Nordic Congress of Allergology

Oral presentations

O 1 - Low numbers of IL-12 producing cord blood mononuclear cells as a predictor of allergic disease in early childhood

Nilsson C1, Larsson AK2, Söderlund A2, Gabrielsson S2, Troye Blomberg M2, Lilja G1

Objective: To investigate the cytokine profile (IFN-gamma, IL-4 and IL-12) in CBMC after in vitro stimulation with different allergens and to relate the responses to the outcome of allergic disease at two years of age.

Methods: CBMC were isolated from 82 new born children among whom 65 % had atopic heredity. The responses towards ovalbumin, birch, cat, phytohaemagglutinin (PHA) and purified protein derivative (PPD) were investigated by the ELISpot technique. The numbers of IFN-gamma, IL-4 and IL-12-producing CBMC were counted for each stimulation. The children were followed prospectively from birth to two years of age and clinically examined. Skin prick test (SPT) and RAST analyses towards selected food and inhalant allergens were performed at 24 months of age.

Results: Fifteen (18.3%) children were classified as IgE sensitised (positive SPT; > 3 mm and/or RAST; > 0.35 kU/l). The numbers of IL-12-producing CBMC after stimulation with the selected allergens birch, ovalbumin and cat were lower among IgE sensitised children, although only statistically significant for cat. IFN-gamma-producing cells, irrespective of antigen/mitogen stimulation, did not differ between the sensitised and non-sensitised children. Children with atopic dermatitis during the observation (n= 53) had significantly lower numbers of IFN-gamma-producing CBMC after stimulation with ovalbumin and cat.

Conclusions: Our data suggests that a low number of IL-12-producing CBMC is associated with IgE sensitisation during early childhood and that a reduced number of IFN-gamma-producing CBMC promotes the development of atopic dermatitis during the first two years of life.

O 2 - Expression of the chemokine receptors CCR4 and CXCR3 in response to endotoxin stimulation is differentially regulated in cord blood T cells from neonates at high or low allergy risk

Haddeland U1, Bø KO2, Bergsjø Karstensen A3, Brandtzaeg P1, Nakstad B3

Exposure to high levels of bacterial products in infancy and vaccination with killed mycobacteria have been shown to have an allergy-reducing effect. Therefore, bacterial products might be used in future vaccines against allergic diseases. However, new insight into the mechanisms involved in such a protective effect is needed.

Aim 1: To further clarify the mechanisms by which bacterial products modulate T-cell responses in the neonate.

Early life establishment of a commensal gut flora, infections and contact with environmental bacterial products gradually induce a shift from Th2 to Th1 responses. However, neonates with a family history of allergic diseases seem to have an "immature" response to these stimuli, as suggested by impaired production of the Th1 cytokines.

Aim 2: To further analyze the immature responses to bacterial products seen in newborns with a family history of allergic diseases.

Methods: In a preliminary study, we stimulated cord blood mononuclear cells from neonates at high or low allergy risk with a combination of endotoxin (from the bacterial cell wall of gram-negative bacteria) and the cow's milk antigen b-lactoglobulin (BLG) and measured: proliferation detected by incorporation of radioactive thymidine; proliferation detected by expression of the nuclear proliferation marker Ki-67 in combination with CD3 and CCR4 or CXCR3 by flow cytometry.

Results: Cord blood CD3+ T-cells from neonates at low allergy risk upregulated the chemokine receptor CCR4 upon stimulation with endotoxin+BLG. This response was impaired in neonates at high risk of allergies (Wilcoxon rank-sum test: significant difference between the groups, p=0.036). On the other hand, endotoxin+BLG stimulation induced a higher proliferation rate in cord blood from the high risk group. Staining for Ki-67 demonstrated that almost all of the proliferating cells were CXCR3+.

Conclusions: The bacterial product endotoxin matures the immune system of the newborn, perhaps by inducing more efficient migration of antigen-primed T-cells towards activated dendritic cells in lymphoid organs by upregulating CCR4. Such endotoxin-induced maturation was impaired in neonates at high allergy risk. At birth, T cells from the low-risk group had already developed immune tolerance as revealed by reduced proliferative response to endotoxin, whereas in the high-risk group, T cells with a non-specific tissue infiltrating phenotype (CXCR3+) proliferated extensively.

O 3 - Early pet ownership in relation to sensitisation and allergic symptoms at age four

Sandin A, Bråbäck L, Björkstèn B

Objectives: To assess the relationship between atopic status at the age of four with pet keeping during the first year of life based on a non-selected birth cohort.

Methods: Families were enrolled at the prenatal clinic or at birth and information on pet keeping, home environment, parental allergy and symptoms were collected with repeated questionnaires.

Results: 817 children were skin-prick tested at both one and four years of age with positive test in 13% of the children at age four. Sensitisation and wheezing at four years of age had no relationship with cat keeping during the first year of life. By contrast, dog keeping during the first year of life was associated with a decreased risk of sensitisation to pollen allergen at age four. The lower risk of sensitisation to pollen persisted after multiple logistic regression with adjustment for older siblings, maternal smoking, parental hay fever and asthma and avoidance of pet keeping because of allergies in other family members (adjusted OR, 0.3, 95% CI 0.1 - 0.9). Dog keeping during the first year of life had an additional, independent and inverse relationship with non-infectious rhinitis at 4 years of age (adjusted OR 0.4 95% CI 0.2 - 0.9).

Conclusions: Dog keeping during the first year of life was associated with a decreased risk of sensitisation to pollen and non-infectious rhinitis at age four and this was found significant even after exclusion of families where pet keeping had been avoided because of allergy in other family members.

O 4 - Atopic allergy and delayed type hypersensitivity in Estonian children

Julge K, Björkstèn B

The aim of our study was to investigate delayed type hypersensitivity (DTH) response in atopic and non-atopic children in a population with a low prevalence of allergic disorders.

Skin prick tests (SPT) were performed with fresh egg white and extracts of 5 inhalant allergens, i.e. cat, dog, house dust mite (D. pteronyssinus), birch and timothy and DTH response was evaluated by Multitest ® CMI in 72 Estonian 4-6 year old children.

The frequency of response to diphtheria was significantly increased in SPT positive children (55% vs 26%, c2 = 5.5; p = 0.038). The induration to diphtheria (2.4±0.5 vs 0.9±0.2 mm; p = 0.004), and tetanus (3.5±0.6 vs 2.1±0.3 mm; p = 0.025) was significantly greater in the SPT positive children. The cumulative size of induration in the positive DTH tests was significantly greater in the SPT positive children (9.0±1.2vs 5.2±0.6 mm, p = 0.01).

Conclusion: In this group of children our findings do not support the hypothesis of an immune deviation with decreased Th1 and increased Th2 responses leading to atopic disease, but rather a process of immune modulation whereby both Th1 and Th2 responses are increased in atopic subjects.

O 5 - Total and fine drug particle mass generated from two dry powder inhalers. (DPIs) by children with asthma aged 4 or 8 years

Gustafsson P1, Andersson H1, Glad M1, Johal B2, Burnell PKP2

Aim: To assess the dose delivery generated when inhaling through Seretide Diskus® and Symbicort Turbuhaler® (TH).

Methods: After training, full inhalation pressure/time profiles through the inhalers were recorded in 20 four-year old and 20 eight-year old asthmatic children. These profiles were replicated ex vivo through both inhalers using the Electronic Lung. The total emitted dose (TED) and fine particle mass (FPM; < 4.7 mm) of component drugs were measured using an Andersen cascade impactor (28.3 L/min) (ERJ 1998; 11:1111), expressed as % label claim (for TH "metered dose"), and were correlated with PIF (R2 = correlation coefficient). Results for salmeterol and formoterol are tabulated at the bottom of the page.

Conclusions: Dose delivery from the Turbuhaler® increases with PIF in 4-year old children and varies markedly for a given PIF also in 8-year olds. Delivery from the Diskus is highly consistent and independent of PIF. The data suggest that asthmatic children from the age of 4 years can generate predictable and consistent total and fine particle drug aerosols from the Diskus® but not from the Turbuhaler®.

Supported by GlaxoSmithKline (DEV40026)

O 6 - The connection between air pollution and asthma

Endre L

Statistical studies on large populations, and also in vitro and in vivo animal and human investigations in various research laboratories throughout the world, have confirmed that air pollutants resulting from road traffic promote the development of asthma and worsen the symptoms in existing asthma.

The prevalence of bronchial asthma in childhood in Hungary is low relative to that in the industrially most developed countries. The data provided by the physicians treating more than 100,000 children in Budapest in 1995 indicated a prevalence of 1.88 %, the corresponding data on more than 130,000 children in 1999 pointed to a prevalence of 2.26 %, i.e. an increase of 20 % within 4 years. During this period, the air pollution data (SO2, O3, CO, NO2, and aerial dust) were measured continuously at 7 points in Budapest, these data were combined and means were calculated from them. It was found that there was not a significant deterioration in any of these air pollutants in the 4 years in question. As regards the level of air pollution, Budapest occupies an intermediate position in the list of large cities in the world.

Our studies have revealed that the reason why there are far fewer asthmatic children in Budapest than in the large British cities, for example, is not that the level of air pollution is better in Budapest. Moreover, the cause of the 20 % increase in the prevalence of asthma in childhood is not a deterioration in the level of air pollution.

O 7 - Airway inflammation and remodeling in elite athletes

Boulet LP, Turcotte H, Langdeau JB, Chakir J

Objectives: To determine if there are lower airway inflammatory or structural changes in high-level swimmers and runners, and look at the effects of intense training on sputum cell differential.

Subjects and methods: Swimmers and runners with increased airway responsiveness (AR) as defined by a PC20 methacholine <16 mg/ml (mean PC20 2.27 (n:12) and 3.2 (n:10) respectively) or normal AR (> 16 mg/ml, mean PC20: 32.2, (n=10) and 41.5 (n=13) were studied. All subjects had in random order, two methacholine tests and induced sputum (IS) analyses, after 3 days without training and 24 h after training. Two subjects agreed to have bronchial biopsies (BB).

Results: PC20 methacholine was unchanged after training (p> 0.05, all groups). The median % inflammatory cells on IS were within the normal range on baseline. After training, neutrophils increased similarly in all groups (p>0.05), although it reached statistical significance (pre-post training) only in the group of swimmers with increased AR (p = 0.039). There were no changes in other inflammatory cells on IS after training. Histological staining of BB obtained from an atopic swimmer with normal AR and a non-atopic swimmer with increased AR, showed the presence of subepithelial fibrosis, proeminent blood vessels and, in the atopic subject only, a slight inflammatory infiltrate.

Conclusion: There are evidences of airway remodeling in elite athletes although minimal airway inflammation. Intense training induced an increase in airway neutrophils but AR remained unchanged. We need to evaluate if increased AR and changes in airway structure in athletes could be related to mechanisms other than inflammatory.

O 8 - Specific Allergen Immunotherapy attenuates early and late phase reactions in lower airways of birch pollen asthmatic patients. A double blind placebo controlled study.

Arvidsson MB, Löwhagen O, Rak S

Objectives: Few studies have examined the effect of specific allergen immunotherapy on early and late phase asthmatic reactions and placebo-controlled pollen studies are lacking. We have therefore undertaken a placebo-controlled study investigating the effect of one-year specific allergen immunotherapy with birch pollen extract (Alutard® SQ, ALK-Abelló, Denmark) on early and late phase asthmatic reactions in adult asthmatic patients.

Methods: Nineteen patients with a history of birch-pollen-induced symptoms from upper and lower airways, positive skin prick test and in vitro specific IgE to birch pollen (Betula verrucosa) extract were included. Allergen and metacholine bronchial challenges were performed and blood samples obtained for analyses of total eosinophil count and ECP, before and after one year of immunotherapy.

Results: All patients developed early and sixteen both early and late phase asthmatic reactions. Following allergen challenge a significant increase in allergen dose required to evoke early asthmatic reaction was found in the immunotherapy, but not in the placebo group after one year of treatment. The difference between the groups was significant, p<0.01. The size of late asthmatic reaction was significantly reduced in the immunotherapy group compared with placebo treated patients, p<0.01. Methacholine sensitivity following late asthmatic reaction, number of total eosinophils and ECP increased significantly in the placebo, but not in the immunotherapy group after allergen challenge.

Conclusions: Specific allergen immunotherapy with standardised birch pollen extract decreases sensitivity to allergen as reflected by early asthmatic reaction and development of inflammatory response as assessed by late asthmatic reaction in birch pollen allergic patients.

O 9 - Specific immunotherapy for latex allergy

Pereira C1, Pedro E2, Tavares B1, Ferreira MB2, Carrapatoso I1, Rico P3, Santos MC2, Palma-Carlos AG2, Chieira C1

We describe 4 patients (3 adult females + 13y old boy) with latex allergy. They all had symptoms with increasing severity. The 3 females had severe symptoms in the workplace. The boy had spina bifida with 9 previous surgeries and needed further surgical interventions. All of them developed anaphylaxis related with latex and oral-latex-fruit syndrome. Positive skin prick tests, the presence of serum latex specific IgE (CAP-RAST, Pharmacia-Upjohn, Sweden- class 3 in the 3 females and class 4 in the boy) and clinical symptoms demonstrated the sensitisation.

All 3 patients were treated with specific immunotherapy (SIT) with aqueous extract (ALK-Abelló, Spain) administered subcutaneously at the hospital, by rush modified method. A maintenance dose (MD) of 0.35mg protein was established according to the magnitude of local reactions. In one patient a higher dose induced the appearance of a systemic reaction 40 min after administration, which promptly remitted with treatment. After establishing MD, all 3 females remained assymptomatic at workplace. A challenge test with latex gloves was performed 2 months after MD was reached (2 females are negative and another one had slight symptoms of rino-conjuntivitis). The boy was subjected to surgical intervention with no allergic reaction.

We also observed a reduction on skin reactivity prick tests to latex in all patients. We consider SIT with latex to be highly effective, and the allergenic extract used to be safe and well tolerated at this dose.

O 10 - Presence of IgE, Activated Eosinophils and T-cells in Duodenal Biopsies from Adults with Birch Pollen Allergy

Magnusson J1,2, Ping Lin X2, Dahlman-Höglund A3, Hanson LÅ2, Magnusson O4, Telemo E 2, Bengtsson U1, Ahlstedt S5

The pathophysiological connection between the upper, lower respiratory and gastrointestinal (GI) tract are still not understood in the allergic desease. The aim of this study was to determine presence of IgE, eosinophils and T-cells in GI-mucosa in patients with birch pollen allergy, during the birch season compared to off-season, using gender and age-matched healthy controls.

Three men and six women, mean age 40 years, allergic to birch pollen, verified by skin prick test and serum IgE antibodies, were included. The duodenal biopsies obtained in the end of the birch pollen season and six months later, were studied by immunostaining for IgE, MBP, CD3, CD4 and CD8.

During the pollen-season significantly increased infiltration of IgE-bearing cells was shown, compared to off-season (p=0.008) and with controls in season (p=0.002), but not off-season (ns). The MBP+ cells were elevated in season (p=0.008) and also compared to controls in season (p=0.009), but not off-season (ns). Increased infiltration of T-cells, (p=0.008), were found in the birch pollen season compared with patients off-season and with controls in season, CD3+ (p=0.0005), CD4+ (p=0.002), CD8+ (p=0.0007). CD8+ T-cells were still elevated (p=0.02) in patients compared to healthy controls off-season, while CD3+ and CD4+ cells were normal (ns).

Our results showed a significant increase of IgE-carrying mast cells, eosinophils and T-cells in the GI-mucosa in patients with birch pollen allergy, indicating an ongoing local allergic response. The clinical importance of the duodenal inflammation seen in these patients is uncertain, but our study gives evidence for the interplay between the airways and the gut.

O 11 - Characterisation of nasal nitric oxide in patients with allergic rhinitis

Palm J1,2, Alving K1, Lundberg J1

Nitric oxide (NO) is present in the human nasal airways and has been suggested to originate primarily in the paranasal sinuses. Several studies have attempted to assess nasal NO levels quantitatively in allergic rhinitis. However, there seem to be differences in the results obtained, some studies showing an increase while other showing no difference. We therefore wanted to investigate this further, using two methods for nasal NO measurements at three flow rates of air. We studied the NO output (nl/min) at 0.5, 3 and 9 l/min in nasally aspirated and nasally exhaled (into a nose mask, using a single breath method) air of 18 patients with steroid-naive allergic rhinitis during pollen season and 18 controls. Using the aspiration method, the NO output (Mean ± S.D) was 160±75 versus 153±36 nl/min at 0.5 l/min, 211±103 versus 198±45 at 3 l/min and 271±217 versus 232±62 at 9 l/min. Thus, we found an increase with flow in NO output, but no significant difference between patients and controls at any modality. Notably, the variation in individual values was markedly greater in patients than in controls. We conclude that we found no difference in nasal NO output, whereas there was a greater inter-individual variation in nasal NO output in patients with allergic rhinitis compared to controls. This greater spread may be due to variation in mucosal thickening obstructing the paranasal sinus ostiae and in mucosal enzymatic NO production.

O 12 - Bakers' rhinitis and its relation to bronchial reactivity: I. Sensitization to environmental allergens in Norwegian bakeries

Storaas T1, Aasen TB1, Greiff L2, Steinsvaag SK1, Florvaag E1

Objectives: The aim of the present study was to determine the prevalence of work-related symptoms in 6 bakeries in Bergen, Norway, as well as the prevalence of sensitisation to environmental allergens in the baking industry, and the exposure-levels of flour-dust. Furthermore we wanted to relate these findings to nasal and bronchial reactivity tests. This was the second phase in a cohort-study, and from the originally 208 employees, 197 were possible to enroll into this phase.

Methods: Blood samples were obtained from 183 (93%) for total IgE, specific IgE (common aeroallergens and baking-allergens), and histamine release test, and skin prick test was executed.

Results: All together 30% of the present cohort were sensitized to one or more of the baking-allergens. The most frequent causes of sensitization were different species of storage mites. Every fifth baker was sensitized either to Acarus Siro, Lepidoglyphus Destructor or Tyrophagus Putrescentiae. Less than half of those sensitized to a storage mite were also sensitized to the common house-dust mite Dermatophagoides Pteronyssinus. Furthermore, 12% were sensitized to wheat and 7% to a-amylase. The group of wheat-sensitized constituted also those sensitized to rye (10%). 13 of the 22 wheat-sensitized were also sensitized to the grass pollen timothy. None of the present cohort were sensitized to the mould Cladosporium Herbarium, only 3 to Soya bean, and 5 (2,7%) to German cockroach.

Conclusions: We conclude that a large proportion of bakers (20%) are sensitized to a storage mite. Other major sensitizing allergens being wheat (12%), and alpha-amylase (7%).

O 13 - Bakers' rhinitis and its relation to bronchial reactivity: II. Work-related symptoms and flour-dust exposure

Storaas T1, Årdal L1, Florvaag E1, Greiff L2, Steinsvaag SK1, Aasen TB1

Objectives: The aim of the present study was to determine the prevalence of work-related symptoms in 6 bakeries in Bergen, Norway, as well as the prevalence of sensitisation to environmental allergens in the baking industry, and the exposure-levels of flour-dust. Furthermore we wanted to relate these findings to nasal and bronchial reactivity tests.

Methods: This was the second phase in a cohort-study, and from the originally 208 employees, 197 were possible to enroll into this phase. Of these 180 (91%) answered a questionnaire and 181 (92%) were interviewed. Exposure to flour-dust was measured by personal-borne Gelman- and Respicon-cassettes. The employees were grouped according to their present and earlier work-tasks, bakery, night or day shift.

Results: 22 work-titles were identified, and each employee was grouped in one of 5 categories of last year exposure. 43 (24%) reported 2 of 3 main nasal symptoms, a specific baking ingredient that worsened the symptoms, and improvement in vacations. 40 (22%) experienced coughing, shortness of breath, or wheezing at work, and improvement in vacations. Altogether 58 (32%) reported both upper and lower respiratory tract symptoms at work. The interview supported these figures, and identified nasal symptoms nearly always to precede lower respiratory tract symptoms. Far less work-related nasal symptoms were experienced beneath the exposure-level of 1mg/m3 flour-dust.

Conclusions: Every fourth employee in the bakeries has an occupational rhinitis. Nasal symptoms precede lower respiratory tract symptoms. Work-related symptoms are well controlled if the exposure-level of flour-dust is kept beneath 1 mg/m3 (total dust).

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