Differential IgE reactivity to Der p 1 and Der p 2 allergens of Dermatophagoides pteronyssinus in mite-sensitized patients (original) (raw)
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Variability of IgE reactivity profiles among European mite allergic patients
European Journal of Clinical Investigation, 2008
Background House dust mites (HDM) Dermatophagoides pteronyssinus are a frequent indoor allergen source. Our aim was to determine the frequencies of IgE reactivity to purified HDM allergen molecules in mite allergic patients from different parts of Europe in order to establish an allergen panel for diagnosis of HDM allergy. Materials and methods Populations of D. pteronyssinus-allergic patients from Austria (n = 56), France (n = 55), Italy (n = 67) and Sweden (n = 65) and storage mite allergic patients from Sweden (n = 31) were analysed for IgE reactivity to eight purified natural (n) and recombinant (r) D. pteronyssinus allergens (nDer p 1, rDer p 2, nDer p 4, rDer p 5, rDer p 7, rDer p 8, rDer p 10 and rDer p 14) in RAST-based dot blot assays. Results Using a combination of Der p 1 and Der p 2, at least 97% of the D. pteronyssinus-allergic patients could be diagnosed in each of the HDM allergic populations. However, more than 50% of the patients also reacted with other allergens and significant variabilities regarding the frequencies of IgE reactivity to individual allergen molecules were found. Patients with a predominant storage mite allergy showed none or only very weak IgE reactivity to purified D. pteronyssinus allergens. Conclusions Purified Der p 1 and Der p 2 are sufficient for the diagnosis of ≥ 97% of D. pteronyssinus allergic patients in Europe, but other allergens may also play an important role for the diagnosis and treatment of HDM allergy.
Clinical & Experimental Allergy, 2002
Background Sensitization to indoor allergens, particularly to dust mites, is a strong risk factor for asthma in children and adults. Assessment of sensitization is carried out using in vivo and in vitro tests to detect specific IgE antibodies. Objective To investigate IgE antibody responses to mites in patients with asthma, wheezing and/or rhinitis, using chimeric ELISA to measure specific IgE antibodies to mite allergens Der p 1 and Der p 2. Methods Specific IgE antibodies to Der p 1 and Der p 2 were quantified by chimeric ELISA, and compared with IgE to Dermatophagoides pteronyssinus (Dpt) measured using the CAP system (Pharmacia). A panel of sera from 212 patients with asthma, wheezing and/or rhinitis and 11 controls was analysed. Results There was a significant correlation between IgE to Dpt measured by CAP and IgE to Der p 1 (r 0.81, P < 0.001), Der p 2 (r 0.79, P < 0.001) and combined Der p 1 and Der p 2 (r 0.86, P < 0.001). Seventy per cent of all patients had IgE to Dpt, and of those, 76.5% had IgE to Der p 1, 79.2% had IgE to Der p 2 and 83.1% had IgE to Der p 1 and Der p 2 combined. Considering the cutoff level of 2 IU/mL of IgE to either Der p 1 or Der p 2, the predictive value for a positive IgE to Dpt by CAP was greater than 95%. Conclusions The chimeric ELISA allowed accurate quantification of IgE antibodies to Dpt allergens Der p 1 and Der p 2, and it could be useful for studying immune responses to mites in patients with asthma and/or rhinitis.
Clinical and Developmental Immunology, 2013
One of the purposes of specific immunotherapy (SIT) is to modulate humoral immune response against allergens with significant increases in allergen-specific IgG levels, commonly associated with blocking activity. The present study investigated in vitro blocking activity of allergen-specific IgG antibodies on IgE reactivity to Dermatophagoides pteronyssinus (Dpt) in sera from atopic patients. Dpt-specific IgG antibodies were purified by ammonium sulfate precipitation followed by protein-G affinity chromatography. Purity was checked by SDS-PAGE and immunoreactivity by slot-blot and immunoblot assays. The blocking activity was evaluated by inhibition ELISA. The electrophoretic profile of the ammonium sulfate precipitated fraction showed strongly stained bands in ligand fraction after chromatography, compatible with molecular weight of human whole IgG molecule. The purity degree was confirmed by detecting strong immunoreactivity to IgG, negligible to IgA, and no reactivity to IgE and IgM. Dpt-specific IgG fraction was capable of significantly reducing levels of IgE anti-Dpt, resulting in 35%-51% inhibition of IgE reactivity to Dpt in atopic patients sera. This study showed that allergen-specific IgG antibodies purified from mite-allergic patients sera block the IgE recognition of Dermatophagoides pteronyssinus antigens. This approach reinforces that intermittent measurement of serum allergen-specific IgG antibodies will be an important objective laboratorial parameter that will help specialists to follow their patients under SIT.
Journal of Allergy and Clinical Immunology, 1996
Background: Monitoring the response to immunotherapy entails' understanding exposure to relevant allergens. For the major indoor allergens, this requires sampling of dust from the patient's house. The objectives of this study were to measure indoor allergen levels" during a controlled trial of dust mite immunotherapy for asthma and to relate these results to serum antibody levels. Methods: Eighty-eight asthmatic patients with mite allergy from seven geographic areas in the United States were enrolled in and completed a course of immunotherapy with Dermatophagoides extract or placebo control. Sensitization was evaluated by quantitative measurements of IgG and lgE antibodies. Dust samples" were assayed for group I mite (Der p 1 and Der f 1), cat (Fel d 1), and cockroach (Bla g 1) allergens by monoclonal antibodybased ELISA. Results: Over the 4 years of the study, each of the houses had at least one sample that contained more than 2 txg of group I mite allergen per gram of dust. Mean mite allergen levels, however, varied over a wide range, from 0.2 ixg/gm or less" to more than 50 lag/grn. IgE antibodies to mite were present in sera from 78% of the patients, whereas IgE antibodies" to cat and cockroach allergens were found in sera from 34% and 11% of patients, respectively. Sixty-four pelvent of the patients had exposure and sensitization to mite, whereas the comparable figure for each of the other allergens was 5%. Conclusions: Examination of the results suggested that allergen exposure, relative to a trial Q[ immunotherapy, could be expressed as (1) the maximum level found in the house, (2) the percentage of sites having greater than 2 Ixg/grn, or (3) the mean value at the site with the maximum level. This report provides a background for evaluating the clinical results of immunotherapy in these patients and a model for the way in which sensitization and exposure should be monitored in studies of this kind.
International Archives of Allergy and Immunology, 2016
sensitized to Der p 23, and 11 patients were negative for all HDM MeDALL chip components. Seven sera were available for further testing, and 3 of them showed IgE reactivity to dot-blotted nDer p 1, and 2 reacted with high-molecular weight components (>100 kDa) in nitrocellulose-blotted HDM extract when tested with 125 I-labeled anti-IgE in a RASTbased assay. The HDM extract-specific IgE levels of the 11 patients were <3.9 kU/l. Conclusions: Recombinant allergen-based IgE serology is of great value when conventional IgE diagnostics fails. Der p 23 is an important HDM allergen, especially when major allergens are negative. Therefore, it would be desirable to have Der p 23 commercially available. Further research concerning the prevalence and clinical significance of different HDM allergens is needed.
Lack of human IgE cross-reactivity between mite allergens Blo t 1 and Der p 1
Allergy, 2003
It has been well established that mite species such as Dermatophagoides pteronyssinus, Dermatophagoides farinae and Euroglyphus maynei from the family Pyroglyphidae are important clinical species (1-4). In recent years, Blomia tropicalis mite classified under the family Glycyphagidae (5) is an important source of indoor allergens that associate with allergic asthma and rhinitis in the tropics (6-11). The first major B. tropicalis allergen cloned was Blo t 5 (12, 13). Subsequently, cDNA encoding for Blo t 3, Blo t 4, Blo t 6, Blo t 10, Blo t 11, Blo t 12, Blo t 13, and Blo t 19 were isolated by us and others . The estimated frequency of human IgE reactivity to Blo t 3, Blo t 5, Blo t 10, Blo t 11, Blo t 12, and Blo t 13 with mite allergic sera was about 51, 70, 20-29, 52, 50, and 11%, respectively.
Journal of Allergy and Clinical Immunology, 1998
Background: The use of allergen extracts will hamper studies into quantitative aspects of allergic responses because the precise amount of relevant allergen for each patient is unknown. Objective: We applied isolated IgE-binding components (major allergens) in the technique of bronchial allergen challenge to determine the role of patient characteristics in the early asthmatic response (EAR). Methods: In 30 patients with mild-to-moderate asthma, the EAR was investigated after inhalation of an isolated major allergen of Dermatophagoides pteronyssinus (i.e., Der p 1 [n = 16] or Der p 2 [n = 14]). The degree of early-phase bronchial responsiveness to allergen (the cumulated dose of allergen causing a 20% fall in FEV 1 [PD 20 allergen]) was related to the degree of nonspecific bronchial responsiveness (the concentration of histamine causing a 20% fall in FEV 1 [PC 20 histamine]) and the level of specific IgE or allergen thresholds as found in skin tests and basophil histamine release assays. Results: Twenty-seven patients with an immediate response during allergen and histamine challenges (∆FEV 1 , ≥20%) were analyzed. In these patients, a strong correlation was found between PD 20 allergen and PC 20 histamine (r = 0.81, p < 0.001). Weak correlations were found between PD 20 allergen and the level of specific IgE (r = -0.36, p = 0.07) or allergen thresholds as found in skin tests (skin prick test, r = 0.36 and p = 0.07; intracutaneous test, r = 0.49 and p = 0.01) or basophil histamine release assays (r = 0.37, p = 0.08). Moreover, no significant contribution of these indices of IgE-mediated hypersensitivity to the prediction of PD 20 allergen by multilinear regression models with PC 20 histamine was found. Conclusion: In asthmatic patients allergic to house dust mites the degree of nonspecific bronchial hyperresponsiveness is the main determinant of early-phase bronchial responsiveness to allergen. In these patients the degree of allergic sensitivity does not contribute to the prediction of the EAR after allergen inhalation. (J Allergy Clin Immunol 1998;102:24-31.)
Clinical and Developmental Immunology, 2011
Allergic rhinitis (AR) is a public health problem with high prevalence worldwide. We evaluated levels of specific IgE, IgA, and IgG4 antibodies to the Dermatophagoides pteronyssinus (Dpt) house dust mite and to its major allergens (Der p1 and Der p2) in serum and saliva samples from allergic and nonallergic children. A total of 86 children were analyzed, from which 72 had AR and 14 were nonallergic healthy children. Serum IgE and serum/salivary IgG4 levels to Dpt, Der p1, and Der p2 were higher in allergic children whereas serum/salivary IgA levels to all allergens were higher in nonallergic children. IgE levels positively correlated with IgG4 and IgA to all allergens in allergic children, while IgA levels negatively correlated with IgG4 to Dpt and Der p1 in nonallergic children.
Journal of Allergy, 2012
Background. Allergen-specific immunotherapy (SIT) is one of the important regimens for the treatment of allergic diseases. Predictive tests for the clinical response to SIT are limited. In this study we aimed to evaluate whether specific IgE/total IgE levels can predict clinical improvement in monosensitized patients to house dust mite treated with immunotherapy.Patients and Methods. We analyzed 32 patients who had undergone 2 years of SIT. Serum t-IgE and s-IgE levels, and serum s-IgE/t-IgE ratios were calculated and tested for correlation with clinical response to SIT. Asthma symptom score (ASS), rhinitis symptom score (RSS), pulmonary functions and visual analogue scales (VAS) were evaluated at the beginning and after 2 years.Results. There were 17 boys and 15 girls with the mean age of10.78±3.03years. The mean serum house dust mite s-IgE level was128.62±142.61 kU/L, t-IgE608.90±529.98 IU/mL, and s-IgE/t-IgE ratio33.83±53.18. Before immunotherapy, ASS was6.23±1.63, RSS;8.20±1.88,...