A European-Japanese study on peach allergy: IgE to Pru p 7 associates with severity.

BACKGROUND: Pru p 3 and Pru p 7 have been implicated as risk factors for severe peach allergy. This study aimed to establish sensitization patterns to five peach components across Europe and in Japan, to explore their relation to pollen and foods and to predict symptom severity. METHODS: In twelve European (EuroPrevall project) and one Japanese outpatient clinic, a standardized clinical evaluation was conducted in 1231 patients who reported symptoms to peach and/or were sensitized to peach. Specific IgE against Pru p 1, 2, 3, 4 and 7 and against Cup s 7 was measured in 474 of them. Univariable and multivariable Lasso regression was applied to identify combinations of parameters predicting severity. RESULTS: Sensitization to Pru p 3 dominated in Southern Europe but was also quite common in Northern and Central Europe. Sensitization to Pru p 7 was low and variable in the European centers but very dominant in Japan. Severity could be predicted by a model combining age of onset of peach allergy, probable mugwort, Parietaria pollen and latex allergy, and sensitization to Japanese cedar pollen, Pru p 4 and Pru p 7 which resulted in an AUC of 0.73 (95% CI 0.73-0.74). Pru p 3 tended to be a risk factor in South Europe only. CONCLUSIONS: Pru p 7 was confirmed as a significant risk factor for severe peach allergy in Europe and Japan. Combining outcomes from clinical and demographic background with serology resulted in a model that could better predict severity than CRD alone.

Component-resolved diagnosis and beyond: Multivariable regression models to predict severity of hazelnut allergy.

BACKGROUND: Component-resolved diagnosis (CRD) has revealed significant associations between IgE against individual allergens and severity of hazelnut allergy. Less attention has been given to combining them with clinical factors in predicting severity. AIM: To analyze associations between severity and sensitization patterns, patient characteristics and clinical history, and to develop models to improve predictive accuracy. METHODS: Patients reporting hazelnut allergy (n = 423) from 12 European cities were tested for IgE against individual hazelnut allergens. Symptoms (reported and during Double-blind placebo-controlled food challenge [DBPCFC]) were categorized in mild, moderate, and severe. Multiple regression models to predict severity were generated from clinical factors and sensitization patterns (CRD- and extract-based). Odds ratios (ORs) and areas under receiver-operating characteristic (ROC) curves (AUCs) were used to evaluate their predictive value. RESULTS: Cor a 9 and 14 were positively (OR 10.5 and 10.1, respectively), and Cor a 1 negatively (OR 0.14) associated with severe symptoms during DBPCFC, with AUCs of 0.70-073. Combining Cor a 1 and 9 improved this to 0.76. A model using a combination of atopic dermatitis (risk), pollen allergy (protection), IgE against Cor a 14 (risk) and walnut (risk) increased the AUC to 0.91. At 92% sensitivity, the specificity was 76.3%, and the positive and negative predictive values 62.2% and 95.7%, respectively. For reported symptoms, associations and generated models proved to be almost identical but weaker. CONCLUSION: A model combining CRD with clinical background and extract-based serology is superior to CRD alone in assessing the risk of severe reactions to hazelnut, particular in ruling out severe reactions.

Conjunctival allergen provocation test : guidelines for daily practice.

Conjunctival allergen provocation test (CAPT) reproduces the events occurring by instilling an allergen on the ocular surface. This paper is the compilation of a task force focussed on practical aspects of this technique based on the analysis of 131 papers. Main mechanisms involved are reviewed. Indications are diagnosing the allergen(s)-triggering symptoms in IgE-mediated ocular allergy in seasonal, acute or perennial forms of allergic conjunctivitis, especially when the relevance of the allergen is not obvious or in polysensitized patients. Contraindications are limited to ongoing systemic severe pathology, asthma and eye diseases. CAPT should be delayed if receiving systemic steroids or antihistamines. Local treatment should be interrupted according to the half-life of each drug. Prerequisites are as follows: obtaining informed consent; evidencing of an allergen by skin prick tests and/or serum-specific IgE dosages; being able to deal with an unlikely event such as acute asthma exacerbation, urticaria or anaphylaxis, or an exacerbation of allergic conjunctivitis. Allergen extracts should be diluted locally prior to administration. Positive criteria are based on itching or quoted according to a composite score. An alternative scoring is based on itching. CAPT remains underused in daily practice, although it is a safe and simple procedure which can provide valuable clinical information.

The EuroPrevall outpatient clinic study on food allergy: background and methodology.

BACKGROUND: The EuroPrevall project aimed to develop effective management strategies in food allergy through a suite of interconnected studies and a multidisciplinary integrated approach. To address some of the gaps in food allergy diagnosis, allergen risk management and socio-economic impact and to complement the EuroPrevall population-based surveys, a cross-sectional study in 12 outpatient clinics across Europe was conducted. We describe the study protocol. METHODS: Patients referred for immediate food adverse reactions underwent a consistent and standardized allergy work-up that comprised collection of medical history; assessment of sensitization to 24 foods, 14 inhalant allergens and 55 allergenic molecules; and confirmation of clinical reactivity and food thresholds by standardized double-blind placebo-controlled food challenges (DBPCFCs) to milk, egg, fish, shrimp, peanut, hazelnut, celeriac, apple and peach. RESULTS: A standardized methodology for a comprehensive evaluation of food allergy was developed and implemented in 12 outpatient clinics across Europe. A total of 2121 patients (22.6% <14 years) reporting 8257 reactions to foods were studied, and 516 DBPCFCs were performed. CONCLUSIONS: This is the largest multicentre European case series in food allergy, in which subjects underwent a comprehensive, uniform and standardized evaluation including DBPCFC, by a methodology which is made available for further studies in food allergy. The analysis of this population will provide information on the different phenotypes of food allergy across Europe, will allow to validate novel in vitro diagnostic tests, to establish threshold values for major allergenic foods and to analyse the socio-economic impact of food allergy.

Predictors of health-related quality of life of European food-allergic patients.

BACKGROUND: Although food allergy has universally been found to impair HRQL, studies have found significant differences in HRQL between countries, even when corrected for differences in perceived disease severity. However, little is known about factors other than disease severity which may contribute to HRQL in food-allergic patients. Therefore, the aim of this study was to identify factors which may predict HRQL of food-allergic patients and also to investigate the specific impact of having experienced anaphylaxis and being prescribed an EAI on HRQL. METHODS: A total of 648 European food-allergic patients (404 adults, 244 children) completed an age-specific questionnaire package including descriptive questions. Multivariable regression analyses were performed to develop models for predicting HRQL of these patients. RESULTS: For adults, the prediction model accounted for 62% of the variance in HRQL and included perceived disease severity, type of symptoms, having a fish or milk allergy, and gender. For children, the prediction model accounted for 28% of the variance in HRQL and included perceived disease severity, having a peanut or soy allergy, and country of origin. For both adults and children, neither experiencing anaphylaxis nor being prescribed an epinephrine auto-injector (EAI) contributed to impairment of HRQL. CONCLUSIONS: In this study, food allergy-related HRQL may be predicted to a greater extent in adults than in children. Allergy to certain foods may cause greater HRQL impairment than others. Country of origin may affect HRQL, at least in children. Experiencing anaphylaxis or being prescribed an EAI has no impact on HRQL in either adults or children.

Ocular allergy: recognizing and diagnosing hypersensitivity disorders of the ocular surface.

Ocular allergy includes several clinically different conditions that can be considered as hypersensitivity disorders of the ocular surface. The classification of these conditions is complex, and their epidemiology has not been adequately studied because of the lack of unequivocal nomenclature. Ocular allergy symptoms are often, but not always, associated with other allergic manifestations, mostly rhinitis. However, specific ocular allergic diseases need to be recognized and managed by a team that includes both an ophthalmologist and an allergist. The diagnosis of ocular allergy is usually based on clinical history and signs and symptoms, with the support of in vivo and in vitro tests when the identification of the specific allergic sensitization is required for patient management. The aims of this Task Force Report are (i) to unify the nomenclature and classification of ocular allergy, by combining the ophthalmology and allergy Allergic Rhinitis and its Impact on Asthma criteria; (ii) to describe current methods of diagnosis; (iii) to summarize the therapeutic options for the management of ocular allergic inflammation.

Lack of association between aspirin-triggered 15-hydroxyeicosatetraenoic acid release and mast cell/eosinophil activation in nasal polyps from aspirin-sensitive patients.

BACKGROUND: The mechanism of aspirin sensitivity in patients with asthma and rhinosinusitis has been attributed to arachidonic acid metabolism abnormalities. OBJECTIVE: We aimed to test whether aspirin-triggered generation of 15-hydroxyeicosatetraenoic acid (15-HETE) in nasal polyp dispersed cells (NPDCs) from aspirin-sensitive patients is associated with activation of inflammatory cells. METHODS: Polyps were obtained from 11 aspirin-sensitive and 19 aspirin-tolerant patients with chronic rhinosinusitis. NPDCs were stimulated by aspirin or calcium ionophore. Levels of 15-HETE, leukotriene (LT) C4, eosinophil cationic protein (ECP), and tryptase were measured in NPDC supernatant. RESULTS: NPDCs from aspirin-sensitive patients contained more eosinophils (14% vs 9%, P < .05) and released 2.4-fold more ECP (P < .01) at baseline. Stimulation with aspirin (200 microM) resulted in a significant increase in 15-HETE generation only in tissue from aspirin-sensitive patients (mean increase, 82%) but did not induce any increase in the release of LTC4, ECP, or tryptase. Preincubation with calcium ionophore resulted in significantly enhanced generation of 15-HETE, ECP, tryptase, and LTC4 in patients from both groups. Incubation of NPDCs with misoprostol inhibited aspirin-induced 15-HETE generation in aspirin-sensitive patients and calcium ionophore-induced 15-HETE, ECP, and tryptase release in both aspirin-sensitive and aspirin-tolerant patients. CONCLUSION: Our study demonstrated that aspirin-induced 15-HETE generation in nasal polyps from aspirin-sensitive patients is not associated with activation of mast cells and eosinophils. Misoprostol has a potent inhibitory effect on the activation of cells derived from the site of nasal mucosal inflammation, regardless of sensitivity to aspirin.

T cell inflammatory response, Foxp3 and TNFRS18-L regulation of peripheral blood mononuclear cells from patients with nasal polyps-asthma after staphylococcal superantigen stimulation.

BACKGROUND: Staphylococcal superantigens may modulate airway inflammatory disease. OBJECTIVE: We assessed the effect of Staphylococcus aureus enterotoxin B (SEB) on T cell activation in patients with nasal polyps and asthma, and its possible link to aspirin hypersensitivity. METHODS: Leucocytes were isolated from five healthy subjects (controls), five asthmatics with nasal polyps without (NP-ATA) and five with aspirin-induced asthma (NP-AIA). Cells were incubated with increasing concentrations of SEB for 4 and 18 h. Release of T(H)1/T(H)2 cytokines was assessed by Cytometric Bead-Array. Foxp3 and TNFRS18-L expression were analysed by qPCR and flow cytometry. RESULTS: After 4 and 18 h, SEB significantly increased IFN-gamma, IL-4, TNF-alpha, IL-5 and IL-2 concentrations in supernatants of both NP polyp groups compared with controls. Baseline Foxp3 was significantly decreased in both NP-asthma groups. Incubation with SEB for 4 h induced a limited up-regulation of Foxp3 in NP-AIA patients, which was switched off consecutively. Foxp3 was significantly up-regulated in the control group after 18 h, but not in the NP-asthmatic groups. In parallel, TNFRS18-L mRNA significantly increased after 18 h in the NP-asthma groups compared with control subjects. This molecule was highly expressed in CD11c(+)CD14(+) cells and its levels increased after 18 and 24 h culture in the NP-asthma patients. CONCLUSION: SEB induces both T(H)1 and T(H)2 pro-inflammatory responses in patients with nasal polyps and asthma regardless of the presence of aspirin hypersensitivity. The nature of this response may be linked to a basal deficiency of Foxp3 observed in the NP-asthmatic patients and/or to the up-regulation of TNFRS18-L on monocytes/dendritic cell precursors.

Involvement of 15-lipoxygenase and prostaglandin EP receptors in aspirin-triggered 15-hydroxyeicosatetraenoic acid generation in aspirin-sensitive asthmatics.

BACKGROUND: The mechanism of aspirin (acetylsalicylic acid: ASA) hypersensitivity in asthmatic patients is related to arachidonic acid metabolism abnormalities, and specific triggering by ASA of 15-hydroxyeicosatetraenoic acid (15-HETE) generation was observed in leucocytes from aspirin-sensitive (AS) but not from aspirin-tolerant (AT) asthmatics. OBJECTIVE: The aim of this study was to identify the enzymatic pathway involved in ASA-induced 15-HETE generation in AS asthmatics and to assess the regulatory role of prostaglandin EP receptors. METHODS: Peripheral blood leucocytes (PBLs) were isolated from AS (n=18) and AT (n=20) asthmatics and challenged with ASA, with and without pre-incubation with caffeic acid (CA) [15-lipoxygenase (15-LO) inhibitor] or prostaglandin receptor non-specific (misoprostol, sulprostone) and specific EP1-4 receptors agonists. Eicosanoids were measured in supernatants using specific immunoassays. RESULTS: Aspirin triggered 15-HETE generation in PBLs of AS asthmatics (mean increase 292%) but not in AT asthmatics and inhibited prostaglandin(2) (PGE(2)) generation in both groups of patients to the same degree. Leucocytes from AS patients produced less PGE(2), both before and after ASA incubation. Pre-incubation of PBLs with CA decreased basal 15-HETE production in all patients and completely inhibited ASA-induced 15-HETE generation in AS asthmatics. CA did not change basal PGE(2) production but enhanced induced by ASA inhibition of PGE(2). Non-specific agonists of EP receptors (misoprostol and sulprostone) did not affect basal 15-HETE production but inhibited in a dose-dependent manner the ASA-induced increase of 15-HETE generation in AS asthmatics. On the contrary, in AT asthmatics, pre-incubation of PBLs with misoprostol or sulprostone resulted in a significant increase in 15-HETE generation after addition of ASA (200 microm). EP1-3 receptor agonists inhibited (range 72-94%) the ASA-induced 15-HETE production significantly. CONCLUSION: Our study demonstrated that ASA-triggered 15-HETE generation involves the activation of 15-LO and is modulated by prostaglandin EP1-3 receptors. The relevance of these observations to the mechanism of in vivo ASA-induced asthmatic attack remains to be established.