Association between body mass index and allergy in teenage girls in Taiwan

BACKGROUND: The prevalence of atopy and asthma is affected by age, sex and lifestyle factors. Obesity was reported to be a risk factor for asthmatic symptoms in children and adults. OBJECTIVE: To examine the relation between body mass index (BMI) and the prevalence of atopy, rhinitis, wheezing and bronchial responsiveness in adolescents. METHODS: BMI (kg/m2), skin-prick test, bronchial hyperresponsiveness (BHR) to methacholine, and self-reported rhinitis and airway symptoms were assessed in a cross-sectional survey in 1459 eighth-grade students (age 13.2 to 15.5, mean 13.6 years) of seven junior high schools in northern Taiwan. RESULTS: The prevalence of atopy was 42% in boys and 27% in girls. The study population was grouped into quintiles of BMI by sex. Girls in the highest BMI quintile had higher prevalence of atopy and rhinitis symptoms. Compared with the middle three quintiles, they had increased risk of atopy in multivariate analyses adjusted for area of living, sibling number, parent education level and family history of asthma (odds ratio = 1.77, 95% confidence interval = 1.15-2.73). Girls with the lowest BMI quintile had lower prevalence of BHR and wheezing. Compared with the middle three quintiles, they had reduced risk of BHR in multivariate analyses adjusted for area of living, atopy, family history of asthma, and baseline pulmonary function (odds ratio = 0.40, 95% confidence interval = 0.20-0.81). No association between BMI and atopy or BHR was seen in boys. CONCLUSION: BMI was a significant predictor of atopy, allergic symptoms and BHR in teenage girls.     

Prenatal paracetamol exposure and risk of asthma and elevated immunoglobulin E in childhood

BACKGROUND: We recently found that paracetamol (acetaminophen) use in late pregnancy was associated with an increased risk of early wheezing in the offspring. OBJECTIVE: To see whether use of paracetamol in late pregnancy is associated with an increased risk of asthma, wheezing and other atopic outcomes in the child at school age. METHODS: In the population-based Avon Longitudinal Study of Parents and Children, we measured associations of paracetamol and aspirin use in late pregnancy (20-32 weeks) with asthma, hayfever, eczema (n = 8511) and wheezing (8381) in the offspring at 69-81 months, and with atopy (positive skin prick test to Dermatophagoides pteronyssinus, cat or grass, n = 6527) and blood total IgE (n = 5148) at 7 years. We used logistic and linear regression to analyse binary outcomes and log-transformed IgE, respectively, controlling for potential confounders. RESULTS: Use of paracetamol, but not aspirin, in late pregnancy was positively associated with asthma (odds ratios (ORs), comparing children whose mothers took paracetamol 'sometimes' and 'most days/daily' with those whose mothers never took it, 1.22 (95% confidence interval (CI): 1.06-1.41) and 1.62 (95% CI: 0.86-3.04), respectively; P trend = 0.0037), wheezing (ORs 1.20 (95% CI: 1.02-1.40) and 1.86 (95% CI: 0.98-3.55), respectively; P trend = 0.011), and total IgE (geometric mean ratios 1.14 (95% CI: 1.03-1.26) and 1.52 (95% CI: 0.98-2.38), respectively; P trend = 0.0034), but not hayfever, eczema or skin test positivity. The proportion of asthma attributable to paracetamol use in late pregnancy, assuming a causal relation, was 7%. CONCLUSION: Paracetamol exposure in late gestation may cause asthma, wheezing and elevated IgE in children of school age.     

Bidirectional interactions between viral respiratory illnesses and cytokine responses in the first year of life

BACKGROUND: Viral infections are the major cause of acute wheezing illnesses in childhood. Variations in immunologic responses at birth may be determinants of the risk of acquiring these illnesses. OBJECTIVES: To determine the immunologic risk factors for virus-induced wheezing in high-risk infants. METHODS: The study involves 285 children with a parental history of asthma and/or respiratory allergies. Mononuclear cells obtained at birth (umbilical cord blood) and at 1 year of age were incubated with phytohemagglutinin, respiratory syncytial virus, or rhinovirus, and supernatants were analyzed for IL-5, IL-10, IL-13, and IFN-gamma. Nasal secretions obtained at well child visits and during respiratory illnesses were analyzed for common respiratory viruses. RESULTS: Respiratory syncytial virus-induced wheezing was associated with reduced phytohemagglutinin-induced IL-13 responses (medians, 213 vs 304 pg/mL; P = .026) from cord blood cells, and similar trends were found for wheezing in general. Furthermore, median IL-13 responses diminished by 28% in non-wheezing children by age 1 year, versus only 3% in wheezing children (P = .013). Children with > or =2 episodes of wheezing had lower phytohemagglutinin-induced IFN-gamma responses and were less likely to have rhinovirus-induced IFN-gamma responses at birth (P < .05). Finally, children with measurable cord blood IFN responses to respiratory syncytial virus were less likely to wheeze in their first year (odds ratio, 0.43 [0.23, 0.79]). CONCLUSION: In children with a family history of allergies and/or asthma, mononuclear cell phytohemagglutinin-induced IL-13 and virus-induced IFN-gamma responses at birth are indicative of the risk for wheezing in the first year of life.     

Asthma onset and relapse in adult life: the British 1958 birth cohort study.

BACKGROUND: Few studies have investigated adult-onset wheezing because of difficulties identifying childhood asthma or wheeze retrospectively. OBJECTIVE: To investigate risk factors for the incidence and recurrence of wheezing illness in adulthood. METHODS: British children born during 1 week in 1958 (N = 18,558) were followed up periodically. Information on wheezing illness was obtained via parental interviews at ages 7, 11, and 16 years and via cohort member interviews at ages 23, 33, and 42 years. At ages 44 to 45 years a subset (N = 12,069) was targeted for biomedical survey, and total IgE and specific IgE responses to grass, cat, and dust mite were measured. RESULTS: Incidences of wheezing illness at ages 17 to 33 and 34 to 42 years were positively associated with atopy (any specific IgE -0.3 kU/L) and cigarette smoking. For ages 17 to 42 years, proportions of incident "asthma" and incident "wheeze without asthma" associated with atopy, adjusted for sex and smoking, were estimated to be 34% (95% confidence interval [CI], 26%-42%) and 5% (95% CI, 1%-9%), respectively, whereas proportions associated with cigarette smoking, adjusted for sex and atopy, were estimated to be 13% (95% CI, 0%-26%) and 34% (95% CI, 27%-40%), respectively. Among participants with no reported wheezing illness at ages 17 to 23 or 33 years, wheeze prevalence at the age of 42 years was positively associated with symptoms in childhood. CONCLUSIONS: Onset and relapse of wheezing illness in adult life seem to be similarly affected by atopy and cigarette smoking, although the nature of these effects may differ between asthma and wheeze without asthma. Children who apparently "outgrow" early wheezing illness remain at increased risk for relapse or recurrence during midlife.     

Parental history of atopic disease and concentration of cord blood IgE

Background A family history of atopy, and cord blood immunoglobulin E concentration, have been shown to be predictors of atopic disease in children. Several studies have suggested that parental atopy may be related to newborn immunoglobulin E. Objective The purpose of our analysis was to evaluate whether parental history of allergic disease was associated with cord blood immunoglobulin E concentration. Methods The study subjects were from a defined population of 777 newborns delivered between 1987 and 1989. The mothers of these children completed a questionnaire during pregnancy concerning themselves and the child's father, including parental history of physician diagnosis of allergic diseases (allergies, hay fever and asthma). Total immunoglobulin E levels were quantitated in cord blood samples with an enzyme-hnked immunoassay. Results Median cord blood immunoglobulin E concentration was higher among infants whose mothers had a history of atopic disease, particularly for those with a history of asthma (P<0.022) and allergen immunotherapy (P<0.016) vs infants whose mothers had no history of any atopic disease. Comparing all babies with a maternal history of asthma, to babies where neither parent had a history of any atopic disease, the median cord blood immunoglobulin E was significantly higher (0.36IU/mL vs 0.21 IU/mL; P<0.009). This association was found only among female infants (0.49IU/mL vs 0.20 IU/mL; P<0.001). Conclusion Maternal, but not paternal, history of atopic disease was associated with an elevated immunoglobulin E among newborns. For maternal asthma, this association was only evident in infant girls.     

CD4+IL13+ T lymphocytes at birth and the development of wheezing and/or asthma during the 1st year of life

BACKGROUND: Despite our knowledge that maternal inheritance influences the development of asthma in childhood, attempts to identify a clear-cut Th2-oriented cytokine production by T lymphocytes at birth have given conflicting results. The prognostic significance of these cells for asthma development later in life remains to be determined. METHODS: We evaluated at the single cell level Th1- and Th2-type cytokines in 208 randomly selected cord blood mononuclear cell (CBMC) samples obtained from pregnant women (group A, n = 68 with diagnosed respiratory allergic disease; group B, n = 140, with no evidence of atopy), and prospectively followed newborns for 1 year. RESULTS: There was no difference in IFN-gamma, IL-4 and IL-5 production at birth between both groups, whereas a correlation between CD4+IL13+ lymphocytes from CBMC samples derived from atopic mothers and the occurrence of wheezing and/or asthma during the 1st year of life was found. CONCLUSIONS: Our observations suggest that the intracellular cytokine profile of cord blood CD4+ cells, in terms of IL-13 production, could be considered a useful tool for a more accurate identification of newborns from atopic mothers who are at high risk of developing asthma.     

Respiratory illnesses in early life and asthma and atopy in childhood

BACKGROUND: The relation between respiratory illnesses in early life and the development of asthma and atopy in childhood is incompletely understood. OBJECTIVE: We sought to examine the relationship between respiratory illnesses in early life and atopic diseases at school age. METHODS: We performed a prospective birth cohort study of the relationship between respiratory illnesses in the first year of life and asthma, atopy (sensitization to >or=1 allergen), and allergic rhinitis at school age in 440 children with a parental history of atopy. Logistic regression was used to examine the relationship between respiratory illnesses and asthma, atopy, and allergic rhinitis. The relationship between respiratory illnesses in early life and repeated measures of wheezing between the ages of 1 and 7 years was investigated by using a proportional hazards models. RESULTS: Physician-diagnosed croup (adjusted odds ratio [OR], 0.30; 95% CI, 0.12-0.72) and having 2 or more physician-diagnosed ear infections (adjusted OR, 0.58; 95% CI, 0.35-0.98) in the first year of life were inversely associated with atopy at school age. Physician-diagnosed bronchiolitis before age 1 year was significantly associated with asthma at age 7 years (adjusted OR, 2.77; 95% CI, 1.23-6.22). Recurrent nasal catarrh (>or=3 episodes of a runny nose) in the first year of life was associated with allergic rhinitis at age 7 years (adjusted OR, 2.99; 95% CI, 1.03-8.67). CONCLUSION: The relationship between early-life respiratory illnesses and asthma and atopy is complex and likely dependent on the type of infection and immune response it initiates. CLINICAL IMPLICATIONS: Certain respiratory illnesses in early life modify the risk of atopy and asthma at school age.     

Mouse allergen exposure, wheeze and atopy in the first seven years of life

Background: Little is known about mouse allergen exposure in home environments and the development of wheezing, asthma and atopy in childhood. Objective: To examine the relation between mouse allergen exposure and wheezing, atopy, and asthma in the first 7 years of life. Methods: Prospective study of 498 children with parental history of allergy or asthma followed from birth to age 7 years, with longitudinal questionnaire ascertainment of reported mouse exposure and dust sample mouse urinary protein allergen levels measured at age 2–3 months. Results: Parental report of mouse exposure in the first year of life was associated with increased risk of transient wheeze and wheezing in early life. Current report of mouse exposure was also significantly associated with current wheeze throughout the first 7 years of life in the longitudinal analysis (P = 0.03 for overall relation of current mouse to current wheeze). However, early life mouse exposure did not predict asthma, eczema or allergic rhinitis at age 7 years. Exposure to detectable levels of mouse urinary protein in house dust samples collected at age 2–3 months was associated with a twofold increase in the odds of atopy (sensitization to >=1 allergen) at school age (95% confidence interval for odds ratio = 1.1–3.7; P = 0.03 in a multivariate analysis. Conclusions: Among children with parental history of asthma or allergies, current mouse exposure is associated with increased risk of wheeze during the first 7 years of life. Early mouse exposure was associated with early wheeze and atopy later in life.     

Mode of delivery is not associated with asthma or atopy in childhood

BACKGROUND: Caesarean-section delivery has been associated with the subsequent development of atopy and wheezing in childhood. OBJECTIVE: To examine the association between mode of delivery (vaginal vs. caesarean section) and development of atopy, asthma and wheezing disorders in a population-based cohort of children. METHODS: The Avon Longitudinal Study of Parents and Children is a longitudinal birth cohort of children born 1 April 1991 to 31 December 1992. Mode of delivery was categorized as vaginal (including forceps and ventouse extractions) or caesarean section (elective and emergency). Primary outcomes were parental report of asthma or wheezing between 69 and 81 months of age, physician-diagnosed asthma (PDA) at 91 months of age and atopy at 7 years by skin prick testing. Possible confounding factors were considered in a multivariable logistic regression model. RESULTS: Total livebirths were 14,062, from which were selected 12 367 born to mothers resident in a defined area and delivered in one of two major obstetric hospitals. Of these infants, 10,980 (88.8%) were delivered vaginally and 1387 (11.2%) by caesarean section. Outcome data were available for 7495 (61%) subjects (asthma 69-81 months); 7389 (60%) (wheeze 69-81 months); 7196 (58%) (PDA 91 months) and 5916 (48%) (atopy 7 years). Adjusted odds ratios [95%confidence interval] for caesarean section compared with vaginal delivery were not statistically significant for any outcome we considered: asthma 69-81 months 1.16 [0.9, 1.5]; wheeze 69-81 months 0.95 [0.7, 1.3]; PDA 1.14 [0.9, 1.4]; atopy 1.04 [0.8, 1.3]. CONCLUSION: Delivery by caesarean section was not associated with the subsequent development of asthma, wheezing or atopy in later childhood in this population.     

Prednisolone reduces recurrent wheezing after a first wheezing episode associated with rhinovirus infection or eczema

BACKGROUND: Rhinovirus-induced early wheezing has been suggested as a new important risk factor for recurrent wheezing. OBJECTIVE: We sought to investigate the risk factors for recurrent wheezing and to determine post hoc the efficacy of prednisolone in risk groups. METHODS: We followed for 1 year 118 children (median age, 1.1 years) who had had their first episode of wheezing and had participated in a trial comparing prednisolone with placebo in hospitalized children. Demographics and laboratory data were obtained at study entry. The follow-up outcome was recurrent wheezing (3 physician-confirmed episodes). RESULTS: Recurrent wheezing was diagnosed in 44 (37%) children. Independent risk factors were age < 1 year, atopy, and maternal asthma. The probability of recurrent wheezing was higher in rhinovirus than respiratory syncytial virus (RSV)-affected children among placebo recipients (hazard ratio, 5.05; 95% CI, 1.00-25.41). Prednisolone decreased the probability of recurrent wheezing in children with eczema (0.15; 95% CI, 0.04-0.63) but not in those without eczema (1.89; 95% CI, 0.83-4.29; P = .007 for interaction). Prednisolone was associated with less recurrent wheezing in the rhinovirus group (0.19; 95% CI, 0.05-0.71), but not in the RSV (2.12; 95% CI, 0.46-9.76) or in the RSV/rhinovirus-negative groups (2.03; 95% CI, 0.83-5.00; P = .017 for interaction). CONCLUSION: Rhinovirus-induced early wheezing is a major viral risk factor for recurrent wheezing. Prednisolone may prevent recurrent wheezing in rhinovirus-affected first-time wheezers. The presence of eczema may also influence the response to prednisolone. CLINICAL IMPLICATIONS: A prospective trial is needed to test the hypothesis that prednisolone reduces recurrent wheezing in rhinovirus-affected wheezing children.     

Association of allergic symptoms in children with those in their parents

This study investigated the association of asthma, allergic rhinitis, and eczema in United Arab Emirates (UAE) schoolchildren with allergic conditions in their parents. A cross-sectional, population-based study among schoolchildren aged 6–14 years was conducted in Al-Ain City, UAE. The field survey was conducted from October 1992 to May 1993. A questionnaire was distributed to 850 UAE government school students from representative, randomly selected schools with a majority of UAE nationals. The student and both or either of the parents were present during the interview. A detailed clinical history of asthma and wheezing in the target children and a history of asthma and allergic rhinitis in their parents and siblings were obtained. It was found that 13.1% of asthmatic children had mothers with asthma (relative risk (RR) = 2.67; 95% confidence intervals (CI)= 1.65–4.35), and 15.2% had fathers who were asthmatic (RR = 2.85; 95% CI = 1.81–4.49). This contrasted with 4.4% of nonasthmatic children who had fathers with asthma, and 4.1% who had mothers with asthma. A similar pattern was seen with symptoms of allergic rhinitis when it was found that 34.3% of children who had asthma had mothers with allergic rhinitis (RR: 2.74; 95% CI: 1.90–3.94). The corresponding figure for fathers was 12.7% (RR: 0.92; 95% CI: 0.5–1.7). The frequency of either parent of the asthmatic children having allergic rhinitis was 28.6%; for both parents, it was 14.5%. It was also found that asthmatic children had 12.5% of their fathers, 32.8% of their mothers, 26.4% of either of their parents, and 33.3% of both their parents suffering from allergic rhinitis. Siblings of the asthmatic children were also studied to establish the relationship between allergic conditions in the siblings and asthma in the study sample. It was found that in the asthmatic study population the frequency of siblings having asthma was 31.9%; of those having allergic rhinitis, 21.3%; and of those having eczema, 16.1%. Twenty-nine percent of either of the parents of the children with eczema had the same condition, and the corresponding figure for allergic rhinitis was 36.5%. The prevalence rate of asthma in the schoolchildren studied increased dramatically to 22% when wheeze, asthma, or nocturnal cough were grouped together. When eczema and allergic rhinitis were also considered together along with the above, the rate increased to 31%. The size of the family did not seem to affect the parent/child association of allergic symptoms. Our findings indicate that there is a strong association between respiratory allergies and eczema in parents and in their asthmatic children, thereby indicating a strong genetic basis for the occurrence of asthma in particular and atopy in general.     

Atopy with recurrent wheezy bronchitis in children

Childhood asthma and wheezy bronchitis are the most frequent chronic diseases of childhood. Unfortunately their clinical symptoms are similar--which makes it difficult to distinguish between the two, and therefore decide on proper treatment of patients. The aim of the study was to establish the parameters leading to right diagnosis. The study was performed in 50 children aged 3-7 years with recurrent wheezy bronchitis. All patients underwent allergological examinations (skin tests with inhaled allergens, personal and family history and serum total and specific IgE levels). 42 of them were tested for ventilatory parameters with bronchodilatation test. Three features of atopy were found in 21 (42%) patients, two features in 7 (14%) patients. In 31 (62%) children at least one feature of atopy was shown. 7 (17%) of the examined children had significant bronchodilatation after salbutamol inhalation. Finally in 24 (48%) of children suffering from wheezy bronchitis, bronchial asthma was diagnosed. The diagnosis was confirmed by antiasthma tic treatment with cromones or inhaled corticosteroids. In great majority (88%) of patients bronchial asthma was atopic. In 23% wheezy bronchitis children not diagnosed with bronchial asthma features of atopy were observed. They are of bronchial asthma risk group.     

Exposure to dust mite allergen and endotoxin in early life and asthma and atopy in childhood

BACKGROUND: There has been no longitudinal study of the relation between concurrent exposure to dust mite allergen and endotoxin in early life and asthma and atopy at school age. OBJECTIVES: To examine the relation between exposure to dust mite allergen and endotoxin at age 2 to 3 months and asthma, wheeze, and atopy in high-risk children. METHODS: Birth cohort study of 440 children with parental history of atopy in the Boston metropolitan area. RESULTS: In multivariate analyses, early exposure to high levels of dust mite allergen (> or =10 microg/g) was associated with increased risks of asthma at age 7 years (odds ratio [OR], 3.0; 95% CI, 1.1-7.9) and late-onset wheeze (OR, 5.0; 95% CI, 1.5-16.4). Exposure to endotoxin levels above the lowest quartile at age 2 to 3 months was associated with reduced odds of atopy at school age (OR, 0.5; 95% CI, 0.2-0.9). In contrast with its inverse association with atopy, endotoxin exposure in early life was associated with an increased risk of any wheeze between ages 1 and 7 years that did not change significantly with time (hazard ratio for each quartile increment in endotoxin levels, 1.23; 95% CI, 1.07-1.43). CONCLUSION: Among children at risk of atopy, early exposure to high levels of dust mite allergen is associated with increased risks of asthma and late-onset wheeze. In these children, endotoxin exposure is associated with a reduced risk of atopy but an increased risk of wheeze. CLINICAL IMPLICATIONS: Early endotoxin exposure may be a protective factor against atopy but a risk factor for wheeze in high-risk children.     

Maternal asthma,infant feeding,and the risk of asthma in childhood

Controversy surrounds the issue of whether children with asthmatic mothers should be breast-fed. The aim of this study was to investigate whether maternal asthma status alters the association between asthma and breast-feeding. In a cohort study of 2602 West Australian children enrolled before birth and followed prospectively, we collected data on method of infant feeding, maternal asthma (as reported by parental questionnaire), atopy (as measured by skin prick test), and current asthma (defined as a physician's diagnosis of asthma and wheeze in the last year) at 6 years of age. The risk of childhood asthma increased if exclusive breast-feeding was stopped (other milk was introduced) before 4 months (odds ratio, 1.28; 95% CI, 1.01-1.62; P =.038), and this risk was not altered by atopy or maternal asthma status. After adjusting for covariates, exclusive breast-feeding for less than 4 months was a significant risk factor for current asthma (odds ratio, 1.35; 95% CI, 1.00-1.82; P =.049). There was no formal statistical interaction between breast-feeding and maternal asthma status (P =.970). In this study maternal asthma status did not modify the association between asthma and breast-feeding duration. We recommend that infants with or without a maternal history of asthma be exclusively breast-fed for 4 months and beyond.     

Serum concentrations of interferon-γ and intercellular adhesion molecule-1 eight years after an early respiratory syncytial virus infection

BACKGROUND: Respiratory syncytial virus (RSV) infection may influence the development of recurrent wheezing and atopy, but the mechanisms are unclear. OBJECTIVE: The purpose was to evaluate serum concentrations of soluble intercellular adhesion molecule-1 (sICAM-1), CD14, IgE, IL-5 and IFN-gamma in children 6-10 years after an RSV infection and their correlation with subsequent asthma and atopy. METHODS: Fifty-one subjects admitted to hospital for RSV infection during the first year of life and controls matched for birth date and sex underwent clinical examinations including lung function, skin prick and blood tests. RESULTS: The RSV subjects had significantly higher serum concentrations of IFN-gamma and sICAM-1 than the controls (for IFN-gamma 224.9 pg/mL (standard deviation (SD) 271.3) vs. 187.1 pg/mL (372.9), difference 37.8 pg/mL, 95% confidence interval (CI) -90.3 to 166.0, P = 0.05; for sICAM-1 170.2 ng/mL (SD 63) vs. 147.8 ng/mL (SD 57), difference 22.4 ng/mL, 95% CI -1.4 to 46.1, P = 0.04). The RSV subjects with asthma had significantly higher concentrations of IFN-gamma than the controls with asthma, and the RSV subjects with wheezing during the previous 12 months had significantly higher concentrations of both IFN-gamma and sICAM-1 than the controls with wheezing. CONCLUSIONS: Children hospitalized for RSV infection in infancy still differ in IFN-gamma and sICAM-1 production 6-10 years after the infection. The data suggest that the pathomechanism of asthma and wheezing after an early RSV infection may be different from that of children without an early RSV infection.     

Urinary eosinophilic protein X, atopy, and symptoms suggestive of allergic disease at 3 years of age

BACKGROUND: Urinary eosinophilic protein X (U-EPX) measurement is easy to perform in children. However, its use for prediction, diagnosis, and monitoring of asthma and atopy is unclear. OBJECTIVE: We sought to investigate the relationship between U-EPX and clinical phenotypes suggestive of allergic diseases. METHODS: U-EPX measurement (RIA), respiratory questionnaires, and skin testing were completed at age 3 years in 903 children followed prospectively from birth. Specific airway resistance was measured in 503 currently asymptomatic children by using whole-body plethysmography during tidal breathing. RESULTS: Nonatopic children with wheezing or eczema had slightly increased U-EPX levels compared with nonatopic asymptomatic children. U-EPX levels (geometric mean EPX/creatinine ratio) were as follows: nonatopic asymptomatic children (n = 313), 61.3 microg/mmol (95% CI, 56.4-66.6 microg/mmol); nonatopic children with wheezing (n = 148), 71.2 microg/mmol (95% CI, 63.2-80.1 microg/mmol); nonatopic children with eczema (n = 90), 65.7 microg/mmol (95% CI, 56.7-76.2 microg/mmol); and nonatopic children with wheezing and eczema (n= 86), 79.7 microg/mmol (95% CI, 67.4-94.3 microg/mmol). Children who had persistent atopy early in life had significantly higher U-EPX levels at age 3 years (nonatopic at 1 and 3 years [n = 263], 63.4 microg/mmol [95% CI, 58.4-69.0 microg/mmol]; atopic at 1 but not 3 years [n = 24], 65.1 microg/mmol [95% CI, 43.8-96.7 microg/mmol]; nonatopic at 1 year and atopic at 3 years [n = 62], 90.0 microg/mmol [95% CI, 74.6-108.4 microg/mmol]; atopic at 1 and 3 years [n = 35], 111.5 microg/mmol [95% CI, 89.2-139.3 microg/mmol]; P <.002). Atopy alone and with wheezing, eczema, or both was associated with significantly increased U-EPX levels (P <.0001). Wheezing appeared to be associated with higher U-EPX levels compared with eczema in both atopic and nonatopic children. The highest U-EPX level was found in atopic children with a history of wheezing and eczema (P <.0001). There was no relationship between U-EPX level and lung function. CONCLUSION: U-EPX level reflects the presence of atopy and associated symptoms and might be useful for monitoring the progression of allergic disease.     

The association between persistent eosinophilia and asthma in childhood is independent of atopic status

BACKGROUND: Although peripheral blood eosinophilia is associated with risk of asthma, the relation with atopy has not been established. OBJECTIVE: To assess the relationship between eosinophils and chronic asthma in childhood, and to determine the factors associated with eosinophil levels over time. METHODS: Percent eosinophils/300 white blood cell (WBC) count ('eos') was measured at 9 months, 6 years and 11 years in subjects participating in the prospective Tucson Children's Respiratory Study. Children were classified based on the number of measurements in which they had low (< or = 2%) or high (>5%) eosinophils, as follows: (1) Persistently low eos (n = 130); (2) Low eos (intermittently low or consistently moderate, but never high, n = 317); (3) Intermittently high eos (n = 192); and (4) Persistently high eos (n = 17). Only children with > or = 2 eos measurements were included in the analysis. Chronic asthma was defined as medical doctor (MD)-diagnosed asthma with reports of wheezing during the previous year, on > or = 3 questionnaires completed between 2 and 13 years of age. Children with at least one positive skin prick test (SPT; > or = 3 mm) at age 6 or 11 were considered 'atopic'. RESULTS: Chronic asthma was linearly related to longitudinally ascertained eosinophils (trend chi2 P<0.001) with prevalence ranging from 5.8% among children with persistently low eos to 37.5% among children with persistently high eos. This relation was independent of atopy. Parental history of asthma was associated with both chronic asthma (P <0.001) and with longitudinal eosinophil status (P < 0.001). After adjusting for atopy and gender, there was a 70% increase in asthma risk with each increase in longitudinal eosinophil level. This stepwise increase was reduced to 48% when parental asthma was added to the model. CONCLUSION: Longitudinal eosinophil levels are linearly associated with chronic asthma in childhood, independent of atopy. The strong association between parental asthma and eosinophil status suggests that genetic background may be an important determinant of eosinophilic response.     

Predictive value of cord blood IgE in the development of atopic disease and role of breast-feeding in its prevention

The predictive value of cord blood IgE in the development of atopic disease was evaluated in a prospective study of two groups of infants. Total serum IgE level was ≥ 0.7 U/ml in 44.3% of the infants with positive family history of atopy and in 16.0% among those with negative family history. The level of cord blood IgE correlated significantly with the subsequent development of atopic disease in both groups. Cord blood IgE higher than 0.7 U/ml was associated with a high risk of development of atopic eczema and wheezing, 52.8% and 58.8% respectively in the groups with or without family history of atopy; compared with 13.4% and 1.1% in the groups with IgE levels less than 0.7 U/ml. Among newborns fed exclusively on breast milk for a minimum of 3 months, the incidence of eczema and wheezing was significantly lower (12%) compared with findings in the formula-fed group (32%).     

Breastfeeding, soluble CD14 concentration in breast milk and risk of atopic dermatitis and asthma in early childhood: birth cohort study

BACKGROUND: Breast milk contains a variety of bioactive substances, among them, soluble CD14 (sCD14), which plays an important role in innate immunity. OBJECTIVE: We analysed data of a large prospective birth cohort study to examine the determinants of sCD14 in breast milk, and investigated whether breastfeeding practice and sCD14 concentrations in breast milk are determinants of the risk of atopic dermatitis (AD) and asthma in children. METHODS: Eight hundred and three mothers and their newborns were included in this analysis. We measured sCD14 concentrations in breast milk samples collected 6 weeks post-partum. During a 2-year follow-up the cumulative incidences of AD and asthma were recorded. RESULTS: Overall, AD was reported for 20.6% of the 2-year-olds and asthma was reported for 19.6%. We found the lowest incidence of physician-reported AD in children of mothers without a history of atopic diseases if breastfed for 6 to less than 9 months. Furthermore, we found an inverse association between duration of breastfeeding and risk of asthma, which was especially evident in children with mothers without a history of atopic disease (P=0.01). These patterns persisted after control for other factors by multivariate analysis methods. The protective effect of breastfeeding seemed to be synergistic with sCD14 concentrations in breast milk (P for trend 0.0005). CONCLUSIONS: The results of this prospective birth cohort study suggest that a longer duration of breastfeeding does decrease the risk for asthma in early childhood, especially in children of mothers without a history of atopic disease. The beneficial effects of breastfeeding might be further supported by high levels of sCD14 in breast milk.     

Early exposure to dichlorodiphenyldichloroethylene, breastfeeding and asthma at age six

Our aims were to assess association of dichlorodiphenyldichloroethylene (DDE) with childhood asthma measured up to age 6 and the effect of DDE on the protective effect of breastfeeding on asthma. In addition, we attempted to assess the relevant time-window of DDE exposure (i.e. at birth or at 4 years). All women presenting for antenatal care in Menorca, Spain over a 12-month period beginning in mid-1997 were invited to take part in a longitudinal study that included a yearly visit. Four hundred eighty-two children were enrolled and 462 provided complete outcome data after 6.5 years of follow-up. Organochlorine compounds were measured in cord serum of 402 (83%) infants and in blood samples of 285 children aged 4. We defined asthma as the presence of wheezing at age 6 and during any preceding year or doctor-diagnosed asthma, and used skin prick test at age 6 to determine atopic status. Results At birth and 4 years of age, all children had detectable levels of DDE (median 1 ng/mL and 0.8 ng/mL, respectively). From birth to age 4, the mean DDE level among children with artificial feeding decreased by 72%, while among breastfed children it increased by 53%. Diagnosed asthma and persistent wheezing were associated with DDE at birth [odds ratio (OR) for an increase in 1 ng/mL, OR=1.18, 95% confidence interval (95% CI)=1.01-1.39 and OR=1.13, 95% CI=0.98-1.30, respectively], but not with DDE at 4 years. Neither breastfeeding nor atopy modified these associations (P>0.3). Breastfeeding protected against diagnosed asthma (OR=0.33, 95% CI=0.08-0.87) and wheezing (OR=0.53, 95% CI=0.34-0.82) in children with low and high DDE levels at birth. Conclusion In a community without known dichlorodiphenyltrichloroethane environmental releases, this study strengthens the evidence for an effect of DDE on asthma by measuring the disease at age 6 and does not support the hypothesis that DDE modifies the protective effect of breastfeeding on asthma.