Centre January 1999 to March 2015 were invited to participate. The study included blood samples from the time of reaction and time of investigation and blood samples drawn prospectively over several years., Results: Overall, 23 patients were included. Specific IgE within hours of reaction was available in eight patients and was >0.35 kUA/L in six of these. During allergy investigations, usually 2-4 months later, specific IgE was >0.35 kUA/L in 22 of 23 patients. In the following months/years specific IgE declined <0.35 kUA/L in 17 of 23 patients (most rapidly within 4 months). Nine re-exposures in the healthcare setting were reported by seven patients (35%). Most re-exposures caused symptoms and were followed by an increase in specific IgE. Two patients with specific IgE <0.35 kUA/L reacted upon re-exposure., Conclusions & Clinical Relevance: Time from reaction should be considered when interpreting specific IgE results. Specific IgE is >0.35 kUA/L in most patients at time of reaction but should be repeated after a few weeks/months if negative. The optimal sampling time seems to be >1 month and <4 months. A value <0.35 kUA/L neither excludes allergy nor implies loss of reactivity in previously sensitized patients. Re-exposures are common, often iatrogenic, and can cause a rebound in specific IgE., (© 2016 John Wiley & Sons Ltd.)

The availability of allergen molecules ('components') from several protein families has advanced our understanding of immunoglobulin E (IgE)-mediated responses and enabled 'component-resolved diagnosis' (CRD). The European Academy of Allergy and Clinical Immunology (EAACI) Molecular Allergology User's Guide (MAUG) provides comprehensive information on important allergens and describes the diagnostic options using CRD. Part A of the EAACI MAUG introduces allergen molecules, families, composition of extracts, databases, and diagnostic IgE, skin, and basophil tests. Singleplex and multiplex IgE assays with components improve both sensitivity for low-abundance allergens and analytical specificity; IgE to individual allergens can yield information on clinical risks and distinguish cross-reactivity from true primary sensitization. Part B discusses the clinical and molecular aspects of IgE-mediated allergies to foods (including nuts, seeds, legumes, fruits, vegetables, cereal grains, milk, egg, meat, fish, and shellfish), inhalants (pollen, mold spores, mites, and animal dander), and Hymenoptera venom. Diagnostic algorithms and short case histories provide useful information for the clinical workup of allergic individuals targeted for CRD. Part C covers protein families containing ubiquitous, highly cross-reactive panallergens from plant (lipid transfer proteins, polcalcins, PR-10, profilins) and animal sources (lipocalins, parvalbumins, serum albumins, tropomyosins) and explains their diagnostic and clinical utility. Part D lists 100 important allergen molecules. In conclusion, IgE-mediated reactions and allergic diseases, including allergic rhinoconjunctivitis, asthma, food reactions, and insect sting reactions, are discussed from a novel molecular perspective. The EAACI MAUG documents the rapid progression of molecular allergology from basic research to its integration into clinical practice, a quantum leap in the management of allergic patients., (© 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Background: IgE-mediated activation of mast cells has been reported to induce the release of tumour necrosis alpha (TNF-α), which may display autocrine effects on these cells by inducing the generation of the tissue remodelling protease matrix metalloproteinase-9 (MMP-9). While mast cells and basophils have been shown to express complementary and partially overlapping roles, it is not clear whether a similar IgE/TNF-α/MMP-9 axis exists in the human basophil. The purpose of this study was thus to investigate whether IgE-mediated activation of human basophils induces TNF-α and MMP-9 release., Methods: Human peripheral blood mononuclear cells (PBMC), isolated basophils and monocytes were stimulated up to 21 h with anti-IgE. Mediator releases were assessed by ELISA, and surface expressions of mediators were detected by flow cytometry. Upregulation of cytokine production was detected by Western blot and polymerase chain reaction (PCR)., Results: IgE-mediated activation of basophils induced the synthesis and release of both TNF-α and MMP-9 from PBMC. In contrast, IgE-mediated activation of purified basophils induced the release and cellular expression of TNF-α but not MMP-9. Isolated monocytes did not release MMP-9 upon anti-IgE stimulation, but MMP-9 release was induced by stimulating monocytes with supernatants from activated basophils, and this release was inhibited by anti-TNF-α neutralizing antibodies., Conclusion: Our results strongly indicate that human basophils release TNF-α following IgE-dependent activation and that this cytokine subsequently stimulates MMP-9 release from monocytes. These findings support a direct involvement of basophils in inflammation as well as suggesting a role for the basophil in tissue remodelling., (© 2013 John Wiley & Sons A/S. Published by Blackwell Publishing Ltd.)

Background: The aim of this study was to test, on a multinational level, the pholcodine (PHO) hypothesis, i.e. that the consumption of PHO-containing cough mixtures could cause higher prevalence of IgE antibodies to PHO, morphine (MOR) and suxamethonium (SUX). As a consequence the risk of anaphylaxis to neuromuscular blocking agents (NMBA) will be increased., Methods: National PHO consumptions were derived from the United Nations International Narcotics Control Board (INCB) database. IgE and IgE antibodies to PHO, MOR, SUX and P-aminophenyl-phosphoryl choline (PAPPC) were measured in sera from atopic individuals, defined by a positive Phadiatop test (>0.35 kU(A)/l), collected in nine countries representing high and low PHO-consuming nations., Results: There was a significant positive association between PHO consumption and prevalences of IgE-sensitization to PHO and MOR, but not to SUX and PAPPC, as calculated both by exposure group comparisons and linear regression analysis. The Netherlands and the USA, did not have PHO-containing drugs on the markets, although the former had a considerable PHO consumption. Both countries had high figures of IgE-sensitization., Conclusion: This international prevalence study lends additional support to the PHO hypothesis and, consequently, that continued use of drugs containing this substance should be seriously questioned. The results also indicate that other, yet unknown, substances may lead to IgE-sensitization towards NMBAs.

Background: The high affinity IgE receptor (FcepsilonRI) on mast cells and basophils is up-regulated by its own ligand IgE; however, the mechanism is unknown., Objective: To study the IgE-mediated effect on FcepsilonRI on basophils by using the human basophilic cell line KU812., Methods: Expression of cell surface FcepsilonRI was assessed by flow cytometry. Western blot technique was used to illustrate tyrosine-phosphorylation and the Ca2+ level in KU812 was measured by fluorescence of Fura-2. Soluble specimens of the alpha-chain from FcepsilonRI (FcepsilonRIalpha) were obtained by lysing 107 KU812 pr. mL. FcepsilonRIalpha was detected by a sandwich immunoradiometric assay employing the IgE-binding capacity of FcepsilonRIalpha in conjunction with a monoclonal antibody. Polyclonal rabbit anti-FcepsilonRIalpha was used for detection of FcepsilonRIalpha by Western blotting., Results: We found that monomeric IgE did not induce tyrosine-phosphorylation in KU812, which was the case when stimulating with IgE cross-linked by anti-IgE binding. Further, only cross-linking of IgE, but not monomeric IgE, increased the Ca2+ level. Using the immunoradiometric assay, we found a temperature dependent reduction in the amount of FcepsilonRIalpha. Samples incubated at 37 degrees C for 5 h displayed a 16-fold decrease in the FcepsilonRIalpha level compared with samples incubated at 4 degrees C. In the presence of IgE the reduction at 37 degrees C was only threefold., Conclusion: These results indicate that IgE does not induce intracellular signals in KU812, i.e., tyrosine-phosphorylation or Ca2+ release. Instead it appears that FcepsilonRIalpha is an unstable protein that IgE stabilizes and thereby protects from a temperature dependent turnover.

The introduction of novel proteins into foods carries a risk of eliciting allergic reactions in individuals sensitive to the introduced protein. Therefore, decision trees for evaluation of the risk have been developed, the latest being proposed by WHO/FAO early in 2001. Proteins developed using modern biotechnology and derived from fish are being considered for use in food and other applications, and since allergy to fish is well established, a potential risk from such proteins to susceptible human beings exists. The overall aim of the study was to investigate the potential allergenicity of an Ice Structuring Protein (ISP) originating from an arctic fish (the ocean pout, Macrozoarces americanus) using the newly developed decision tree proposed by FAO/WHO. The methods used were those proposed by FAO/WHO including amino acid sequence analysis for sequence similarity to known allergens, methods for assessing degradability under standardised conditions, assays for detection of specific IgE against the protein (Maxisorb RAST) and histamine release from human basophils. In the present paper we describe the serum screening phase of the study and discuss the overall application of the decision tree to the assessment of the potential allergenicity of ISP Type III. In an accompanying paper [Food Chem. Toxicol. 40 (2002) 965], we detail the specific methodology used for the sequence analysis and assessment of resistance to pepsin-catalysed proteolysis of this protein. The ISP showed no sequence similarity to known allergens nor was it stable to proteolytic degradation using standardised methods. Using sera from 20 patients with a well-documented clinical history of fish allergy, positive in skin prick tests to ocean pout, eel pout and eel were used, positive IgE-binding in vitro to extracts of the same fish was confirmed. The sera also elicited histamine release in vitro in the presence of the same extracts. The ISP was negative in all cases in the same experiments. Using the proposed decision tree, we demonstrated the safety of the ISP to patients already sensitised to fish, as well as to individuals potentially susceptible to producing IgE responses to proteins. Furthermore, the practicability of the new decision tree was confirmed.

Background: Immunoglobulin E (IgE) is important in allergic reactions and in host defense against parasites. IgE may also participate in the acute-phase response to physical stress. This study aimed to determine whether major abdominal surgery induced increased serum IgE levels, and whether treatment with ranitidine or prednisolone influenced the IgE response to surgery., Methods: For assessment of the IgE response to surgery and the effect of ranitidine, 24 patients scheduled for major abdominal surgery were randomized to receive either perioperative treatment with ranitidine or no treatment. To evaluate the effect of glucocorticoids, 24 patients undergoing major elective abdominal surgery were randomized to receive preoperative treatment with either prednisolone or placebo. IgE levels were determined in serum samples drawn pre- and postoperatively., Results: In the ranitidine study, both the control group and the ranitidine-treated group displayed a postoperative increase (P<0.001) of serum IgE. In the prednisolone study, a postoperative increase (P<0.05) of serum IgE was detected in the placebo group. No significant increase was found in the prednisolone-treated group., Conclusions: Major abdominal surgery induces an increase of serum IgE. This increase can be prevented by preoperative treatment with prednisolone, but not with ranitidine.

Background: The exacerbation of atopic dermatitis may be associated with infection of the skin with Staphylococcus aureus (S.aureus). S. aureus isolated from the skin of patients with atopic dermatitis secretes enterotoxin A, B, and toxic shock syndrome toxin 1. This is of interest because these patients may develop specific IgE antibodies against components from staphylococci., Objective: The objective was to demonstrate IgE-sensitization to components of Staphylococcus aureus enterotoxins A and B (purified and partially purified), toxic shock syndrome toxin 1, and the bacterial cell component lipoteichoic acid, in patients with atopic dermatitis., Methods: Blood samples from 34 patients with atopic dermatitis and 10 controls were tested by leukocyte histamine release to the enterotoxins and lipoteichoic acid. The toxins were separated by sodium dodecylsulfate polyacrylamide gel electrophoresis and analyzed by IgE-immunoblotting with sera from the same patients., Results: The majority of patients (96%) with clinical signs of skin infection produced specific IgE-antibodies to all three toxins. Nearly half of the patients produced IgE to enterotoxin A and B. Only 63% of the patients with atopic dermatitis showed cellular response judged by the release of histamine from patient basophils when challenged in vitro with the toxins. This may indicate clinically unimportant sensitization in a number of patients. The immunoblotting revealed that the major allergens of the toxins were 24 and 28 kD proteins. Partially purified toxins showed a higher frequency of leukocyte histamine release responses than purified toxin. The only obvious difference was a difference in the content of pure toxin of the two preparations. Lipoteichoic acid showed nonspecific activity., Conclusion: These findings suggest that staphylococcal enterotoxins may act as specific allergens and induce IgE-antibodies to enterotoxins that may exacerbate the skin inflammation in some patients with atopic dermatitis.

Background: Fish is reported to be one of the most common causes of food allergic reactions. Species specificity and patterns of cross-reactivity are still to be defined., Objective: To demonstrate the immunologic reactivity of clinically codfish-allergic adults to four species of fish: cod, mackerel, herring, and plaice., Methods: IgE reactivity was measured in eight clinically codfish-allergic adult patients, confirmed by double-blind, placebo-controlled challenges with fresh raw codfish, and in 30 codfish-tolerant control subjects, by means of skin prick test, histamine release test, specific IgE tests, SDS-PAGE, and immunoblotting., Results: All eight patients had positive skin prick tests to plaice and herring, seven of eight to mackerel, whereas fish-induced histamine release from basophil leukocytes was positive in five, four, and six of six patients, respectively. Elevated specific IgE to the fish species was found in all eight, and reactions among the control subjects using an in-house method, the Maxisorp RAST, with freshly prepared fish extracts, were fewer (n = 8) than found with Phadebas RAST (n = 12) and Pharmacia CAP System (n = 11). Sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblotting revealed individual and common antigenic proteins in freshly prepared extracts. Sera from all eight patients recognized a protein in the area of 11 to 14 kD in all fish species. This is believed to be a protein fraction analogous to Gad cl. Inhibition of the codfish Maxisorp RAST was obtained with mackerel, herring, and plaice. No cross-reactivity to shrimp or milk was shown., Conclusion: This study suggests that serologic cross-reactivity to different fish species in clinically codfish-allergic adults exists, and that cod, mackerel, herring, and plaice share a common antigenic structure.

Cytokines-in particular interleukin 4 (IL-4), IL-5 and interferon gamma (IFN-gamma)-regulate both IgE synthesis and eosinophil activation in atopic diseases. To elucidate whether distinct profiles of cytokine production were related to serum level of IgE and eosinophilia, the spontaneous and inducible in vitro cytokine secretion from peripheral blood mononuclear cells (PBMC) was investigated. PBMC were isolated and cultured from three groups of donors: (1) patients with atopic dermatitis (AD) and high levels of serum IgE (> 5000 IU/ml, n = 11), (2) patients with diagnosed inhalant allergy (IA) and serum IgE in the range of 200-2000 IU/ml (n = 10), and (3) non-allergic individuals (NA) with serum IgE below 100 IU/ml (n = 10). The production of cytokines was determined in cultures after 24 h [IL-1 alpha, IL-4, IL-5, IL-6, tumour necrosis factor alpha (TNF-alpha), and TNF-beta] or 72 h (IL-2, IFN-gamma). The spontaneous production of IL-1 alpha was increased in the AD group compared to NA (P = 0.002), whereas for unstimulated cultures no other cytokine differed between patient groups. To identify conditions for optimal cytokine production, various combinations of phytohaemagglutinin (PHA), calcium ionophore (ION), and phorbol ester (PMA) were tested as stimuli. The combination ION + PMA induced the highest levels of IL-2, IL-4, IL-5, IFN-gamma and TNF-alpha, whereas maximal production of IL-6 and TNF-beta were induced by PHA and PHA + PMA, respectively. The AD group demonstrated a significantly lower production of TNF-alpha and IFN-gamma compared with the two other groups, and IL-4 and IL-5 production increased in the IA group. The results suggest that in spite of the common features, i.e. raised serum IgE and eosinophilia, in IA and AD patients, the underlying aberrations in the cytokine network is different.

The binding of IgE to egg white proteins was investigated for 34 sera from adults with a positive case history and/or positive RAST towards egg, and the impact of experimental conditions on IgE binding in commonly used methods was studied. Radioimmunoblotting after SDS-PAGE of both reduced and unreduced egg white extracts showed complex reaction patterns. The results were confirmed by crossed radioimmunoelectrophoresis (CRIE). Radio dot immunobinding was used to investigate the effect of treatment of allergens for SDS-PAGE and to evaluate the other methods. As a conclusion, the use of combinations of at least two methods is recommended for the identification of IgE-binding egg white proteins. Of the 34 sera, 18 reacted with ovotransferrin, 13 with ovomucoid, 11 with ovalbumin and 5 with lysozyme. The amounts of IgE bound to ovalbumin and lysozyme were generally lower than the amounts bound to ovotransferrin and ovomucoid.

Levels of specific serum IgE to cow's milk, whole hen's egg, egg white, and egg yolk were compared to the outcome of double-blind, placebo-controlled food challenge (DBPCFC) with fresh egg and/or milk in 21 adults with a case history of immediate hypersensitivity to egg and/or milk. Specific serum IgE was measured by four different commercially available tests and by an inhouse Maxisorp RAST using freshly prepared food extracts. Sensitivities and negative predictive accuracies were generally high with egg white and milk, but low with egg yolk. Specificities and positive predictive accuracies were low for all allergens and tests. Changing the cutoff levels did not improve the ability of the tests to predict clinical allergy. Among commercially available test allergens, egg white gave the most consistent results in levels and class scores, and the highest degree of concordance with DBPCFC, whereas egg yolk and milk varied more. Applying freshly prepared food extracts in Maxisorp RAST did not improve diagnostic value. Measuring specific serum IgE levels in control subjects tolerant to egg/milk showed that false positive reactions occurred frequently among patients with another food allergy and atopic dermatitis, whereas most tests were likely to be negative in pollen-allergic and nonallergic volunteers. In conclusion, specific IgE measurements with egg white and milk were useful for exclusion of symptomatic hypersensitivity to egg and milk in patients with a positive history, whereas DBPCFC is still mandatory in patients with positive history and positive test. Measuring egg-yolk-specific IgE or using freshly prepared food extracts for specific IgE measurements added no further diagnostic information. The rate of clinically insignificant positive test results seems to be influenced by the prevalence of other food allergies and/or atopic dermatitis in the population under study.

Distinct subtypes of T-helper cells have been incriminated as sources of a common regulatory mechanism behind IgE synthesis and eosinophil activation in IgE-mediated diseases. To investigate whether IgE-producing cells are in fact stimulated in vivo or have an increased susceptibility to certain stimuli, the in vitro IgE synthesis was compared for different patient groups. Peripheral blood mononuclear cells (PBMC) were isolated from three groups of donors: (1) patients with atopic dermatitis and high levels of serum IgE (> 5000 IU/ml, n = 11); (2) patients with diagnosed inhalant allergy and serum IgE in the range of 200-2,000 IU/ml (n = 10), and (3) nonallergic donors with serum IgE below 100 IU/ml (n = 10). PBMC were tested for the spontaneous and IL-4-induced IgE synthesis in 11-day cultures during which adhering cells were removed on day 2 by transferring the suspended cells and the medium to new wells. The three groups differed markedly in their capacity to synthesize IgE. The atopic dermatitis group demonstrated high spontaneous IgE synthesis (median 11.8 ng/ml), which was doubled (24.3 ng/ml, p < 0.05) by stimulation by IL-4. The two other groups had low spontaneous synthesis (0.7 and 0.3 ng/ml) but this increased (1.7 and 0.7 ng/ml, p < 0.01) upon IL-4 stimulation. The spontaneous production of IFN-gamma in the cultures did not differ between the groups, but upon stimulation with phorbol myristate acetate, the atopic dermatitis group demonstrated significantly lower IFN-gamma levels compared to the two other groups. The IL-4 production in the cultures were generally below the detection limit (100 pg/ml), and whereas plasma levels of 1-2 ng/ml of soluble IL-4 receptor could be detected in all donors, no differences could be detected between the groups. These data suggest that reduced ability in atopic dermatitis of mounting an IFN-gamma response may account for the high levels of plasma IgE and IgE synthesis found in these patients.

We have determined the correlation between IgE in cord blood and capillary serum from 98 mature children at 5 days of age. Sixty-six per cent had no family history of atopy, 29% had a single and 5% a double disposition. The study showed a good correlation, rho = 0.75, p < 10(-5), between IgE levels in cord blood and capillary blood samples drawn on the 5th day of life in children both with and without a heredity of atopic diseases. There was no correlation between the concentrations of cord blood IgE and IgA.

Based on a 3-year prospective study of 20 pollen-allergic patients, where a detailed analysis of the IgE, IgG1 and IgG4 immune response was performed, we propose that a common regulatory mechanism exists between the IgE and IgG1 synthesis and between IgE and IgG4 synthesis during immunotherapy. It was found that the IgE immune response to a number of antigens was quantitatively diminished during the period of immunotherapy when IgG1 was present early (week 12), and for other antigens there was a rise in IgE without an early IgG1 antibody response. Additionally, it was found that for some antigens a rise in IgE antibodies was contrasted by a fall in the IgG4 antibody response and for other antigens the opposite was true, indicating a regulatory mechanism between the IgE and the IgG4 synthesis. A statistical analysis showed that these findings were statistically significant at the 0.01% level for the IgE/IgG1 relationship and at the 0.05% level for the IgE/IgG4 relationship. These findings could have implications for future immunotherapy regimens.

Several cell types, including mast cells, basophils, macrophages/monocytes, lymphocytes, platelets and eosinophils, may bind or contain IgE. To investigate the source of cell-associated IgE and its relation to spontaneous IgE synthesis, peripheral blood mononuclear cells from allergic and non-allergic donors were examined. Using a combination of different cell fractionation techniques and varying methods for extraction of cell-associated IgE, data were obtained indicating that monocytes constitute a major source of cell-associated IgE in human blood. The amount of cell-associated IgE in peripheral blood mononuclear cells from allergic and non-allergic donors varied more than 100-fold but correlated closely to the level of serum IgE (r = 0.84, p < 0.001, n = 38). Spontaneous and mitogen-induced in vitro syntheses of IgA, IgE and IgG were compared for allergic and non-allergic donors. Only one donor with very high serum IgE demonstrated spontaneous or mitogen-induced in vitro IgE synthesis despite synthesis of IgA and IgG.

We have previously reported that a lipophilic yeast, Pityrosporum ovale (P. ovale) produced a high frequency of positive skin prick tests and in vitro histamine-release (HR) tests in patients suffering from atopic dermatitis (AD) of the face, scalp, and neck. In the present study, our aim was to confirm the involvement of P. ovale-specific IgE and to produce a standardized extract for diagnostic tests; 7/20 sera from patients with a positive HR test were positive in RAST. Several IgE-binding proteins could be detected with sodium dodecyl sulfate-polyacrylamide gel electrophoresis, followed by immunoblotting. Comparison of different extraction methods demonstrated that allergens were not released from P. ovale until after mechanical destruction of the yeast cells. Extraction of cultured P. ovale, obtained from the skin of various individuals suffering from AD of the face, scalp, and neck, resulted in very heterogenous patterns of constituents in sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblotting analysis. Nevertheless, all extracts were recognized by patients' IgE. P. ovale may express varying protein patterns, depending on either source or stage of differentiation. Thus, at present, skin and HR tests may be superior to other available assays for diagnosing type I reactions to P. ovale in AD of the face, neck, and scalp.

In a previous study guinea pigs inbred for their ability to develop respiratory anaphylaxis to experimental antigens have been used for comparison of different forms of immunotherapy (IT). Passive, active and combined (immune complexes prepared from antigen and specific IgG) IT was compared with placebo. In the present study methods were evaluated for determination of the allergen-specific IgE and IgG. IgE was determined by the passive cutaneous anaphylactic test (PCA) and the variability of this test on different strains of the recipient guinea pig was investigated. The same strain as used for the IT study was found to produce the most potent response. Radioimmunometric assays (RIA) were developed and validated for determination of specific IgG1 and IgG2. The IgE and IgG immune response in animals from the IT study were then evaluated by means of PCA and RIA. Animals from all four treatment groups were sensitized during the first part of the IT study, and responded with a marked IgE synthesis which later stabilized on a more moderate level. In spite of notably reduced symptoms in groups treated with active and combined IT, no difference in the IgE level was found between the four groups. In contrast to IgE, mean group titers of IgG1 and IgG2 in the groups receiving active or combined IT rose drastically during the first part of therapy and closely paralleled the clinical response during the rest of the study period. However, in the individual animals, no correlations were found between immune response and clinical symptoms. Thus, the strong IgG response during immunotherapy may not be causally related to the outcome of treatment.

Detailed evaluation of the IgE and IgG-subclass immune response during immunotherapy can now be performed by crossed radio immunoelectrophoresis (CRIE). Some new concepts are introduced facilitating the handling of the vast amount of data obtained by quantitating the immune response. These concepts are "distance" between antibody responses and "immune response width". The 20 patients included in this study were pollen-allergic patients who underwent specific immunotherapy in a 3-year prospective study. It was found that the immune response during immunotherapy was restricted to IgG1 and IgG4 antibodies. The semi-quantitative CRIE analysis correlated with the RAST analysis for the IgE samples before start of immunotherapy, for the IgG1 samples at week 12, and for all the IgG4 samples. During immunotherapy the number of IgG1 antibodies directed to the different antigens increased towards 11 antigens and decreased towards six. For the IgG4 antibodies the number of reactions increased towards 15 antigens and decreased towards four. The increase is generally paralleled by an increase in quantitative immune response as well. For some of the antigens a rise in the IgE antibodies is contrasted by a fall in the IgG4 antibody response, and for other antigens the opposite was true, indicating a regulatory mechanism between the IgE and the IgG4 synthesis. The IgE immune response to a number of antigens, including the major allergens before the start of immunotherapy, was quantitatively diminished during the period of immunotherapy when IgG1 was present early (week 12) in the period, and for other antigens there was a rise in IgE without an early IgG1 antibody response. This suggests that IgG1 can have a regulating influence on the IgE synthesis. Finally, we have found that IgE antibodies with specificities not present in the samples taken before immunotherapy were formed during immunotherapy. These new IgE antibodies do not, however, seem to impair the outcome of treatment.

Studies of the regulation of the IgE synthesis have been hampered by the difficulties in making lymphocytes produce IgE in vitro. Synthesis of IgE, IgG1 and IgM were investigated in a murine coculture system in which a conalbumin-specific T helper cell line of Th2 type was cultured together with nonadherent splenocytes from normal MHC-matched mice. Help provided by the antigen-stimulated T cell line induced significant IgE production (20 ng/ml), along with IgG1 (5 micrograms/ml) and IgM (250 micrograms/ml). Immunoglobulin synthesis in cultures was detectable at day 3-4 and culminated at day 7-8. IL-4 production was observed within the first 2 days of culture. The kinetics of the synthesis of the three isotypes were parallel. Stimulation of the Th2 cell line with Con A produced dose-response curves resembling those after antigen stimulation, whereas supernatant from these cells was unable to induce synthesis of IgE. The presence of interferon-gamma in the cultures, inhibited synthesis of IgE, IgM and IgG1, but this inhibition was not due to interference with the IL-4 production, which increased in the presence of high doses of interferon-gamma.

For determination of allergen-specific IgE in cell culture supernatants and other highly diluted IgE preparations a radioallergosorbent test (RAST) based on high adsorption polystyrene test tubes has been developed ("Maxisorp RAST"). Cladosporium herbarum extract was used as a model allergen but timothy grass pollen, house dust mite and dog dander showed similar results. The test showed specificities of both allergen and immunoglobulin isotype and significant correlations (r = 0.67-0.88) with established RAST procedures were found. Based on immunosorbent-purified allergen-specific IgE the estimated sensitivity was within the order of 150-300 pg allergen-specific IgE per ml. The within-assay variation was 4-9% and the inter-assay-variation 17-29%. The Maxisorp RAST is useful as an inhibition assay for quantitating allergenic activity down to 0.1 biological units/ml of allergen extracts.

An immunoradiometric assay for immunoglobulin E (IgE) using high adsorption polystyrene test tubes as the solid phase (the 'Maxisorp' assay) is described. The sensitivity of the method was found to be 50 pg IgE/ml and the within-assay reproducibility was 3-7%. The accuracy was estimated by means of a comparison between the Maxisorp assay and paper radioimmunosorbent test (PRIST) and a correlation coefficient of 0.98 (P less than 0.001) was obtained. We conclude that the Maxisorp assay is a fast and reliable assay for IgE determination in cord blood, cell culture supernatants and other highly diluted IgE preparations.

In older children, adolescents, and adults, a substantial part of all IgE-mediated food allergies is caused by cross-reacting allergenic structures shared by inhalants and foods. IgE stimulated by a cross-reactive inhalant allergen can result in diverse patterns of allergic reactions to various foods. Local, mild, or severe systemic reactions may occur already after the first consumption of a food containing a cross-reactive allergen. In clinical practice, clinically relevant sensitizations are elucidated by skin prick testing or by the determination of specific IgE in vitro. Component-resolved diagnosis may help to reach a diagnosis and may predict the risk of a systemic reaction. Allergy needs to be confirmed in cases of unclear history by oral challenge tests. The therapeutic potential of allergen immunotherapy with inhalant allergens in pollen-related food allergy is not clear, and more placebo-controlled studies are needed. As we are facing an increasing incidence of pollen allergies, a shift in sensitization patterns and changes in nutritional habits, and the occurrence of new, so far unknown allergies due to cross-reactions are expected. [ABSTRACT FROM AUTHOR]

Individuals suffering from IgE-mediated food allergy usually have to practise life-long food allergen avoidance. This document aims to provide an overview of recent evidence-based recommendations for allergen risk assessment and management in the food industry and discusses unmet needs and expectations of the food allergic consumer in that context. There is a general duty of care on the food industry and obligations in European Union legislation to reduce and manage the presence of allergens alongside other food hazards. Current evidence enables quantification of allergen reference doses used to set-up reliable food safety management plans for some foods. However, further work is required to include a wider variety of foods and to understand the impact of the food matrix as well as additional factors which affect the progression and severity of symptoms as a function of dose. Major con-cerns have been raised by patients, carers and patient groups about the use of pre-cautionary 'may contain' labelling to address the issue of unintended presence of allergens; these therefore need to be reconsidered. New and improved allergen detec-tion methods should be evaluated for their application in food production. There is an urgent requirement for effective communication between healthcare professionals, patient organizations, food industry representatives and regulators to develop a better approach to protecting consumers with food allergies. [ABSTRACT FROM AUTHOR]

Background We investigated the accuracy of tests used to diagnose food allergy. Methods Skin prick tests (SPT), specific-IgE ( sIgE), component-resolved diagnosis and the atopy patch test (APT) were compared with the reference standard of double-blind placebo-controlled food challenge. Seven databases were searched and international experts were contacted. Two reviewers independently identified studies, extracted data, and used QUADAS-2 to assess risk of bias. Where possible, meta-analysis was undertaken. Results Twenty-four (2831 participants) studies were included. For cows' milk allergy, the pooled sensitivities were 53% (95% CI 33-72), 88% (95 % CI 76-94), and 87% (95% CI 75-94), and specificities were 88% (95% CI 76-95), 68% (95% CI 56-77), and 48% (95% CI 36-59) for APT, SPT, and sIgE, respectively. For egg, pooled sensitivities were 92% (95% CI 80-97) and 93% (95% CI 82-98), and specificities were 58% (95% CI 49-67) and 49% (40-58%) for skin prick tests and specific-IgE. For wheat, pooled sensitivities were 73% (95% CI 56-85) and 83% (95% CI 69-92), and specificities were 73% (95% CI 48-89) and 43% (95% CI 20-69%) for SPT and sIgE. For soy, pooled sensitivities were 55% (95% CI 33-75) and 83% (95% CI 64-93), and specificities were 68% (95% CI 52-80) and 38% (95% CI 24-54) for SPT and sIgE. For peanut, pooled sensitivities were 95% (95% CI 88-98) and 96% (95% CI 92-98), and specificities were 61% (95% CI 47-74), and 59% (95% CI 45-72) for SPT and sIgE. Conclusions The evidence base is limited and weak and is therefore difficult to interpret. Overall, SPT and sIgE appear sensitive although not specific for diagnosing IgE-mediated food allergy. [ABSTRACT FROM AUTHOR]

Fish allergy is one of the most common food allergies in both children and adults and patients with allergic reactions to one fish species have in many cases been given the advice to avoid all fish, without further evaluation. The possible common reactivity between different fish species is not well studied. Because of this and a possible exploitation of fish species hitherto not much used in the Scandinavian diet ocean pout, eelpout and eel were evaluated. We examined the serological and biological cross-reactivity of these species in double-blind challenged-confirmed codfish-allergic patients usingCAP, Maxisorp-radio allergosorbent test (RAST) inhibition, western blot, skin prick test (SPT) and histamine release (HR). All 18 codfish allergic patients had specific IgE to ocean pout, eelpout and eel determined by Maxisorp-RAST. All four fish species could induce basophil HR using blood from 16 of 18 patients and all patients tested reacted in SPT. This study demonstrates that patients with a verified clinical allergy to codfish in a high frequency express biological cross-reactivity to other fish species. By RAST inhibition this common reactivity was shown to be a true cross-reactivity. [ABSTRACT FROM AUTHOR]

Background: Serum specific IgE, basophil histamine release, and blood eosinophil parameters are associated with allergic rhinitis, but investigations of the relationship to the severity of allergic symptoms are few and conflicting. Our study aimed to investigate the seasonal changes in the following laboratory tests: specific IgE, basophil histamine release, eosinophil counts, and serum and plasma eosinophil cationic protein (ECP) and eosinophil protein X (EPX), and to analyze, in detail, the relationship of each individual test to the severity of symptoms in rhinitis patients allergic to both birch and grass pollen. Methods: The above tests were performed on blood samples obtained from 49 allergic rhinitis patients during the birch‐pollen season, during the grass‐pollen season, and after the seasons. Symptom‐medication diaries were filled in during both pollen seasons. We used partial least square (PLS) analysis to establish an optimal statistical link between the symptom score and medication and the laboratory tests, in an investigator‐independent way. Results: Increases in specific IgE, basophil histamine release, eosinophil counts, serum ECP and EPX, and plasma EPX were observed from the birch‐pollen season to the grass‐pollen season, followed by a decrease from the grass‐pollen season to after the pollen seasons, except for the specific IgE. No seasonal changes in plasma ECP and total IgE were seen. The PLS analysis found a relationship between symptom score and medication and the aggregate laboratory tests (F‐test value 40.2, correlation 0.34 for the cumulative relation). However, the variation in laboratory tests could explain only half of the total variation in symptoms and less than a quarter of the total variation in medication. The symptom score and, to a minor degree, medication were especially correlated with the basophil histamine‐release results, with a decreasing relevance of specific... [ABSTRACT FROM AUTHOR]

Background At present, several in vitro tests for immunoglobulin E (IgE)-mediated food allergy are available. An estimation of the diagnostic accuracy of the various tests used in predicting clinical sensitivity to codfish in a well-characterized allergic material is necessary. Objectives To compare the diagnostic value of four specific IgE tests, and histamine release from basophils (HR) in identifying clinical type I allergy to codfish. As a true diagnosis, double-blind, placebo-controlled food challenges (DBPCFC) were employed. Methods Eight clinically codfish-allergic adult patients were investigated together with 30 codfish-tolerant control subjects for evidence of codfish-specific reactivity by Phadebas RAST® (PHA). Pharmacia CAP System RAST® (CAP). Magic® Lite(ML) and HR. To characterize the diagnostic properties ofa freshly prepared raw codfish extract, experiments were conducted employing an in-house radioallergosorbent test (RAST), the Maxisorp RAST (MAXI) and HR. Finally, protein profile and IgE-reacting allergens were detected by means of sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and immunoblotting. Results The sensitivities of HR with commercial extract and the three commercially available specific IgE analyses were 0.83 and 1.00 respectively. Specificities were 1.00 (HR) and 0.87-1.00 (specific IgE tests). Freshly prepared codfish extracts improved the sensitivity of HR. SDS-PAGE revealed ≈29 bands (< 14.3-200 kDa) including a band of 12-13 kDa. and in immunoblotting 18 sera identified 17 IgE-binding bands. The protein migrating at 12-13 kDa was identified in the fresh codfish extract tested with sera from all clinical codfish allergies, while no significant reaction was seen in the control subjects. Conclusion Based on the small number of adult patients included in our study, the in vitro assays with commercial and fresh extracts have high sensitivity and are acceptable for screening for codfish allergy. Specificity of Phadebas. CAP. and our in-house RAST was less than unity, whereas ML and strong binding of IgE to a 12-13 kDa protein completely matches DBPCFC results, and thus seems sufficient for establishing the diagnosis. [ABSTRACT FROM AUTHOR]

The worldwide dissemination of acquired imrnunodeficiency syndrome (AIDS) and various forms of hepatic viruses increases the risk of virus transmission in connection with the handling of blood samples for allergy testing. In order to reduce the risk of viral infection in laboratory staff and others handling blood samples, researchers have implemented a method for destruction of lipid-encapsulated viruses, comprising hepatitis B (HBV), non-A, non-B hepatitis (NANB), and HTLV-HI, in serum and plasma samples. Moreover, a solvent-detergent treatment method was used to reduce live virus particles in plasma samples. In the study, described in this article, researchers have tested whether determinations of IgE protein or specific IgE changed when serum samples from allergic patients had undergone a treatment which should eliminate viral infectivity.