Relation between stressful life events, neuropeptides and cytokines: results from the LISA birth cohort study

Hyper-inflammation of astrocytes in patients of major depressive disorder: Evidence from serum astrocyte-derived extracellular vesicles

Astrocyte-derived extracellular vesicles (ADEs) allow the in vivo probing of the inflammatory status of astrocytes practical. Serum sample and ADEs were used to test the inflammatory hypothesis in 70 patients with major depressive disorder (MDD) and 70 matched healthy controls (HCs). In serum, tumor necrosis factor α (TNF-α) and interleukin (IL)-17A were significantly increased, where as IL-12p70 was significantly reduced in the MDD patients compared with HCs. In ADEs, all inflammatory markers (Interferon-γ, IL-12p70, IL-1β, IL-2, IL-4, IL-6, TNF-α, and IL-17A) except IL-10 were significantly increased in the MDD patients, the Hedge's g values of elevated inflammatory markers varied from 0.48 to 1.07. However, there were no differences of all inflammatory markers whether in serum or ADEs between MDD-drug free and medicated subgroups. The association of inflammatory biomarkers between ADEs and serum did not reach statistically significance after multi-comparison correction neither in the HCs nor MDD patients. The spearman coefficients between inflammatory factors and clinical characteristics in the MDD patients, such as onset age, disease course, current episode duration, and severity of depression, were nonsignificant after multi-comparison correction. In the receiver operating characteristic curves analysis, the corrected partial area under the curve (pAUC) of each inflammatory markers in ADEs ranged from 0.522 to 0.696, and the combination of these inflammatory factors achieved a high pAUC (>0.9). Our findings support the inflammatory glial hypothesis of depression, and suggests that in human ADEs could be a useful tool to probe the in vivo astrocyte status.

Autoimmune pre-disease

Approximately 5% of the world-wide population is affected by autoimmune diseases. Overall, autoimmune diseases are still difficult to treat, impose a high burden on patients, and have a significant economic impact. Like other complex diseases, e.g., cancer, autoimmune diseases develop over several years. Decisive steps in the development of autoimmune diseases are (i) the development of autoantigen-specific lymphocytes and (often) autoantibodies and (ii) potentially clinical disease manifestation at a later stage. However, not all healthy individuals with autoantibodies develop disease manifestations. Identifying autoantibody-positive healthy individuals and monitoring and inhibiting their switch to inflammatory autoimmune disease conditions are currently in their infancy. The switch from harmless to inflammatory autoantigen-specific T and B-cell and autoantibody responses seems to be the hallmark for the decisive factor in inflammatory autoimmune disease conditions. Accordingly, biomarkers allowing us to predict this progression would have a significant impact. Several factors, such as genetics and the environment, especially diet, smoking, exposure to pollutants, infections, stress, and shift work, might influence the progression from harmless to inflammatory autoimmune conditions. To inspire research directed at defining and ultimately targeting autoimmune predisease, here, we review published evidence underlying the progression from health to autoimmune predisease and ultimately to clinically manifest inflammatory autoimmune disease, addressing the following 3 questions: (i) what is the current status, (ii) what is missing, (iii) and what are the future perspectives for defining and modulating autoimmune predisease.

Adverse childhood experiences and biomarkers of inflammation in a diverse cohort of early school-aged children

Objective

The objective of this study was to evaluate the relationship between ACEs and inflammatory profiles (i.e., pro- and anti-) in early childhood and to examine whether patterns differ for racial/ethnic subgroups.

Study design

Using longitudinal data from the Multidimensional Assessment of Preschoolers Study (MAPS) (N = 122), we examined the relationship between adverse childhood experiences (ACEs) beginning at birth, C -reactive protein (CRP), and both pro-inflammatory (i.e., IL-1 β, IL-6, TNF, and CRP) and anti-inflammatory (i.e. IL-4 and IL-10) biomarkers during early school age (ages 6-8 years).

Results

No children in the sample were reported to have experienced 0 ACES, 7% had 1 ACE, 51% had 2-3 ACEs, and 42% had 4 or more ACEs accumulated by the early school-age wave (ESA). There were no significant associations between cumulative ACEs and inflammatory markers. However, parental substance abuse, a specific ACE, was positively correlated with a pro-inflammatory profile at early school age (r = 0.18, p<.05). Specifically, substance abuse as an ACE was associated with higher levels of pro-inflammatory markers such as IL-1 β and IL-6. Additionally, Hispanics with ACEs had higher levels of CRP than Black and white individuals.

Conclusions

Children with histories of ACEs, especially those with parental substance abuse, may have higher levels of inflammation. Better understanding the role of inflammation in the development of chronic diseases for individuals with ACEs may allow earlier identification and prevention of disease during childhood for those at the highest risk.

Childhood adversity and mechanistic links to hypertension risk in adulthood

Adverse childhood experiences (ACEs), defined as traumatic events in childhood that range from various forms of abuse to household challenges and dysfunction, have devastating consequences on adult health. Epidemiological studies in humans and animal models of early life stress (ELS) have revealed a strong association and insight into the mechanistic link between ACEs and increased risk of cardiovascular disease (CVD). This review focuses on the mechanistic links of ACEs in humans and ELS in mice and rats to vasoactive factors and immune mediators associated with CVD and hypertension risk, as well as sex differences in these phenomena. Major topics of discussion in this review are as follows: (a) epidemiological associations between ACEs and CVD risk focusing on hypertension, (b) evidence for association of ACE exposures to immune-mediated and/or vasoactive pathways, (c) rodent models of ELS-induced hypertension risk, (d) proinflammatory mediators and vasoactive factors as mechanisms of ELS-induced hypertension risk. We also provide some overall conclusions and directions of further research. LINKED ARTICLES: This article is part of a themed section on Immune Targets in Hypertension. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v176.12/issuetoc.

Stressful life events in childhood and allergic sensitization

Stressful life events evidently have an impact on development of allergic diseases, but the mechanism linking stress to pathological changes of immune system function is still not fully understood. The aim of our study was to investigate the relationship between stressful life events, neuropeptide and cytokine concentrations in children as well as the association between early stressful life events and atopic eczema (AE). Within the LISA plus (Life style – Immune system – Allergy) study, blood samples from children of 6 years of age were analyzed for concentration of the neuropeptides vasoactive intestinal peptide (VIP), somatostatin (SOM), substance P (SP) and the Th1/Th2 cytokines IFN-γ and IL-4. Life events such as severe disease or death of a family member, unemployment or divorce of the parents were assessed with a questionnaire filled in by the parents. Furthermore, lifetime prevalence of AE and incidence after the assessment period of life events were compared. Our data suggest that separation/ divorce of parents increase childrens risk of developing AE later in life. Children with separated/divorced parents showed high VIP levels and high concentrations of the Th2 cytokine IL-4 in their blood. Severe diseases and death of a family member were neither associated with neuropeptide levels nor with cytokine concentrations. Unemployment of the parents was associated with decreased IFN-γ concentrations in childrens blood but not with neuropeptide levels. Thus, the neuropeptide VIP might be a mediator between stressful life events and immune regulation contributing to the Th2-shifted immune response in children with separated/divorced parents.

Influence of early-life parental severe life events on the risk of type 1 diabetes in children: the DiPiS study

AIMS

Stress and severe life events (SLEs) modify autoimmune disease susceptibility. Here, we aimed to establish if SLEs reported by parents during the first 2 years of life influence the risk of developing type 1 diabetes (T1D) using data from the prospective Diabetes Prediction in Skåne (DiPiS) study.

METHODS

Prospective questionnaire data recorded at 2 months (n = 23,187) and 2 years of age (n = 3784) from the DiPiS cohort of children were included in the analysis. SLEs were analyzed both by groups and as a combined variable. A Cox proportional hazards model was used to calculate hazard ratios (HRs) for T1D diagnosis for the total cohort and for the HLA-DQ2/8 high-risk population. Affected first-degree relatives, HLA-DQ risk group, paternal education level, and parents' country of birth were included as covariates.

RESULTS

There was a significantly increased risk of T1D in children with SLEs occurring during the child's first 2 years of life for both the total cohort (HR 1.67; 95% CI 1.1, 2.7; p = 0.03) and the DQ2/8 cohort (HR 2.2; 95% CI 1.1, 4.2; p = 0.018). Subgroup analysis of events related to unemployment, divorce, or family conflict showed a significant hazard for these events occurring both during and after pregnancy in the DQ2/8 cohort (HR 2.17; 95% CI 1.1, 4.3; p = 0.03 and HR 4.98; 95% CI 2.3, 11; p < 0.001, respectively) and after pregnancy in the total cohort (multiple regression HR 2.07; 95% CI 1.01, 4.2; p = 0.047).

CONCLUSIONS

Children of parents experiencing an SLE during the child's first 2 years of life were at increased risk of T1D. Further studies including those measuring immune and stress-related biomarkers are necessary to validate the findings.

Offspring of parents who were separated and not speaking to one another have reduced resistance to the common cold as adults

Exposure to parental separation or divorce during childhood has been associated with an increased risk for physical morbidity during adulthood. Here we tested the hypothesis that this association is primarily attributable to separated parents who do not communicate with each other. We also examined whether early exposure to separated parents in conflict is associated with greater viral-induced inflammatory response in adulthood and in turn with increased susceptibility to viral-induced upper respiratory disease. After assessment of their parents' relationship during their childhood, 201 healthy volunteers, age 18-55 y, were quarantined, experimentally exposed to a virus that causes a common cold, and monitored for 5 d for the development of a respiratory illness. Monitoring included daily assessments of viral-specific infection, objective markers of illness, and local production of proinflammatory cytokines. Adults whose parents lived apart and never spoke during their childhood were more than three times as likely to develop a cold when exposed to the upper respiratory virus than adults from intact families. Conversely, individuals whose parents were separated but communicated with each other showed no increase in risk compared with those from intact families. These differences persisted in analyses adjusted for potentially confounding variables (demographics, current socioeconomic status, body mass index, season, baseline immunity to the challenge virus, affectivity, and childhood socioeconomic status). Mediation analyses were consistent with the hypothesis that greater susceptibility to respiratory infectious illness among the offspring of noncommunicating parents was attributable to a greater local proinflammatory response to infection.

Adversity in preschool-aged children: Effects on salivary interleukin-1β

Exposure to early life adversity is linked to impaired affective, cognitive, and behavioral functioning and increases risk for various psychiatric and medical conditions. Stress-induced increases in pro-inflammatory cytokines may be a biological mechanism of these effects. Few studies have examined cytokine levels in children experiencing early life adversity, and very little research has investigated cytokines or other markers of inflammation in saliva. In the present study, we examined salivary interleukin (IL)-1β and C-reactive protein (CRP) levels in relation to stress exposure in 40 children aged 3 to 5 years who were enrolled in a larger study of early life adversity. Childhood maltreatment status was assessed via review of child welfare records. Contextual stress exposure, traumatic life event history, and symptoms of psychopathology were assessed via caregiver interviews at a home visit. In a subsequent visit, salivary IL-1β and CRP were obtained before and after participation in four emotion-eliciting tasks. The number of past-month contextual stressors, lifetime contextual stressors, and traumatic life events each demonstrated a significant main effect on IL-1β. Baseline IL-1β was positively associated with each of the significant main-effect adversities. Postchallenge IL-1β displayed positive associations with each adversity variable, but these were not significant. CRP was not significantly associated with any of the adversity variables. Given the evidence suggesting the involvement of IL-1β in the neuropathology of psychiatric conditions, these results may have important implications for developmental outcomes.

Can prenatal maternal stress increase the risk of asthma?

Maternal stress adversely affects a mother's well-being and health and also negatively impacts her offspring. That this relationship also holds true for maternal stress during the pregnancy period is intuitive. However, whether maternal stress increases the risk of asthma development in her offspring is less clear and will be evaluated in this review. There is evidence from murine models to suggest that maternal stress during pregnancy increases the risk of asthma in the offspring. While recent experimental research adds to the increasing body of evidence supporting a causal relationship between prenatal maternal stress and asthma risk in the offspring, the epidemiological evidence supporting this notion is insufficient. Almost all existing observational studies suffer from severe methodological limitations. Nevertheless, the results from experimental work on maternal stress during pregnancy and asthma risk in the offspring, in concert with other obvious adverse health effects in the offspring are sufficient to justify a recommendation to reduce maternal stressors, particularly during pregnancy.

Childhood Adversities and Adult Cardiometabolic Health: Does the Quantity, Timing, and Type of Adversity Matter?

OBJECTIVE

Adverse events in childhood can indelibly influence adult health. While evidence for this association has mounted, a fundamental set of questions about how to operationalize adverse events has been understudied.

METHOD

We used data from the National Survey of Midlife Development in the United States to examine how quantity, timing, and types of adverse events in childhood are associated with adult cardiometabolic health.

RESULTS

The best-fitting specification of quantity of events was a linear measure reflecting a dose-response relationship. Timing of event mattered less than repeated exposure to events. Regarding the type of event, academic interruptions and sexual/physical abuse were most important. Adverse childhood events elevated the risk of diabetes and obesity similarly for men and women but had a greater impact on women's risk of heart disease.

DISCUSSION

Findings demonstrate the insights that can be gleaned about the early-life origins of adult health by examining operationalization of childhood exposures.

Air pollution and cytokine responsiveness in asthmatic and non-asthmatic children

Epidemiological studies indicate that asthmatic children are more susceptible to traffic-related air pollution exposure than non-asthmatic children. Local and systemic inflammation in combination with oxidative stress have been suggested as a possible susceptibility factor. We investigated effect modification by asthma status for the association between air pollution exposure and systemic effects using whole blood cytokine responsiveness as an inflammatory marker. The study was nested within the two German birth cohort studies GINIplus and LISAplus and initially designed as a random sub-sample enriched with asthmatic children. Using data from 27 asthmatic and 59 non-asthmatic six-year-old children we measured the production of Interleukin-6 (IL)-6, IL-8, IL-10, monocyte chemotactic protein-1 (MCP-1), tumour necrosis factor-alpha (TNF-alpha) and interferon-gamma (IFN-gamma) in whole blood after ex-vivo stimulation with urban particulate matter (EHC-93). Air pollution exposure (nitrogen dioxide (NO2), nitrogen oxides (NOx), particulate matter with an aerodynamic diameter <10μm (PM10), particulate matter with an aerodynamic diameter <2.5μm (PM2.5mass), coarse particulate matter (PMcoarse) and PM2.5absorbance (PM2.5abs)) was modelled for children´s home addresses applying land-use regression. To assess effect modification by asthma status linear regression models with multiplicative interaction terms were used. In asthmatics exposure to NO2 was associated with higher production of pro-inflammatory cytokines: adjusted means ratio (MR) 2.22 (95% confidence interval 1.22-4.04) for IL-6 per 2.68µg/m³ NO2. The interaction term between asthma status and NO2 exposure was significant. Results for NOx, PM10, PM2.5mass and PM2.5abs were in the same direction. No association between air pollution and cytokine responsiveness was found in the group of non-asthmatic children and in the overall group. Traffic-related air pollution exposure is associated with higher pro-inflammatory cytokine responsiveness in whole blood of asthmatic children.

S100B blood levels and childhood trauma in adolescent inpatients

BACKGROUND

Serum levels of the astrocytic protein S100B have been reported to indicate disruption of the blood-brain barrier. In this study, we investigated the relationship between S100B levels and childhood trauma in a child psychiatric inpatient unit.

METHOD

Levels of S100B were measured in a group of youth with mood disorders or psychosis with and without history of childhood trauma as well as in healthy controls. Study participants were 93 inpatient adolescents admitted with a diagnosis of psychosis (N = 67), or mood disorder (N = 26) and 22 healthy adolescents with no history of trauma or psychiatric illness. Childhood trauma was documented using the Life Events Checklist (LEC) and Adverse Child Experiences (ACE).

RESULTS

In a multivariate regression model, suicidality scores and trauma were the only two variables which were independently related to serum S100B levels. Patients with greater levels of childhood trauma had significantly higher S100B levels even after controlling for intensity of suicidal ideation. Patients with psychotic diagnoses and mood disorders did not significantly differ in their levels of S100B. Patients exposed to childhood trauma were significantly more likely to have elevated levels of S100B (p < .001) than patients without trauma, and patients with trauma had significantly higher S100B levels (p < .001) when compared to the control group. LEC (p = 0.046), and BPRS-C suicidality scores (p = 0.001) significantly predicted S100B levels.

CONCLUSIONS

Childhood trauma can potentially affect the integrity of the blood-brain barrier as indicated by associated increased S100B levels.

Stressful life-events in childhood and risk of multiple sclerosis: a Danish nationwide cohort study

Background:

Current knowledge concerning the association between exposure to stressful life-events (SFLEs) in childhood and later risk of multiple sclerosis (MS) is sparse.

Objectives:

We studied the associations between SFLEs in childhood and subsequent risk of MS in a nationwide cohort of 2.9 million Danes born from 1968 to 2011.

Methods:

A SFLE in childhood was defined as exposure before age 18 years to parental divorce, parental death, or death of a sibling, using information from the Danish Civil Registration System. MS cases in the cohort were identified in the Danish Multiple Sclerosis Registry. Associations of SFLE with MS risk were evaluated by incidence rate ratios (RR) of MS obtained in log-linear Poisson regression models.

Results:

Persons exposed to any SFLE in childhood were at 11% elevated risk of MS (RR = 1.11; 95% confidence interval: 1.03–1.20), compared to non-exposed persons. Stratification by subtype of SFLE showed that parental death and death of a sibling were not associated with MS risk. However, persons exposed to parental divorce were at 13% increased risk of developing MS compared to non-exposed (RR = 1.13; 1.04–1.23).

Conclusions:

Associations of SFLEs in childhood with risk of MS are weak. However, parental divorce is somehow associated with modestly increased risk of MS.

Nerve-derived transmitters including peptides influence cutaneous immunology

Clinical observations suggest that the nervous and immune systems are closely related. For example, inflammatory skin disorders; such as psoriasis, atopic dermatitis, rosacea and acne; are widely believed to be exacerbated by stress. A growing body of research now suggests that neuropeptides and neurotransmitters serve as a link between these two systems. Neuropeptides and neurotransmitters are released by nerves innervating the skin to influence important actors of the immune system, such as Langerhans cells and mast cells, which are located within close anatomic proximity. Catecholamines and other sympathetic transmitters that are released in response to activation of the sympathetic nervous system are also able to reach the skin and affect immune cells. Neuropeptides appear to direct the outcome of Langerhans cell antigen presentation with regard to the subtypes of Th cells generated and neuropeptides induce the degranulation of mast cells, among other effects. Additionally, endothelial cells, which release many inflammatory mediators and express cell surface molecules that allow leukocytes to exit the bloodstream, appear to be regulated by certain neuropeptides and transmitters. This review focuses on the evidence that products of nerves have important regulatory activities on antigen presentation, mast cell function and endothelial cell biology. These activities are highly likely to have clinical and therapeutic relevance.

Substance P and vasoactive intestinal peptide levels in middle ear effusions of children

CONCLUSION

This is the first report demonstrating high levels of substance P (SP) that inversely correlate with vasoactive intestinal peptide (VIP) levels in middle ear effusions (MEEs) of patients with otitis media with effusion (OME). Increased SP and decreased VIP levels might play a role in the pathogenesis of chronic OME.

OBJECTIVE

The etiology of OME is multifactorial, and neurogenic inflammation may play a significant role. SP and VIP levels were not evaluated previously in MEEs of children with OME.

METHODS

Fifty patients aged 2-12 years (mean age 5.24 ± 2.64) were included in the study. MEEs were classified as mucoid or serous based on the gross appearance. SP and VIP levels were determined using ELISA.

RESULTS

High levels of SP were detected in MEEs. In addition SP levels were significantly higher in serous samples (2910.55 ± 307.96 vs 2218.55 ± 262.30 pg/ml). There were also age-dependent changes, such that SP levels were significantly higher in children aged 2-3 years compared with those who were 4-5 and 6-12 years old. VIP levels were undetectable in 30% of patients and the mean level of VIP was 50.91 ± 16.01 pg/ml in serous middle ear effusions and 54.86 ± 15.91 pg/ml in mucoid MEEs.

Cough and dyspnoea may discriminate allergic and infectious respiratory phenotypes in infancy

Asthma symptoms are non-specific during infancy, making the identification of different subgroups among preschool children with early respiratory manifestations an important challenge. We previously used a clustering approach to identify bronchial obstructive phenotypes in 1-yr-old infants from the Pollution and Asthma Risk: an Infant Study (PARIS) birth cohort. In the present study, we examined whether these phenotypes were stable at 3 yr and studied their comorbidity and risk factors. Partitioning around medoids (PAM) method was applied at 1 and 3 yr of age to cluster children according to wheezing, dry night cough, dyspnoea with sleep disturbance and breathlessness. The resulting groups were used to derive phenotypes in 2084 children during their first 3 yr of life. Analysis of associated comorbidity and risk factors was conducted using multinomial logistic regression. PAM groups were similarly defined at both ages so that two respiratory phenotypes were identified between birth and 3 yr: cough phenotype (CP) and dyspnoea phenotype (DP) including 14.1% and 30.7% of children, respectively. CP infants experienced more often allergic features than DP, dominated by respiratory infections. Parental history of allergy, potential allergen exposure and psychosocial factors were associated with CP. Day care centre attendance was more frequent in DP as well as exposure to domestic chemical pollution, suggesting a greater vulnerability to pathogens. Finally, dry night cough and dyspnoea disturbing the sleep appear to be markers of two respiratory profiles potentially allergic and infectious before 3 yr old.

Childhood adversity and immune and inflammatory biomarkers associated with cardiovascular risk in youth: a systematic review

BACKGROUND

Research suggests that adverse experiences in childhood affect the development of cardiovascular disease (CVD), and immune and inflammation dysregulation has been postulated to play role. However, it is unclear whether the effects of social adversity on immune-related biomarkers are evident in early life, and if these biomarkers may provide an early risk marker for targeting prevention and intervention. The purpose of this review is to evaluate research on the relationship between adversity and CVD-relevant immune biomarkers in youth, assess the consistency of the findings, and consider what additional research is needed.

METHODS

PubMed and PsycINFO searches were conducted through September 2011. Studies were selected using criteria related to the childhood exposure, biomarker outcome, age range, and sample selection. Twenty articles were identified, examining associations between childhood adversity and immune biomarkers (assessed during childhood) that are potential risk markers for CVD later in life.

RESULTS

Although childhood adversity was not consistently related to youth levels of inflammatory and other immune markers relevant to CVD, a trend toward positive findings was observed. No detectable patterns were evident based on measure of adversity, biomarker, study design, or sample size.

CONCLUSIONS

Overall, our findings suggest this avenue of research is worth continued investigation. We offer recommendations for future research related to (1) study design and sample, (2) definition and measurement of adversity, (3) statistical analysis, and (4) outcomes that will help distinguish whether there are immunologic alterations related to adversity and subsequent CVD risk that can be reliably detected in childhood.

Stressful life events in childhood and risk of infectious disease hospitalization

Individuals exposed to high levels of stress might have an increased risk of infectious diseases. However, most of the previous studies have been conducted among adults. To examine the effect of childhood stress, we conducted a nationwide cohort study including all Danish children born from 1977 to 2004. Stressful life events (SFLE) included parental death, death of sibling or parental divorce. Outcome was defined as hospitalizations due to less severe (LSID) or severe infectious diseases (SID). Children were followed until the age of 15 years. The association between SFLE and risk of infections was evaluated through rate ratios (RR) comparing infectious disease incidence ratios in children with and without a history of SFLE. Overall, children exposed to SFLE were at 13% increased risk of LSID (RR = 1.13 (1.10-1.15)), but at no increased risk of SID hospitalization (RR = 1.05 (0.97-1.14)). Looking at the specific type of SFLE, parental divorce increased the risk of LSID (RR = 1.11 (1.09-1.14)) and SID hospitalization (1.11 (1.02-1.21)) by 11%, whereas no increased risk of LSID and SID hospitalization was observed following parental death. Finally, a 34% increased risk of LSID hospitalization (RR = 1.34 (1.23-1.45)) was observed following death of sibling, in contrast to no increased risk of SID hospitalization.

CONCLUSION

Childhood exposure to SFLE, especially parental divorce seems to increase the risk of infectious disease hospitalization. Although we cannot determine whether our observations are the result of a biological effect of stress, adoption of unhealthy behaviours or increased likelihood of hospitalization, our findings do have public health relevance as a considerable proportion of the children today will be exposed to SFLE, the majority to parental divorce.

Stress, atopy and allergy: A re-evaluation from a psychoneuroimmunologic persepective

Since the early days of psychosomatic thinking, atopic disease was considered exemplary. In the 70s and 80s numerous reports stated increased anxiety, depression or ill stresscoping in atopics in correlation with enhanced disease activity. Employed patient groups however were small and diverse and controls rare. Therefore, the question remained, whether psychopathological findings in atopics were of pathogenetic relevance or an epiphenomenon of chronic inflammatory disease. Recently, the discussion has been revived and refocused by psychoneuroimmunological findings. We now know that atopic disease is characterized by an imbalance of the classical stress-axis response along the hypothalamus-pituitary-adrenal axis (HPA) and the sympathetic axis (SA). This imbalance can be found shoulder-to-shoulder with enhanced expression of newly emerging neuroendocrine stress mediators such as substance P (SP) and nerve growth factor that form up to a third stress axis (neurotrophin neuropeptide axis: NNA). Together they can alter the inflammatory as well as the neuroendocrine stress-response on several levels. In skin, the immediate inflammatory response to stress involves neuropeptide release and mast cell degranulation, in short neurogenic inflammation. Systemically, antigen-presentation and TH2 cytokine bias are promoted under the influence of cortisol and neuropeptides. Imbalanced stress-responsiveness may therefore be at the core of exacerbated allergic disease and deserves re-evaluation of therapeutic options such as neutralization of SP-signaling by antagonists against its receptor NK1, cortisol treatment as supplementation and relaxation techniques to balance the stress-response.

Association between attendance of day care centres and increased prevalence of eczema in the German birth cohort study LISAplus

BACKGROUND

Day care centre attendance is much more common in East than in West Germany. Although there is evidence that early day care might be protective against atopic diseases, several studies have shown a higher prevalence of childhood eczema in East Germany compared to West Germany.

OBJECTIVES

To compare prevalence and cumulative incidence of eczema in a birth cohort study in East and West Germany and to identify risk factors that are associated with eczema, which might explain regional differences.

METHODS

We used data from the ongoing population-based birth cohort study Influence of Life-style factors on the development of the Immune System and Allergies in East and West Germany Plus the influence of traffic emissions and genetics. In 1997, 3097 children from study areas in East and West Germany were recruited. Cumulative incidence and 1-year prevalences of eczema up to the age of 6 years were determined from yearly questionnaires. Cox regression and generalized estimating equations/logistic regression were used to quantify regional differences and to identify risk factors that might explain them.

RESULTS

Prevalence and incidence of eczema were higher in children living in East Germany than those living in West Germany. We identified 11 risk factors that showed significant regional differences. From these factors, only 'day care attendance during the first 2 years of life' was significantly associated with eczema (odds ratio 1.56, 95% confidence interval CI 1.31-1.86). The regional differences in eczema could be explained by differences in early day care utilization.

CONCLUSION

Day care centre attendance is associated with an increased prevalence and incidence of eczema. Regional differences in eczema prevalence could be explained by regional differences in utilization of early day care.

Neuroticism, extraversion, stressful life events and asthma: a cohort study of middle-aged adults

BACKGROUND

Stressful life events can trigger asthma exacerbations, but could also contribute to the development of incident asthma. However, only few studies have investigated the association between stressful life events and adult asthma prospectively. Likewise, stress-related personality traits (e.g. neuroticism and extraversion) may increase asthma risk, but this has been examined in only one prospective study. We therefore aimed to investigate the association between neuroticism, extraversion, stressful life events and incident asthma.

METHODS

A population-based sample of 5114 middle-aged adults completed questionnaires between 1992 and 1995. Among those alive in 2002/2003, 4010 (83%) were followed-up by questionnaires. Exposures of interest included neuroticism, extraversion and three stressful life events (unemployment, having broken off a life partnership and death of a close person). Associations with incident asthma were estimated by multivariable risk ratios (RR) and 95% confidence intervals (95% CI) using Poisson regression.

RESULTS

High vs low neuroticism predisposed to developing asthma (RR = 3.07, 95% CI = 1.71-5.48), but high extraversion did not (RR = 1.30, 95% CI = 0.79-2.15). Having broken off a life partnership significantly increased asthma risk (RR = 2.24, 95% CI = 1.20-4.21) in contrast to death of a close person (RR = 1.06, 95% CI = 0.64-1.75) or unemployment (RR = 1.65, 95% CI = 0.72-3.78).

CONCLUSIONS

High levels of neuroticism may increase the risk of asthma in middle-aged adults. Having broken off a life partnership was the only stressful event, which was associated with incident asthma. Synthesized with evidence from earlier studies, this could reflect that interpersonal conflicts may increase asthma risk, possibly along an immunological pathway.

The role of neuro-immune cross-talk in the regulation of inflammation and remodelling in asthma

Despite recent advances in the development of anti-asthmatic medication, asthma continues to be a major health problem worldwide. The symptoms of asthmatic patients include wheezing, chest tightness, cough and shortness of breath, which, together with airway hyperresponiveness, previously have been attributed to a dysfunction of airway nerves. However, research in the last two decades identified Th2-sensitization and the subsequent allergic reaction to innocuous environmental antigens as a basic immunological mechanism leading to chronic airway inflammation. Recent evidence suggests that the development of allergic asthma is influenced by events and circumstances in early childhood and even in utero. Allergen, ozone or stress exposure, as well as RSV infection in early life could be able to induce irreversible changes in the developing epithelial-mesenchymal trophic unit of the airways. The co-existence of chronic inflammation and neural dysfunction have recently drawn attention to the involvement of interaction pathways between the nervous and the immune system in the airways. Intensive basic research has accumulated morphological as well as functional evidence for the interaction between nerves and immune cells. Neuropeptides and neurotrophins have come into focus of attention as the key mediators of neuro-immune interactions, which lead to the development of several pharmacological compounds specifically targeting these molecules. This review will integrate our current knowledge on the involvement of neuro-immune pathways in asthma on the cellular and molecular level. It will summarize the results of pharmacological studies addressing the potential of neuropeptides and neurotrophins as novel therapeutic targets in asthma.