Atopic sensitization among children in an Arctic environment

BACKGROUND: Asthma has been reported to be rare among Inuits, but so far total and specific IgE levels have never been determined in arctic populations. OBJECTIVE: To determine the prevalence of atopy in children living in an arctic environment, and to examine whether atopy and total IgE levels were associated with parental place of birth, as a measure of ethnicity, and travel history. MATERIAL AND METHODS: All schoolchildren in Sisimiut, a community on the West coast of Greenland, were screened for atopy. Blood samples were analysed for total IgE and for specific IgE against inhalant and food allergens. Information on place of birth of children and their parents was obtained from national registries. Information on travel history was obtained from self-administered questionnaires. RESULTS: A total of 1031 schoolchildren aged 5 to 18 years had a blood sample drawn (85% of available children for the study). Of these, 151 (14.6%) children were sensitized to at least one inhalant allergen and 42 (4.1%) to at least one food allergen. Sensitization to grass was most common, whereas sensitization to mugwort, birch, animal-dander and house-dust mite was infrequent. Children whose parents were both born abroad had a higher risk of sensitization to inhalant allergens compared with children born of Greenlandic parents (OR = 8.6, 95% CI 2.8-27.1). Furthermore, children who had been abroad had a higher risk of sensitization towards pollen (OR = 1.6, 95% CI 1.0-2.5) and animal-dander (OR = 2.1, 95% CI 1.0-4.6) after adjustment for confounders. Both atopic and non-atopic children demonstrated high levels of total IgE (medians of 251 and 58 kU/L). CONCLUSIONS: Compared with European findings Greenlandic children have high levels of total IgE but a low prevalence of allergic sensitization towards inhalant allergens. This may be due to a low genetic susceptibility to atopy and less allergen exposure, as well as to living conditions in an arctic environment.     

Sensitization to different pollens and allergic disease in 4-year-old Swedish children

BACKGROUND: Although the relationship between sensitization to different inhalant allergens in adolescents and adults has been intensively studied, information concerning sensitization in children is scarce in particular to pollens. OBJECTIVES: In 4-year-old children to elucidate the pollen immunoglobulin (IgE) antibody profile (birch only, timothy only and combinations of three pollens (birch, timothy or mugwort) and to relate the results to other inhalant and food allergens, as well as the presence of allergic diseases. METHODS: A total of 2551 4-year-old children belonging to a prospective birth cohort, which has been followed longitudinally (BAMSE), were investigated with respect to IgE antibodies to pollen and other inhalant and food allergens, and expression of allergic disease, based on questionnaire data. RESULTS: Eleven percent (n=285) of the children were sensitized to pollen. Birch was the dominating cause of pollen sensitization (birch sensitization only, n=133); followed by timothy grass pollen (n=56) and a combination of two (n=64) or three (n=30) pollens. A remarkably high proportion of the children sensitized only to birch was also sensitized to other inhalant allergens. This was not seen for children sensitized only to timothy. The highest frequencies of IgE reactivity to food were found in the group of children sensitized to the combination of birch, timothy and mugwort pollen. Children sensitized to timothy only, exhibited symptoms of allergic disease significantly less frequently compared with children sensitized to birch only. Sensitization to birch pollen was found to be closely associated with rhinitis and eczema compared with asthma. The highest frequency of asthma and/or rhinitis and/or eczema was reported in children sensitized to at least two pollens. CONCLUSION: Our results demonstrate that birch is the dominating source of pollen sensitization at the age of four in Sweden. This might associate with the pattern of sensitization to other inhalant and food allergens as well as influence on the expression of allergic disease in this particular age group.     

Genetic linkage of HLA–class II locus to mite-specific IgE immune responsiveness

BACKGROUND: IgE response to common inhalant allergens seems to be the major determinant of the development of atopic rhinitis and asthma but it has been difficult to demonstrate genetic control of the IgE response. OBJECTIVE: To investigate genetic linkage between specific IgE reactions to purified aero-allergens (grass, birch, cat, mite) and the HLA-class II locus. METHODS: DNA-based HLA-class II typing was performed for determination of DRB1, DQB1 and DPB1 alleles. Linkage was studied by the affected sibpair method and the extended transmission disequilibrium test in 100 children from 40 nuclear families selected from a homogeneous population in south-western Germany. RESULTS: Significant linkage of mite-specific IgE response to HLA-DPB (P = 0.00001), HLA-DRB (0.02) and HLA-DQB (P = 0.001) was revealed by sibpair analysis of MHC class II alleles and confirmed by the extended transmission disequilibrium test for HLA-DRB (P = 0.01) and HLA-DPB (P = 0.04). No consistent significant linkage between the HLA-class II locus and IgE response to grass pollen, birch pollen, and cat dander could be demonstrated. CONCLUSION: The findings are consistent with the existence of one or more genes in the HLA-class II region modifying the IgE immune response to common environmental allergens.     

IgE-mediated allergy in adults with severe atopic eczema

A study was carried out of 45 adults with atopic eczema sequentially admitted to the Dermatology wards in the Royal Infirmary, Edinburgh. The clinical course of the eczema, the associated atopic conditions and the possible role of inhalant and food allergens were assessed. Most subjects had developed eczema in early childhood, but nine of the 45 developed it for the first time after the age of 15 yr. Eleven subjects outgrew their eczema around puberty only to experience recrudescence in their late teens. In 18 subjects the eczema was flexural until the late teens, when it became widespread. In this group of severely affected subjects, 25 had a history of asthma, 29 had either seasonal or perennial rhinitis, and 10 had current symptoms of food allergy. All but one had elevated total serum IgE concentrations (range 63-50,000 kU/l). Using dilutions of the subjects' serum in the radio-allergosorbent test, an estimate of the specific IgE to 10 allergens (three inhalants, seven foods) was obtained, where 1 RAST unit is roughly equivalent to 1 IU total IgE. Most of the IgE was produced in response to the inhalant allergens tested (grass pollen, house dust mite and cat epithelium), 32 of the subjects having a RAST score of 3 or 4 to each of the three inhalant allergens, with the remaining 13 having a RAST score of 3 or 4 to at least one. The highest levels were to house dust mite, exceeding 1000 RAST units in 13 subjects. Thirteen subjects had a RAST score of 4 to at least one food allergen, with levels up to 1000 RAST units. Although this usually correlated with a history of allergy to the food (except in the case of wheat), some subjects with a positive RAST to a specific food could eat the food without problem.(ABSTRACT TRUNCATED AT 250 WORDS)     

Relationship between IgG1 and IgG4 antibodies to foods and the development of IgE antibodies to inhalant allergens. II. Increased levels of IgG antibodies to foods in children who subsequently develop IgE antibodies to inhalant allergens

In the present investigation we have tested the hypothesis that children with a high IgG antibody response to foods have an increased risk of developing IgE antibodies to inhalant allergens. Sera from 106 children with an increased risk of developing IgE-mediated allergy were analysed. During the follow-up, in 54 of these children IgE antibodies to inhalant allergens appeared. A positive/negative IgG1 and IgG4 anti-food score was determined as described previously: sera from age-clustered unselected children were tested for the levels of IgG1 and IgG4 antibodies to common foods. For each IgG RAST and each age group, the 75-percentile was chosen as cut-off value. Each antibody level was thus converted into a positive (higher than the 75-percentile of the age group) or negative value. The number of positive tests was used as the score. High-risk children with a high IgG1 anti-food score more often developed inhalant-specific IgE antibodies than high-risk children with low IgG1 titres: 50% of the children with a high IgG1 anti-food score developed IgE antibodies to grass pollen. Fifty per cent of the children with a high and 14% of the children with a low IgG1 anti-food score developed IgE antibodies to cat dander. For the prediction of the development of IgE anti-mite (house dust mite), the IgG4 anti-food scores appeared less useful than the IgG1 anti-food scores; 46% of the IgG4 high responders versus 22% of the IgG4 low responders acquired IgE anti-mite, whereas for IgG1 these percentages were 73 and 19, respectively.     

A community survey of IgG4 antibody levels

Precise and specific radioimmunoassays have been developed to quantify IgG4 and IgG4 antibodies. A community survey has demonstrated that men have significantly higher total serum lgG4 levels than women: geometric mean values of 0.581 mg/ml versus 0.302 mg/ml. This sex difference was extended to total IgE values. Circulating levels of IgG4 antibodies against foods, especially egg-and milk, were normally higher than those against the three most common U.K. inhalant allergens–grass pollen, house dust mite and cat epithelium,     

Quantitative measurement of IgE antibodies to purified allergens using streptavidin linked to a high-capacity solid phase

BACKGROUND: Commercially available assays for IgE antibody provide results in international units per milliliter for many allergen extracts, but this is not easily achieved with purified or novel allergens. OBJECTIVE: To develop assays for IgE antibody suitable for purified or novel allergens by using a commercially available immunosorbent. METHODS: Streptavidin coupled to a high-capacity immunosorbent (CAP) was used to bind biotinylated purified allergens from mite (Der p 1 and Der p 2), cat (Fel d 1), and dog (Can f 1). Assays for IgE antibody to these allergens were performed on sera from children (asthma and control) as well as adults with atopic dermatitis. RESULTS: The results were validated by serial dilution of sera with high and low levels of IgE antibody and were quantitated in international units per milliliter by using a standard curve. Values for IgE antibody to Der p 1, Der p 2, and Fel d 1 correlated with values obtained with the allergen extracts (r2 = 0.80, 0.84, and 0.95, respectively; P < .001 in each case). Furthermore, the values for IgE antibody in sera from children with high exposure to mite and cat allergens demonstrated 10-fold higher levels of IgE antibody to Der p 1 and Der p 2 than to Fel d 1 (P < .001). CONCLUSION: The streptavidin immunosorbent technique provides a new method for quantifying IgE antibody to purified proteins. The results provide evidence about the high quantities of IgE antibody to purified inhalant allergens in patients with atopic dermatitis. In addition, the results demonstrate major differences in IgE antibodies specific for mite and cat allergens among children with high exposure to both allergens.     

Do levels of immunoglobulin G antibodies to foods predict the development of immunoglobulin E antibodies to cat,dog and/or mite?

BACKGROUND: In children at high risk of inhalation allergy, food sensitization is associated with an increased risk for sensitization to inhalant allergens. Furthermore, this association was also found in a cross-sectional study. OBJECTIVE: To examine in a prospective study, whether levels of IgG to foods (i.e. mixture of wheat and rice, mixture of soy bean and peanut, egg white, cow's milk, meat, orange and potato) indicate an increased risk for the future development of IgE antibodies to inhalant allergens in a low-risk population and whether they can be used as predictors of the subsequent development of IgE antibodies in young, initially IgE-negative children. METHODS: Coughing children, aged 1-5, visiting their GPs, were tested for IgE antibodies to mite, dog and cat (RAST) and IgG (ELISA) to foods. All IgE-negative children were retested for IgE antibodies after two years. The IgG results (66 percentiles) of the first blood sample were compared to the RAST-scores of the second blood sample. RESULTS: After two years, 51 out of 397 (12.8%) originally IgE-negative children, had become IgE-positive for cat, dog and/or mite. An increased IgG antibody level to wheat-rice (OR = 2.2) and to orange (OR = 2.0) indicated an increased risk of developing IgE to cat, dog or mite allergens. In addition to IgG to a mixture of wheat-rice and orange; total IgE, breastfeeding, eczema as a baby and age were the most important predictors for the subsequent development of IgE to inhalant allergens. DISCUSSION: An increased IgG antibody level to a mixture of wheat-rice or orange, indicates an increased risk of developing IgE to cat, dog or mite allergens. This indicates that excessive activity of the mucosal immune system is present before IgE antibodies to airborne allergens can be demonstrated. Nevertheless, IgG to foods is not very helpful (with a positive predictive value of 16.5%, and negative predictive value of 90.6%) in identifying individual children at risk in clinical practice. However, besides other risk factors, IgG to wheat-rice and to orange could be useful as a screening test for studies in the early identification, i.e. before IgE antibodies can be detected, of children with an increased risk of developing IgE antibodies in the future.     

Citrus red mite (Panonychus citri) is the most common sensitizing allergen of asthma and rhinitis in citrus farmers.

OBJECTIVE: To evaluate type I hypersensitivity to citrus red mite (Panonychus citri), its prevalence, and relationship to respiratory dysfunction, a cross-sectional survey was performed among citrus farmers on Cheju Island, Korea. MATERIALS AND METHODS: Questionnaires, and skin prick test responses to 11 common inhalant allergens and citrus red mite were performed in 181 citrus farmers, and serum-specific IgE antibodies to citrus red mite were measured by ELISA in sera of 123 subjects. To determine airway hyperresponsiveness, methacholine bronchial provocation tests were performed in 55 subjects who complained of recurrent lower respiratory symptoms. RESULTS: The prevalence of asthma-based on presence of asthmatic symptoms on the questionnaire and airway hyperresponsiveness to methacholine, and allergic rhinitis based on presence of nasal symptoms on the questionnaire and positive skin-test response were 12.1% and 19.3%, respectively. The positive rate of skin responses to one or more of 11 common inhalant allergens excluding citrus red mite was 17.1%, and if citrus red mite was included, 25.9% of farmers had positive responses. On skin prick tests, citrus red mite (16.5%) was the most common sensitizing allergen, followed by cockroach (11.0%), Dermatophagoides pteronyssinus (9.9%), and D. farinae (9.3%). Among farmers with asthma and allergic rhinitis, the positive skin responses to citrus red mite were noted in 54.5 and 68.5%, respectively. Serum-specific IgE antibodies to citrus red mite were detected in 45 farmers (36. 5%) of the 123 tested, and there was significant correlation between specific IgE level and weal (A/H ratio) to citrus red mite (r = 0.57, P < 0.001). The prevalence of asthma was higher in subjects with positive skin responses or high serum-specific IgE antibodies to citrus red mite than in those without skin response or serum specific IgE (P < 0.05, respectively). CONCLUSION: Citrus red mite is the most important allergen in citrus farmers with asthma and rhinitis in which causative allergen has not been identified. It should be included in the skin test battery for screening the causative allergen in farmers exposed to citrus red mite.     

Exposure to a farming environment has allergen-specific protective effects on TH2-dependent isotype switching in response to common inhalants

BACKGROUND: IgE synthesis by human B cells results from allergen-dependent, T(H)2-mediated isotype switching. Exposure to a farming environment protects against IgE responses. OBJECTIVE: We reconstructed allergen-dependent switching patterns in vivo to identify the level or levels at which farm exposure acts to protect against atopy. METHODS: Serum IgG1 to IgG4 and IgE to grass (rPhl p 1 and rPhl p 5), cat (rFel d 1), and mite (rDer p 2) were assessed by means of ELISA in the Allergy and Endotoxin study population (812 children). Farm exposure was defined as currently living on a farm, exposure to stables/farm milk in the first year of life, or both. RESULTS: Farm exposure did not affect allergen-specific IgG2 and IgG3 levels but had complex allergen-specific effects on IgG1, IgG4, and IgE levels. Exposure protected against grass-specific responses at every step along the IgG1/IgG4/IgE switching pathway but had no significant effect on mite responses. Protection from cat responses was concentrated at the IgG1 level. For all allergens, failure to express IgG1 was associated with low prevalence of IgG4 or IgE responses. Notably, coexpression of IgG1, IgG4, and IgE to grass was associated with increased risk of allergic disease and higher IgE levels compared with production of IgG1 and IgE without IgG4, suggesting IgG4 coexpression marks stronger activation of T(H)2-dependent events. CONCLUSION: The protective effects of farm exposure were confined to T(H)2-dependent IgG1, IgG4, and IgE expression and were allergen and switch stage specific, suggesting that distinct mechanisms regulate individual steps within allergen-induced class switching in vivo. CLINICAL IMPLICATIONS: Environmental interventions to prevent IgE expression might need to be tailored to specific allergens.     

Dichotomy of food and inhalant allergen sensitization in eosinophilic esophagitis

BACKGROUND: Eosinophilic esophagitis (EE) is an emerging condition where patients commonly present with symptoms of gastroesophageal reflux disease and fail to respond adequately to anti-reflux therapy. Food allergy is currently recognized as the main immunological cause of EE; recent evidence suggests an etiological role for inhalant allergens. The presence of EE appears to be associated with other atopic illnesses. OBJECTIVES: To report the sensitization profile of both food and inhalant allergens in our EE patient cohort in relation to age, and to profile the prevalence of other allergic conditions in patients with EE. METHOD: The study prospectively analyzed allergen sensitization profiles using skin prick tests to common food allergens and inhalant allergens in 45 children with EE. Patch testing to common food allergens was performed on 33 patients in the same cohort. Comorbidity of atopic eczema, asthma, allergic rhinitis and anaphylaxis were obtained from patient history. RESULTS: Younger patients with EE showed more IgE and patch sensitization to foods while older patients showed greater IgE sensitization to inhalant allergens. The prevalence of atopic eczema, allergic rhinitis and asthma was significantly increased in our EE cohort compared with the general Australian population. A total of 24% of our cohort of patients with EE had a history of anaphylaxis. CONCLUSION: In children with EE, the sensitization to inhalant allergens increases with age, particularly after 4 years. Also, specific enquiry about severe food reactions in patients presenting with EE is strongly recommended as it appears this patient group has a high incidence of anaphylaxis.     

Association between sensitized to food allergens and childhood allergic respiratory diseases in Taiwan

BackgroundSensitization to allergen has long been known to be relate to childhood allergic diseases. Polysensitised children have more severe atopic diseases, whereas allergic rhinitis or asthma children with cosensitized to food and inhalant allergens were under-researched.ObjectiveTo realize the association between sensitization to food allergens and pediatric allergic rhinitis and asthma in Taiwan.MethodsWe included 138 participants with sensitized to allergen as assessed by serum-specific IgE. 87 of 138 participants had allergic rhinitis and 51 participants had asthma. All participants underwent a physical examination and measurement of serum total and specific IgE values. Besides, nasal peak expiratory flow rate (nPEFR) that was performed by the participants with allergic rhinitis and were requested to complete the Pediatric Rhinoconjunctivitis Quality of Life Questionnaires (PRQLQ). Lung function test and asthma control test (ACT)/child asthma control test (C-ACT) were performed by the participants with asthma.Results39 of 87 allergic rhinitis participants with sensitized to food and inhalant allergens (AR food group), 48 of 87 allergic rhinitis participants with sensitized to inhalant allergen alone (AR inhalant group). The AR food group had significantly lower nPEFR values and higher total IgE values (p < 0.05) compared with the AR inhalant group. The AR food group had higher PRQLQ scores than the AR inhalant group. 24 of 51 asthma participants with sensitized to food and inhalant allergens (Asthma food group), 27 of 51 asthma participants with sensitized to inhalant allergen alone (Asthma inhalant group). The Asthma food group had significantly higher total IgE values (p < 0.05) compared with the Asthma inhalant group. The Asthma food group had lower lung function test values and asthma control test (ACT) scores than the other group.ConclusionsChildren with cosensitized to food and inhalant allergens have more severe clinical symptoms and abnormal laboratory findings. Sensitization to food allergen was more related to pediatric allergic rhinitis than asthma. We may need larger, longer and extended studies to confirm these findings.     

Predictivity of allergic sensitization (RAST) for the onset of allergic diseases in adults

Background:  Specific IgE antibodies are often detected without any clinical manifestation of allergies. We aimed to analyse the predictivity of allergic sensitization for incident symptoms of allergic diseases in adults during a 10-year follow-up .
Methods:  In 1994/95 specific IgE antibodies against five common inhalant allergens (grass pollen, birch pollen, house dust mite, cat dander and Cladosporium ) were diagnosed by radioallergosorbent test in 4178 adults aged 25–74 years. A subset of 2656 participants could be re-evaluated in 2004/05. Information on socio-economic factors and medical history, including data on atopic diseases, was assessed by a combination of a personal interview and a self-administered questionnaire. Logistic regression models were applied to study associations between allergic sensitization and incident allergic diseases.
Results:  Allergic sensitization was an important predictor for incident hay fever (OR 7.95, CI 95% 4.64–13.62) and asthma (OR 1.82, CI 95% 1.29–2.57). Specific IgE antibodies were mainly related to outdoor allergens (grass and birch pollen) for hay fever and indoor allergens (mite and cat dander) for asthma, while for atopic dermatitis no specific IgE antibodies were identified as major predictors.
Conclusions:  Allergic sensitization not only covers clinically apparent allergies, but indicates a prognostic factor for later allergies, even in adulthood.     

Association between the occurrence of the anticardiolipin IgM and mite allergen-specific IgE antibodies in children with extrinsic type of atopic eczema/dermatitis syndrome

BACKGROUND: As the literature has only controversial data on the role of nonallergen-specific antibodies in atopic eczema dermatitis syndrome, the authors investigated the link between the occurrence of the antiphospholipid [anticardiolipin (ACL), anti-beta2-glycoprotein I] and allergen-specific immunoglobulin E (IgE) antibodies in 72 children with atopic eczema/dermatitis syndrome (AEDS). METHODS: The measurement of antiphospholipid antibodies was carried out by enzyme-linked immunosorbent assay (ELISA), serum total IgE by nephelometry, and allergen-specific IgE by immunoblotting assay. The statistical analysis was carried out by Fisher's exact test and odds ratio was calculated. RESULTS: Thirteen of 72 children with AEDS (mean age 8.3 years) had elevated serum levels of ACL, and eight anti-beta2-glycoprotein I antibodies. The presence of allergen-specific IgE against inhalant allergens and nutritive allergens was among eight of 13 and three of eight in the cases with elevated ACL. The ratio of patients with highly increased severity scoring of atopic dermatitis (SCORAD) index (>75) was significantly higher in the group with elevated (4/13) than in those with the normal ACL levels (2/59). There was a significant association between the appearance of mite (Dermatophagoides pteronyssinus, D. farinae)-specific IgE and ACL IgM antibodies (6/13). CONCLUSION: These findings show that there are significant linkage and association between the appearance of ACL IgM or the production of allergen-specific IgE against inhalant (mainly mite) allergens in children with atopic eczema/dermatitis syndrome.     

Rhinoconjunctivitis in 5-year-old children: a population-based birth cohort study

BACKGROUND: There is a paucity of data on the prevalence, risk factors and natural history of rhinitis in early childhood. OBJECTIVE: Within the context of a whole-population birth cohort we investigated the prevalence of and risk factors for current rhinoconjunctivitis (CRC) at age 5 years. METHODS: Children were followed prospectively to age 5 years [questionnaires (n = 815), skin testing (n = 717), specific immunoglobulin E (n = 478), lung function (n = 711), dry air challenge (n = 556)]. Endotoxin and allergen exposures were measured in dust samples. RESULTS: The prevalence of rhinitis ever, current rhinitis and rhinoconjunctivitis was 28.2%, 26.1%, and 12.1%, respectively. Asthma, wheeze and eczema coexisted with CRC (P < or = 0.01). In a multivariate model, maternal asthma (OR 2.38, 95% CI: 1.30-4.38, P = 0.005), paternal hay fever (1.96, 1.11-3.46, P = 0.02) and sensitization to grass (3.46, 1.86-6.42, P < 0.001) and cat (2.42, 1.14-5.18, P = 0.02) remained significant and independent associates of CRC. Whilst almost half of children with CRC were nonatopic, there was little difference in risk factors between atopic and nonatopic CRC. Amongst children with current wheeze, the presence of concurrent CRC had no effect on either severity or frequency of wheezy episodes. There was no difference in specific airway resistance, forced expiratory volume in 1 second (FEV(1)) or airway reactivity between children with and without CRC after adjustment for the presence of wheeze. CONCLUSION: Family history of allergic disease and sensitization to inhalant allergens are risk factors for rhinoconjunctivitis in preschool children. In this age group, there is no association between the presence of rhinoconjunctivitis and severity of wheeze, increased airway reactivity and reduced lung function.     

过敏性鼻炎患儿过敏原特异性IgE检测与临床意义

目的 了解过敏性鼻炎儿童主要过敏原分布情况及特点,以指导临床防治.方法 采用免疫印迹法体外定量检测患儿血清中特异性IgE抗体及20种常见过敏原.结果 938例过敏性鼻炎患儿中,100%至少对一种以上的过敏原呈阳性反应,其中487例患儿总IgE〉400IU/Ml,230例患儿总IgE在200IU/ml~400IU/ml之间.在检测20种过敏原中以户尘螨和屋尘的阳性率最高（90.0%,80.8%）.结论 过敏性鼻炎患儿至少有一种特异性IgE抗体显著增加,户尘螨、屋尘、动物皮屑、羊肉和牛奶是引起儿童过敏性鼻炎的主要过敏原.儿童在春秋温暖季节易发过敏性鼻炎.     

The association of sensitization to inhalant allergens with allergy symptoms: the influence of bronchial hyperresponsiveness and blood eosinophil count

BACKGROUND: We investigated whether the association of allergy symptoms with sensitization to inhalant allergens depends on bronchial hyperresponsiveness, blood eosinophil count, or the degree and nature of sensitization. METHODS: Data on asthma and rhino-conjunctivitis symptoms were obtained from 1904 subjects from a random sample of the Dutch population, aged 20-70 years by the ECRHS questionnaire. Total IgE and specific IgE to four inhalant allergens were measured using CAP System. Bronchial hyperresponsiveness (BHR) was defined as PD20 相似文献   

Some immunological aspects of patients with rhinitis in Lebanon

Background: Hitherto immunological determinates in Lebanese patients with rhinitis have not been investigated.

Objective: To identify causative allergens in Lebanese patients with allergic rhinitis and determine possible correlation's among serum allergen specific antibody, polyclonal IgE, IL-4, IL-5 and peripheral eosinophil levels.

Methods: One hundred and thirteen patients with a long lasting history of nasal obstruction, rhinorrhea, sneezing and nasal itching were investigated. Serum allergen specific antibodies using a panel of 10 potential allergens, IL-4 and IL-5 levels were determined by enzyme immunoassays. Polyclonal IgE levels were estimated by an immunochromatographic assay and eosinophil counts by a Coulter STKS counter.

Results: Based on the presence of serum allergen-specific IgE antibodies, 74 patients were considered to have an allergic etiology. Polyclonal IgE levels were elevated in 41 of the 74 allergic rhinitis patients while the other 33 patients had normal serum levels. In the remaining 39 specific IgE antibody-negative patients, 32 had normal, and 7 had elevated, polyclonal IgE levels. IgE specific antibodies to more than one allergen were detected in 59 of 74 patients. The most common causative allergens were mite, Dermatophagoides pteronyssinus, Dpt (83.8%) and Dermatophagoides farinae, Df (78.4%). Analysis of the data indicated that elevated polyclonal IgE levels correlated with the concentration of serum specific IgE antibodies and the number of the detected causative allergens per patient. Fifty-nine of 74 allergic rhinitis patients had elevated IL-4 levels and 44 had elevated IL-5 levels. The number of allergic patients with both elevated IL-4 and IL-5 levels was 24. Finally, only 9 allergic rhinitis patients had peripheral eosinophilia.

Conclusion: Mite Dpt and Df were the most common causative agents of allergic rhinitis in the Lebanese group studied. A prerequisite for Specific Immunotherapy is the identification of the causative allergen. Determinations of polyclonal IgE level and peripheral eosinophil count alone, as an aid to diagnosis are insufficient and may be misleading. On the other hand, determination of all the parameters studied in conjunction appears to be of diagnostic value.     

Evaluation of the nasal provocation test for its necessity in the diagnosis of nasal allergy to house dust mite

The aim of this study was to evaluate rhinomanometric responses to nasal allergen provocation in children with allergic rhinitis sensitized to house dust mite. We studied 51 children, aged 6-16 years (mean: 11.5 +/- 2.6 years), with clinical symptoms of perennial allergic rhinitis without asthma and 20 non-atopic healthy controls in the same age range (mean: 11.8 +/- 3.8 years). All of the patients had positive skin prick test (SPT) results and serum specific IgE above 0.70 kU/l to Dermatophagoides pteronyssinus (Dp). Nasal provocation testing (NPT) was performed with increasing concentrations of Dp extracts and the nasal response was evaluated by active anterior rhinomanometry. A 100% increase of resistance in one or both nasal cavities was considered positive. There was a statistically significant difference of baseline nasal resistance (total, right and left sides) between the control and the patient groups (p < 0.001). A positive response to house dust mite allergens was recorded in 47/51 (92.2%) patients by rhinomanometry. The NPT presented no significant correlation with age, weight, height, SPT diameter, serum total and specific IgE levels to Dp and baseline nasal airway resistance values. This study suggests that a nasal provocation test with allergen is unnecessary in children with positive skin prick test and serum IgE specific to house dust mite. The rhinomanometric response to the allergen provocation does not correlate with the diameter of the skin prick test and the level of serum specific IgE.     

Skin prick tests and specific IgE in adults from three different areas of Sweden

The aims of this part of the European Respiratory Health Survey were to estimate the prevalence of atopic sensitization to inhalant allergens among adults in three different areas of Sweden and to investigate the association between sensitization and certain risk factors. Randomly selected subjects aged 20–46 years from Göteborg, Uppsala, and Västerbotten were investigated with the skin prick test (SPT), analyses for specific IgE antibodies in serum (specific IgE) and total serum immunoglobulin E (total IgE), and a questionnaire. SPT was performed in 1572 subjects and analyses of specific IgE in 1470. One or more positive SPT were found in 35.6% and one or more positive specific IgE in 31.7% - approximately the same values in all three areas. Birch, grass, cat, and dog were the most frequent sensitizing agents and occurred at similar prevalences, i.e., around 15%, in all areas. The SPT to mite was positive in 14.1% in Göteborg, 7.4% in Uppsala, and 7.9% in Västerbotten. A positive SPT to pellitory of the wall ( Parietaria ), not described previously in Sweden, was found in 3.4% in Göteborg. Living in Göteborg was independently associated with a higher risk of a positive SPT to mite and Parietaria. Heredity, male sex, and low age were independently associated with atopy. Birth in the Scandinavian countries was independently associated with sensitization to cat, whereas birth in other countries was associated with sensitization to mite. The overall prevalence of atopy was similar in the three Swedish areas, but the sensitizing allergens varied. There is an indication that sensitization is increasing in the population, as low age was associated with sensitization. Sensitization to cat, but not to mite, appears to be particularly important in persons born in the Scandinavian countries.