Bell pepper allergy: different sensitization profiles

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Analysis of mite allergic patients in a diverse territory by improved diagnostic tools.

BACKGROUND: There are few studies comparing the sensitization with mite allergens from different mite species which could potentially be the cause of allergy. OBJECTIVE: To improve the diagnosis of mite allergic patients from a diverse territory in which D. pteronyssinus/D. farinae mites together with storage mites could be present in the environment. METHODS: Four hundred and seventy-seven patients (both children and adults) from different regions, covering the main mite prevalent areas of Spain, were recruited. sIgE to eight allergens was measured together with SPT to whole mite extracts, level of mite allergen exposure, and specific IgG(4) . BAT and CAST was performed in a subgroup of patients. RESULTS: D. pteronyssinus and L. destructor were more prevalent in Atlantic areas, whereas D. farinae predominate in Mediterranean areas. About 90% of patients were sensitized to group 1 and/or group 2 allergens. Group 2 was the most prevalent, and the IgE response/intensity of sensitization in BAT was higher. sIgE to Der p 2/Der f 2 was almost fully cross-reactive, but no cross-reactivity was detected with Lep d 2. Group 1 allergens were also cross-reactive, but in some patients a species-specific response was observed. sIgE to Lep d 2 was associated with SPT results to storage mites. Sensitization to Der p 1 was more frequent in children, whereas Lep d 2 sensitization was more frequent in adults. A higher ratio IgE/IgG(4) to Der p 2 was associated with the presence of allergic asthma. CONCLUSION: An improved diagnosis algorithm has been established. Group 2 allergens seem to have a leading role in mite allergy, but as group 1 sensitization could be species-specific in some patients and its prevalence is higher in children, an adequate balance on major mite species and major allergens must be consider in the design of mite allergy vaccines.

Potential hypersensitivity due to the food or food additive content of medicinal products in Spain.

The Drug Allergy Committee of the Spanish Society of Allergology and Clinical Immunology reviewed the allergenic potential of several substances of food origin that are found in the composition of some drugs. Despite recent legislation on labeling, many labels do not clearly state whether the drug contains raw material (active ingredients, excipient, or other manufacturing intermediate) with an origin in any of the substances in the list of the 14 groups of food allergens that are subject to mandatory declaration. The objective of legislation is that the drug package, the Summary of Product Characteristics, and the patient information leaflet clearly state the food content in order to improve the safety of allergic patients. Therefore, any food or allergen derivative that must be declared should be clearly stated on the drug label. Of all the evaluated products, egg and milk derivatives are the most frequently discussed in literature reviews. The natural or synthetic origin of potentially allergenic substances such as lysozyme, casein, lactose, albumin, phosphatide, and aromatic essences should be clearly stated. Providing this information has 2 clear advantages. First, allergic reactions to drugs in patients with food allergy could be avoided (if the substances have a natural origin). Second, prescription would improve by not restricting drugs containing synthetic substances (which do not usually induce allergic reactions).

Depigmented and polymerised house dust mite allergoid: allergen content, induction of IgG4 and clinical response.

BACKGROUND: Polymerised allergenic extracts (allergoids) are commonly used in allergen immunotherapy. Clinical efficacy and safety of these extracts have been demonstrated. Recently, allergen sequences have been identified by mass spectrometry in depigmented and polymerised (Dpg-Pol) extracts. The objectives of this study were to investigate the presence of allergens in Dpg-Pol extracts of house dust mite and to analyze the immunological changes induced by these extracts in asthmatic patients enrolled in a double-blind, placebo-controlled study. METHODS: Dpg-Pol extracts were manufactured and vaccines with a composition of 50% Dermatophagoides pteronyssinus and 50% D. farinae (100 HEPL/ml) were prepared. Allergen composition was analyzed by mass spectrometry. Patients with asthma and rhinoconjunctivitis were treated in a 1-year, double-blind, placebo-controlled, parallel-group study with 6 up-dosing and monthly maintenance injections. Specific IgE and IgG4 titres to D. pteronyssinus, Der p 1 and Der p 2 were measured in patients' sera using the CAP system and direct ELISA experiments. RESULTS: Sequences from the major allergens Der p 1 and Der p 2 and from other allergens were identified in native and Dpg-Pol extracts. There was a statistically significant increase in specific IgG4, a decrease in the ratio of IgE/IgG4 to D. pteronyssinus and a significant increase in specific IgG4 to Der p 1 and Der p 2 in the patients allotted to active treatment. CONCLUSIONS: The detection of allergen sequences suggests preservation of major and minor allergens in Dpg-Pol allergoids from house dust mites. Efficacy in asthma treatment and the increase in specific IgG4 seem to be associated with the presence of major allergens in Dpg-Pol allergen extracts.

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.

Reacciones adversas durante la administración de fluoresceína endovenosa / Adverse reactions related with intravenous fluorescein

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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.

A prospective and multicenter safety-monitoring study of a short up-dosing schedule of immunotherapy with a mass-units-standardized extract of mites.

A prospective, multicenter pharmacovigilance study was carried out to evaluate the safety of a new 7-dose treatment schedule of subcutaneous immunotherapy as opposed to the conventional 13 doses normally recommended. The study was carried out in 14 centers and included 261 patients (children and adults) with respiratory allergic disease due to sensitization to mites (Dermatophagoides pteronyssinus and/or farinae). A total of 2290 doses were administered under the direct supervision of the participating specialists. One hundred and ten reactions in 63 patients (24.1%) were recorded, representing 4.8% of the total doses administered. Most of the reactions (98) were local. Only 12 were systemic (0.5% of the administered doses) and occurred in 10 patients (3.8% of the sample). Ten reactions reverted quickly with rescue medication. The maintenance dose had to be lowered in one patient and another patient was withdrawn from the study after suffering two asthmatic crises after two consecutive doses. In view of the results obtained, we can conclude that the new schedule shows an acceptable tolerance profile and does not present a greater risk of reactions than the conventional scheme of 13 doses using an identical extract. Moreover, the new schedule represents substantial savings in the number of doses and visits required to reach the maintenance dose.

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.