Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.4.22.65 (Der p 1)
 346 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

House features contribute to house dust mite abundance and, therefore, exposure to mite allergens. Our study assessed the hypothesis that modernization of the domestic environment in a tropical setting may lead to a level of allergen from the house dust mites Dermatophagoides pteronyssinus (Trouessart) and D. farinae Hughes that previously has been defined clinically as at risk for people who suffer from allergic disease. Allergen (Der p 1 and Der f 1) levels were measured at 4 sites (mattress, bedroom floor, living room floor, and furniture) in 17 houses in Barbados during dry and rainy seasons. Der p 1(17 of 17 homes) at all 4 sites did not vary significantly from the dry to rainy season. Allergen levels varied according to site, and were highest in living room furniture in both seasons (geometric mean 40.37 and 64.17 micrograms/g, respectively). Concentration of Der p 1 allergens were higher in concrete than in wood or mixed concrete and wood houses. Der f 1(9 of 17 homes) levels were lower than Der p 1 by 1/1,000 (both seasons). Results indicate that season is less important in regard to levels of Der p 1 than house construction and confirm other studies that implicate D. pteronyssinus as a more abundant source of allergen than D. farinae in this tropical setting.
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PMID:Spetial and temporal distribution of house dust mite (Astigmata:Pyroglyphidae) allergens Der p 1 and Der f 1 in Barbadian homes. 910 65

Der f 1, the group I allergen in Dermatophagoides farinae extracts, is a major source of inhalation allergens in Japan. Using the mixture of a panel of overlapping synthetic peptides that spread over the entire Der f 1 molecule, we found that polyclonal Der f 1-specific short-term T cell lines prepared from peripheral blood of 6 individuals allergic to Der f who carry most of the common HLA haplotypes seen in the Japanese population can respond to 16 different peptides. Eight of 16 peptides stimulated T cells of more than 2 donors, regardless of the HLA types. Proliferative responses of four T cell lines were markedly inhibited by mAb HU4 (anti-HLA-DRB1+B5), one was inhibited partially by HU11 (anti-HLA-DQ4+5+6), and one was inhibited fully by a combination of HU4, L243 (anti-HLA-DRB1+B4) and PLM16 (anti-HLA-DRB3) but only partially by each of these mAbs. One of these T cell lines, DT, of which the proliferative response was partially inhibited by HU11, was cloned. Indeed, the T cell clones were restricted by DQ6 molecules on an HLA-DRB1*1501-DRB5*0101-DQA1*0102-DQB1*0602 haplotype. These results indicate that patients' T cells recognize Der f 1 in association mainly with HLA-DRA/DRB1, but that DQAI/DQB1, DRA/DRB3 and possibly DRA/DRB4 gene products also function as antigen-presenting molecules. Thus, although some peptides have a more potent T cell-stimulatory activity than others, the T cell receptor ligands formed with the Der f 1 molecule are highly heterogeneous.
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PMID:Dermatophagoides farinae-1-derived peptides and HLA molecules recognized by T cells from atopic individuals. 910 92

According to the maximum tolerated dose (MTD) achieved, we assessed the changes in clinical and laboratory parameters, induced by specific immunotherapy (SIT), in a group of 43 asthmatic patients sensitized to Dermatophagoides pteronyssinus, over a period of 18 months. A standardized extract (100 Bu/ml; 40 micrograms/ml of Der p 1; 20 micrograms/ml of Der p 2) was used. The patients were divided into two groups: the high-dose immunotherapy (HDI) group (MTD > or = 4 micrograms Der p I) and the conventional immunotherapy (CI) group (MTD < 4 micrograms Der p 1). Changes in clinical severity index, medication, and symptom scores; in cutaneous and conjunctival reactivity; and in the levels of specific IgE, IgG, IgG1, and IgG4 to D. pteronyssinus (Der p 1 and Der p 2) were measured (ELISA monoclonal antibodies). Safety was monitored according to the EAACI guidelines. The range of the MTD was 0.8-16 micrograms of Der p 1. Ninety percent of the patients tolerated a dose of 3.2 micrograms, but only 18% of the patients reached a maintenance dose of 16 micrograms. The medians of the accumulated dose were 197 micrograms of Der p 1 for the HDI group, and 50 micrograms for the CI group. Conjunctival and cutaneous reactivity was significantly lowered (P < 0.001) after SIT, as were the clinical severity score and medication score in both groups, without significant differences between the groups, except for cutaneous reactivity. Levels of specific IgE decreased significantly (P < 0.01) in both groups, again without significant differences between the groups. The range of the increase in medians of specific IgG, IgG1, and IgG4 was 4.4-120-fold for the HDI group and 3-24-fold for the CI group (P < 0.01). The increase in the levels of Der p 1 and Der p 2 IgG4 were correlated to the changes in cutaneous and conjunctival reactivity (P < 0.01). These results show that a maintenance dose of 3.2 micrograms Der p 1 (8 BU) can induce pronounced clinical and immunologic changes with an excellent safety profile.
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PMID:Immunotherapy with standardized extract of Dermatophagoides pteronyssinus in bronchial asthma: a dose-titration study. 910 21

There is a lack of consensus as to the best way to quantify settled house-dust mite Der p 1 allergen from planar and nonplanar surfaces. To investigate the most appropriate measure of settled house-dust mite Der p 1 allergen, we determined the relationship between Der p 1 allergen content and collected dust weight from planar-surface (mattress) and nonplanar-surface (living-room) samples in 58 homes. There was a direct relationship between Der p 1 content and dust weight for both planar-surface (mattress, n = 217) samples (r = 0.50, P < 0.0001) and nonplanar-surface (living-room, n = 48) samples (r = 0.61, P < 0.0001). Correction for the surface area of the planar surface (mattress) vacuum-cleaned resulted in no additional benefit. We conclude that expression of Der p 1 levels per weight of collected dust appears to be the best method for both planar and nonplanar surfaces.
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PMID:House-dust mite allergen Der p 1: amount or concentration? 910 29

Recommendations for allergen avoidance or allergen reduction measures play an important part in the treatment of allergic asthmatic patients. The purpose of this study was to test recently developed air-cleaners with respect to their capacity to capture airborne allergen particles and to improve clinical parameters of asthmatic patients sensitized to aeroallergens. Forty five allergic asthmatic patients were studied in a double-blind procedure for 6 months. The patients were divided into three groups of 15 patients. In Group 1, the intervention consisted of the application of active air-cleaners in living-rooms and bedrooms. In Group 2, placebo air-cleaners were used in combination with allergen-impermeable mattress covers. In Group 3, the same intervention was performed as in Group 2 but with active air-cleaners. Allergen levels in mattress and floor dust were measured before, and 3 and 6 months after the interventions. After 6 months, the air-cleaners were dismantled and the filters were analysed for the amount of dust collected and allergen content. Immunological and lung function parameters were measured before, and 3 and 6 months after the interventions. Considerable amounts of airborne dust and allergenic particles were captured in the filters of the air-cleaners. Up to the 18.9 g of dust, 4,513 ng of house dust mite allergen, Der p 1, and 50,000 mU of cat allergen, Fel d 1, (in houses with cats) were collected by air-cleaners in living-rooms. Only in Group 3 (in which both active air-cleaners and mattress covers were used) was a small (less than 1 doubling dose) but statistically significant improvement of provocative concentration of histamine causing a 20% fall in forced expiratory volume in one second (PC20) observed (from 5.96 to 9.02 mg x mL(-1)). The amount of dust and house dust mite allergen collected in the filters was significantly correlated with an improvement of peak flow variation. In combination with other allergen avoidance measures, the examined air-cleaners can contribute to diminished allergen exposure and improvement of airway hyperresponsiveness in asthmatic patients.
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PMID:Allergen reduction measures in houses of allergic asthmatic patients: effects of air-cleaners and allergen-impermeable mattress covers. 919 16

To determine the tolerance of an allergen extract standardized in mass units, we closely monitored the side-effects, during the buildup phase of immunotherapy treatment, in 88 patients with well-documented respiratory allergy to house-dust mite (Dermatophagoides pteronyssinus). Thirty-four patients (38.6%) suffered from moderate perennial rhinitis, and 54 had mild to moderate bronchial asthma (61.4%). For the desensitizing treatment, we used a depot extract adsorbed in aluminum hydroxide of D. pteronyssinus (Pangramin Depot UM), biologically standardized and having the major allergens Der p 1 and Der p 2 quantified in micrograms. A total of 1244 doses were administered. All patients except one (98.9%) reached the expected maximum dose of 4 micrograms Der p 1. Only five patients suffered mild adverse reactions (5.7%). All adverse reactions except one appeared to be related to the vial of maximum concentration: vial III (4 micrograms Der p 1). Considering the number of patients who had adverse reactions and the frequency of adverse reactions per dose, we found no significant differences between rhinitis and asthma sufferers. We think that immunotherapy in doses of 4 micrograms Der p 1 and 2 micrograms Der p 2 is well tolerated and should not be avoided in mildly to moderately asthmatic patients when treating house-dust mite allergy.
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PMID:A prospective safety-monitoring study of immunotherapy in mite-allergy patients with mass-units-standardized extract. 920 72

To explore the relationship between sensitization to inhalant allergens and adult asthma, we performed two nested case-control studies of men being followed in the VA Normative Aging Study. In Study A, 46 subjects (mean age, 61.2 +/- 8.1 yr) with symptoms of asthma and an abnormal methacholine challenge test (cases) were compared with 92 age- and smoking-history-matched subjects, who denied symptoms and had normal methacholine challenge tests (controls). The age of onset of wheezing symptoms for the cases was 49.0 +/- 15.7 yr. Serum IgE reactivity to the aeroallergens Der P 1 and 2, cat, ragweed, and mouse was compared in cases and controls. Cases were more likely to be sensitized to cat allergen (23.9% versus 4.4%, p < 0.001) than were controls. Prevalences of sensitization to Der p 1, Der p 2, ragweed, and mouse were low and similar in the two groups. In Study B, 33 cases who developed new onset airway hyperresponsiveness on methacholine challenge testing were compared with 66 age-matched controls who maintained normal methacholine challenge tests. Cases had a higher prevalence of serum IgE reactivity to cat allergen (18.2% versus 6.1%, p = 0.059) and Der p 2 (21.2% versus 10.6%, p = 0.153) measured in serum obtained 3 yr before the development of airway hyperresponsiveness. These results suggest that in older men, sensitization to cat allergen is associated with asthma and that sensitization predates airway hyperresponsiveness to methacholine.
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PMID:Sensitization to cat allergen is associated with asthma in older men and predicts new-onset airway hyperresponsiveness. The Normative Aging Study. 923 Jul 21

Exposure chambers have proven to be valuable tools in the study of reactions to aeroallergens, and in monitoring the efficacy of antiallergic therapy. In the present study, 15 house-dust-mite-allergic asthmatics and five nonallergic volunteers were challenged in a recently developed exposure chamber. The trial was performed double-blinded with house-dust-mite allergen or placebo. Patients with allergy to house-dust mite (Dermatophagoides pteronyssinus) (Der p) were included by positive skin prick test, allergen-specific IgE, and conventional bronchial allergen challenge, with nebulizer and mouthpiece. In the exposure chamber, a total allergen dose corresponding to 1200 ng Der p 1 was applied. All participants kept diaries, recording peak expiratory flow rates, symptoms, and medication in periods of at least 2 weeks before and after each challenge. Twelve of the 15 asthmatics reacted with asthmatic symptoms with a median change in FEV1 of -16.4% when exposed to the allergen, but not to placebo, in the exposure chamber. Three patients had only minor symptoms during both chamber exposures and experienced no impairment of pulmonary function. Late-phase reactions were less frequent (one vs three) after the exposure chamber challenges, as compared to the traditional challenges. None of the healthy subjects reacted to the challenges. In conclusion, our exposure chamber was able to elicit symptoms in allergic subjects, and this ability was obtained with only minor amounts of house-dust-mite allergen. The described method could prove to be a more physiologically relevant model to monitor individual responses to aeroallergens.
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PMID:Exposure chamber for allergen challenge. A placebo-controlled, double-blind trial in house-dust-mite asthma. 928 81

This double-blind, placebo-controlled study investigated whether the application of an acaricide (Acarosan) on mattresses and on textile floor coverings in living rooms and bedrooms can contribute to improvement in lung function and airway hyperresponsiveness in 40 adult asthmatic patients sensitized to house-dust mite. In a second group of 19 patients who refused chemical intervention, the clinical effects of application of allergen-impermeable mattress encasings were studied. In all three treatment groups, Der p 1 levels in mattress dust were statistically significantly decreased after 12 months. However, this decrease was much greater in the group who received mattress encasings (final mean level 430 ng/g) than in groups with acaricide- or placebo-treated mattresses (final mean levels 1730 and 2100 ng/g, respectively). Treatment of textile floors with either Acarosan or placebo chemical caused a statistically significant decrease in the level of the house-dust-mite allergen Der p1 in floor dust. In the group with mattress encasings, no significant changes of floor dust Der p 1 were found. Airway hyperresponsiveness (as measured by the PC20 histamine) improved significantly in the mattress cover group after 6 months. The Acarosan group also showed a small but statistically significant improvement after 12 months.
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PMID:Allergen-avoidance measures in homes of house-dust-mite-allergic asthmatic patients: effects of acaricides and mattress encasings. 929 77

We investigated by ELISA the IgE response to whole extract of the house-dust mite Dermatophagoides pteronyssinus (Dp) and to the native major allergens, Der p 1 and Der p 2, in sera from 18 adult patients (group A) with Dp-allergic asthma before (t0) and 1, 2, 3, and 4 (t1-t4) years after subcutaneous specific immunotherapy (SIT). A qualitative reduction (P = 0.05) of the IgE responses to Dp and Der p 2 was observed from t1 to t4, but a highly statistical significant decrease appeared at t3 (P < 0.01). With regard to Der p 1 IgE values, the immunotherapy induced a significant decrease (P < 0.01) at t3, but not before. In group A, the IgE responses to Der p 1 and Der p 2 were not correlated at t0 (rs = 0.31; P = 0.21) but were correlated at t3 (rs = 0.78; P = 0.001). We also examined sera from 14 adult patients (group B, same SIT schedule as group A) who were without respiratory symptoms at the end of the third year (t3) of Dp SIT. At this time (t3), there were no significant differences in Der p 1 and Der p 2 IgE levels between group A and group B.
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PMID:IgE responses to Dermatophagoides pteronyssinus native major allergens Der p 1 and Der p 2 during long-term specific immunotherapy. 940 65


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