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Abstract: Background: Chronic spontaneous urticaria (CSU) is a frequent disorder with recurrent itchy wheals and/or angioedema. Despite the known effectiveness of omalizumab therapy, the relevant IgE antigens are largely unknown. Recently, increased rates of elevated levels of IgE towards Staphylococcus aureus enterotoxins (SEs) were described in CSU. Aim: To assess the prevalence and functional relevance of IgE to SEs in CSU. Method: We investigated serum levels of IgE against SEs in 49 CSU patients and in 15 CSU patients additional specific IgE to SE components and basophil histamine release (BHR). Sera of 15 healthy controls (HCs) served as control group. Results: Twenty‐five (51%) of the CSU patients had detectable levels of SE‐IgE as compared to 5 (33%) of HCs. Specific IgE to one of the SEs, Staphylococcus enterotoxin B (SEB), was present in 5 (33%) of 15 randomly selected CSU patients vs 3 (20%) of HC. Total IgE serum levels in CSU patients were significantly correlated with SE‐IgE (r = .52, P < .001) and SEB‐IgE (r = .54, P = .04) serum concentrations. Interestingly, SEB‐IgE levels were strongly correlated with disease activity (UASday) in CSU patients (r = .657, P = .01). Furthermore, BHR in response to SEB was significantly higher in basophils loaded with the serum of CSU patients compared to HC (P < .05) and was clinically correlated with duration of disease (r > .51, P < .05). Discussion: IgE against SEs may contribute to the pathogenesis of CSU in a subpopulation of patients. Its role and relevance in the pathophysiology of CSU need to be further analysed. [ABSTRACT FROM AUTHOR]

Abstract: Background: Nasal hyperreactivity (NHR) is an important clinical feature of allergic rhinitis (AR). The efficacy of MP29‐02 (azelastine hydrochloride (AZE) and fluticasone propionate [FP]) nasal spray on local inflammatory mediators and NHR in AR is unknown. We tested if MP29‐02 decreases inflammatory mediators and NHR in AR and if this effect is due to restoration of nasal epithelial barrier function. Methods: A 4‐week double‐blinded placebo‐controlled trial with MP29‐02 treatment was conducted in 28 patients with house dust mite (HDM) AR. The presence of NHR was evaluated by measuring reduction in nasal flow upon cold dry air exposure. The effects of AZE ± FP on barrier integrity and airway inflammation were studied in a murine model of HDM‐induced NHR and on reduced activation of murine sensory neurons and human mast cells. Results: MP29‐02 but not placebo reduced NHR (P < .0001 vs P = .21), levels of substance P (P = .026 vs P = .941), and β‐hexosaminidase (P = .036 vs P = .632) in human nasal secretions. In wild‐type C57BL6 mice, the reduction in β‐hexosaminidase levels (P < .0001) by AZE + FP treatment upon HDM challenge was found in parallel with a decreased transmucosal passage (P = .0012) and completely reversed eosinophilic inflammation (P = .0013). In vitro, repeated applications of AZE + FP desensitized sensory neurons expressing the transient receptor potential channels TRPA1 and TRPV1. AZE + FP reduced MC degranulation to the same extent as AZE alone. Conclusion: MP29‐02 treatment reduces inflammatory mediators and NHR in AR. The effects of AZE + FP on MC degranulation, nasal epithelial barrier integrity, and TRP channels provide novel insights into the pathophysiology of allergic rhinitis. [ABSTRACT FROM AUTHOR]

Background: Persulphates from hair bleaching products are considered the major cause of occupational-rhinitis and asthma in hairdressers. The specific inhalation challenge (SIC) is considered 'reference standard' for diagnosing persulphate-induced asthma and rhinitis; however, the currently validated method of performing SIC with persulphate powder is time consuming with a duration of up to 4 days. The value of skin prick tests (SPTs) and histamine release tests (HRTs) with persulphates is unknown. The aim of this study was to establish a novel rapid SIC with persulphate powder to test for both rhinitis and asthma simultaneously in 1 day. In addition, we assessed the suitability of SPTs and HRTs for detecting persulphate-induced respiratory diseases. Methods: The study population included 19 hairdressers with a history of work-related rhinitis and/or asthma symptoms, 12 symptomatic controls (10 with concurrent allergic asthma and rhinitis and two with non-allergic asthma), and 40 healthy controls. A previous severe asthmatic reaction and/or anaphylactic reaction to persulphates was considered an exclusion criterion for hairdressers. The 19 hairdressers and 12 symptomatic controls had SIC performed with 3 × 5 min exposures to potassium persulphate powder in a provocation chamber. All participants, including the 40 healthy controls, were subjected also to SPTs and HRTs with three persulphate salts at concentrations of 2-20 % and 0.03-1 %, respectively. Results: None of the symptomatic controls had a nasal or bronchial response to SIC with potassium persulphate. Six hairdressers presented a nasal and two a bronchial response. No severe reactions occurred. No positive SPTs were recorded, neither among hairdressers, symptomatic controls, nor healthy controls. All three groups showed nonspecific non-IgE mediated histamine release to persulphates in HRT. Conclusions: The proposed method for performing SIC showed a high specificity for detecting persulphate-induced asthma and rhinitis. The rapid SIC was able to produce positive nasal and bronchial responses in symptomatic hairdressers without any severe reactions occurring. SPTs and HRTs cannot predict asthma or rhinitis caused by persulphates. [ABSTRACT FROM AUTHOR]

Introduction The Danish Anaesthesia Allergy Centre ( DAAC) investigated 89 adult patients with suspected perioperative cefuroxime-associated hypersensitivity reactions between 2004 and 2013. The goals were to determine whether the time to index reaction after cefuroxime exposure could be used to implicate cefuroxime as the cause of the reactions and explore different test modalities in diagnosing cefuroxime hypersensitivity. Method Skin tests, in vitro tests, and titrated provocations were used to determine cefuroxime hypersensitivity. Patients were deemed cefuroxime positive on the basis of at least two positive tests and/or a positive provocation. Results One or more tests were positive for cefuroxime in 24 of 89 (27.0%) patients. One was only specific IgE positive and was deemed cefuroxime negative. Twenty-three (25.8%) were deemed cefuroxime positive. There were four specific IgE-, 4 histamine release test-, 13 skin test-, and 14 provocation positive patients. There were eight (34.8%) patients who were only provocation positive. Data on time to index reaction after cefuroxime exposure were available for 80 patients (22 in the positive group and 58 in the negative group), 22 of 22 (100%) of positive patients reacted in <15 min vs. only 38 of 58 (65.5%) of negative patients. Conclusion All patients with confirmed hypersensitivity to cefuroxime reacted within 15 min of administration, but so did 65.5% of Cefuroxime negative patients, making timing of administration an unreliable predictor of causation in the perioperative setting. Provocations were always positive when carried out in skin test positive patients; however, eight patients had positive provocations only, highlighting the need for provocation in skin test negative patients. [ABSTRACT FROM AUTHOR]

Background Perioperative allergic reactions to chlorhexidine are often severe and easily overlooked. Although rare, the prevalence remains unknown. Correct diagnosis is crucial, but no validated provocation model exists, and other diagnostic tests have never been evaluated. The aims were to estimate (i) the prevalence of chlorhexidine allergy in perioperative allergy and (ii) the specificity and sensitivity for diagnostic tests for chlorhexidine allergy. Methods We included all patients investigated for suspected perioperative allergic reactions in the Danish Anaesthesia Allergy Centre during 2004-2012. The following tests were performed: specific Ig E ( Immunocap®; Phadia AB, Sweden), histamine release test ( HR) ( RefLab Ap S, Denmark), skin prick test ( SPT) and intradermal test ( IDT). Positivity criteria were as follows: specific Ig E >0.35 k UA/l; HR class 1-12; SPT mean wheal diameter ≥3 mm; IDT mean wheal diameter ≥ twice the diameter of negative control. Chlorhexidine allergy was post hoc defined as a relevant clinical reaction to chlorhexidine combined with two or more positive tests. Based on this definition, sensitivity and specificity were estimated for each test. Results In total, 22 of 228 patients (9.6%) met the definition of allergy to chlorhexidine. Estimated sensitivity and specificity were as follows: specific Ig E (sensitivity 100% and specificity 97%), HR (sensitivity 55% and specificity 99%), SPT (sensitivity 95% and specificity 97%) and IDT (sensitivity 68% and specificity 100%). Conclusions In patients investigated for suspected perioperative allergic reactions, 9.6% were diagnosed with allergy to chlorhexidine. Using our definition of chlorhexidine allergy, the highest combined estimated sensitivity and specificity was found for specific IgE and SPT. [ABSTRACT FROM AUTHOR]

Background Skin testing in duplicate, correlation between case history of immediate and nonimmediate reactions and challenge outcome and prolonged oral treatment with penicillin in the diagnostic evaluation of allergic reactions to β-lactam antibiotics, mimicking real-life situations, have only been addressed in few studies. Methods A total of 342 patients suspected of having β-lactam allergy were investigated according to the European Network for Drug Allergy ( ENDA) guidelines and patients found to be negative in the ENDA program were supplemented with a 7-day oral treatment with penicillin. Skin testing with penicillins was performed in duplicate. Patients with case histories of reactions to other β-lactams were also subsequently challenged with the culprit drug. Results Nineteen patients were IgE-sensitized to penicillin. Then, intracutaneous tests ( ICTs) were performed, in which 35 patients tested positive for allergy, 21 with delayed and 14 with immediate reactions. Only three patients tested positive for the major ( PPL) and/or minor ( MDM) penicillin determinants, all being positive for penicillin G in ICT. The remaining 291 patients were challenged with penicillin: 10 tested positive in single-dose challenge and 23 tested positive in the 7-day challenge. A total of 17 of 78 patients with a negative penicillin challenge tested positive during challenges with other β-lactams. We found no correlation between case histories of immediate and nonimmediate reactions and reaction time during challenge. Conclusion The data suggest that case history is often insufficient to discriminate between immediate reactors and nonimmediate reactors. A 7-day challenge with the culprit β-lactam may yield more positive reactions than the accepted one- or 2-day challenge. Interpretation of skin testing should be made with caution. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Background Recently, peanut-allergic patients have reported symptoms upon ingestion of bean sprouts produced from various legumes. Objective This study was designed to identify immunoreactivity to seeds and sprouts of legumes other than peanut in sera from peanut-allergic patients. Methods Crude protein extracts of seeds and sprouts (comprising cotelydons and hypocotyls/epicotyls) of peanut, soybean, green pea, blue lupine, mung bean, alfalfa, broad bean, and azuki bean were prepared. The reactivity of sera from 10 peanut-allergic patients to these extracts was analysed by indirect histamine release (HR), enzyme-allergosorbent test (EAST), EAST inhibition, and Western blots. Skin prick tests (SPTs) were performed on the patients with fresh legume seeds as well as four commercial legume sprouts, and food challenges with soybean, pea, and lupine were performed on a subgroup of the patients. Results All legume seeds and commercial sprouts induced positive SPTs in some of the patients. Indirect HR experiments indicated an extensive co-reactivity between peanut and the legumes, and cross-reactivity was observed for soybean, pea, and lupine seeds as well as lupine hypocotyls in EAST inhibition experiments. Of the 16 protein extracts, soybean, pea, and lupine seed extracts produced visible bands in Western blots. Conclusion The symptoms reported by peanut-allergic patients after legume sprout intake might be caused by cross-reactivity of peanut-specific antibodies. The intake of raw legume sprouts might cause symptoms in peanut-allergic patients. [ABSTRACT FROM AUTHOR]

Background Environmental perfume exposure may cause respiratory symptoms. Individuals with asthma and perfume contact allergy report such symptoms more frequently than others. However, immunologic mechanisms have not been demonstrated and the symptoms are not associated with IgE-mediated allergy. The study aimed to investigate whether basophils from patients with respiratory symptoms related to perfume released more histamine in the presence of perfume as compared with healthy volunteers. Methods Histamine release was measured by the glass fibre method. Blood was obtained from healthy volunteers ( n=20) and patients with respiratory symptoms related to perfume ( n=17) attending a dermatological outpatient clinic for patch testing. The effect of an international brand perfume was investigated using the basophil histamine release test with perfume. Furthermore, basophils from a healthy non-atopic donor were incubated with participant's sera and histamine release induced by perfume was measured. Results In both groups incremental perfume concentrations showed a positive and significant ( P<0.001) dose-response effect on the release of histamine. At the highest perfume concentration, the basophils released significantly ( P<0.05) more histamine in patients as compared with healthy volunteers. No difference was found between the groups when sera were incubated with basophils from a healthy non-atopic donor. Conclusion Perfume induces a dose-dependent non-IgE-mediated release of histamine from human peripheral blood basophils. Increased basophil reactivity to perfume was found in patients with respiratory symptoms related to perfume. [ABSTRACT FROM AUTHOR]

Background: Immunoglobulin (Ig)E-sensitized persons with positive skin prick test, but no allergy symptoms, are classified as being asymptomatic skin sensitized (AS). The allergic type 1 disease is dependant on IgE binding to the high affinity IgE-receptor (Fc ℇRI) expressed on basophils and mast cells. However, a relationship between the AS status and Fc ℇRI has not been investigated. We aimed to characterize basophils from AS by looking at histamine release (HR) (sensitivity and reactivity) and the Fc ℇRI molecule, and compare it with nonatopic (NA) or allergic (A) persons. Methods: Blood was obtained from NA ( n = 14), grass and/or birch A persons ( n = 17) and mono-sensitized grass or birch pollen AS ( n = 12). The basophil sensitivity and reactivity were examined by anti-IgE triggered HR. Surface expression of Fc ℇRI and IgE were measured by flow cytometry, Fc ℇRI α protein was identified using a radioimmunoassay and Western blot. mRNA coding for the classic Fc ℇRI β-chain and the truncated form (Fc ℇRI βT) were determined by real-time PCR. Results: The AS group was less reactive than NA or A persons when triggered by anti-IgE and had a significant higher number of nonresponders. However, there was no difference in sensitivity among the three groups and furthermore; the groups did not vary in Fc ℇRI- and IgE-surface expression, Fc ℇRI α-protein level or β/ βT ratio. Conclusion: Basophils from AS persons are less reactive and include more nonresponders than basophils from NA and A persons, but do not differ regarding the Fc ℇRI molecule. [ABSTRACT FROM AUTHOR]

Endogenous histamine-releasing factors (HRFs) are involved in 30–60% of patients with chronic urticaria (CU). Evidence for their existence comes from in vivo studies of autoreactivity with the autologous serum skin test (ASST), in vitro immunoassays demonstrating autoantibodies against the immunoglobulin E (IgE) or the high affinity IgE receptor (Fc ℇRI) and serum-induced histamine release (HR) from basophils and mast cells. We have examined the correlation between the ASST and a new basophil histamine-releasing assay (the HR-Urtikaria test) in a group of well-characterized CU patients and subsequently determined the frequency of HR-Urticaria-positive sera from a larger population of CU patients. Group 1 consisted of 28 patients with CU (16 were ASST-positive) 20 patients with atopic dermatitis, 24 patients with allergy to birch and nine healthy controls. Group 2 consisted of 873 unselected CU patients. White blood cells containing 1–2% basophils from a healthy nonatopic donor were incubated with patients sera in the presence of interleukin (IL)-3. Histamine was measured by the glass fibre method. Using the ASST as the true outcome, the HR-Urticaria test showed a sensitivity and specificity of 75% in group 1 using a cut-off value for HR of >16.5%. None of the controls was positive in the HR-Urticaria test. In group 2, we found no difference in the frequency of positives between male (34.6%, n = 254) and female adults (35.1%, n = 576) but twice as many females as males were tested. Our studies have shown that the HR-Urticaria test has a good sensitivity and specificity for endogenous HRFs demonstrated by the ASST in patients with CU and that about one-third of unselected patients with CU have a positive result. [ABSTRACT FROM AUTHOR]

Background: Our aim was to investigate the frequency of pine allergy in woodworkers with respiratory symptoms and to identify high molecular weight allergens in pine wood extracts. Methods: In a cross-sectional study we examined work-related respiratory symptoms in 2033 furniture workers and 474 controls by questionnaires. Clinical examination was performed in 365 wood dust exposed and 116 nonexposed subjects. Blood samples were collected for measuring pine-specific immunoglobulin (Ig)E by an immunoassay and Western blots. Results: Eleven exposed and three nonexposed subjects had pine-specific IgE. In the group with clinically defined asthma eight persons (5.4%) had pine-specific IgE compared with six persons (1.8%) in the group without asthma (P < 0.05). In the groups with and without respiratory symptoms, 13 (3.8%) and one (0.7%) subject, respectively, had pine-specific IgE (P = 0.06). Western blots demonstrated pine-specific IgE to components in the molecular range of 14 – 100 kD in eight samples (all wood dust exposed). Five samples had pine-specific IgE against components in a 43 – 59 kD zone and against two bands at 27 and 29 kD that are candidates for major allergens. Conclusion: Some workers in the Danish furniture industry are specific IgE sensitized against pine wood dust. Pine-specific IgE probably explains a minor part of the respiratory symptoms in workers exposed to pine wood dust. [ABSTRACT FROM AUTHOR]

Summary Background The high affinity IgE receptor (FcεRI) 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 FcεRI on basophils by using the human basophilic cell line KU812. Methods Expression of cell surface FcεRI 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 α-chain from FcεRI (FcεRIα) were obtained by lysing 107 KU812 pr. mL. FcεRIα was detected by a sandwich immunoradiometric assay employing the IgE-binding capacity of FcεRIα in conjunction with a monoclonal antibody. Polyclonal rabbit anti-FcεRIα was used for detection of FcεRIα 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 FcεRIα. Samples incubated at 37 °C for 5 h displayed a 16-fold decrease in the FcεRIα level compared with samples incubated at 4 °C. In the presence of IgE the reduction at 37°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 FcεRIα is an unstable protein that IgE stabilizes and thereby protects from a temperature dependent turnover. [ABSTRACT FROM AUTHOR]

Background: Allergy to hazelnuts is a common example of birch pollen related food allergy. Symptoms upon ingestion are often confined to the mouth and throat, but severe systemic reactions have been described in some patients. The aim of the study was to evaluate the reduction in allergenicity by roasting of the nuts. Methods: Double-blind, placebo-controlled food challenges (DBPCFC) with roasted hazelnuts (140°C, 40 min) were performed in 17 birch pollen allergic patients with DBPCFC-confirmed food allergy to raw hazelnuts. The effect of roasting was further evaluated by skin prick test (SPT), histamine release (HR), measurement of specific IgE, and IgE-inhibition experiments. Results: In 5/17 patients the DBPCFC with the roasted nuts were positive. The symptoms were generally mild and included OAS (oral allergy syndrome) in all patients. Roasting of the nuts significantly reduced the allergenic activity evaluated by SPT, HR, specific IgE, and IgE-inhibition. Immunoblotting experiments with recombinant hazelnut allergens showed sensitization against Cor a 1.04 in 16/17 patients and against Cor a 2 in 7/17 patients. None of the patients were sensitized to Cor a 8. Challenge-positive patients did not differ from the rest in IgE-binding pattern. Conclusions: All the applied methods indicated that roasting of hazelnuts reduces the allergenicity, but since 5/17 birch pollen allergic patients were DBPCFC-positive to the roasted nuts, ingestion of roasted hazelnuts or products containing roasted hazelnuts can not be considered safe for a number of hazelnut allergic consumers. For patients with a history of severe allergic symptoms upon ingestion of hazelnuts, thorough and conscientious food labelling of hazelnuts and hazelnut residues is essential. [ABSTRACT FROM AUTHOR]

BackgroundRecent reports have indicated cetirizine, a potent H1-receptor antagonist, to possess a number of anti-inflammatory effects, e.g. inhibition of mast cell degranulation and inhibition of leucocyte migration and activation. ObjectiveThe aim of this study was to compare the effects of cetirizine on skin responses and mediator release in intact skin in immediate and developing late-phase allergic reactions by microdialysis technique. MethodsCetirizine 10 mg once daily or matching placebo were administered to 10 atopic subjects for 6 days followed by a 2-week washout in a randomized, double-blind, placebo-controlled, cross-over trial. Immediate skin test responses to allergen, codeine, and histamine and late-phase reactions to allergen were assessed. The time course of extracellular levels of inflammatory mediators in intact skin were monitored by microdialysis techniques using 2 kDa and 3 MDa cut‐off fibers, respectively. ResultsCetirizine significantly reduced immediate weal and flare reactions to allergen, codeine, and histamine. Injection of allergen, but not buffer controls, induced a significant release of histamine, tryptase, prostaglandin D2, total protein, and eosinophilic cationic protein. No significant increase of leukotriene B4 and myeloperoxidase was observed. Cetirizine inhibited early total protein extravasation by 40%, but this did not reach a significant level. None of the inflammatory mediators were significantly inhibited by cetirizine. Cetirizine significantly reduced the late-phase skin induration to allergen by approximately 30%. ConclusionCetirizine potently reduced skin responses in immediate allergic reactions without inhibition of early mediators. These data indicate cetirizine to be a potent H1-receptor antagonist with no effect on mast cell activation. It did not inhibit any of the late-phase mediators, but it reduced the late skin reaction. These data suggest that mediators... [ABSTRACT FROM AUTHOR]

Summary We report that interleukin (IL)‐4 and IL‐10 can significantly up‐ or down‐regulate CXC chemokine receptor 4 (CXCR4) expression on CD4+ T lymphocytes, respectively. Stromal cell‐derived factor‐1α (SDF‐1α)‐induced CD4+ T‐lymphocyte chemotaxis was also correspondingly regulated by IL‐4 and IL‐10. IL‐4 and IL‐10 up‐ or down‐regulated CXCR4 mRNA expression in CD4+ T lymphocytes, respectively, as detected by real‐time quantitative reverse transcription–polymerase chain reaction (RT–PCR). Scatchard analysis revealed a type of CXCR4 with affinity (Kd ≈ 6·3 nm), and ≈ 70 000 SDF‐1α‐binding sites per cell, among freshly isolated CD4+ T lymphocytes, and two types of CXCR4 with different affinities (Kd1 ≈ 4·4 nm and Kd2 ≈ 14·6 nm), and a total of ≈ 130 000 SDF‐1α‐binding sites per cell, among IL‐4‐stimulated CD4+ T lymphocytes. The regulation of CXCR4 expression in CD4+ T lymphocytes by IL‐4 and IL‐10 could be blocked by a selective inhibitor of protein kinase (staurosporine) or by a selective inhibitor of cAMP‐ and cGMP‐dependent protein kinase (H‐8), indicating that these cytokines regulate CXCR4 on CD4+ T lymphocytes via both cAMP and cGMP signalling pathways. The fact that cyclosporin A or ionomycin were able to independently change the CXCR4 expression and block the effects of IL‐4 and IL‐10 on CXCR4 expression implied that the capacity of IL‐4 and IL‐10 to regulate CXCR4 on CD4+ T lymphocytes is not linked to calcium‐mobilization stimulation. These results indicate that the effects of IL‐4 and IL‐10 on the... [ABSTRACT FROM AUTHOR]

Background: Salmeterol is a long-acting β 2-agonist which in animal studies has been shown to possess anti-inflammatory effects on early (EAR) and late (LPR) phase allergic responses.¶ Purpose: To evaluate the anti-inflammatory effects of intradermally injected salmeterol and salbutamol on clinical and biochemical EAR and LPR in human skin. ¶ Methods: Measurement of wheal and flare reactions to allergen, codeine, and histamine, and LPR (induration) to allergen. Assessment of histamine and prostaglandin D2 (PGD2) release by microdialysis technique in EAR, and measurement of mediators in LPR by suction blister technique. ¶ Results: Both β 2-agonists inhibited allergen-induced histamine release and wheal and flare reactions with maximum inhibition of 40-50% at 10-6M, a concentration which reduced PGD2 synthesis by approximately 55%. Histamine release by codeine and skin reactions to codeine and histamine were not or only marginally reduced. Salmeterol and salbutamol (10-6M) inhibited clinical LPR at 6h by 71% and 48%, Except for the clinical LPR, no statistical differences were found between the two drugs on any parameters. None of the drugs inhibited levels of histamine, tryptase, myeloperoxidase, or eosinophil cationic protein in LPR. ¶ Conclusions: Salmeterol and salbutamol inhibited allergen-induced skin responses, and reduced mediator release in EAR but not LPR. In general, the anti-inflammatory effects of salmeterol did not differ from those induced by salbutamol. [ABSTRACT FROM AUTHOR]

Objective and Design: Pituitary adenylate cyclase activating polypeptide (PACAP) is a neuropeptide homologous with vasoactive intestinal polypeptide (VIP) which is known to induce histamine release in human skin mast cells. PACAP has not been detected in human skin. The purposes of the study were to investigate the occurrence of PACAP in human skin and to evaluate the histamine releasing activity of the two common pro-PACAP products, PACAP-27 and PACAP-38.¶ Material: Fourteen human surgical skin samples were obtained. PACAP and VIP were visualized by immunohistochemistry. A microdialysis technique was used to measure histamine release in intact skin samples following intradermal injections of the peptides.¶ Results: PACAP and VIP were localized in dermal nerves in connection with sweat glands. Intradermal injection of 3 or 10 μm PACAP significantly released histamine. Kinetics of histamine release showed peak release 2–4 min after skin challenge. Ten μm of PACAP-27, VIP and somatostatin caused histamine release with similar efficacy, whereas PACAP-38 was less effective. Substance P was twice as efficient as PACAP-27, whereas calcitonin gene-related peptide did not release histamine.¶ Conclusions: PACAP is found in human skin and is capable of releasing histamine from skin mast cells. [ABSTRACT FROM AUTHOR]

Objective and Design: Currently no method is available for measurement of mediator release from intact human lung. In this study, a microdialysis technique was used to measure histamine release from mast cells in human lung tissue ex vivo.¶ Material: Microdialysis fibers of 216 μm were inserted into lung tissue and perfused with Krebs Ringer buffer at a rate of 3 μl/min. After a 15 min period of steady-state perfusion, anti-IgE and vehicle were injected into the lung tissue above individual fibers. Samples from each fibre were collected for 20 min at 2 min intervals. Histamine was assayed fluorometrically.¶ Results: Anti-IgE concentrations of 40–40,000 U/ml dose-dependently released histamine, significant histamine release being demonstrated with anti-IgE concentrations of 400 U/ml and greater. The kinetics of histamine release showed peak values 2–8 min after the injection. Great individual responses were observed but data could be reproduced within individual donors. Monocyte chemoattractant protein-1, a potent basophil secretagogue, did not induce histamine release in lung tissue which indicated mast cells to be the histamine source. Substance P did not release histamine in the lung tissue.¶ Conclusions: The microdialysis technique allowed measurements of histamine release from mast cells in intact lung ex vivo. The method may prove useful since a number of experiments can be performed in a few hours in intact lung tissue without any dispersion or enzymatic treatment. [ABSTRACT FROM AUTHOR]

Background: Studies in rodents' skin have indicated substance P to be the main inflmmatory mediator involved in neurogenic inflammation, acting partly be release of histamine from skin mast cells. The mediators released in neurogenic inflammation in human skin remain to be determined. Objectives: To determine the effects of intradermally injected and topically applied capsaicin on the release of histamine and substance P and skin responses in intact human skin in vivo. Methods: Extracellular skin levels of histamine and substance P were measured by microdialysis technique and assayed by enzyme and radio immunoassays. Two kinds of dialysis fibres (210 μm, 2 kDa, and 500 μm, 20 kDa) were inserted intradermally into forearm skin for studies of histamine release to topically administered capsaicin and intradermally injected capsaicin and substance P. Results: Baseline histamine skin levels were 8.0 ± 0.7 nM. Intradermally injected capsaicin (0.3-30 μM, 750 pmol) caused significantly and dose-related flare and pain reactions, but no significant histaine (peak levels being 90 and 475 nM), 25 and 75 pmol) released significant amounts of histamine (peak levels being 90 and 475 nM), evoked weal-and-flare reactions, but did not cause pain. Capsaicin 2% ointment, applied on the skin for 2.5 h, increased skin blood flow by 300-400% as measured by laser Doppler flometry, elicited a long standing burning sensation, but did not release histamine. Substance P-like immunoreactivity (SP-LI) way below the 1.8 pM detection limit following insertion of 20 kDa dialysis fibre and after intradermal injection of capsaicin 3 μM. Intradermal injection of injection of 1μM of substance P increased SP-LI levels to values greater than 4500 pM, confirming the ability of the dialysis fibre to recover this peptide. Conclusions: Capsaicin-induced neurogenic activation does not involve the release of histamine from mast cells or detectable amounts of substance P release from sensory nerves in normal human skin in vivo. [ABSTRACT FROM AUTHOR]

The ability of skin prick test (SPT) and histamine release from basophils (HR) to diagnose clinical type I allergy to egg and milk was investigated as compared with double-blind, placebo-controlled food challenge (DBPCFC) in 17 adults suspected of type 1 egg and/or milk allergy. In both SPT and HR. commercial allergen extracts commonly used for SPT were compared with fresh, standardized foods. With commercial extracts the overall sensitivities of SPT and HR were 0.75 and 0.56 respectively, arid none of the tests showed concordance with DBPCFC. With fresh, standardized foods the overall sensitivities of SPT and HR were 1.00 and 0.89 respectively, and both tests now showed a significant concordance with DBPCFC (P<0.05). Specificity was only slightly improved in SPT. and unchanged in HR. Thus, the use of fresh, standardized foods significantly improved the outcome of both tests, as regards to sensitivity and concordance with DBPCFC. The diagnostic ability of SPT and HR appear to be strongly influenced by the allergen quality. [ABSTRACT FROM AUTHOR]

A simple microtiter assay for eosinophil activation is described. The assay used 1000-4000 eosinophils/microtiter well, and the design allows for a separate or simultaneous quantitative assessment of eosinophil adhesion to protein-coated microtiter wells and degranulation after stimulation with eosinophil-activating factors. The number of adherent eosinophils is quantified indirectly by expressing the amount of eosinophil cationic protein (ECP) extracted from the adherent fraction of cells in percentage of the total amount of ECP extracted from the cells added to the wells. Degranulation is quantified in the same way by expressing the amount of ECP or eosinophil protein X (EPX) released to the supernatant in percentage of the total amount of ECP or EPX. Known eosinophil-activating agents such as PMA, interleukin (IL)-3, IL-5, GM-CSF, and platelet-activating factor (PAF) all induced a time- and dose-dependent adhesion to albumin-coated wells, whereas L-PAF did not. Kinetic experiments showed that most adhesion occurred within the first 15-30 min, reaching a plateau around 60 min. After prolonged incubation, a decline in adhesion was detected. GM-CSF-induced adhesion was completely inhibited by incubation with monoclonal antibodies directed against the common β2-chain (CD18) of the LFA-1, Mac-1, p150,95 complexes. Monoclonal antibodies against CD11a, CD11b, CD11c, VLA-4 ALFA, ICAM-1, VCAM-1, Sialyl-Lex, ELAM-1, and LECAM had no inhibitory effect. Simultaneous monitoring of adhesion and degranulation after stimulation of eosinophils in albumin-coated wells with either PMA or GM-CSF showed that adhesion always preceded degranulation. Replacing the albumin coating of the microtiter wells with IgG or secretory IgA augmented both the spontaneous and the PMA- or GM-CSF-stimulated responses. In conclusion, the assay allows dynamic evaluation of eosinophil activation and can be used to assess soluble eosinophil-activating factors as well as to study eosinophil activation by solid-phase-bound proteins. [ABSTRACT FROM AUTHOR]

A number of investigations have indicated that cholinergic agonists release histamine from isolated mast cells and suggested that cholinergic stimulation releases histamine in vivo. The purpose of this study was to investigate whether the cutaneous wheat-and-flare reaction induced by methacholine challenge in human skin involves histamine release as measured by the skin microdialysis technique. Five hollow dialysis fibers were inserted intradermally in forearm skin in eight healthy subjects. Each fiber was perfused with Kreb's-Ringer bicarbonate at a rate of 3 μ/min. Dialysates were collected in 2-min fractions before skin challenge and for 20 min after intradermal injection of methacholine 10-3-10-1 M, the vehicle, and a positive control, codeine phosphate 0.3 mg/ml. Histamine was assayed spectrofluorometrically. Methacholine caused a statistically significant dose-related wheal-and-flare reactions the flare reaction to methacholine 10-1 M being comparable with that seen with codeine 0.3 mg/ml. No significant histamine release was observed with methacholine, cumulative histamine release of 16 ± 8 nM by methacholine 10-1 M being similar to vehicle responses of 15 ± 9 nM. Histamine release by codeine was 2524 ± 435 nM. In conclusion. methacholine-induced wheat-and-flare reactions in human skin appeared not to involve histamine release from skin mast cells. [ABSTRACT FROM AUTHOR]

A microfiberglass-based histamine assay (HRM) was compared with an automated fluorometric histamine assay (HRA). Twenty-four subjects with and 24 without a case history (CH) of milk and/or egg allergy were tested by HRM and HRA, skin prick test (SPT), and specific serum IgE (RAST). Six different concentrations of milk, egg, and anti-IgE were used to stimulate washed leukocytes (250 μl for HRA) and whole blood samples (25 μl for HRM) in parallel. When we compared scores representing basophil sensitivity, correlation coefficients (rs) were positive (r(anti-IgE) = 0.88, r(egg) = 0.95, r(milk) = 0.88, P < 0.001), but no significant correlations were found after exclusion of the negatives in both tests. In some individual dose-response curves, the scores obtained by HRM were shifted to higher allergen and anti-IgE concentrations. A high degree of concordance was found in positive and negative responses between the two tests: anti-IgE 91%, egg 92%, milk 86%. Finally, we found a good concordance between, on one side, HRM and, on the other, CH, SPT, and RAST (HRM vs. CH/SPT/RAST): egg 92/82/82%; milk 89/74/67%. We conclude that HRM is in good qualitative, but poor quantitative, agreement with the autoanalyzer-based fluorometric histamine assay. [ABSTRACT FROM AUTHOR]

Basophil leukocytes from a non-atopic donor, who responded well to anti-IgE, were depleted of their native membrane-bound IgE by acid treatment and passively sensitized with plasma containing either Phleum pratense-, Dermatophagoides pteronyssinus- or dog dander- specific IgE obtained from 18 allergic children. Histamine release was then performed on the passively sensitized cells and the results were compared with those of bronchial provocation test (BPT), allergen-specific serum IgE (RAST), skin prick test (SPT), and conventional histamine release test (HR). A high coincidence rate was found between BPT, RAST and histamine release after passive sensitization (HR-PS), but compared to HR, it was lower. This could be because several of the patients had nonresponding basophils (i.e. no release after challenge with anti-IgE) in the conventional histamine release asssay. The lower rate was not related to a lack of antigen-specific IgE, since after passive sensitization of basophils, anti-IgE and allergen provocation could induce release. It is concluded that plasma from allergic children with non-responding basophil leukocytes contain antigen-specific IgE capable of binding to Fc-receptors on the basophils of a non-atopic donor. In addition it was found that the plasma could change the cell reactivity (maximal histamine release) of the donor cells, since the amount of histamine released varied according to the plasma used for passive sensitization. The lack of histamine release response in some patients could be because their own membrane-bound IgE is unable to induce mediator release or, more likely, activation of one or more of the subcellular steps involved in the release is impaired. [ABSTRACT FROM AUTHOR]

Preseasonal hyposensitization stimulated an intercorrelated increase in both serum-specific IgE and allergen-specific IgG. Subsequent perennial treatment depressed the stimulated IgE response and the basophil cell sensitivity, whereas the allergen-specific IgG response showed further increase and persisted at a high level. Nasal IgE response was stimulated from the second pollen season and subsequently became depressed. One year after the end of hyposensitization the allergen-specific IgG response had fallen by 25-50%. [ABSTRACT FROM AUTHOR]

Plants from the Verbenaceae family may cause contact dermatitis of unknown nature. This report describes 2 cases of allergic reactions to the Verbena species. A teenage boy developed an anaphylactic allergic response following contact with the leaves of Verbena hybrida. Characterization of the patient's specific IgE response to Verbena hybrida, using Western blots and autoradiography, identified the specific 62000 Dalton allergen present in the verbena leaves to which the patient reacted. This is the first report of an IgE-mediated immediate contact hypersensitivity reaction to Verbena hybrida, a common perennial in South African gardens. The other case was a 23-year-old female gardener who developed immediate and delayed-type contact dermatitis from Verbena elegans 'Cleopatra' produced in a Danish nursery. Prick tests to plant material were considered positive and of an allergic nature. [ABSTRACT FROM AUTHOR]

A letter to the editor is presented in response to the article "Diagnosis of penicillin allergy revisited: the value of case history, skin testing, specific IgE and prolonged challenge" by J. Hjortlund, C.G. Mortz, and P.S. Skov.

The article presents the case of a 39-year-old female with a 10-year case history of severe debilitating delayed pressure urticaria (DLP). The patient was presented with leucocytosis of unknown origin, which became normal after treatment with azithromycin 500 mg for 3 days and positive test for autoimmune urticaria. The report determined the effectiveness of anti-immunoglobulin (IgE) Omalizumab for the treatment of DLP.

Discusses a case of hypersensitivity to wood dust. Presenting symptoms of the patient; Release experiments performed on nonallergic individuals.