Molecular Allergen Profiling of Dual Mite Sensitization in Severe Allergic Rhinitis.

BACKGROUND: Mites are the most prevalent source of indoor allergens. The present study used a component-resolved diagnosis (CRD) approach to investigate the mite-specific IgE sensitization profile for Dermatophagoides pteronyssinus and Blomia tropicalis. We also assessed the performance of a commercially available CRD approach in patients with severe allergic rhinitis. METHODS: We selected 63 consecutive patients with dual sensitization to D pteronyssinus and B tropicalis and persistent severe rhinitis according to the ARIA guidelines. We performed skin prick tests with standardized extracts and determined specific serum IgE to both mites, along with serum specific IgE to Der p 1, Der p 2, Der p 23, Der p 10, and Blo t 5. RESULTS: Fifty-eight and 59 patients had positive sIgE to the whole extracts of D pteronyssinus and B tropicalis, respectively. While 91.67% of patients were sensitized to specific IgE to Der p 1, Der p 2, and/or Der p 23, specific IgE to Blo t 5 (≥0.3 ISU-E) was not detected in most of the serum samples (55%). CONCLUSIONS: Although the combination panel of the commercially available major allergens Der p 1, Der p 2, and Der p 23 identified more than 90% of the D pteronyssinus-allergic patients, Blo t 5 performed somewhat poorly in those sensitized to B tropicalis. Improvements in CRD and further research concerning the prevalence and clinical relevance of serodominant allergens are needed to achieve a genuine molecular diagnosis, as well as patient-centered mite allergy-specific immunotherapy.

European Survey on Adverse Systemic Reactions in Allergen Immunotherapy (EASSI): a real-life clinical assessment.

BACKGROUND: Outside clinical trials, data on systemic reactions (SRs) due to allergen immunotherapy (AIT) are scarce. METHODS: A prospective, longitudinal, web-based survey of 'real-life' respiratory allergen immunotherapy (AIT) clinical practice was conducted in France, Germany and Spain. SRs were recorded and coded according to the Medical Dictionary for Regulatory Activities (MedDRA) and risk factors associated with SRs were identified. RESULTS: A total of 4316 patients (corresponding to 4363 ongoing courses of AIT) were included. A total of 109 SRs were recorded, and 90 patients (2.1%) presented at least one SR. Most of the SRs occurred in subcutaneous allergen immunotherapy (SCIT) (89%, n = 97). The most frequently reported symptoms were urticaria, rhinitis, dyspnoea and cough. Respiratory symptoms appeared before skin symptoms. Most SRs occurred during the up-dosing phase (75.8%) and were mild in severity (71.6%). Intramuscular adrenaline was administered in 17 SRs, but only 65% of these were subsequently classified as anaphylaxis. Independent risk factors for SRs during SCIT were as follows: the use of natural extracts (odds ratio, OR) [95% confidence interval (CI)] = 2.74 [1.61-4.87], P = 0.001), the absence of symptomatic allergy medications (1.707 [1.008-2.892], P = 0.047), asthma diagnosis (1.74 [1.05-2.88], P = 0.03), sensitization to animal dander (1.93 [1.21-3.09], P = 0.006) or pollen (1.16 [1.03-1.30], P = 0.012) and cluster regimens (vs rush) (4.18 [1.21-14.37], P = 0.023). A previous episode of anaphylaxis increased the risk for anaphylaxis in SCIT (OR [95% CI] = 17.35 [1.91-157.28], P = 0.01). CONCLUSION: AIT for respiratory allergy is safe, with a low number of SRs observed in real-life clinical practice. A personalized analysis of risk factors could be used to minimize SRs.

Assessment of a new brand of determinants for skin testing in a large group of patients with suspected beta-lactam allergy.

BACKGROUND: Skin testing with major and minor determinants of benzylpenicillin is recommended standard practice for the evaluation of patients with immediate hypersensitivity reactions to beta-lactams. However, commercial reagents for this purpose were recently dropped from the European market. OBJECTIVE: In the present study, we assessed a new brand of reagents for use in skin testing in patients with suspected penicillin allergy. METHODS: Prick tests and intradermal tests were performed with benzylpenicilloyl polylysine (PPL) and minor determinant mixture (MDM). Penicillin G, amoxicillin, and the culprit beta-lactam were also tested. If skin tests were negative, a single-blind oral challenge test was performed with the culprit active principle or penicillin. If both skin tests and challenge tests were negative, the same procedure was repeated between 2 and 4 weeks later. RESULTS: A total of 636 patients were assessed. The allergy study was positive in 69 patients. Skin tests with PPL were positive in 30 patients (46.8%) and with MDM in 28 (43.7%). Sixteen patients displayed a positive reaction to both PPL and MDM (25%), while 42 patients (65.6%) had a positive reaction to either PPL or MDM alone. Thirty-two patients had positive skin test reactions to penicillin G or another p-lactam antibiotic. Five patients in whom a negative result was obtained in skin tests had a positive reaction to oral challenge. CONCLUSIONS: Our results indicate that a new brand of determinants that is commercially available in Europe is a reliable and useful tool for the diagnosis of beta-lactam allergy. The new reagents are a safe alternative to the previously available brand.

[Evaluation of nasal inflammation]. / Valoración de la inflamación nasal.

In the reaction of immediate hypersensibility to alergene is joined to its specific type IgE antibody, also united to the high affinity receptors for IgE (FccI) of the effecters cells fundamentally mastocites and basophiles. The interbreeding of these molecules Fcc to RI, after the union ofpolyvalent antigenes to IgE, active these cells, producing three biologic responses: excitosis of the preformed content of its granules, synthesization of lipidic mediators and citoquine secretion. The inflammation mediators are in last term, substances responsible of the clinic symptomatology. They can be divided generally in preformed mediators (biogene amines and macromolecules of the granules) and of new synthese mediators (lipidic and citoquine mediators).

Olerance of a cluster schedule with a house dust mite extract quantified in mass units: multicentre study.

The standardisation of allergenic extracts in micrograms of the major allergen has encouraged the search for new treatment schedules, with the purpose of shortening the number of visits and doses required to reach the maintenance dose without eliciting a greater risk of adverse reactions for the patients. With this objective, a prospective multicentre pharmacovigilance study was designed that included 200 patient with allergic rhinoconjunctivitis and/or allergic asthma sensitised to mites (Dermatophagoides pteronyssinu and/or farinae). The dose increment period was carried out using a cluster schedule, where the optimal dose wa reached after 4 visits, administering two doses in each visit. The duration of the study was 5 months and a total o 1902 doses were administered. At the end of the trial, 31 adverse reactions in 23 patients were recorded. Six of these were systemic (0.3% of t administered doses) recorded in 6 patients (3% of the sample). One was an immediate reaction (grade 1) and delayed (4 mild and 1 moderate). Two were asthmatic exacerbations, 2 cutaneous reactions, 1 rhinitis and 1 an unspecific symptom (not IgE-mediated). Two appeared upon administration of the first vial and the remaining 4 after administration of the third cluster. Therefore, the schedule tested presents an adequate tolerance profile, suggesting savings (compared to th conventional schedule of 13 doses per patient) of 1800 visits and 1000 treatment doses in the whole study.

Clinical cross-reactivity between Artemisia vulgaris and Matricaria chamomilla (chamomile).

Artemisia vulgaris is a common weed and an important source of allergens on the subtropical island of Tenerife, Canary Islands, Spain. It pollinates mainly from July to September, although, due to some local climatic conditions, it may flower throughout the year. Cross-reactivity with hazelnut, kiwi, birch, several Compositae (Ambrosia, Chrysanthemum, Matricaria, Solidago) and grass allergens has been suggested. Few studies have addressed the issue of in vivo cross-reactivity between A. vulgaris and Matricaria chamomilla. The objective of this study was to perform conjunctival and bronchial challenges with A. vulgaris and M. chamomilla and oral challenge with chamomile in 24 patients with asthma and/or rhinitis sensitized primarily to A. vulgaris. Skin prick tests with M. chamomilla were positive in 21 patients. Eighteen patients had a positive conjunctival provocation test with a A. vulgaris pollen extract and 13 patients had a positive conjunctival provocation test with a M. chamomilla pollen extract. Bronchial provocation tests with A. vulgaris were positive in 15 patients and with M. chamomilla pollen in another 16 individuals. Oral provocation tests, conducted with a commercial chamomile infusion were positive in 13 patients. Nine of these individuals were skin test positive to food allergens and 17 to others pollens of the Compositae family. This study confirms a high degree of in vivo cross-reactivity between A. vulgaris and M. chamomilla. Sensitization to A. vulgaris seems to be a primary risk factor for experiencing symptoms after the ingestion of chamomile infusions. Based on the results of bronchial provocation tests, M. chamomilla pollen could be a relevant inhalant allergen.

Skin tests and conjunctival and bronchial challenges with extracts of Blomia tropicalis and Dermatophagoides pteronyssinus in patients with allergic asthma and/or rhinoconjunctivitis.

BACKGROUND: Blomia tropicalis and Dermatophagoides pteronyssinus are important mite species in Tenerife, Canary Islands, Spain. Several studies have demonstrated a variable degree of allergenic cross-reactivity in vitro. However, only a few have addressed their allergenic cross-reactivity using challenge tests. OBJECTIVE: The objective of this study was to conduct conjunctival and bronchial challenge tests with B. tropicalis and D. pteronyssinus extracts in a group of 42 patients with allergic asthma and/or rhinoconjunctivitis sensitised to house dust mites (31 females, 11 males; mean age 21.7 +/- 7.02 years). METHODS: Prick tests using standardised extracts and specific IgE determinations using the CAP system were performed. Bronchial and/or conjunctival challenges were conducted using freeze-dried extracts of both mite species. A patient was considered sensitive to a mite species if she/he had a positive prick and/or CAP test result. A total of 32 conjunctival and 15 bronchial challenges were performed with both mite species. RESULTS: Prick tests were positive to B. tropicalis in 23 patients (54.7%) and to D. pteronyssinus in 41 (97.6%). One patient (2.4%) was exclusively sensitive to B. tropicalis. The CAP test was positive for B. tropicalis in 28 patients and for D. pteronyssinus in 41. Conjunctival challenges to B. tropicalis were positive in 20 patients (18 sensitised and 2 non-sensitised) and negative in 12 (5 sensitised and 7 non-sensitised patients). Conjunctival challenges with D. pteronyssinus were positive in all 31 D. pteronyssinus-sensitised patients who underwent conjunctival challenges. Bronchial challenges with B. tropicalis were positive in 9 sensitised patients and negative in 6 patients (2 sensitised and 4 non-sensitised). Bronchial challenges with D. pteronyssinus were positive in all patients except 1, who only reacted to B. tropicalis. CONCLUSIONS: Allergens of the mite species B. tropicalis induce positive conjunctival and bronchial challenges in B. tropicalis-sensitised individuals. Our results suggest that although there is a low to moderate degree of in vivo cross-reactivity between B. tropicalis and D. pteronyssinus, B. tropicalis seems to be a relevant source of allergens in areas where patients are exposed.