Early sensitisation and development of allergic airway disease - risk factors and predictors

The relationship between toxic air pollution, health expenditure, and economic growth in the European Union: fresh evidence from the PMG-ARDL model

Air pollution is a danger to economies throughout the European Union. Industry, population expansion, a building boom owing to housing and infrastructure development, increasing vehicle traffic, crowded streets, a lack of availability of clean fuel, and ineffective control programs are the primary causes. Toxic air is a double-edged sword for a country's health since it affects just a tiny fraction of Europe's population. The financial burden and healthcare expenses for people rise when health expenditures rise. The present research looks at how dangerous air levels, healthcare costs, and the expansion of the European Union's economy are all connected. The findings are based on data collected over 29 years and account for the abovementioned variables. The results of the unit root test have the significant probability values of all variables: health expenditures (HE), gross domestic product (GDP), nitrous oxides (NOX), and carbon dioxides (CO2) emissions at both level and first difference. We used the Johansen, Kao, and Pedroni cointegration tests to test the null hypothesis of no cointegration to see that sample variables had a long-term association. The PMG-ARDL test was used to get these findings. The results confirmed the significant probability values of dependent variables in long- and short-run results that GDP has a positive and significant effect on health expenditure, while NOX and CO2 emissions have a negative and significant impact on (HE), in the European Union. To verify the results, we applied the robustness test, fully modified OLS (FMOLD), and dynamic OLS (DOLS); the robustness test results validated the PMG-ARDL test results. Environmental pollution (CO2, NOX) has a significant and negative impact on healthcare expenditures and a significant effect on GDP (HE) in the EU region. The findings of this research have implications for a wide range of parties, including those who would examine the link between factors in a study meant to improve air quality, distribute health resources, or develop strategies for economic development.

Medical cost of environmental pollution: evidence from the Chinese Social Survey

Environmental pollution impairs residents' health, while the pursuit of health is highly correlated to medical costs. Understanding how environmental pollution affects medical costs is closely linked to the welfare of society. Based on theoretical analysis, this paper uses data from 5112 households of the Chinese Social Survey (CSS) in 2019, constructs a composite indicator to quantify environmental pollution using respondents' evaluations, and empirically investigates the causal effect of environmental pollution on household medical cost and the mechanism. The conclusions are shown as follows. First, environmental pollution can increase household medical costs, and this estimation result still holds after dealing with the endogeneity problem and other robustness tests. Second, there is heterogeneity in the impact of environmental pollution on household medical costs, households in the upper socioeconomic class, with heavy pension burdens or with strong health insurance coverage are more sensitive to environmental pollution and incur relatively higher household medical costs. Third, environmental pollution reduces residents' satisfaction with their spiritual life, which adversely affects their physical and mental health and can increase household medical costs. Residents' satisfaction with their spiritual life is an important mechanism for environmental pollution to affect household health care expenditures. Therefore, governments should enhance the enforcement of environmental protection and governance, strengthen the awareness of green issues and health education, and increase the supply of facilities for leisure and sports, thus reducing medical costs due to environmental pollution and easing the medical burden of residents.

Environmental influences on childhood asthma: Allergens

Allergen exposure is associated with the development of allergen-specific sensitization, but their relationship is influenced by other contemporaneous exposures (such as microbial exposure) and the genetic predisposition of the host. Clinical outcomes of the primary prevention studies that tested the effectiveness of allergen avoidance in pregnancy and early life on the subsequent development of sensitization and asthma published to date are inconsistent. Therefore, we cannot provide any evidence-based advice on the use of allergen avoidance for the primary prevention of these conditions. The evidence about the impact of allergen exposure among and among sensitized children with asthma is more consistent, and the combination of sensitization and high exposure to sensitizing allergen increases airway inflammation, triggers symptoms, adversely impacts upon disease control, and is associated with poorer lung function in preschool age. However, there are differing opinions about the role of inhalant allergen avoidance in asthma management, and recommendations differ in different guidelines. Evidence from more recent high-quality trials suggests that mite allergen-impermeable bed encasings reduce hospital attendance with asthma attacks and that multifaceted targeted environmental control improves asthma control in children. We therefore suggest a pragmatic approach to allergen avoidance in the management of childhood asthma for clinical practice, including the recommendations to: (1) tailor the intervention to the patient's sensitization and exposure status by using titer of allergen-specific IgE antibodies and/or the size of the skin test as indicators of potential response; (2) use a multifaceted allergen control regime to reduce exposure as much as possible; and (3) start intervention as early as possible upon diagnosis.

Early-life inhalant allergen exposure, filaggrin genotype, and the development of sensitization from infancy to adolescence

Background

We hypothesized that filaggrin (FLG) loss-of-function mutations modify the effect of allergen exposure on the development of allergic sensitization.

Objective

We sought to determine whether early-life exposure to inhalant allergens increases the risk of specific sensitization and whether FLG mutations modulate these odds.

Methods

In a population-based birth cohort we measured mite, cat, and dog allergen levels in dust samples collected from homes within the first year of life. Sensitization was assessed at 6 time points between infancy and age 16 years. Genotyping was performed for 6 FLG mutations.

Results

In the longitudinal multivariable model (age 1-16 years), we observed a significant interaction between FLG and Fel d 1 exposure on cat sensitization, with the effect of exposure being significantly greater among children with FLG mutations compared with those without (odds ratio, 1.36; 95% CI, 1.02-1.80; P = .035). The increase in risk of mite sensitization with increasing Der p 1 exposure was consistently greater among children with FLG mutations, but the interaction did not reach statistical significance. Different associations were observed for dogs: there was a significant interaction between FLG and dog ownership, but the risk of sensitization to any allergen was significantly lower among children with FLG mutations who were exposed to a dog in infancy (odds ratio, 0.16; 95% CI, 0.03-0.86; P = .03).

Conclusions

FLG loss-of-function mutations modify the relationship between allergen exposure and sensitization, but effects differ at different ages and between different allergens.

Quality of life, salivary cortisol and atopic diseases in young children

Background

Children with atopic disease may have reduced health-related quality of life (QoL) and morning cortisol. Possible links between QoL, morning cortisol and atopic disease are unclear. We aimed to determine if QoL was associated with morning salivary cortisol at two years of age, and if asthma, atopic dermatitis and/or allergic sensitisation influenced this association. Secondarily, we aimed to determine if QoL at one year of age was associated with salivary cortisol one year later.

Methods and findings

The Bronchiolitis All SE-Norway study included infants during hospitalisation for acute bronchiolitis in infancy (bronchiolitis group) and population-based control infants (controls). The present study included all 358 subjects with available Infant Toddler Quality of Life Questionnaire (ITQOL) from parents, consisting of 13 domains and morning salivary cortisol at two years of age. Answers from the same 0–100 score questionnaire, with optimal score 100 nine months after enrolment, was also available for 289 of these children at about one year of age. Recurrent bronchial obstruction was used as an asthma proxy. Atopic dermatitis was defined by Hanifin and Rajka criteria and allergic sensitisation by a positive skin prick test. Due to different inclusion criteria, we tested possible interactions with affiliation groups. Associations between QoL and cortisol were analysed by multivariate analyses, stratified by bronchiolitis and control groups due to interaction from affiliation grouping on results. At two years of age, QoL decreased significantly with decreasing cortisol in 8/13 QoL domains in the bronchiolitis group, but only with General health in the controls. The associations in the bronchiolitis group showed 0.06–0.19 percentage points changes per nmol/L cortisol for each of the eight domains (p-values 0.0001–0.034). The associations remained significant but diminished by independently including recurrent bronchial obstruction and atopic dermatitis, but remained unchanged by allergic sensitisation. In the bronchiolitis group only, 7/13 age and gender adjusted QoL domains in one-year old children were lower with lower cortisol levels at two years of age (p = 0.0005–0.04).

Conclusions

At two years, most QoL domains decreased with lower salivary cortisol among children who had been hospitalised for acute bronchiolitis in infancy, but for one domain only among controls. Recurrent bronchial obstruction and to a lesser extent atopic dermatitis, weakened these associations that nevertheless remained significant. After bronchiolitis, lower QoL in one-year old children was associated with lower salivary cortisol at two years.

Dust-mite inducing asthma: what advice can be given to patients?

Introduction: Amongst allergic asthmatics, high allergen exposure increases asthma severity. However, there is no consensus on the role of mite allergen avoidance in the management of asthma, and various guidelines differ in their recommendations. Areas covered: Several systematic reviews/meta-analyses on mite avoidance in the management of asthma have been published, and their findings have been used for a call to provide a recommendation in British guidelines that dust-mite control measures should not be recommended. However, there are several problems with such analysis (such as combining studies in adults and children), and we question whether these are appropriate tools to evaluate available evidence about mite allergen avoidance, and whether it is correct to rely disproportionately on the results of meta-analyses/systematic reviews to inform clinical practice in this area. Recent evidence in children suggests that mite-impermeable bed encasings reduce emergency hospital attendance with severe asthma exacerbations. Expert opinion: The practical questions include how to achieve a sufficient real-life reduction allergen exposure, and how to identify patients who will benefit from effective intervention. The intervention should start early in the natural history of asthma, and consideration for choosing patients should include using the titre of allergen-specific IgE antibodies or the size of skin test wheal as an indicator.

Risk of Allergic Rhinitis, Allergic Conjunctivitis, and Eczema in Children Born to Mothers with Gum Inflammation during Pregnancy

Purpose

Despite links between maternal and child health status, evidence on the association between gum infection in pregnant mothers and childhood allergies is scarce. We aim to evaluate the risk of developing allergy in children born to periodontal mothers in a nationwide study.

Methods

We conducted a 9-year population-based, retrospective cohort study using Taiwan’s National Health Insurance database. A study cohort of 42,217 newborns born to mothers with periodontal disease during pregnancy was identified in 2001 and matched with 42,334 babies born to mothers without any infection (control) by mother’s age at delivery and baby sex. With a follow-up period from 2001 to 2010, we observed the incidence of allergic rhinitis (AR), allergic conjunctivitis (AC), and eczema in these children. Cox proportional hazards regression models were performed with premature deaths as competing risk for the estimation of allergic disease risks.

Results

Nine-year cumulative incidences were the highest among children born to periodontal mothers; they reached 46.8%, 24.2%, and 40.4% (vs. 39.5%, 18.3% and 34.8% in control) for AR, AC, and eczema, respectively. Our results showed moderately increased risks for the allergies in children born to periodontal mothers relative to their matched non-inflammatory control (adjusted HRs: 1.17, 95% CI: 1.15–1.20; 1.27, 1.24–1.31; 1.14, 1.12–1.17, respectively). Because the impact of food consumption and living environment cannot be considered using insurance data, we attempted to control it by adjusting for parental income and mother’s residential area.

Conclusions

Overall cumulative incidence and risks of children born to periodontal mothers for AR, AC, and eczema are significantly higher than those born to non-inflammatory mothers. Gum infection in women during pregnancy is an independent risk factor for allergic diseases in children, thus its intergenerational consequences should be considered in gestational care.

The Interaction Between Prenatal Exposure to Home Renovation and Reactive Oxygen Species Genes in Cord Blood IgE Response is Modified by Maternal Atopy

PURPOSE

Although home renovation exposure during childhood has been identified as a risk factor for the development of allergy, there is limited information on the association between prenatal exposure to home renovation and cord blood (CB) IgE response. The aims of this study were to identify the effect of prenatal exposure to home renovation on CB IgE levels, and to investigate whether this exposure interacts with neonatal genes and whether the effect can be modified by maternal atopy.

METHODS

This study included 1,002 mother-neonate pairs from the COhort for Childhood Origin of Asthma and allergic diseases (COCOA). Prenatal environmental factors were collected using a questionnaire. The levels of CB IgE were measured by the ImmunoCAP system, and DNA was extracted from CB.

RESULTS

Exposure to home renovation during the prenatal period was associated with significantly higher levels of CB IgE only in neonates from atopic mothers, and the effect of renovation exposure on CB IgE levels persisted from 31 months before birth. Furthermore, prenatal exposure to home renovation increased the risk of CB IgE response interacting with polymorphisms of NRF2 and GSTP1 genes only in neonates from atopic mothers.

CONCLUSIONS

Maternal atopy modified the effect of prenatal exposure to home renovation on CB serum IgE response as well as the interaction between the exposure and neonatal genes involved in the oxidative stress pathway. These findings suggest that the genetically susceptible offspring of atopic mothers may be more vulnerable to the effect of prenatal exposure to home renovation on the development of allergy.

Biological memory of childhood maltreatment: current knowledge and recommendations for future research

Child maltreatment (CM) not only has detrimental and lifelong psychological consequences, but also can lead to lasting alterations in core physiological systems--a biological memory of CM. Furthermore, some of these alterations might even be transmitted to the next generation. This article describes current knowledge about the effects of CM on the stress system (i.e., the hypothalamus-pituitary-adrenal axis), on cellular aging (i.e., telomere length and telomerase activity), and on the immune system. Furthermore, we want to initiate research on the question of transmission of the described physiological alterations subsequent to CM to the next generation--possibly through epigenetic imprinting. As diverse neurobiological factors and epigenetics are closely linked, these different research fields should join forces to gain a deeper understanding of the biological determinants and sequelae of CM and its transmission.

An investigation of airborne allergenic pollen at different heights

BACKGROUND AND AIMS

Airborne pollen is an important source of allergens in a number of allergic diseases. Data on the concentrations of pollen at different heights in the air are scarce. The aim of the present study was to investigate different types and numbers of airborne pollen and their seasonal variation at different heights in the urban area of Shenzhen (China) and their associations with meteorological factors.

METHODS

The concentration of airborne pollen at different heights was monitored with Burkard traps from July 1, 2006, to June 30, 2007, in Shenzhen; the results were analyzed with SAS 9.13 software.

RESULTS

In total, 1,095 films (at 3 heights, 365 films at each height) were exposed throughout the year, and 48 families and 85 genera of pollen taxa were identified. The total pollen count was 55,830 grains (25,204 grains at 1.5 m; 16,218 grains at 35 m, and 14,408 grains at 70 m); pollen grains were present in the atmosphere throughout the year, with two peaks of airborne pollen: one peak in February to April and the other in September to November.

CONCLUSIONS

On the basis of our local investigations, the pollen concentrations and the pollen types in the air decrease gradually with increasing height. The distribution and concentrations of airborne pollen at different heights in the atmosphere were influenced by composite factors such as the season and meteorological factors.

Diagnostic approach and management of cow's-milk protein allergy in infants and children: ESPGHAN GI Committee practical guidelines

OBJECTIVES

This guideline provides recommendations for the diagnosis and management of suspected cow's-milk protein allergy (CMPA) in Europe. It presents a practical approach with a diagnostic algorithm and is based on recently published evidence-based guidelines on CMPA.

DIAGNOSIS

If CMPA is suspected by history and examination, then strict allergen avoidance is initiated. In certain circumstances (eg, a clear history of immediate symptoms, a life-threatening reaction with a positive test for CMP-specific IgE), the diagnosis can be made without a milk challenge. In all other circumstances, a controlled oral food challenge (open or blind) under medical supervision is required to confirm or exclude the diagnosis of CMPA.

TREATMENT

In breast-fed infants, the mother should start a strict CMP-free diet. Non-breast-fed infants with confirmed CMPA should receive an extensively hydrolyzed protein-based formula with proven efficacy in appropriate clinical trials; amino acids-based formulae are reserved for certain situations. Soy protein formula, if tolerated, is an option beyond 6 months of age. Nutritional counseling and regular monitoring of growth are mandatory in all age groups requiring CMP exclusion. REEVALUATION: Patients should be reevaluated every 6 to 12 months to assess whether they have developed tolerance to CMP. This is achieved in >75% by 3 years of age and >90% by 6 years of age. Inappropriate or overly long dietary eliminations should be avoided. Such restrictions may impair the quality of life of both child and family, induce improper growth, and incur unnecessary health care costs.

Prenatal negative life events increases cord blood IgE: interactions with dust mite allergen and maternal atopy

BACKGROUND

Prenatal exposure to both stress and aeroallergens (dust mite) may modulate the fetal immune system. These exposures may interact to affect the newborn immune response. We examined associations between prenatal maternal stress and cord blood total IgE in 403 predominately low-income minority infants enrolled in the Asthma Coalition on Community, Environment, and Social Stress (ACCESS) project. We also examined potential modifying effects of maternal atopy and maternal dust mite exposure.

METHODS

The Crisis in Family Systems survey was administered to mothers prenatally, and a negative life event domain score was derived to characterize stress. Dust mite allergen was quantified in dust from pregnant mothers' bedrooms. Cord blood was analyzed for total IgE. Using linear regression, we modeled the relationship of stress with cord blood IgE and interactions of stress with dust mite and/or maternal atopy, adjusting for potential confounders.

RESULTS

Higher prenatal maternal stress (β = 0.09; P = 0.01) was associated with increased cord blood IgE. The interactive effects between stress and dust mite groups (high vs low) were significantly different for children of atopic vs nonatopic mothers (P for three-way interaction = 0.005). Among children of atopic mothers, the positive association between stress and IgE was stronger in the high dust mite group. In children of mothers without a history of atopy, the positive association between stress and IgE was most evident in the low allergen group.

CONCLUSIONS

Prenatal stress was independently associated with elevated cord blood IgE. Mechanisms underlying stress effects on fetal immunomodulation may differ based on maternal atopic status.

Effects of Helicobacter pylori, geohelminth infection and selected commensal bacteria on the risk of allergic disease and sensitization in 3-year-old Ethiopian children

BACKGROUND

Epidemiological studies have suggested that gastro-intestinal infections including Helicobacter pylori, intestinal microflora (commensal bacteria) and geohelminths may influence the risk of asthma and allergy but data from early life are lacking.

OBJECTIVE

We aimed to determine the independent effects of these infections on allergic disease symptoms and sensitization in an Ethiopian birth cohort.

METHODS

In 2008/09, 878 children (87% of the 1006 original singletons in a population-based birth cohort) were followed up at age 3 and interview data obtained on allergic symptoms and potential confounders. Allergen skin tests to Dermatophagoides pteronyssinus and cockroach were performed, levels of Der p 1 and Bla g 1 in the child's bedding measured and stool samples analysed for geohelminths and, in a random subsample, enterococci, lactobacilli, bifidobacteria and H. pylori antigen. The independent effects of each exposure on wheeze, eczema, hayfever and sensitization were determined using multiple logistic regression.

RESULTS

Children were commonly infected with H. pylori (41%; 253/616), enterococci (38.1%; 207/544), lactobacilli (31.1%; 169/544) and bifidobacteria (18.9%; 103/544) whereas geohelminths were only found in 8.5% (75/866). H. pylori infection was associated with a borderline significant reduced risk of eczema (adjusted OR 0.49, 95% CI 0.24-1.01, P=0.05) and D. pteronyssinus sensitization (adjusted OR 0.42, 95% CI 0.17-1.08, P=0.07). Geohelminths and intestinal microflora were not significantly associated with any of the outcomes measured.

CONCLUSION AND CLINICAL RELEVANCE

Among young children in a developing country, we found evidence to support the hypothesis of a protective effect of H. pylori infection on the risk of allergic disease. Further investigation of the mechanism of this effect is therefore of potential therapeutic and preventive value.

Epidemiology of stress and asthma: from constricting communities and fragile families to epigenetics

Several epidemiologic frameworks, exemplified through extant research examples, provide insight into the role of stress in the expression of asthma and other allergic disorders. Biologic, psychological, and social processes interact throughout the life course to influence disease expression. Studies exploiting a child development framework focus on critical periods of exposure, including the in utero environment, to examine the influence of stress on disease onset. Early stress effects that alter the normal course of morphogenesis and maturation that affect both structure and function of key organ systems (eg, immune, respiratory) may persist into adult life underscoring the importance of a life course perspective. Other evidence suggests that maternal stress influences programming of integrated physiologic systems in their offspring (eg, neuroendocrine, autonomic, immune function) starting in pregnancy; consequently stress effects may be transgenerational. A multilevel approach that includes an ecological perspective may help to explain heterogeneities in asthma expression across socioeconomic and geographic boundaries that to date remain largely unexplained. Evolving studies incorporating psychological, behavioral, and physiologic correlates of stress more specifically inform underlying mechanisms operating in these critical periods of development. The role of genetics, gene by environment interactions, and epigenetic mechanisms of gene expression have been sparsely examined in epidemiologic studies on stress and asthma although overlapping evidence provides proof of concept for such studies in the future.

Does genetic regulation of IgE begin in utero? Evidence from T(H)1/T(H)2 gene polymorphisms and cord blood total IgE

BACKGROUND

Elucidation of early life factors is critical to understand the development of allergic diseases, especially those manifesting in early life such as food allergies and atopic dermatitis. Cord blood IgE (CBIgE) is a recognized risk factor for the subsequent development of allergic diseases. In contrast with numerous genetic studies of total serum IgE in children and adults, limited genetic studies on CBIgE have been conducted.

OBJECTIVE

To test the associations between functional or tagging single nucleotide polymorphisms (SNPs) in genes involved in the T(H)1/T(H)2 pathway and CBIgE in a large US inner-city birth cohort.

METHODS

CBIgE, measured by Phadia ImmnunoCAP, was analyzed as a continuous and a binary variable. The association of each SNP with the 2 outcomes was tested using tobit and logistic regression models, respectively, with adjustment for pertinent covariates, ancestral proportion, and multiple testing. Ethnic heterogeneity and gene-gene interactions were also explored.

RESULTS

Three SNPs (rs1800925, rs2069743, and rs1295686) in the IL13 gene were significantly associated with CBIgE concentration (P ≤ 6 × 10(-4), FDR-corrected P < .05). These SNPs jointly influenced CBIgE in a dose-response manner (P for trend = 9 × 10(-8)). Significant associations also were observed for SNPs in the IL-13 receptor α1 (rs5956080) and signal transducer and activator of transcription 6 (rs11172106) genes. Ethnicity-specific genetic effects were observed for SNPs in the IL5 and GATA3 genes. Several gene-gene interactions (including IL13-IL4 receptor and IL13-signal transducer and activator of transcription 6 interactions) were detected in relation to CBIgE.

CONCLUSION

Our data demonstrated that multiple SNPs were individually and jointly associated with CBIgE, with evidence of gene-gene interactions and ethnic heterogeneity. These findings suggest that genetic regulation of IgE may begin in utero.

Health-care cost reduction resulting from primary-care allergy testing in children in Italy

Background

Allergy places a considerable cost burden on society. Specific immunoglobulin E (spIgE) testing may improve the management of allergy patients. There is therefore a reason to quantify the economic consequences of the use of spIgE testing in the diagnosis of allergic conditions.

Methods

The expected costs of spIgE testing versus no-testing were calculated using a clinical decision model based on a prospective clinical trial performed in primary care.

Results

The expected costs per patient over 2 years decreased from 802 euros in the "no-test strategy" to 560 euros in the spIgE "test strategy". Cost savings persisted even after assumptions about the prevalence of allergy and the prices of medications were changed. The "test strategy" increased the percentage of patients correctly diagnosed from 54 to 87%.

Conclusions

spIgE testing of children with respiratory and/or skin problems in primary care in Italy reduces overall costs to society. These cost savings mostly result from a reduction in the use of medications, particularly corticosteroids. The study indicates that spIgE testing of all children with respiratory and/or skin symptoms would be a cost-effective strategy.

Childhood asthma and early life exposure to indoor allergens, endotoxin and beta(1,3)-glucans

BACKGROUND

Divergent results have been reported regarding early life exposure to indoor environmental agents and the risk of asthma and allergic sensitization later in life.

OBJECTIVE

To assess whether early exposure to indoor allergens, beta(1,3)-glucans and endotoxin modifies the risk of allergic diseases at 10 years of age.

METHODS

The concentrations of mite, cat and dog allergens, endotoxin and beta(1,3)-glucans were determined in dust from the homes of 260 two-year-old children with lung function measured at birth (tidal flow volume loops) in the Environment and Childhood Asthma study in Oslo. At 10 years, the health status was assessed in a follow-up study including a structured interview of the parents and an extended clinical examination.

RESULTS

Cat and dog keeping at 2 years of age was reported in 6.5% and 5.5% of the families, respectively. Mite allergens were detected in only 4/260 dust samples. The adjusted odds ratio for asthma at age 10 was 1.20 (95% confidence interval: 1.01-1.43) and 1.22 (1.02-1.46) for bronchial hyperresponsiveness (BHR) per 10 microg/g dust increase in cat allergen exposure at 2 years of age. No association was seen with allergic sensitization. Moreover, endotoxin and beta(1,3)-glucan exposure did not modify the risk of asthma or allergic sensitization. None of the measured environmental factors were associated with lung function at 10 years of age or a relative change in lung function from birth.

CONCLUSION

In a community with a low prevalence of pet keeping and low mite allergen levels, exposure to cat allergens early in life increased the risk of late childhood asthma and BHR, but not the risk of allergic sensitization. No risk modification was seen for dog allergens, endotoxin and beta(1,3)-glucans.

Maternal interpersonal trauma and cord blood IgE levels in an inner-city cohort: a life-course perspective

BACKGROUND

Prenatal stress affects immunocompetence in offspring, although the underlying mechanisms are not well understood.

OBJECTIVE

We sought to examine associations between maternal lifetime interpersonal trauma (IPT) and cord blood total IgE levels in a sample of urban newborns (n = 478).

METHODS

Maternal IPT during childhood and adolescence (birth to 17 years), adulthood (18 years to index pregnancy), and the index pregnancy were ascertained by using the Revised Conflict Tactics Scale at 28.4 +/- 7.9 weeks' gestation. Cord blood IgE levels were derived by using a fluoroenzyme immunoassay. We examined effects of maternal IPT on increased cord blood IgE levels (upper quartile, 1.08 IU/mL) by using logistic regression, adjusting for confounders and mediating variables.

RESULTS

Maternal trauma was categorized as unexposed (n = 285 [60%]), early (childhood and/or teenage years only, n = 107 [22%]), late (adulthood and/or index pregnancy only, n = 29 [6%]), and chronic (early and late, n = 57 [12%]) exposure. Relative to no IPT, early (odds ratio [OR], 1.78; 95% CI, 1.05-3.00) and chronic maternal IPT (OR, 2.25; 95% CI, 1.19-4.24) were independently associated with increased IgE levels in unadjusted analyses. When adjusting for standard controls, including maternal age and race, season of birth, child's sex, and childhood and current socioeconomic status, early effects became nonsignificant (OR, 1.48; 95% CI, 0.85-2.58). Chronic exposure remained significant in fully adjusted models, including standard controls, current negative life events, allergen exposure, and potential pathway variables (maternal atopy, prenatal smoking, and birth weight; OR, 2.18; 95% CI, 1.06-4.50).

CONCLUSION

These data link chronic trauma over the mother's life course with increased IgE levels in infants at birth. Research examining associations between maternal trauma and indicators of offspring's atopic risk might be particularly relevant in inner-city high-risk populations.

Relationships among prenatal aeroallergen exposure and maternal and cord blood IgE: project ACCESS

BACKGROUND

Whereas some evidence suggests that antigen sensitization may begin prenatally, the influence of maternal allergen exposure during pregnancy has not been fully elucidated.

OBJECTIVES

We examined the relationship between prenatal maternal aeroallergen exposure and cord blood total IgE and the potential mediating/indirect effect of maternal immune response.

METHODS

This study was performed in 301 mother-infant pairs enrolled in the Asthma Coalition on Community, Environment, and Social Stress (ACCESS) project, a study examining the effects of prenatal and early life social and physical environmental exposures on urban asthma risk. Dust samples collected prenatally from mothers' bedrooms were analyzed for cockroach and dust mite allergens. Cord blood was analyzed for total IgE, and maternal serum collected during pregnancy for total and specific IgE. We assessed the relationship between prenatal exposure and cord blood total IgE and the potential mediation effect adjusting for maternal age, race, education, smoking status, and dust collection season; and child's sex and season of birth.

RESULTS

In multivariate models, elevated prenatal dust mite levels (>0.2 microg/g) increased cord blood IgE concentrations by 29% (P = .08), and continuous dust mite concentration was associated with a significant nonlinear increase in cord blood IgE (P = .02). Elevated prenatal exposure to cockroach allergen (>2 U/g) was not associated with cord blood IgE, but showed a significant indirect relationship through maternal total IgE (beta = 0.23; 95% CI, 0.08-0.41).

CONCLUSION

These results demonstrate that maternal prenatal exposure to household allergens may affect cord blood IgE, albeit the underlying mechanism may be allergen-specific.

On the role of breastfeeding in health promotion and the prevention of allergic diseases

Based on animal models, we specify the major role of different bioactive milk components known to participate significantly in neonatal health promotion and in protection against a large number of infectious diseases and the development of allergies and asthma.

Application of the personal aeroallergen sampler to assess personal exposures to Japanese cedar and cypress pollens

We have recently developed the Personal Aeroallergen Sampler (PAAS), a passive sampler for aeroallergens. In the present study, the applicability of the PAAS for personal exposure assessments of cedar and cypress pollens was investigated by comparing with existing reference samplers. To investigate the usability of the PAAS as a personal sampler for the airborne pollens, it was compared with the Institute of Occupational Medicine (IOM) sampler, a traditionally used active personal sampler. Overall, the result showed a good correlation between the two methods, that is, R(2)=0.8082, suggesting the usability of the PAAS for the personal pollen samplings. The ratio of the pollen numbers collected by the PAAS to the IOM sampler was approximately 30%, which was consistent with our previous study investigating ambient dust particles. Meanwhile, the comparability of the PAAS to the Durham sampler, the most widely used stationary pollen trap, was also assured. Furthermore, we exemplified the seasonal peak of the personal pollen exposures was not necessarily reflected by the outdoor concentrations, indicating insufficiency of the stationary outdoor monitoring to represent the personal pollen exposures. The PAAS, a simple passive method, could be used in future field studies to elucidate the detailed mechanisms of allergic airway diseases such as cedar pollinosis.

Predictors of cord blood IgE levels in children at risk for asthma and atopy

BACKGROUND

Increased cord blood IgE levels, in conjunction with a family history of atopy, are associated with the development of allergic diseases in children. However, little is known about predictors of cord blood IgE levels.

OBJECTIVE

Our objective was to identify predictors of cord blood IgE levels among infants at increased risk of atopy.

METHODS

Cord blood IgE levels were measured in 874 infants who were screened for participation in a birth cohort. Questionnaires were administered after birth of the infant, and maternal and cord blood was obtained for measurement of IgE levels. Logistic and tobit regression models were used to study the association between perinatal factors and cord blood IgE levels.

RESULTS

In multivariable models infant male sex, increased maternal total IgE level, maternal allergen sensitization, Hispanic ethnicity, and residence in low-income areas were associated with detectable or increased cord blood IgE levels, whereas increasing maternal age was associated with undetectable or lower cord blood IgE levels. Although maternal smoking during pregnancy was positively associated with cord blood IgE levels in univariable models, the effect did not persist after adjusting for potential confounders.

CONCLUSION

Maternal allergen sensitization, markers of socioeconomic disadvantage and race/ethnicity, maternal age, and infant sex might influence fetal production of IgE. We found no association of maternal parity, mode of delivery, gestational age, or season of birth with cord blood IgE levels.

CLINICAL IMPLICATIONS

The identification of these definable familial and environmental factors that predict cord blood IgE levels might help in the early detection of infants at risk for atopic disorders.

Occurrence of IgE in foals: Evidence for transfer of maternal IgE by the colostrum and late onset of endogenous IgE production in the horse

IgE is the key antibody involved in type I allergies. Allergen mediated crosslinking of IgE bound to high affinity Fcepsilon-receptors on mast cells and basophils stimulates cellular degranulation and release of inflammatory mediators and cytokines. In this report, we demonstrate that IgE antibodies can be transferred from the mother to offspring in horses via the colostrum. We found a clear correlation between the IgE concentration in colostrum and the total IgE concentration in foal sera on day 2 after birth (r(sp)=0.83). Maternal IgE was detected in foal sera by ELISA and on peripheral blood leukocytes of foals by flow cytometry. Both serum and cell membrane-bound IgE were undetectable in newborn foals before colostrum uptake and peaked on days 2-5 after birth. Cell-bound IgE became undetectable at 2 months after birth. Serum IgE disappeared from the circulation within the first 3-4 months of age. These kinetics suggest that the IgE antibodies which are detectable in foals during the first 4 months after birth are of maternal origin only. The endogenous IgE production was found to begin at 9-11 months of age, when IgE could be detected on peripheral blood leukocytes and in foal sera again. After 18 months of life, the total IgE concentrations in foal sera were comparable to those detected in their dams. The late onset of endogenous IgE production offers an explanation for observations that IgE mediated allergies are generally not observed in horses before puberty. The roles of the passively transferred maternal IgE in newborn foals are not yet known, but could be manifold, ranging from passive immunity and induction of immunoregulatory functions to determinative influences of maternal IgE on the antibody repertoire in the offspring.

Mite and pet allergen exposure in Brazilian private cars

BACKGROUND

The role of mite and pet allergens in the development of allergic diseases has been recognized for many years.

OBJECTIVE

To determine mite (Dermatophagoides pteronyssinus [Der p 1] and Dermatophagoidesfarinae [Der f 1]), cat (Felis domesticus [Fel d 1]), and dog (Canis familiaris [Can f 1]) allergen levels in Brazilian private cars.

METHODS

Mite, cat, and dog allergens were measured in dust samples collected from 60 upholstered seats of private vehicles using enzyme-linked immunosorbent assays.

RESULTS

Mean levels of Der p 1 (0.24 microg/g of dust; range, 0.06-2.05 microg/g of dust) and Der f 1 (0.29 microg/g of dust; range, 0.06-2.07 microg/g of dust) were extremely low in most dust samples analyzed. In contrast, sensitizing mean levels of Can f 1 (1.51 microg/g of dust; range, 0.14-30.96 microg/g of dust) and Fel d 1 (0.43 microg/g of dust; range, 0.02-5.75 microg/g of dust) were observed in 32 (53%) and 12 (20%) samples, respectively. Mean Can f 1 levels were significantly higher in cars whose owners kept dogs at home (3.27 microg/g of dust) than in those without pets (0.57 microg/g of dust; P = .008). There were no significant differences in allergen levels regarding the age of the vehicle or the number of users and whether the owners transport pets inside the vehicles.

CONCLUSIONS

Private cars constitute an important pet, but not mite, allergen reservoir for continuous contamination of the indoor environment. Pet allergens may be present even in cars whose owners do not have pets. Effective measures to reduce allergen exposure in cars should be taken routinely, especially for pet-allergic patients.

Clinically diagnosed childhood asthma and follow-up of symptoms in a Swedish case control study

Background

Childhood asthma has risen dramatically not only in the western societies and now forms a major and still increasing public health problem. The aims of this study were to follow up at the age of ten the patterns of asthma symptoms and associations among children with a clinically diagnosed asthma in a sizeable urban-rural community and to in compare them with demographic controls using a standardised questionnaire.

Methods

In a defined region in Sweden with a population of about 150 000 inhabitants, all children (n = 2 104) born in 1990 were recorded. At the age of seven all primary care and hospital records of the 1 752 children still living in the community were examined, and a group of children (n = 191) was defined with a well-documented and medically confirmed asthma diagnosis. At the age of ten, 86 % of these cases (n = 158) and controls (n = 171) completed an ISAAC questionnaire concerning asthma history, symptoms and related conditions.

Results

Different types of asthma symptoms were highly and significantly over-represented in the cases. Reported asthma heredity was significantly higher among the cases. No significant difference in reported allergic rhinitis or eczema as a child was found between cases and controls. No significant difference concerning social factors or environmental exposure was found between case and controls. Among the control group 4.7 % of the parents reported that their child actually had asthma. These are likely to be new asthma cases between the age of seven and ten and give an estimated asthma prevalence rate at the age of ten of 15.1 % in the studied cohort.

Conclusion

A combination of medical verified asthma diagnosis through medical records and the use of self-reported symptom through the ISAAC questionnaire seem to be valid and reliable measures to follow-up childhood asthma in the local community. The asthma prevalence at the age of ten in the studied birth cohort is considerably higher than previous reports for Sweden. Both the high prevalence figure and allowing the three-year lag phase for further settling of events in the community point at the complementary roles of both hospital and primary care in the comprehensive coverage and control of childhood asthma in the community.

Early life risk factors for current wheeze, asthma, and bronchial hyperresponsiveness at 10 years of age

STUDY OBJECTIVES

We sought to identify early life factors (ie, first 4 years) associated with wheeze, asthma, and bronchial hyperresponsiveness (BHR) at age 10 years, comparing their relative influence for these conditions.

METHODS

Children were seen at birth, and at 1, 2, 4, and 10 years of age in a whole-population birth cohort study (1,456 subjects). Information was collected prospectively on genetic and environmental risk factors. Skin-prick testing was performed at 4 years of age. Current wheeze (in the last 12 months) and currently diagnosed asthma (CDA) [ie, current wheeze and ever-diagnosed asthmatic subject] were recorded at 10 years of age when BHR was measured at bronchial challenge. Independent significant risk factors for these outcomes were identified by logistic regression.

RESULTS

Independent significance for current wheeze occurred with maternal asthma (odds ratio [OR], 2.08; 95% confidence interval [CI], 1.27 to 3.41) and paternal asthma (OR, 2.12; 95% CI 1.29 to 3.51), recurrent chest infections at 2 years (OR, 3.98; 95% CI, 2.36 to 6.70), atopy at 4 years of age (OR, 3.69; 95% CI, 2.36 to 5.76), eczema at 4 years of age (OR, 2.15; 95% CI, 1.24 to 3.73), and parental smoking at 4 years of age (OR, 2.18; 95% CI, 1.25 to 3.81). For CDA, significant factors were maternal asthma (OR, 2.26; 95% CI, 1.24 to 3.73), paternal asthma (OR, 2.30; 95% CI, 1.17 to 4.52), and sibling asthma (OR, 2.00; 95% CI, 1.16 to 3.43), recurrent chest infections at 1 year of age (OR, 2.67; 95% CI, 1.12 to 6.40) and 2 years of age (OR, 4.11; 95% CI, 2.06 to 8.18), atopy at 4 years of age (OR, 7.22; 95% CI, 4.13 to 12.62), parental smoking at 1 year of age (OR, 1.99; 95% CI, 1.15 to 3.45), and male gender (OR, 1.72; 95% CI, 1.01 to 2.95). For BHR, atopy at 4 years of age (OR, 5.38; 95% CI, 3.06 to 9.47) and high social class at birth (OR, 2.03; 95% CI, 1.16 to 3.53) proved to be significant.

CONCLUSIONS

Asthmatic heredity, predisposition to early life atopy, plus early passive smoke exposure and recurrent chest infections are important influences for the occurrence of wheeze and asthma at 10 years of age. BHR at 10 years of age has a narrower risk profile, suggesting that factors influencing wheezing symptom expression may differ from those predisposing the patient to BHR.

Chemokine receptors: understanding their role in asthmatic disease

The incidence, prevalence, and severity of asthma have been increasing steadily in recent years. Prophylactic treatment of this disease and of episodic asthmatic flares is aimed at preventing excessive inflammation in lung tissue and airways. Because chemokines and chemokine receptors are critical mediators of leukocyte trafficking and recruitment, there is the potential to pharmaceutically target these proteins to regulate inflammation. Asthma-associated inflammation is characterized by the infiltration of eosinophils and T helper type 2 cells. Early studies investigated the role of chemokine receptors, which have been shown to predominate on these cell populations.

Differential diagnosis of IgE-mediated allergy in young children with wheezing or eczema symptoms using a single blood test

BACKGROUND

Allergy-like symptoms are common in young children, but the case history and physical examination cannot identify the underlying origins of overlapping symptom profiles.

OBJECTIVE

To evaluate a blood test, Phadiatop Infant (Pharmacia Diagnostics AB, Uppsala, Sweden), for differentiating the capability of IgE-mediated disease in young children with recurrent wheezing, eczema, or both.

METHODS

One hundred forty-seven children (mean age, 2.0 years) were consecutively referred to 2 allergy centers by their primary care physician for recurrent wheezing, eczema, or both. The allergist's clinical evaluation included medical history, physical examination, skin prick testing with inhalant and food allergens, and specific IgE determinations in blood. The accuracy of Phadiatop Infant was evaluated in a masked manner against the allergist's final diagnosis.

RESULTS

Sixty-nine children had wheezing, 69 had eczema, and 9 had both symptoms. Sixty-one children were clinically diagnosed as having IgE-mediated allergy, 78 as having non-IgE-associated disease, and 8 as having an inconclusive diagnosis. Fifty-six of the 61 children with IgE-mediated allergy had positive Phadiatop Infant test results, and 64 of 78 without the condition had negative results. Sensitivity was 92% and specificity was 82%, with positive and negative predictive values of 80% and 93%, respectively. Thirteen children with a positive Phadiatop Infant test result and a negative final diagnosis were retested after 2 years; 12 of them were diagnosed as having IgE-mediated allergy using a masked evaluation.

CONCLUSIONS

The Phadiatop Infant blood test discriminates between IgE- and non-IgE-mediated symptoms in children younger than 4 years.

Prognostic value of asymptomatic skin sensitization to aeroallergens

PURPOSE OF REVIEW

Asymptomatic skin sensitization to aeroallergens is frequently encountered in epidemiological studies and in everyday clinical life. Correct management of the condition is essential to avoid both progression into allergic disease and unnecessary intervention. Understanding immunological mechanisms in asymptomatic skin sensitization might provide new insights into the natural history and treatment of respiratory allergy.

RECENT FINDINGS

Research on asymptomatic skin sensitization is rare, and the present review unites previous studies with recent findings. It is a common condition affecting 8-30% of the population when using a local standard panel of aeroallergens. Clinically, immediate but not late-phase reactions are induced by allergen challenge. Absent eosinophil stimulation and migration and low IL-5 levels appear to be sentinel mechanisms. Prospective studies show that 30-60% become allergic, depending on allergens and follow-up period. No prospective intervention studies have been performed; however, allergen avoidance seems efficacious in reducing allergy development to occupational and domestic allergens. Asymptomatic skin sensitization due to an erroneously positive skin test must be ruled out before allergen avoidance measures are initiated.

SUMMARY

Surprisingly few papers exist on asymptomatic skin sensitization epidemiology and immunology, despite the intriguing question as to why symptoms do not develop in IgE-sensitized patients. It is a common condition and a risk factor for later development of respiratory allergic disease. Cross-sectional intervention studies suggest that allergy development is reduced by allergen avoidance. Immunologically, control of eosinophil stimulation and migration seems to be pivotal. How this control is maintained remains to be elucidated.

Determinants of neonatal IgE level: parity, maternal age, birth season and perinatal essential fatty acid status in infants of atopic mothers

OBJECTIVE

The hygiene hypothesis suggests that the protective 'siblings effect' against atopic diseases such as atopic dermatitis, allergic asthma and hay fever is a result of recurrent infections during early childhood. A recent study and review have indicated that this protective effect may already arise in utero. Lower n-3 essential fatty acid (EFA) status is associated with increased parity, and EFA status has also been related to atopy. The present study confirms the negative association between parity and neonatal immunoglobulin E (IgE) levels and further unravel the role of perinatal EFA status.

METHODOLOGY

In a prospective cohort study in 184 atopic mothers and their neonates, we simultaneously measured serum total IgE and EFA levels in plasma phospholipids, both in the mother at 34-36 weeks of gestation and in the neonate at the age of 1 week. Linear regression analysis was used to estimate the effect of parity on maternal and neonatal IgE and EFA status, and the independent effects of parity and EFA status on IgE, controlling for confounding factors such as maternal age and birth season.

RESULTS

Parity was associated with lower neonatal IgE level (P < 0.01), as well as with lower docosahexanoic acid (DHA, 22:6n-3) status of the mother (P = 0.01) but not of the neonate (P > 0.69). In the multivariate analysis, higher parity, higher maternal IgE, lower maternal age and birth in the first 3 months of the year were independently associated with neonatal IgE level. No association was detected between maternal or neonatal EFA status and neonatal IgE.

CONCLUSIONS

As neonatal total serum IgE is predictive of later atopy, our results support the hypothesis that the sibling effect in atopy is already being programmed in utero. Our data also confirm earlier findings that DHA status is lower in multiparous women, but this did not confound the relation between parity and neonatal IgE.

Environmental prevention in atopic eczema dermatitis syndrome (AEDS) and asthma: avoidance of indoor allergens

Indoor allergens represent an important precipitating factor for both asthma and atopic eczema dermatitis syndromes (AEDS). There is also accumulating evidence that sensitization to those allergens is associated with the onset of atopic disorders. Patients with AEDS present aeroallergen-specific T-cell responses associated with worsening of symptoms when exposed to specific aeroallergens. Furthermore, application of indoor allergens to the skin of patient with AEDS induces a local eczematous response in one-third of these patients. Exposure to high concentrations of mite allergens in early infancy have been demonstrated to be a risk factor for developing atopic dermatitis during the first 3 years of life. Moreover, a clear dose-response relationship has been documented between mite exposure and disease activity. Primary prevention of AEDS by avoiding indoor allergen exposure has been proved to be effective only when allergenic foods have also been avoided. Mite allergen avoidance in infants with AEDS and food allergy may however, prevent mite sensitization and the onset of asthma. Indoor allergen avoidance has been demonstrated to be effective in the majority of studies performed in patients with established AEDS. Negative results may be explained either by individual susceptibility variation, by long duration of disease with the consequent irreversible pathological changes in the target tissue or by exposure to allergens outside the house. Education of the patients and public consciousness of the problems are crucial for the efficacy of indoor allergen avoidance in allergic diseases.

Measurement of Bovine IgG by Indirect Competitive ELISA as a Means of Detecting Milk Adulteration

The aim of this work was to develop an assay capable of detecting adulteration of high premium milk with milk from cheaper sources. An indirect, competitive ELISA was developed for the rapid detection of cows' milk in the milk of goat, sheep, and buffalo. The assay uses a monoclonal antibody produced against bovine IgG. This antibody recognizes a species-specific epitope on the heavy chain of both bovine IgG1 and IgG2. A peroxidase-conjugated anti-mouse IgG antibody was used to detect bound monoclonal antibody and subsequent enzymatic conversion of substrate resulted in clear differences in absorbance when assaying different mixtures of milks adulterated with cows' milk. Once optimized, the ELISA was found to be highly specific. Detection limits of the assay are 1.0 microg/mL of bovine IgG, or 0.1% (vol/vol) adulteration with cows' milk. The assay was highly reproducible (CV < 10%) and performed equally well when used to detect bovine IgG in mixtures with the 3 types of milk tested. The ELISA performance makes it suitable for development as a kit, for use in the field as a high throughput screening ELISA.

Environmental pollution and the global burden of disease

Exposures to environmental pollution remain a major source of health risk throughout the world, though risks are generally higher in developing countries, where poverty, lack of investment in modern technology and weak environmental legislation combine to cause high pollution levels. Associations between environmental pollution and health outcome are, however, complex and often poorly characterized. Levels of exposure, for example, are often uncertain or unknown as a result of the lack of detailed monitoring and inevitable variations within any population group. Exposures may occur via a range of pathways and exposure processes. Individual pollutants may be implicated in a wide range of health effects, whereas few diseases are directly attributable to single pollutants. Long latency times, the effects of cumulative exposures, and multiple exposures to different pollutants which might act synergistically all create difficulties in unravelling associations between environmental pollution and health. Nevertheless, in recent years, several attempts have been made to assess the global burden of disease as a result of environmental pollution, either in terms of mortality or disability-adjusted life years (DALYs). About 8-9% of the total disease burden may be attributed to pollution, but considerably more in developing countries. Unsafe water, poor sanitation and poor hygiene are seen to be the major sources of exposure, along with indoor air pollution.