Allergen-induced cytokine production, atopic disease, IgE, and wheeze in children

Prenatal blood metals, per- and polyfluoroalkyl substances and antigen- or mitogen-stimulated cord blood lymphocyte proliferation and cytokine secretion

BACKGROUND

Evidence suggests that prenatal per- and polyfluoroalkyl substances (PFAS) and metals, two classes of chemicals found ubiquitously in human populations, influence immune system development and response.

OBJECTIVE

We evaluated whether first trimester blood PFAS and metals were associated with antigen- or mitogen-stimulated cord blood lymphocyte proliferation and cytokine secretion.

METHODS

We measured six PFAS, as well as six nonessential and four essential metals, in first trimester blood from participants in the longitudinal pre-birth Project Viva cohort, recruited between 1999 and 2000 in eastern Massachusetts. We measured antigen- or mitogen-stimulated cord blood mononuclear cell proliferation responses (n = 269-314) and cytokine secretion (n = 217-302). We used covariate-adjusted least absolute shrinkage and selection operator (LASSO) for variable selection and multivariable regression to estimate associations with the immune markers.

RESULTS

Each ng/mL of MeFOSAA was associated with a 3.6% (1.4, 5.8) higher lymphocyte proliferation response after stimulation with egg antigen, as well as 0.8 (0.7, 1.0) reduced odds of having IFN-γ detected in response to dust mite. Each ng/g increment of cesium was associated with 27.8% (-45.1, -4.9) lower IL-10 levels in response to dust mite. Each ng/g increment of mercury was associated with 12.0% (1.3, 23.8) higher IL-13 levels in response to mitogen PHA. Each ng/g increment of selenium and zinc was associated with 0.2% (0.01, 0.4) and 0.01% (0.002, 0.02) higher TNF-α in response to mitogen PHA, respectively.

CONCLUSIONS

Prenatal metals and PFAS influence cord blood lymphocyte proliferation and cytokine secretion in ways that may increase risk for atopic disease in childhood.

Effect of early postnatal supplementation of newborns with probiotic strain E. coli O83:K24:H31 on allergy incidence, dendritic cells, and microbiota

Introduction

Probiotic administration seems to be a rational approach to promote maturation of the neonatal immune system. Mutual interaction of the microbiota with the host immune system is critical for the setting of appropriate immune responses including a tolerogenic one and thevmaintenance of homeostasis. On the other hand, our knowledge on the modes of actions of probiotics is still scarce.

Methods

In our study, probiotic strain Escherichia coli O83:K24:H31 (EcO83) was administered to neonates of allergic mothers (AMs; neonates with increased risk for allergy development) within 48 h after the delivery, and the impact of this early postnatal supplementation on allergy incidence and selected immune markers has been analyzed 10 years after the primary EcO83 administration.

Results

We have observed decreased allergy incidence in 10-year-old children supplemented with EcO83 (13 of 52 children were allergic) in comparison with non-supplemented children of AMs (16 of 42 children were allergic). The early postnatal EcO83 supplementation appeared to limit the allergy in the high-risk group (children of AMs) compared to that in the low-risk group (children of healthy mothers). Dendritic cells (DCs) in the peripheral blood of EcO83-supplemented children do not differ significantly in cell surface presence of CD83. The immunomodulatory capacity of EcO83 on DCs was tested in vitro as well. Both directly isolated myeloid and in vitro monocyte-derived DCs from cord blood increased CD83 expression together with interleukin (IL)-10 secretion after EcO83 stimulation. The effect of early postnatal EcO83 supplementation on the microbiota composition of 10-year-old children was characterized by next-generation sequencing, and we have not observed significant changes in the microbiota composition of EcO83-supplemented and non-supplemented children at the age of 10 years.

Conclusions

Early postnatal EcO83 supplementation appears to lower allergy incidence in children of AMs. It seems that the beneficial effect of EcO83 is mediated via modulation of DC functional capacities without impacting the microbiota composition. Larger-scale studies will be necessary to confirm these preliminary findings.

Examining Associations Between Dietary Inflammatory Index in Pregnancy, Pro-inflammatory Cytokine and Chemokine Levels at Birth, and Offspring Asthma and/or Wheeze by Age 4 Years

BACKGROUND

Few studies have demonstrated associations between maternal dietary inflammatory index (DII) during pregnancy and offspring asthma and/or wheeze.

OBJECTIVE

The study aimed to assess associations between maternal DII during pregnancy and 1) offspring cord sera pro-inflammatory cytokines (interleukin [IL]-1β, IL-4, IL-6, IL-10, tumor necrosis factor-α) and chemokines (IL-8, monocyte chemoattractant protein-1) at birth and 2) offspring asthma and/or wheeze at age 4 years.

DESIGN

The Healthy Start study is a prospective prebirth longitudinal study that recruited pregnant women in Denver, Colorado and tracked their offspring.

PARTICIPANTS AND SETTING

This study used data from 1228 mother-child dyads enrolled in the Healthy Start study. Pregnant women were recruited in Denver, Colorado, between 2009 and 2014, and offspring tracked until age 4 years.

MAIN OUTCOME MEASURES

Cord sera cytokines and chemokines were analyzed with multiplex panel immunoassays. Offspring diagnosis of asthma and/or wheeze by age 4 years was extracted from electronic medical records.

STATISTICAL ANALYSES PERFORMED

Unadjusted and adjusted linear and logistic regression models were used to assess associations. Covariates included factors such as nulliparity, race/ethnicity, gestational smoking, and maternal history of asthma.

RESULTS

Unadjusted analysis showed that increasing maternal DII scores were associated with increased odds of child asthma and/or wheeze by 4 years (odds ratio = 1.17; 95% CI: 1.07-1.27), but the association was attenuated and no longer statistically significant in the adjusted model (odds ratio = 1.15; 95% CI: 0.99-1.33). There were no significant associations between DII scores and cord sera cytokine or chemokine levels.

CONCLUSIONS

The study showed that the inflammatory profile of the maternal diet was not associated with cytokines and chemokine levels at birth. The results suggested that a more inflammatory maternal diet was associated with increased odds of offspring asthma and/or wheeze by age 4 years, which could be considered of clinical relevance but the finding was not statistically significant at the .05 level.

Maternal Allergy Status Has No Impact on Neonatal Immune Responses to Allergen Stimuli

Due to the increasing incidence of allergic diseases, there is a strong need to identify a prognostic marker pointing to increased risk of allergy development allowing introduction of early preventive measures. Cord blood seems to be a good source for searching for such marker. The capacity of cord blood cells to respond to common allergens could point to increased predisposition to later allergy development. In our study, cytokines typical of Th1 (IFN-γ), Th2 (IL-5, IL-13) and Treg (IL-10) immune responses were followed at both the level of gene expression and cytokine secretion in cord blood cells of newborns of healthy mothers (children with relatively low risk of allergy development) and allergic mothers (children with relatively high risk of allergy development) stimulated by allergens (pollen from birch and timothy grass, house dust mite, ovalbumin). We have not observed any difference in the response of cord blood cells of neonates of healthy and allergic mothers to allergen in vitro. Both gene expression and secretion of cytokines in response to allergen stimulation were comparable with the unstimulated controls. It seems that early postnatal events will be more decisive for future allergy development than prenatal sensitization of the foetal immune system with allergen in utero in allergic mothers.

Associations between spontaneous parental perspective-taking and stimulated cytokine responses in children with asthma

OBJECTIVES

Cognitive empathy in parents-reflecting the extent to which one considers the perspectives and emotions of others-is hypothesized to contribute to family social environments in ways that affect youths' physical health. Using a novel assessment technique for cognitive empathy, the current study examined associations between spontaneous parental perspective-taking and key inflammatory processes implicated in pediatric asthma.

METHOD

One hundred thirty children (ages 9-17) with physician-diagnosed asthma, along with 1 parent, participated in the current study. Parents completed an interview from which statements of perspective-taking were coded and youths provided blood samples.

RESULTS

Youths whose parents demonstrated greater spontaneous perspective-taking during the interview had cells that mounted smaller inflammatory responses to stimulation by nonspecific, asthma-specific, and viral analogue ligands, as well as cells that showed greater sensitivity to the anti-inflammatory effects of glucocorticoids. These results were not accounted for by parental warmth or parent or youth depressive symptoms, nor by covariates of race, age, gender, parental education level, use of asthma medications over the past week, or asthma severity.

CONCLUSIONS

These findings suggest that parental perspective-taking may have implications for biological processes relevant to childhood asthma. (PsycINFO Database Record

The effect of the colostral cells on gene expression of cytokines in cord blood cells

Beneficial effect of maternal milk is acknowledged, but there is still question whether maternal milk from allergic mother is as good as from healthy one. In our study, we have assayed the effect of cells from colostrum of healthy and allergic mothers on gene expression of cytokines in cord blood cells of newborns of healthy and allergic mothers. Cytokines typical for Th1 (IL-2, IFN-gamma), Th2 (IL-4, IL-13), Tregs (IL-10, TGF-beta), and IL-8 were followed. We were not able to detect significant influence of colostral cells on gene expression of cytokines in cord blood after 2-day coculture using Transwell system. There was no difference in gene expression of cytokines in nonstimulated cord blood cells of newborns of healthy and allergic mothers, but generally increased gene expression of cytokines except IL-10 and TGF-beta after polyclonal stimulation was detected in cord blood cells of children of allergic mothers. There was no difference in IL-10 expression in stimulated cord blood cells of children of healthy and allergic mothers. Gene expression of TGF-beta was even decreased in stimulated cord blood cells of children of allergic mothers in comparison to healthy ones. We have not observed difference in the capacity of colostral cells of healthy and allergic mothers to influence gene expression of cytokines in cord blood cells, but we have described difference in the reactivity of cord blood cells between children of allergic and healthy mothers.

Mould-sensitized adults have lower Th2 cytokines and a higher prevalence of asthma than those sensitized to other aeroallergens

BACKGROUND

Evidence suggests that specific allergen sensitizations are associated with different allergic diseases which may reflect different underlying immune profiles. We aimed to examine the cytokine profiles of individuals sensitized to eight common aeroallergens.

METHODS

We used data from the Tasmanian Longitudinal Health Study a population-based cohort study of 45-year-olds. Serum cytokines (IL-4, IL-5, IL-6, IL-8, IL-10, TNF-α) were measured in 1157 subjects using the LINCOplex assays. Participants underwent skin prick testing for house dust mite, cat, grasses and moulds. Multivariable linear regression was used to compare serum cytokine levels between sensitized and nonatopic subjects.

RESULTS

The prevalence of allergic sensitization to any aeroallergen was 51% (95% CI 47-54). Being sensitized to any aeroallergen was strongly associated with current asthma (OR = 3.7, 95% CI 2.6-5.3), and being sensitized to any moulds was associated with a very high risk of current asthma (OR = 6.40, 95% CI 4.06-10.1). The geometric mean (GM) levels of Th2 cytokines (IL-4, IL-5 and IL-6) for adults sensitized to Cladosporium were significantly lower than the levels for nonatopic individuals (IL-4 ratio of GMs = 0.25, 95% CI 0.10-0.62, P = 0.003; IL-5 GM = 0.55, 95% CI 0.30-0.99, P = 0.05; and IL-6 GM = 0.50, 95% CI 0.24-1.07, P = 0.07). Individuals sensitized to other aeroallergens all showed elevated Th2 cytokine levels.

CONCLUSION

Our study is the first large population-based study to demonstrate reduced Th2 cytokines levels in people sensitized to mould. Underlying biological mechanisms driving allergic inflammatory responses in adults sensitized to moulds may differ from those sensitized to other aeroallergens. These findings suggest that it may be necessary to tailor treatments in individuals sensitized to moulds compared with other aeroallergens in order to optimize outcomes.

Biomarkers to predict asthma in wheezing preschool children

Wheezing in preschool children is a very common symptom. An adequate prediction of asthma in these children is difficult and cannot be reliably assessed with conventional clinical tools. The study of potential predictive biomarkers in various media, ranging from invasive sampling (e.g. bronchoscopy) to non-invasive sampling (lung function testing and exhaled breath analysis), was comprehensively reviewed. The evolution in biomarker discovery has resulted in an 'omics' approach, in which hundreds of biomarkers in the field of genomics, proteomics, metabolomics, and 'breath-omics' can be simultaneously studied. First, results on gene expression and exhaled breath profiles in predicting an early asthma diagnosis are promising. However, many hurdles need to be overcome before clinical implementation is possible. To reliably predict asthma in a wheezing child, probably a holistic approach is needed, combining clinical information with blood sampling, lung function tests, and potentially exhaled breath analysis. The further development of predictive, non-invasive biomarkers may eventually improve an early asthma diagnosis in wheezing preschool children and assist clinicians in early treatment decision-making.

Dimensions of Socioeconomic Status and Childhood Asthma Outcomes: Evidence for Distinct Behavioral and Biological Associations

OBJECTIVES

The objective of this study was to investigate 2 key dimensions of socioeconomic status (SES)-prestige and resources-and their associations with immune, behavioral, and clinical outcomes in childhood asthma.

METHODS

Children ages 9 to 17 years with a physician's diagnosis of asthma (N = 150), and one of their parents participated in this study. Children and parents completed interviews and questionnaires about SES (prestige = parent education; resources = family assets), environmental exposures, and clinical asthma measures. Spirometry was conducted to assess children's pulmonary function, and blood was collected to measure cytokine production in response to nonspecific stimulation, allergen-specific stimulation, and microbial stimulation.

RESULTS

Higher scores on both dimensions of childhood SES were associated with better clinical outcomes in children (β's from |.18 to .27|, p values < .05). Higher prestige, but not resources, was associated with better home environment control behaviors and less exposure to smoke (β's from |.21 to .22|, p values < .05). Higher resources, but not prestige, was associated with more favorable immune regulation, as manifest in smaller peripheral blood mononuclear cell (PBMC) TH1 and TH2 cytokine responses (β's from -.18 to -.19; p values < .05), and smaller proinflammatory cytokine responses (β = -.19; p < .05) after ex vivo stimulation. Higher resources also were associated with more sensitivity to glucocorticoid inhibition of TH1 and TH2 cytokine production (β's from -.18 to -.22; p values < .05).

CONCLUSIONS

These results suggest that prestige and resources in childhood family environments have different implications for behavioral and immunological processes relevant to childhood asthma. They also suggest that childhood SES relates to multiple aspects of immunologic regulation of relevance to the pathophysiology of asthma.

Atopy, cytokine production, and airway reactivity as predictors of pre-school asthma and airway responsiveness

BACKGROUND

Childhood asthma is often characterized by recurrent wheezing, airway hyper-reactivity, atopy, and altered immune characteristics; however, our understanding of the development of these relationships from early in life remains unclear. The aim of our study was to evaluate whether atopy, cytokine production by peripheral blood mononuclear cells (PBMCs), and airway responsiveness, assessed in infants and toddlers, are associated with asthma and airway responsiveness at 4-years of age.

METHODS

Infants with eczema (N = 116), enrolled prior to wheezing, were assessed at entry (mean age of 10.7 months), at 1-year follow-up (N = 112), and at 4-years of age (N = 94). Total serum IgE, specific IgE to allergens, and cytokines produced by stimulated PBMCs, were assessed at entry and 1-year follow-up. Spirometry was obtained at all 3-visits, while airway reactivity to methacholine was assessed at entry and 1-year follow-up, and bronchodilator (BD) responsiveness, as well as current asthma was assessed at 4-years of age.

RESULTS

We found that pre-school children with asthma had lower spirometry and a greater BD-response. Serum IgE, particularly to egg and/or milk, and altered cytokine production by PBMCs at entry to the study were associated with asthma, lower spirometry, and greater airway responsiveness at 4-years of age. In addition, we found that airway responsiveness, as well as spirometry, tracked from infancy to 4-years of age.

CONCLUSIONS

While spirometry and airway responsiveness track longitudinally from early in life, atopy and cytokine production by PBMCs are associated not only with an increased risk of pre-school asthma, but also lower spirometry and increased airway responsiveness.

The neonatal susceptibility window for inhalant allergen sensitization in the atopically predisposed canine asthma model

Allergic asthma often begins in early life and, although many risk factors have been enumerated, the specific factors that initiate disease progression in an individual remain unclear. Using our dog model of early life allergen inhalation, we tested the hypothesis that the atopically biased neonatal immune system would exhibit tolerance to ragweed if allowed to mature normally before exposure or artificially through innate immune stimulation with early life exposure. Dogs were subjected to a series of inhalational ragweed exposures from 1 to 20 weeks old, with or without inhalation of a Toll-like receptor 4 (TLR4) agonist (CRX-527), or from 13 to 31 weeks old. Serum allergen-specific antibody response was assessed at 4, 8 and 20 weeks after the last sensitizing exposure. At 24 or 35 weeks old, airway hyper-responsiveness to methacholine and ragweed challenges and pulmonary inflammation by bronchoalveolar lavage were tested 1 and 4 days after ragweed challenge at 28 or 39 weeks old. Allergen-free immune maturation resulted in no airway hyper-responsiveness and very little ragweed-specific IgE relative to the control group, but eosinophilia developed upon ragweed challenge. TLR4 agonism yielded no airway hyper-responsiveness, but a strong airway neutrophilia developed upon ragweed challenge. Our data indicate that an atopic predisposition creates a critical window in which allergen exposure can lead to an asthmatic phenotype. Allergen-free immune maturation may lead to allergen tolerance. TLR4 agonism before early life allergen exposure may abrogate the development of allergen-specific bronchonconstriction, but allergen-specific pulmonary inflammation remains a strong concern.

Serum levels of interleukin-13 and interferon-gamma from adult patients with asthma in Mysore

Serum protein analysis for noninvasive quantification of airway inflammation in asthma is a promising research tool in the field of lung diseases. Cytokines are believed to have major role in inflammatory process of the airways of the lung. There is an imbalance between T-helper (Th)-2 cells, which secrete interleukin (IL)-4 and interleukin (IL)-13, and Th1 cells, which secrete interferon (IFN)-gamma in asthma. To test the hypothesis that serum IL-13 and IL-4 levels may be elevated whereas IFN-gamma would be decreased in this cohort of patients, a property that could make them possible candidate biomarkers in determining asthma occurrence and severity, we measured concentrations of IL-4, IL-13 and IFN-gamma in serum samples of 88 subjects (44 normal, 12 with mild asthma, 16 with moderate asthma, and 16 with severe asthma). Serum Levels of IL-4, IL-13, and IFN-gamma were determined by an enzyme-linked immune-sorbent assay (ELISA). Median serum level of IFN-gamma in asthmatic patients was 8.0 pg/ml, while it was 11.4 pg/ml in healthy controls. However, the difference was not significant. Among the different age groups in whom IFN-gamma was assessed, the highest median value in both cases and controls was observed in the age group of 31-40 years. The median serum level of IL-13 was 40.0 pg/ml in asthmatic patients and 58.25 pg/ml in healthy controls. The difference was not significant. On subgroup analysis, no significant difference of IFN-gamma and IL-13 between asthma of different severities was observed. The study also revealed nonsignificant difference of serum cytokines with the duration of asthma, number of allergens, and severity of sensitization. Normal serum levels of IFN-gamma and IL-13 in asthmatic patients suggest their neutral role in the inflammatory process; however, more studies are required to establish the effect of these cytokines in adulthood asthma in different ethnic populations.

Atopy is associated with asthma in adults living in rural and urban southwestern Nigeria

RATIONALE

Factors affecting the course of asthma are not clearly understood in rural and urban communities within low-resource countries. Furthermore, the interactions between atopy, environmental exposure, and helminthic infections in modulating asthma have not been well investigated.

OBJECTIVES

To conduct a feasibility study to examine the relationship between atopy and asthma in adults at two rural Health Centers and urban university college hospital in southwestern Nigeria.

METHODS

A convenient sample of 55 consecutive patients with stable physician-diagnosed asthma and 55 age-matched nonasthmatic controls seen at the outpatient clinics in two rural Health Centers and an urban university hospital were enrolled. All subjects underwent blood test, allergy skin test, and stool examination for ova and parasites. Wilcoxon sign-rank tests were used to compare serum eosinophilia and allergy skin test between the two groups.

RESULTS

Asthmatics in both urban and rural settings had significantly more positive skin reactions to house dust mite, cockroach, mold, and mouse epithelium than nonasthmatic controls (p < .05). Mean total serum IgE was also significantly higher in asthmatics than in nonasthmatic controls (360 vs. 90 IU/L, p <.001). Stool parasitemia was infrequent in both groups and not statistically significant.

CONCLUSION

Atopy is associated with adult asthma in southwest Nigeria. Larger studies to confirm the nature of this association and to examine the role of helminthic infection and other environmental factors on the expression of asthma are needed.

Cytokine expression in cord blood cells of children of healthy and allergic mothers

To determine some early signs connected with the increased risk of future allergy development, gene expression and production of selected cytokines were tested in children of allergic mothers and compared with newborns of healthy mothers. Expression of IL-1β, IL-2, IL-4, IL-8, IL-10, IL-13, IFN-γ, TNF-α, TGF-β and EGF was tested in cord blood cells using real-time PCR and production of these cytokines was evaluated in cord sera by ELISA. Gene expression of IL-2, IL-4, IL-8, IFN-γ, IL-1β, TNF-α and TGF-β was decreased and that of IL-10, IL-13 and EGF increased in children of allergic mothers in comparison with those of healthy mothers. Significant differences in sera of healthy and allergic groups were only in IL-10 and EGF. Different relationship among serum cytokine levels reflects the fact that the cytokines are not produced only by blood cells. Significantly decreased production of EGF in newborns of allergic mothers could negatively influence maturation of mucosal membranes of these children and support thus their easier allergization. Allergic phenotype pointing to the bias to T(H)2 response and to possibly impaired intestine maturation was apparent already on the level of cord blood and could serve as a predictive sign of increased allergy risk.

Maturation of cytokine-producing capacity from birth to 1 yr of age

Little is known about the immunologic maturation in the early stages of life. The aim of this study was to investigate maturation of immune system from birth to 1 yr of age and to compare immune functions between mothers and their children. Also the effect of atopy to the immune responses of children was examined. Cord blood samples (n = 228) and peripheral blood samples of children (n = 200) and their mothers (n = 208) 1 yr after birth were collected. Whole blood samples were stimulated for 24 and 48 h with Staphylococcal enterotoxin B (SEB), lipopolysaccharide (LPS) and the combination of phorbol ester and ionomycin (P/I). Production of TNF-alpha, IFN-gamma, IL-5, IL-8 and IL-10 was determined using ELISA. Significant mother-to-child correlation was detected in cytokine-producing capacity at the age of 1 yr. TNF-alpha (P/I, SEB and LPS stimulation), IFN-gamma (P/I and SEB), IL-5 (P/I and SEB) and IL-10 (P/I, SEB and LPS) producing capacity increased from birth to 1 yr of age. In general, stimulated cytokine responses were higher in mothers' than in children's blood samples, except in the case of P/I and LPS-stimulated IL-8, which were highest at birth. Maternal inhalation atopy was associated with increased cord blood IL-5 (24 and 48 h) and IL-10 (48 h) production following P/I stimulation. Also children of food atopic mothers expressed elevated cord blood IL-10 (48 h, P/I) responses and decreased IFN-gamma/IL-5 ratio (24 h, P/I). In addition, the production of IFN-gamma (24 and 48 h, P/I) and the IFN-gamma/IL-5 ratio (24 h and 48 h, P/I) at the age of 1 yr was lower among children with food atopic mothers. In conclusion, our results suggest that both adaptive and innate immune responses increase from birth to 1 yr of age, but are still weak in comparison to adult responses. Cytokine responses of children begin to correlate with those of their mothers during the first year of life. Although only few associations were observed between atopy and cytokine-producing capacity, our results suggest that children of atopic mothers express T(h)2-polarized cytokine pattern.

Pregnancy IFN-gamma responses to foetal alloantigens are altered by maternal allergy and gravidity status

BACKGROUND

During pregnancy, variations in maternal-foetal cellular interactions may influence immune programming. This study was carried out to determine if maternal responses to foetal alloantigens are altered by maternal allergic disease and/or previous pregnancies.

METHODS

For this cohort study, peripheral blood was collected from allergic (n = 69) and nonallergic (n = 63) pregnant women at 20, 30, 36-week gestation and 6-week postpartum (pp). Cord blood was collected at delivery. Mixed lymphocyte reactions were used to measure maternal cytokine responses [interleukin-6 (IL-6), IL-10, IL-13 and (interferon-gamma) IFN-gamma] at each time point towards foetal mononuclear cells.

RESULTS

Maternal cytokine responses during pregnancy (20, 30 and 36 weeks) were suppressed compared to the responses at 6-week pp. The ratio of maternal IFN-gamma/IL-13 and IFN-gamma/IL-10 responses were lower during pregnancy. Allergic mothers had lower IFN-gamma responses at each time-point during pregnancy with the greatest difference in responses observed at 36-week gestation. When allergic and nonallergic women were further stratified by gravidity group, IFN-gamma responses of allergic multigravid mothers were significantly lower than nonallergic multigravid mothers during pregnancy.

CONCLUSIONS

During normal pregnancy, peripheral T-cell cytokine responses to foetal alloantigens may be altered by both allergic status of the mother and previous pregnancies. These factors could influence the cytokine milieu experienced by the foetus and will be further explored in the development of allergic disease during early life.

Correlation of psychological and physical symptoms with chronically elevated cytokine levels associated with a common immune dysregulation

BACKGROUND

Chronically elevated levels of proinflammatory cytokines are associated with inflammatory diseases and psychological symptoms of depression and tiredness.

OBJECTIVE

To test the prediction that, in a healthy population without medically diagnosed diseases, psychological symptoms (depression and tiredness) associated with proinflammatory cytokines correlate with physical symptoms associated with inflammatory disease.

METHODS

A total of 1,143 women between 45 and 65 years old completed a health complaint checklist containing 11 target symptoms (5 related to allergy, 4 to gastrointestinal symptoms, and 2 to pain), 7 control symptoms or health complaints, and 2 psychological symptoms (depression and tiredness). They also completed a menopausal quality-of-life questionnaire; to compensate for response bias, we removed variance attributable to quality of life.

RESULTS

The partial correlations show that tiredness (but not depression) correlated with 9 of the 11 target symptoms (P < .001) but with 0 of the 7 control symptoms or complaints. Symptoms of both the specific and the systemic components of inflammatory disease are correlated in a healthy population.

CONCLUSION

Immune dysregulation may explain the existence and covariation of psychological and physical symptoms in the healthy population, including people with medically unexplained symptoms.

Elevated allergen-induced IL-13 secretion predicts IgE elevation in children ages 2-5 years

It is unclear if early immune responses to allergens, specifically Th1 and Th2 cytokine production, predict later immune responses, including increased IgE levels. In a group of children (n = 151) with a parental history of allergy or asthma followed from ages 2 through 5 years, we examined IL-13, IL-4, and IFN-gamma secretion by peripheral blood mononuclear cells in response to phytohemagglutinin (PHA), and to dust mite (Der f 1), cockroach (Bla g 2), and cat (Fel d 1) allergens in relation to elevated IgE. Elevated IgE was defined either as a positive IgE-specific response to at least one allergen (dust mite, cockroach, cat, and ovalbumin) or as an elevated total IgE level above a specified cut-off value. In multivariate logistic regression models including 181 observations made between the age of 2 through 5 years and accounting for repeated measures, we found an association between increased IL-13 secretion in response to Der f 1 and elevated IgE (odds ratio [OR] = 1.21, 95% confidence interval [CI] = 1.09-1.34). Age did not modify this relationship. No association was found between allergen-induced IFN-gamma secretion and IgE production. Among the group of children with measurements made at age 4-5 (n = 70), IL-13 in response to Der f 1 (p = 0.046), and IL-4 in response to PHA (p = 0.04) were increased among children with elevated IgE. In a smaller subset of children with measurements made at both age 2-3 and age 4-5 (n = 36), IL-13 levels at age 2-3 were also significantly increased in response to Der f 1 (p = 0.01) and Fel d 1 (p = 0.002) among those with elevated IgE at age 4-5. In a group of children ages 2-5 years, there is an association between IL-13 and elevated IgE.

Antenatal risk factors, cytokines and the development of atopic disease in early childhood

Atopic diseases are complex entities influenced by an array of risk factors, including genetic predisposition, environmental allergens, antenatal exposures, infections and psychosocial factors. One proposed mechanism by which these risk factors contribute to the development of atopic disease is through changes in the production of T helper cell type 1 (Th1) and T helper cell type 2 (Th2) cytokines. The objectives of this review are to discuss antenatal exposures that are associated with paediatric atopic diseases, to discuss the influence of the intrauterine environment on neonatal immune responses, to provide an overview of the Th1 and Th2 pathways and how they relate to atopic disease, and to summarise our current understanding of the association between cytokine responses in cord blood and the development of atopic disease in early childhood.

Allergen-specific in vitro cytokine production in adult patients with eosinophilic esophagitis

Although the pathogenesis of eosinophilic esophagitis (EE) likely involves hypersensitivity reactions against exogenous allergens, allergen-specific cellular immune responses have not been studied. We investigated allergen-induced cytokine production by peripheral blood mononuclear cells (PBMCs) in adult patients with EE (n=15) and healthy controls (HC; n=9). PBMCs were incubated with nine common food and environmental allergens or a nonspecific mitogen, and the levels of interleukin (IL)-5, IL-10, IL-13, and interferon-gamma in the cell-free supernatants were determined. Spontaneous and mitogen-stimulated cytokine production did not differ between EE and HC. House dust mite, ragweed, Aspergillus, milk, and soy induced significantly higher IL-5 production in EE (P < 0.05). House dust mite also augmented IL-13 production in EE (P < 0.05). Furthermore, PBMCs from three EE patients without allergen-specific IgE vigorously produced IL-5 and IL-13 on allergen stimulation. Thus, immune responses in EE are characterized by enhanced production of Th2-like cytokines against both food and environmental allergens.

Prenatal, perinatal, and heritable influences on cord blood immune responses

BACKGROUND

Maternal and perinatal environmental exposures, as well as inherited factors, may influence neonatal immune responses.

OBJECTIVE

To determine relations of maternal and perinatal exposures to antigen-specific cord blood lymphoproliferative responses.

METHODS

In 427 newborns from a Boston pregnancy/birth cohort, lymphoproliferative responses in cord blood mononuclear cells to stimulation with cockroach (Bla g 2), house dust mite (Der f 1), ovalbumin, and mitogen phytohemagglutinin were measured as stimulation index (SI). We used the Wilcoxon rank sum and chi2 tests to evaluate predictors of ovalbumin SI as a continuous ranked or dichotomous outcome. We used t test and Spearman correlation for univariate testing and linear regression to evaluate predictors of natural log-transformed Bla g 2, Der f 1, and phytohemagglutinin SI. Logistic multivariate regression was applied to evaluate predictors of Bla g 2, Der f 1, and phytohemagglutinin SI dichotomized at 2 or at the median for phytohemagglutinin.

RESULTS

Maternal smoking during pregnancy, inadequate or excessive maternal weight gain during pregnancy, neonate black race/ethnicity (compared with white), and Apgar score less than 8 were each independently associated with increased cord blood mononuclear cell proliferative responses to stimulation with Bla g 2 and/or Der f 1. Maternal history of asthma was associated only with increased lymphoproliferative response to ovalbumin stimulation.

CONCLUSIONS

Distinct fetal and perinatal exposures and black race/ethnicity may be associated with increased cord blood lymphoproliferative responses. The implications of these findings for future development of allergy or asthma are, as yet, unknown.

Cytokines, allergy, and asthma

PURPOSE OF REVIEW

This review examines recent articles on the relationship of cytokines to allergy and asthma with particular emphasis on immune mechanisms involved in disease development in early life.

RECENT FINDINGS

It was previously proposed that reduced microbial exposure in early life is responsible for a shift of the Th1/Th2 balance in the immune system towards the proallergenic Th2 response. This Th1/Th2 imbalance results in the clinical expression of allergy and/or asthma. In recent years, accumulating data from mice and humans have identified Th2 cytokines [interleukin (IL)-4, IL-13, and IL-5] as major contributors to allergy and asthma. Interestingly, the Th1 cytokine interferon-gamma has recently been shown to act concurrently with Th2 cytokines in maintaining the chronic inflammatory response in allergic diseases, particularly in asthmatic airways. Most recently, evidence suggests that suppression of T-regulatory cells may contribute to the underlying immune mechanisms involved in allergy and asthma.

SUMMARY

An enhanced Th2 immune response and the elaboration of cytokines such as IL-4, IL-13, and IL-5 contribute to the induction of allergy and asthma. Interferon-gamma, a Th1 cytokine, acts in conjunction with Th2 (IL-4, IL-13, and IL-5) in maintaining chronic allergic inflammation. The mechanisms leading to an enhanced Th2 response are still controversial. Th2-dominated immune responses may result from immune suppression of T-regulatory cells as well as Th1 cells. Understanding early-life immune mechanisms responsible for atopic diseases, specifically how cytokines of T-regulatory cells act to balance the Th1 and Th2 immune response, continues to be a fruitful area of research.

The effect of treatment with montelukast on in vitro interleukin-10 production of mononuclear cells of children with asthma

BACKGROUND

The effects of leukotriene modifiers on IL-10 production have not been studied in children with asthma.

OBJECTIVE

The primary objective of this study was to determine the changes in IL-10 concentrations, clinical efficacy and peripheral blood eosinophil counts after treatment with montelukast.

METHODS

The study was conducted on 27 patients: 13 patients monoallergic to grass pollen during the pollen season (GPs group) and out of the pollen season (GPos group), and on 14 patients monoallergic to house dust mite (HDM) from May to September (HDM group). Main outcome measures were changes in concentrations of IL-10 in the supernatant after a 4-week treatment with montelukast. Measurements of asthma severity score, forced expiratory volume in 1 s (FEV1) and peripheral blood eosinophil counts were the secondary end-points.

RESULTS

Montelukast resulted in a within-group significant increase in IL-10 concentration in the supernatant in the GPs (54.0 vs. 125.5 pg/mL) and in the HDM (51.2 vs. 77.1 pg/mL) group. Montelukast had no effect on changes of IL-10 concentration in the supernatant from peripheral blood mononuclear cell (PBMC) culture after non-sensitizing allergen stimulation. Montelukast significantly improved asthma control and FEV1, and significantly decreased eosinophil blood count in the GPs and in the HDM group after a 4-week treatment. Montelukast did not lead to changes of all measured parameters within the GPos group.

CONCLUSION

Montelukast increased IL-10 concentration in supernatants from sensitizing allergen-stimulated PBMC culture obtained from children with asthma monoallergic to grass pollen during the pollen season, and from children with asthma monoallergic to HDM.

Asthma and farm exposures in a cohort of rural Iowa children

Epidemiologic studies of farm children are of international interest because farm children are less often atopic, have less allergic disease, and often have less asthma than do nonfarm children--findings consistent with the hygiene hypothesis. We studied a cohort of rural Iowa children to determine the association between farm and other environmental risk factors with four asthma outcomes: doctor-diagnosed asthma, doctor-diagnosed asthma/medication for wheeze, current wheeze, and cough with exercise. Doctor-diagnosed asthma prevalence was 12%, but at least one of these four health outcomes was found in more than a third of the cohort. Multivariable models of the four health outcomes found independent associations between male sex (three asthma outcomes), age (three asthma outcomes), a personal history of allergies (four asthma outcomes), family history of allergic disease (two asthma outcomes), premature birth (one asthma outcome), early respiratory infection (three asthma outcomes), high-risk birth (two asthma outcomes), and farm exposure to raising swine and adding antibiotics to feed (two asthma outcomes). The high prevalence of rural childhood asthma and asthma symptoms underscores the need for asthma screening programs and improved asthma diagnosis and treatment. The high prevalence of asthma health outcomes among farm children living on farms that raise swine (44.1%, p = 0.01) and raise swine and add antibiotics to feed (55.8%, p = 0.013), despite lower rates of atopy and personal histories of allergy, suggests the need for awareness and prevention measures and more population-based studies to further assess environmental and genetic determinants of asthma among farm children.

Nuclear factor kappa B activation in human cord blood mononuclear cells

The immunologic signals participating in immune responses early in life have not been completely elucidated. Regarding the characterization of neonatal cells, little is known concerning the activity of transcription factor nuclear factor kappa B (NF-kappaB), which regulates inflammatory genes and cytokine production. The aim of this study was to characterize NF-kappaB activation in cord blood mononuclear cells (CBMC). We analyzed the potential association of NF-kappaB activity with lymphocyte proliferation and influences on cytokine secretion in the early immune system. To determine the contribution of a disease whereby inheritance may impact neonatal immunity, we assessed the influence of maternal allergic disease on NF-kappaB regulation and cytokine secretion. CBMC from healthy newborns were isolated and stimulated with mitogen (n = 28). Nuclear extracts were analyzed by electrophoretic mobility shift assay, cytokine secretion by ELISA. FISH analysis excluded relevant maternal contamination of CBMC. All samples showed a positive lymphoproliferative response, and NF-kappaB activity was both increased and decreased after mitogen stimulation. Increased NF-kappaB activation was significantly associated with decreased TNF-alpha secretion (median 6.1 versus 50.3 pg/mL) in unstimulated CBMC. Mitogen stimulation resulted in increased NF-kappaB activity with a trend to increased IL-13 production. Maternal allergic disease was associated with higher TNF-alpha (median 982 versus 173 pg/mL) and IL-13 secretion (median 1328 versus 1120 pg/mL) after mitogen stimulation. Together, NF-kappaB activity is differentially activated in cord blood and associated with a distinct cytokine pattern. Whether differential NF-kappaB activity in cord blood is related to the subsequent development of immune diseases requires further investigation.