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PubMed2000

Family history of atopy and clinical course of RSV infection in ambulatory and hospitalized infants.

Respiratory syncytial virus (RSV) infection can be severe in pediatric patients. Risk factors for severe disease include age less than 6 months, prematurity, preexisting heart or lung disease or malformations, gastroesophageal reflux, and immunodeficiency. The aim of the present study was to investigate the influence of family history of allergy on the clinical course of RSV infection in ambulatory and hospitalized infants. In a retrospective study, 172 patients younger than 12 months of age (99 inpatients and 73 outpatients) were enrolled. Information was obtained from hospital charts and from questionnaires sent to pediatricians. Inpatients had a significantly higher rate of atopy in their family history than outpatients, 62% and 29%, respectively (P < 0.001). Bronchiolitis was diagnosed more frequently in patients with an atopic burden than those without, 89% versus 74%, respectively (P < 0.02). Inpatients with an atopic family history had a significantly longer hospital stay than those without such a history, 7.4 +/- 3.7 days and 6.1 +/- 2.3 days, respectively (P < 0.04). Factors other than age that are considered a risk for severe infection with RSV (prematurity, preexisting heart or lung disease or malformation, and gastroesophageal reflux) were not confirmed in the present study. We conclude that infants with a family history of atopy are at increased risk for severe RSV infection as indicated by higher rates of hospitalization, longer hospital stay, and more frequent occurrence of bronchiolitis.

Bronchiolitis↗
PubMed2004

Working Group report 3: sensitivity to organic dusts--atopy and gene polymorphisms.

Working Group 3 (Sensitivity to Organic Dusts-Atopy and Gene Polymorphisms) was convened to review the current understanding of how effects of inhaled organic dust may be modified by genetic factors-both those that increase as well as those that may reduce susceptibility. Furthermore, the group was asked to suggest areas that require more investigation in this field. The discussion focused on individual sensitivity to inhaled agents as the most important determinant of inter-individual heterogeneiety in responses to exposures. Genetic modifiers are known for a number of pathologic conditions (including asthma, atopy, chronic obstructive pulmonary disease, and hypersensitivity pneumonitis) associated with inhalation of organic dusts; modifiers are likely to be identified for a number of other disease states. Further studies are required to delineate more precisely the contribution (and the role in inflammatory cascade modulation) of these known polymorphisms, as well as to identify novel genetic factors.

Asthma↗
PubMed1986

The role of atopy in potroom workers' asthma.

A study was performed to clarify a possible role of atopy in the occurrence of acute bronchoconstrictive impairment observed in some workers in a plant using the Alu-Swiss process for the electrolytic extraction of aluminum. Of 227 workers examined the percentage of those with a history of atopy and positive skin tests for common allergens was within the expected range. Six had positive patch test with 2% NaF. Among seven workers with paroxysmal wheezing and dyspnea, of whom three were only light smokers, three had positive skin test with common allergens but only one of them had an increased IgE value. The same worker also had positive patch test for 2% NaF. The average age of workers with paroxysmal wheezing and dyspnea was 32.6 years, and only two had symptoms defined as chronic bronchitis. Although their forced expiratory volumes, with two exceptions, measured at the beginning of work shift were within normal limits, in most of those workers bronchial hyperreactivity was also objectively assessed using nonspecific bronchoprovocative tests with histamine (or metacholine). The results support our previous findings that acute respiratory impairment in some workers is most probably based on bronchial hyperreactivity and not on an allergic mechanism.

Adult↗
PubMed1992

Respiratory disorders and atopy in cotton, wool, and other textile mill workers in Denmark.

A cross-sectional study of respiratory disorders and atopy in Danish textile industry workers was conducted to survey respiratory symptoms throughout the textile industry, to estimate the association of these disorders with atopy, and to study dose-response relationships within the cotton industry. Workers at cotton mills, a wool mill, and a man-made fiber (MMF) mill were examined. Four hundred nine (90%) of the 445 workers participated in this survey, i.e., 253, 62, and 94 workers at the cotton mills, the wool mill, and the MMF mill, respectively. An interview designed to assess the prevalence of common respiratory and allergic symptoms was given to all workers willing to participate, and blood samples were drawn. Lung function measurements determined a baseline FEV1, FVC and the change in FEV1 and FVC during work hours on a Monday. The working environment was examined for dust, bacteria, endotoxins, and molds, and the exposure was estimated for each participant. The mean personal samples of airborne respirable dust and respirable endotoxin were highest in the cotton industry, i.e., 0.17-0.50 mg/m3 and 9.0-126 ng/m3 respectively, whereas mold spores were found in the highest concentrations in the wool mill: 280-791 colony-forming units (cfu)/m3. Only small concentrations of microorganisms were found in the MMF mill. The mean change in FEV1% and FVC% was greatest among atopic individuals in both cotton and wool industry and other textile industries although the differences were not significant. FEV1% and FVC% in the cotton workers were significantly associated with the cumulative exposure to respirable endotoxin. Byssinosis was diagnosed only in the cotton industry. We found a dose-response relationship between endotoxin exposure and byssinosis, and a significant association between A-1-A serum concentrations less than or equal to 35 mumol/liter and byssinosis, a finding we are further evaluating in subsequent studies.

Animals↗
PubMed2001

Detection of parent-of-origin effects for atopy by model-free and model-based linkage analyses.

Parent-of-origin effects for atopy were investigated by a model-free affected sib-pair (ASP) method and two model-based approaches in the Busselton nuclear families. Among the regions showing potential linkages to atopy by the ASP method, a significant excess of paternal allele sharing as compared with maternal allele sharing was observed for a cluster of three markers on chromosome 13. The two model-based methods, which specify either sex-specific recombination rates or different penetrances for heterozygotes according to the parental origin of disease allele (imprinting), led to the same results, both suggesting a paternal effect. Thus, these two ways of modelling parent-of-origin effects appear equivalent in nuclear family data. Further simulations are needed to investigate whether the mechanisms underlying parent-of-origin effects can be distinguished in larger pedigree structures.

Adult↗
PubMed2002

Distribution in allele frequencies of predisposition-to-atopy genotypes in Chinese children.

Asthma is one of the most common chronic diseases in childhood; it is caused by a complex interaction between genetic factors and exposure to environmental allergens and irritants. Previous studies using the candidate gene approach showed that asthma was linked to a number of susceptibility genetic loci in Caucasian subjects. There are, however, only a few studies on asthma predisposition genes in the Chinese population. We studied the distribution of allele frequencies of I50V for the interleukin-4 receptor, two polymorphisms in intron 2 and exon 7 for the high-affinity IgE receptor (Fc epsilon RI-beta), R16G and E27Q for the beta(2)-adrenoceptor,and R275Q (824G/A) for CC chemokine receptor 3 in Chinese children.Seventy-six patients, with a mean age of 10.6 years, and 70 age- and sex-matched controls, were studied. Significantly more subjects in the asthma group had specific IgE antibodies against environmental allergens (P < 0.0001; odds ratio, 9.82). Genotyping of the six genetic markers showed that none of the six polymorphisms was associated with asthma in this cohort. The allele frequencies of I50V, R16G, and E27Q in our population were similar to those published for Asian subjects but not Caucasians. The R275Q substitution was a rare finding in our study and in the published reports. Our results demonstrate ethnic differences in polymorphisms of atopy candidate genes. Additional studies involving larger samples are required to investigate the association between asthma or atopy and the genotypes studied to date in Chinese children.

Asthma↗
PubMed1996

Non random usage of T cell receptor alpha gene expression in atopy using anchored PCR.

The T cell receptor (TCR) alpha beta heterodimer recognises antigenic peptide fragments presented by Class II MHC. This interaction initiates T cell activation and cytokine release with subsequent recruitment of inflammatory cells. Previous work from our group suggests a qualitative difference in variable alpha gene expression in atopy as compared to non atopic controls. In this study we examine TCR alpha repertoire using anchored PCR to provide a quantitative assessment of the V alpha and J alpha repertoire. One atopic (DRB1*0701,DRB1*15: DRB4*0101, DRB5*01: DQB1* 0303, DQB1*601/2) and one non-atopic (DRB1*0701,DRB1*03011/2: DRB4*01, DRB3*0x: DQB1* 0303, DQB1*0201/2) control were studied. Variable gene usage was markedly limited in the atopic individual. V alpha 1, 3, 8 accounted for 60% and J alpha 12, 31 30% of the gene usage. There was evidence of preferential V alpha-J alpha gene pairing and clonal expansion. We conclude that there is a marked non random TCR alpha gene distribution in atopy using both V alpha family and anchored PCR. This may be due in part to antigen driven clonal expansion.

Gene Expression↗
PubMed1987

Bleeding time and PAF-acether-induced platelet aggregation in atopy.

In a double-blind cross-over study 20 mg of aspirin or placebo were administered to 18 patients with respiratory atopy without eczema and to 12 healthy controls. Mean bleeding time before administration of either aspirin or placebo was on average about 1 min. longer in atopics than in the controls, and this difference was significant (p 0.05). Atopics' platelets also aggregated less well in response to arachidonic acid in comparison to controls. On the contrary, no difference in platelet aggregability was detected in response to either PAF-acether alone or to combination of subthreshold, synergistic concentrations of PAF-acether and collagen. Aspirin at a dose used did not affect either bleeding time or platelet aggregability. Thus, in respiratory atopy there exists a moderate hemostatic imbalance, the reason of which remains to be established.

Adult↗
PubMed1996

Prospective study of the atopy preventive effect of maternal avoidance of milk and eggs during pregnancy and lactation.

UNLABELLED: The preventive effect of maternal avoidance of cow's milk and eggs on the development of atopic dermatitis and sensitization to food allergens was studied in a prospective trial with families at high risk for atopy, intervention included encouraging exclusive breast feeding for at least 3 months and delaying the controlled introduction of solid foods. In addition, one group received a maternal diet with the complete avoidance of milk and eggs in the last trimester of pregnancy and during the period of exclusive breast feeding, another group had the same diet starting after delivery, and mothers of the third group had no dietary restrictions. The period prevalences of atopic dermatitis as well as the rates of specific sensitization to eggs and milk at 6 and 12 months were not significantly different between groups. We were unable to demonstrate a significant preventive effect of maternal diet. CONCLUSION: While breast feeding should be promoted for children at risk for atopy, mothers can be encouraged to stay on normal diet during pregnancy and the breast feeding period.

Animals↗
PubMed2002

Atopy Patch Test (APT)--its role in diagnosis of food allergy in atopic dermatitis.

During the past few years, the Atopy Patch Test (APT) has become a valuable additional tool in the diagnostic work-up of food allergy in infants and children with atopic dermatitis. A positive APT may help to prevent restrictive and unnecessary diets which may be the consequence of misjudging late reactions by clinical assessment alone. Furthermore, the combination of positive atopy patch tests together with defined levels of specific IgE (cow milk = 0.35 kU/l and egg = 17.5 kU/l) makes DBPCFC superfluous for suspected milk and egg allergy. However, several open questions indicate the need for further studies.

Dermatitis, Atopic↗
PubMed2005

Effects of common atopy-associated amino acid substitutions in the IL-4 receptor alpha chain on IL-4 induced phenotypes.

The human IL-4 receptor alpha chain gene (IL4R) is highly polymorphic and controversial reports have been published with respect to the association of different single nucleotide polymorphisms (SNPs) with atopy markers. Here we analyzed the functional and associational relevance of common IL4R coding SNPs. Transfection of B cell lines expressing the IL-4R variant V75+R576 did not result in enhanced IL-4 induced CD23 expression compared to cell lines expressing the wild type IL-4R alpha chain. Transfection of the IL-4R variant P503 into a murine T cell line did not influence IL-4 induced T-cell proliferation compared to wild type constructs. Analysis of six IL4R coding SNPs (I75V, E400A, C431R, S436L, S503P, Q576R) and common haplotypes (frequency >/=0.05%) in blood donors (n=300) did not indicate a significant association with elevated serum IgE level. Moreover, the most informative IL4R coding SNPs (I75V, C431R, Q576R) and related two- and three-point haplotypes (frequency >/=0.05%) were analyzed in a second, extended group of blood donors (n=689). Again, no significant association with elevated serum IgE was detectable. We conclude that common coding SNPs in the IL4R gene are unlikely to contribute significantly to increased IgE levels and variations outside the coding region may influence atopy susceptibility.

Amino Acid Substitution↗
PubMed2003

Relationships between atopy and bacterial infections.

Atopy in its most common forms (asthma, allergic rhinitis, and atopic dermatitis) has a significant impact on society in terms of health care costs and quality of life. Aside from having significant morbidity from these diseases, patients with atopy have also been noted to have a high incidence of comorbidities, including bacterial infections such as otitis media and sinusitis. In this paper, current evidence is reviewed that supports the close associations among allergic rhinitis and the two commonly diagnosed bacterial diseases, otitis media and sinusitis.

Asthma↗
PubMed1992

Atopy and environmental factors in upper respiratory infections: an epidemiological survey on 2304 school children.

Upper respiratory infections (URI) during the first years of life are mostly viral in origin. However, a number of observations suggest the influence of both predisposing and triggering factors. Atopy in particular seems to play an important role as do environmental factors. Many children with early symptoms such as blocked or runny nose are likely to become skin-positive later in life to antigens such as, e.g., D. pteronissinus. A standardized questionnaire was administered to 2304 schoolchildren in order to ascertain the URI frequency and to correlate it with family and environmental factors and with results of prick tests for main allergens in our climate (D. pteronissinus and Grasses). Results showed a wide overlapping of URI and lower respiratory illnesses (in particular, asthma), which are widely distributed in the families of patients. Passive smoking and the quality of housing are the main triggering environmental factors. In our sample, skin positivity for D. pteronissinus and Grasses largely exceeds the symptomatic portion of the whole population. It is therefore suggested that many asymptomatic children are "at risk" for allergic respiratory illness. The highest incidence of winter rhinitis in skin-negative subjects (71.7%) and the skin positivity for D. pteronissinus in patients with perennial symptoms, suggest the importance of both atopy and viral infections in the occurrence of URI. Nasal troubles are most frequent in asthmatic subjects and may be considered the actual additional symptom in asthma.

Adolescent↗
PubMed1994

Atopy as a risk factor for cryptogenic fibrosing alveolitis.

In a case-control study of occupational and environmental causes of cryptogenic fibrosing alveolitis we recently observed a higher prevalence of self-reported symptoms of wheeze, rhinitis or conjunctivitis in cases than in controls. To determine objectively whether this was due to a higher prevalence of atopy amongst cases of CFA, we have measured skin sensitivity to common allergens (D. Pteronyssinus, grass pollen, and cat fur), eosinophil counts and total Immunoglobulin E (IgE) in venous blood in the 22 surviving CFA cases from that study who were willing to provide a blood sample, and in one matched control per case. At least one positive skin test was recorded in 13 cases and six controls, the matched odds of one or more positive test being significantly increased in cases by a ratio of 8.0 (95% confidence interval 1.01-64, P = 0.05). Geometric mean eosinophil counts and IgE levels were also increased amongst cases by factors of 1.6 (95% CI 0.96-2.6) and 1.9 (0.9-3.8) respectively, although these differences were not significant. Differences in skin sensitivity, eosinophil counts, and IgE levels all tended to be more obvious in the 13 case control pairs in which the case was not taking steroids or other immunosuppressive treatment. We conclude that cases of CFA showed increased skin sensitivity to common allergens, and had evidence of increased IgE and eosinophilia in peripheral blood. These findings suggest that atopy may be an important determinant of susceptibility to CFA.

Aged↗
PubMed2006

Intestinal microbiota and its effect on the immune system--a nested case-cohort study on prevention of atopy among small children in Trondheim: the IMPACT study.

BACKGROUND: In the past 20-30 years, the prevalence of atopic diseases, particularly among children in the Western world, has increased. It has been suggested that Western lifestyle may have reduced the overall exposure to microbial stimulation early in life. The role of the gut flora in this connection has been studied, but prospective studies are in demand. Within the frame of a comprehensive controlled prospective primary prevention study of atopy and allergic diseases with the aim to reduce the incidence of atopy and allergic diseases among children from birth to six years, a nested case-cohort study is established, "The IMPACT study". AIM: The aim of "The IMPACT study" is to study the impact of gut microbiota composition on cytokine profile development, and on development of atopic disease. DESIGN: Information on risk factors and on disease, together with biological specimens, will be collected prospectively, and analysed in a nested case-cohort design. METHOD: 720 pregnant women are recruited from the control-cohort in the PACT study. The composition of the infant gut microbiota is analysed in stool samples from all children with atopic disease, and randomly selected children sensitized and not sensitized at age 2, at 4, 7, 10 days after birth, and at age 4, 12 and 24 months. 16S rDNA hybridisation technique will be used to specify and quantify the microbial composition in faeces. Cord blood from the same children and venous blood at age 10 days, 4, 12 and 24 months are collected to study the cytokine profile at different ages, in relation to microbial stimulation. Peripheral blood mononuclear cells (PBMC) are stored in liquid nitrogen, and faeces are stored at -80 degrees C. Atopic children will be identified by questionnaire, and the diagnosis confirmed by paediatric examination at age 2 years.

Bifidobacterium↗
PubMed2006

Asthma, atopy, and lung function among racially diverse, poor inner-urban Minneapolis schoolchildren.

As part of an assessment of schoolchildren's environmental exposures and health, a probability sample of 136 children from diverse racial/ethnic backgrounds was drawn from grades 2-5 of two inner-urban Minneapolis schools (Whittier, Lyndale). Questionnaires were administered to a parent/guardian; blood samples for IgE and lung function tests were obtained. Overall adjusted rates for lifetime asthma (15.4%; 95%CI 9.3-21.5%), asthma in the last 12 months (13.6%; 7.8-19.4%), and current asthma medication use (10.5%; 5.3-15.7%) were higher than reported US national rates. Adjusted rates for lifetime physician-diagnosed asthma differed significantly among racial/ethnic groups (P<0.01): African-Americans (25.9%), White/Others (25.8%), Hispanics (9.3%), Somalis (1.8%), Asians (0%). Corresponding rates for atopy (total IgE>100 IU/mL or an allergen-specific IgE>0.35 IU/mL) were: African-Americans (66.6%), White/Others (100%), Hispanics (77.2%), Somalis (78.1%), Asians (81.8%). Lung function (FEV1, FVC) was analyzed by linear regression using log-transformed data: significant race-specific differences in lung function were found relative to White/Others (P<0.001 for each racial/ethnic group): African-Americans (FEV1 -16.5%, FVC -16.9%), Somalis (-22.7%, -26.8%), Hispanics (-12.2%, -11.4%) and Asians (-11.1%, -12.4%). Females had significantly lower FEV1 (-8.8%) and FVC (-11.0%) than males. An unexplained, significant difference in children's lung function was found between the two schools. A history of physician-diagnosed asthma was not associated with decreased lung function. Factors other than poverty, inner-urban living, and IgE levels (atopy) need to be considered in the development of childhood asthma.

Asthma↗
PubMed2004

Presence and timing of cat ownership by age 18 and the effect on atopy and asthma at age 28.

BACKGROUND: Asthma and allergic sensitization to cats frequently coexist, although recent studies show less atopic disease among people who had pets in infancy. However, no longterm evaluations have been performed thus far. OBJECTIVE: We sought to evaluate the relationship between cat ownership at different age periods (< 18, > 18, and both periods and atopic disease at age 28. METHODS: Australian school children aged 8 to 10 years were recruited in 1982 and participated in follow-up surveys until 2002. Cat ownership was defined by surveys in 1992 and 2002 as having a cat before age 18 only, after age 18 only, or in both periods of life. Health outcomes were defined at a mean age of 28.5 years. RESULTS: Complete data were available for 224 subjects, 50 of whom had a cat before 18 years of age only, 14 after age 18 only, and 70 in both periods. Compared with 90 subjects that never had a cat, having a cat before age 18 protected against atopy to outdoor allergens, airway hyperresponsiveness (AHR) to histamine, current wheeze, and current asthma (P < .05). In contrast, subjects who acquired their first cat after age 18 showed a trend toward higher prevalence rates for asthma symptoms and AHR (P > .10). CONCLUSIONS: Having had a cat before 18 years of age protects against adult asthma and atopy.

Adolescent↗
PubMed2004

Effects of dog ownership and genotype on immune development and atopy in infancy.

BACKGROUND: Exposure to furred pets might confer protection against the development of allergic sensitization through a mechanism that is incompletely understood. OBJECTIVE: The objective of this study was to determine the effects of pet exposure and genotype on immunologic development and the incidence of atopic markers and diseases in the first year of life. METHODS: Pet exposure in the home was compared with cytokine secretion patterns (mitogen-stimulated mononuclear cells at birth and age 1 year) and indicators of atopy (allergen-specific and total IgE, eosinophilia, food allergy, atopic dermatitis) in 285 infants. Interactions with genotype at the CD14 locus were also evaluated in the data analyses. RESULTS: Exposure to dogs was associated with reduced allergen sensitization (19% vs 33%, P =.020) and atopic dermatitis (30% vs 51%, P <.001). The risk for atopic dermatitis was further influenced by genotype at the CD14 locus (P =.006), even after adjusting for exposure to dogs (P =.003). Furthermore, infants with the genotype -159TT were less likely to develop atopic dermatitis if they were exposed to a dog (5% vs 43%, P =.04). Last, dog exposure was associated with increased IL-10 (117 vs 79 pg/mL, P =.002) and IL-13 (280 vs 226 pg/mL, P =.013) responses at age 1 year. CONCLUSIONS: Having a dog in infancy is associated with higher IL-10 and IL-13 cytokine secretion profiles and reduced allergic sensitization and atopic dermatitis. These findings suggest that postnatal exposure to dogs can influence immune development in a genotype-specific fashion and thereby attenuate the development of atopy in at-risk children.

Adult↗