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S Dreborg

Publications and source records attributed to S Dreborg.

At least 19 recordsLinked to original sources
PubMed2006

Five-year follow-up on the PAT study: specific immunotherapy and long-term prevention of asthma in children.

BACKGROUND: A 3-year course of specific immunotherapy (SIT) in children with hay fever to grass and/or birch pollen significantly reduced the risk of developing asthma. To investigate the long-term preventive effect, we performed a follow up--2 years after termination of immunotherapy. METHODS: A total of 183 children, aged 6-14 years with grass and/or birch pollen allergy could be investigated 2 years after discontinuation of SIT or no treatment. Conjunctival provocation tests (CPTs) and methacholine bronchial provocation tests were carried out during the season and winter after 5 years. The development of asthma was assessed by clinical evaluation. RESULTS: The significant improvement in hay fever and CPT results observed after 3 years of SIT persisted at the 5-year follow-up. No difference in bronchial responsiveness to methacholine was found after 5 years because of spontaneous improvement during the follow-up period in the control patients. The immunotherapy-treated children had significantly less asthma after 5 years as evaluated by clinical symptoms [odds ratio 2.68 (1.3-5.7)] in favor of SIT for prevention of development of asthma and significantly less patients reported an increase in asthma scores (P < 0.01). CONCLUSION: Immunotherapy for 3 years with standardized allergen extracts of grass and/or birch shows long-term clinical effect and preventive effect on development of asthma in children with seasonal rhinoconjunctivitis.

Adolescent↗
PubMed2003

'EUROPART'. Airborne particles in the indoor environment. A European interdisciplinary review of scientific evidence on associations between exposure to particles in buildings and health effects.

The relevance of particle mass, surface area or number concentration as risk indicators for health effects in non-industrial buildings has been assessed by a European interdisciplinary group of researchers (called EUROPART) by reviewing papers identified in Medline, Toxline, and OSH. Studies dealing with dermal effects or cancer or specifically addressing environmental tobacco smoke, house dust-mite, cockroach or animal allergens, microorganisms and pesticides were excluded. A total of 70 papers were reviewed, and eight were identified for the final review: Five experimental studies involving mainly healthy subjects, two cross-sectional office studies and one longitudinal study among elderly on cardiovascular effects. From most studies, no definite conclusions could be drawn. Overall, the group concluded that there is inadequate scientific evidence that airborne, indoor particulate mass or number concentrations can be used as generally applicable risk indicators of health effects in non-industrial buildings and consequently that there is inadequate scientific evidence for establishing limit values or guidelines for particulate mass or number concentrations.

Air Pollution, Indoor↗
PubMed2003

Variability of airborne cat allergen, Fel d1, in a public place.

Allergen exposure is a risk to develop an IgE-mediated sensitization. The amount of allergen inhaled per unit time should be related to the amount present in the air, i.e. airborne allergen. Thus, measuring allergen levels in the air would be more relevant than measuring allergen levels in dust. Allergens are present in the air in very minute quantities and usually become airborne after disturbance. Large variation of allergen levels have been found in dust. In this study, we measured variability of airborne cat allergen, Fel d1, in a public place using a high-volume air-sampler. We also studied the distribution and relationship between dust and airborne cat allergens in homes and schools. Air samples were collected at three different airflow rates, i.e. 55, 40, and 30 m3 of air per hour. The concentration of airborne Fel d1 in the community gymnastic hall varied from 1 to 10 pg/m3 within a period of 3 weeks, at airflow rates 55-30 m3/h. The coefficient of variation for repeated samplings was 14-43% (day-to-day variation) and 27-38% (within-day variation). As expected, higher levels of airborne cat allergens were found in homes with cats than in cat-free environments. There was a significant relationship between cat allergen levels in dust and air (r=0.7, P<0.01). Our study demonstrates that when measuring airborne cat allergen a large variation is observed within a day and between days. The large variability of measurement may be explained by the disturbance in the environments. We suggest, that when exposure assessment is made the environment in question should be analyzed, if possible in several occasions.

Air Pollution, Indoor↗
PubMed2001

A revised nomenclature for allergy. An EAACI position statement from the EAACI nomenclature task force.

This report has been prepared by an EAACI task force representing the five EAACI Sections and the EAACI Executive Committee composed of specialists that reflect the broad opinion on allergy expressed by various clinical and basic specialties dealing with allergy. The aim of this report is to propose a revised nomenclature for allergic and related reactions that can be used independently of target organ or patient age group. The nomenclature is based on the present knowledge of the mechanisms which initiate and mediate allergic reactions. However, the intention has not been to revise the nomenclature of nonallergic hypersensitivity.

Humans↗
PubMed1999

Biologic activity of Dermatophagoides siboney and Blomia tropicalis allergens in exposed and unexposed mite-allergic individuals. Effect of patient selection on the biologic standardization of mite extracts.

BACKGROUND: This study aimed to investigate the influence of patient selection criteria, i.e., mite-allergic individuals exposed and not exposed to Dermatophagoides siboney and Blomia tropicalis, on the biologic activity of mite extracts. Determination of the potency of mite extracts in vivo requires selection of patients with a clinical history of mite allergy. In Scandinavia, there are some anamnestic criteria for mite allergy, whereas in the tropics, where patients are continuously exposed to high levels of mites, selection of patients with mite allergy by clinical history is difficult. METHODS: A total of 210 Cuban asthmatics with continuous symptoms, and 43 Swedes with a clinical history of mite allergy were investigated. Skin prick tests were performed with D. siboney, D. pteronyssinus, D. farinae, B. tropicalis, Acarus siro, Lepidoglyphus destructor, and Tyrophagus putrescentiae extracts. For analysis of the biologic activity of mite extracts, Cuban patients were divided into four groups: 1) all patients skin-test-positive to mites 2) patients positive to mites, but not to other inhalant allergens 3) patients reacting most to the mite species analyzed 4) patients reactive only to mites and reacting most to the mite species analyzed. The biologic potency was calculated according to the Nordic Guidelines. RESULTS: Due to cross-reactivity between mites, Swedish mite-sensitive patients, with a clear clinical history of mite allergy, but not exposed to D. siboney and B. tropicalis, were more skin reactive to these mites than were Cubans. The estimated potency increased gradually to >200% in group 4. In group 1 Cubans, the reactivity to all mites but B. tropicalis was lower than that in mite-sensitive Swedes. CONCLUSIONS: According to the influence of patient selection criteria on the estimation of the potency of mite extracts, the determination of the biologic activity of allergenic extracts in subjects without a clear-cut clinical history should be replaced by new methods when available.

Adolescent↗
PubMed1998

Mite allergens. Collection, determination, expression of results, and risk levels for sensitization and symptom induction.

The presence of mite allergens in dust can be determined by counting mites at different stages of development in dust and by determination of the major allergen content (Der p 1 ) in dust and air, which is crucially important to allergic patients. For comparison of results, similar methods for collection of dust and air must be used. Due to their size, mite bodies and fecal particles are airborne only directly after disturbance. Special filters should be used for dust collection, and upholstered surfaces should be vacuumed for 2 min/m2 (minimum 4 m2) and hard surfaces for 1 min/m2 (minimum 8 m2). Heavy contaminations should be removed. Preferably, the method given in the ISAAC study should be followed. Samples should be deep-frozen for at least some days to kill the mites. ELISA techniques, preferably using polyclonal antibodies and antigen with all isoforms present, should be used for determination of allergens. The allergen load has been given in ng/g of dust, but allergen/m2 or per sample area should be preferred. Allergen in the air should be given in pg/m3. A tentative limit of 2000 ng/g was proposed for sensitization and asthma. This limit is still valid on a population basis, but recent data indicate that highly susceptible young children become sensitized at concentrations 10-100 times lower and that ng levels of cat allergen/m3, as found in schools, induce chronic asthma.

Air Pollution, Indoor↗
PubMed1998

Concentrations of cat (Fel d1), dog (Can f1) and mite (Der f1 and Der p1) allergens in the clothing and school environment of Swedish schoolchildren with and without pets at home.

To investigate whether our hypothesis that cat and dog owners bring allergens to public areas in their clothes was true or not, we studied the levels of Fel d1, Can f1, Der p1 and Der f1 in dust from the clothes and classrooms of children in a Swedish school. We also investigated the levels of allergen in different areas in the four classrooms used by the children. Thirty-one children were selected in four classes, forming three groups: cat owners, dog owners and children without a cat or dog at home. Furthermore, a group of children with asthma was included. Cat and dog allergens were detected in all 57 samples from clothes and classrooms. Mite allergen Der f1 was detected in low concentrations in 6 out of 48 and Der p1 in 5 out of 46 samples investigated. The concentrations of Can f1 were higher than those of Fel d1 in samples from clothes (geometric mean: 2676 ng/g fine dust and 444 ng/g) and classrooms (Can f1: 1092 ng/g, Fel d1: 240 ng/g). The dog owners had significantly higher concentrations of Can f1 (8434 ng/g fine dust) in their clothes than cat owners (1629 ng/g, p < 0.01), children without cat or dog (2742 ng/g, p < 0.05) and children with asthma (1518 ng/g, p < 0001). The cat owners did not have significantly higher levels of Fel d1 (1105 ng/g) in their clothes compared to the other three groups. (D: 247 ng/g, nCnD: 418 ng/g) but the levels were significantly higher than for all children without a cat at home (345 ng/g, p < 0.05). No concentrations of mite allergen and low concentrations of Fel d1 and Can f1 were found in the children's hair. There were significantly higher concentrations of Fel d1 and Can f1 in dust from curtains than in samples from floors and bookshelves (p < 0.05). There was no significant difference between the allergen concentrations in samples from curtains and from desks and chairs, including the teachers' chairs, the only upholstered furniture in the rooms. Our results support the hypothesis that cat and dog owners bring allergens to public areas in their clothes and support other studies showing that textiles and upholstered furniture function as reservoirs of cat and dog allergens. Thus, children with asthma and other allergic diseases will be exposed to cat and dog allergens at school and by contact with pet owners, even if they avoid animal allergens at home.

Adolescent↗
PubMed1998

Cross-reactivity between Dermatophagoides siboney and other domestic mites. II. Analysis of individual cross-reacting allergens after SDS-PAGE and Western blotting inhibition.

BACKGROUND: Dermatophagoides siboney (Ds) cross-reacted with other mite allergens in mite-allergic patients. The aim of this study was to investigate the cross-reactivity between individual allergens responsible for this cross-reactivity. METHODS: The inhibition of IgE binding to Ds allergens was investigated by non-reducing SDS-PAGE and Western blotting. Nitrocellulose membranes were incubated with a pool of sera from mite-sensitive asthmatics, after the addition of serial dilutions of D. farinae (Df), D. pteronyssinus (Dp), D. microceras (Dm), Lepidoglyphus destructor (Ld), Tyrophagus putrescentiae (Tp), Acarus siro (As) and Blomia tropicalis (Bt). N-terminal amino acid sequences and amino acid analysis of the purified major allergens, Der s 1, 2 and 3, were performed after transfer to polyvinylidene difluoride membranes. RESULTS: The inhibition was higher with Df(86%), Dp (54%) and Dm (49%) extracts than with Ld (20%), Tp (11%), As (18%) and Bt (6%). The dose-response inhibition showed a diverse pattern for the individual allergens. Despite the high cross-reactivity between the pyroglyphid mites, some proteins of Ds were less inhibited, e.g. by the Df and Dp 80-kD protein, and by the Dm and Dp 52-, 37-, 30- and 14-kD allergens. The 65-, 62-, 37- and 30-kD proteins were always inhibited more than 50% by all the mite extracts at the maximum concentration used. The 80-, 52-, 43-, 27- and 14-kD proteins cross-reacted to a lesser extent. Individual allergens of Ds were much less inhibited by non-pyroglyphid mites. However, at the highest concentration, Ld also inhibited most of the Ds allergens. All the ten selected allergens were inhibited to some extent by the heterologous mite extracts. The N-terminal sequences of Der s 1, 2 and 3 allergens showed higher homology to Df and Dm than to Dp. The homology of the group 2 allergens was higher than that of the group 1 allergens. CONCLUSION: The individual allergens of Ds were more similar to Df and Dm than to Dp. There was a limited and variable cross-reactivity with non-pyroglyphid mites. No single allergen was unique for Ds.

Allergens↗
PubMed1997

Asthma, bronchial hyperreactivity and mediator release in children with birch pollinosis. ECP and EPX levels are not related to bronchial hyperreactivity.

BACKGROUND: Symptoms of allergic asthma are triggered by allergen exposure inducing allergic inflammation and hyperreactivity of the bronchi. OBJECTIVES: To investigate the possible relationship between clinical symptoms and signs of asthma, i.e. bronchial variability as measured by peak expiatory flow rate (PEFR), bronchial hyperreactivity (BHR) and mediators of allergic inflammation. METHODS: Twenty-eight children with pollinosis, but no obvious history of asthma, were studied at three occasions, i.e. before, during and after (autumn) the birch pollen season. Twelve children sensitive to birch pollen were considered as the case group. Sixteen children, who were only clinically sensitive to grass pollen, served as controls. Subjective symptoms of asthma were recorded by visual analogue scale, BHR was estimated by methacholine bronchial provocation tests, bronchial variability PEFR and circulating mediators of inflammation, i.e. eosinophil cationic protein, eosinophil protein X, myeloperoxidase and tryptase in serum. RESULTS: Bronchial hyperreactivity and by PEFR was more pronounced after than during the season (P < 0.01), whereas eosinophil mediators and the peak expiratory flow rate increased during the season (P < 0.05). Except for between PEFR variability and BHR in the autumn (r = 0.45; P = 0.014), no correlations were found. However, in the autumn, the majority of children were still hyperreactive in the bronchi and showed PEFR variability but the levels of eosinophil mediators in serum had returned to normal levels. CONCLUSION: Signs and symptoms of asthma did not correlate with serum levels of mediators of allergic inflammation. Bronchial hyperreactivity and PEFR variability persisted after the pollen season when signs of bronchial inflammation had disappeared. We hypothesize that eosinophil mediators and other markers of allergic inflammation disappear after the late-phase reaction, whereas BHR persists. This would explain the lack of correlation between the levels of eosinophil mediators in serum and symptoms of asthma and BHR.

Adolescent↗
PubMed1997

Purification and IgE binding capacity of Der s 3, a major allergen from Dermatophagoides siboney.

BACKGROUND: Sensitization to the house dust mite Dermatophagoides siboney has been demonstrated in asthmatic patients. Previously, Dermatophagoides siboney group 1 and group 2 allergens, named Der s 1 and Der s 2, respectively, have been purified. OBJECTIVES: The aim of this study was to purify and to study the IgE reactivity of 30 kDa component, suspected to correspond to group 3 allergens. METHODS: The protein was purified by affinity chromatography using anti-Der f 3 monoclonal antibodies and semi-preparative SDS-PAGE. The IgE binding capacity of the purified fractions was tested with sera from 106 mite-sensitive asthmatic patients using a modified chemiluminiscent method. RESULTS: Affinity chromatography resulted in fractions containing the 30 kDa component which was further purified to homogeneity by SDS-PAGE. Seventy-three per cent of the sera showed IgE reactivity to this protein, indicating that it is a major allergen. The protein also reacted with anti Der f 3 polyclonal antibodies and had tryptic activity. There were differences in the reactivity to Der s 3 according to the age of the patients. CONCLUSION: Based on the frequency of IgE reactions and the reactivity with antibodies directed to Der f 3, it is proposed to name this 30 kDa allergen from D. siboney, Der s 3.

Adolescent↗
PubMed1996

Allergens of horse dander: comparison among breeds and individual animals by immunoblotting.

Some patients who are allergic to horses have reported that they can tolerate certain breeds, and the presence of breed-specific allergens has been suggested. Breeders and patients with asthma have claimed that Bashkir horses are nonallergenic. We used sodium dodecylsulfate-polyacrylamide gel electrophoresis and immunoblotting to determine IgE-binding profiles of extracts of dander obtained from horses of several breeds. We found considerable inter-breed and within-breed variation but no breed-specific allergens. Danders from all breeds investigated contained the most important allergens, and the allergenic content of dander from Bashkir horses was similar to that of other breeds. Difference in scale production could account for differences in sensitivity to breeds and individual horses.

Allergens↗