Asthma and atopy in Western and Eastern communities--current status and open questions

Allergic diseases of the eye

The prevalence of ocular allergy is clearly underappreciated; it has been an underdiagnosed and undertreated area in primary care medicine. The ocular symptoms associated with the most common ocular allergy conditions,such as seasonal and perennial AC, are twice as likely to affect the allergy sufferer as nasal symptoms alone. The emergence of new medications for the specific treatment of ocular symptoms over the course of the past 15 years offers a new field for improved patient care by the primary and sub-specialty health care providers.

Mothers in Stress: Consequences for the Offspring

No memories exist on one's time before birth. However, this does not imply that the developing fetus is not susceptible to external impulses. On the contrary, the fetus is extremely vulnerable e.g. to environmental challenges, and a wealth of data reveals that conditions in utero affect the health of the fetus before and after birth. Threats for the growing fetus include psychological challenges perceived by the mother, e.g. high levels of stress during pregnancy. However, stress experienced during pregnancy not only leads to pregnancy complications like miscarriage, pre-eclampsia, preterm parturition, low birth weight or major congenital malformations, stress also increases the risk of the child to develop diseases in the subsequent periods of life. This condition is termed fetal programming of adult disease. Programming agents seem to include growth factors, cytokines and hormones, all of which can be altered by stress. As a consequence, such 'stress-modified' systems of the offspring are more susceptible to environmental influences during later life, e.g. the development of atopic diseases upon exposure to antigens. The present review illuminates the complexity of stress perception on fetal programming focusing predominately on the onset of atopic diseases on the background of published evidence from immunology, endocrinology, neurobiology and neonatology.

Smoking and atopy as determinants of sputum eosinophilia and bronchial hyper-responsiveness in adults with normal lung function

Data concerning the determinants of sputum eosinophilia and bronchial hyper-responsiveness (BHR) in large cohorts of individuals with normal lung function are limited. Here, we assessed the occurrence of sputum eosinophilia and BHR and identified the risk factors for these variables in two populations living in North Karelia, Finland, and in Pitkäranta, the Republic of Karelia, Russia. These areas are geographically adjacent, but differ, however, fundamentally in major cultural, socioeconomical and lifestyle aspects. The study population comprised 790 Finns and 387 Russian, aged 25-54 years, who were randomly enrolled from the population registers. A methacholine challenge test to measure BHR was successfully performed in 581 (74%) Finns and 307 (79%) Russians with virtually normal lung function (FEV1 > 70% of predicted). Of these, induced sputum samples were obtained from 41% of the Finns and from 67% of the Russians. The proportion of current smokers was 27% among the former and 42% among the latter. Sputum eosinophilia was assessed using a semi-quantitative method, and total concentrations of sputum eosinophilic cationic protein (ECP) and myeloperoxidase (MPO) were measured using an immunoassay. Risk factors for BHR and sputum eosinophilia were identified with a regression analysis. The prevalence of sputum eosinophilia was 22% among the Finns and 19% among the Russians, and the respective figures for BHR were 14% and 13%. The median ECP concentration in sputum was significantly higher among the Russians as compared with the Finns (P<0.001), whereas for MPO, the difference did not achieve significance. Current smoking was significantly associated with both sputum eosinophilia and BHR in Russia (OR 3.1, 95% CI 1.2-7.6 for sputum eosinophilia, 2.8, 1.3-6.1 for BHR) and with BHR in Finland (2.1, 1.3-3.7). Atopy showed a tendency to be another risk factor for BHR in Finland (1.6, 0.98-2.6). In conclusion, sputum eosinophilia and BHR occurred commonly among the Finns and the Russians with normal lung function. Current smoking was significantly associated with BHR in both countries and additionally with sputum eosinophilia in Russia. Atopy was identified as a risk factor, albeit of borderline significance, for BHR in Finland only, suggesting that there may be differences in the aetiology and nature of BHR between the two countries.

Maternal stress and T-cell differentiation of the developing immune system: possible implications for the development of asthma and atopy

The constant increase in asthma and atopy prevalences--despite improved treatment and knowledge of many aspects of the diseases--has raised growing concern. Accumulating evidence suggests that these increases in atopic diseases are largely attributable to environmental and lifestyle factors, and the lack of systemic childhood infections has in many studies emerged as a major factor. In addition to current high standards of hygiene and the lack or scarcity of such infections, another factor characteristic of our present-day lives could be involved. This review briefly outlines the possibility that prolonged maternal stress associated with sustained excessive cortisol secretion could affect the developing immune system--especially T(H)1/T(H)2 cell differentiation--and further increase the susceptibility to asthma and atopy in genetically predisposed individuals. This hypothesis is critically evaluated in the light of current knowledge.

T cell reactivity in neonates from an East and a West German city--results of the LISA study

BACKGROUND

Within an ongoing birth cohort study (LISA) the cytokine production of cord blood T cells was compared between neonates from Leipzig (East Germany) and Munich (West Germany). The aim of this study was to analyse regional differences and influencing factors of the immune status.

METHODS

Cytokine production was measured in a randomly selected subgroup of 158 children from the LISA (Life style - Immune system - Allergy) cohort by intracellular cytokine staining. Information on family "atopy" history (FAH) and home characteristics was obtained from questionnaires.

RESULTS

Reduced numbers of interferon-gamma (IFN-gamma) and tumor necrosis factor-alpha (TNF-alpha) producing T cells were found in association with biparental FAH and housing renovation during pregnancy. In addition, cytokine production was influenced by season. In Munich, the frequency of biparental FAH and of renovation measures during pregnancy was significantly higher as compared to Leipzig. Neonates from Munich showed significantly decreased amounts of IFN-gamma and TNF-alpha and elevated levels of interleukin-4 (IL-4) producing T cells. Differences in cytokine production between Munich and Leipzig were influenced by season (IL-4) and housing renovation (IFN-gamma, TNF-alpha).

CONCLUSIONS

Since differences in the T cell cytokine production of neonates in Munich and Leipzig are independent from FAH our findings may provide evidence for the impact of environmental factors upon the fetal immune system.

The distribution in specific IgE and the prevalence of allergic symptoms in 25-64-years old inhabitants of an eastern and a western German city--results from Augsburg and Erfurt

BACKGROUND

In an earlier study it has been found that allergic symptoms and sensitization in adults were more frequent in Hamburg (northern part of West Germany) compared to Erfurt (East Germany). The purpose of this study was to replicate these findings using data from Augsburg, a city from the southern part of West Germany. Furthermore the study population in this analysis was extended to higher age groups.

METHODS

The prevalence of respiratory symptoms, assessed by a self-administered questionnaire, was compared in a random sample of adults, 25-64 years of age, living in Augsburg (n = 1572) and Erfurt (n = 1648). From a subset (n = 754, resp. 1144) specific IgE to common aeroallergens were measured and atopic sensitization was defined as the presence of at least one positive specific IgE (CAP > 0).

RESULTS

The prevalence of allergic rhinitis, wheezing, asthma and atopic sensitization was higher in Augsburg than in Erfurt (OR: 2.0; 1.3; 2.1; 1.7; all p < 0.01). For these differences no specific explanation could be found, i.e. the percentage of sensitized persons was equally increased in Augsburg for asthmatics, patients with hay fever or asymptomatic subjects. Furthermore, sensitization was equally increased for all common allergens. The differences were largest for the youngest age group, but also existed for higher ages.

CONCLUSIONS

The increased prevalence of allergies observed in Hamburg, a northern city of West Germany, is also found in Augsburg, a southern city of West Germany, both compared to Erfurt in East Germany. This supports the finding that unspecific causes related to western lifestyle play an important role. Further research is needed to identify the causal influences.

Prevalence of atopy and asthma in eastern versus western Europe: why the difference?

LEARNING OBJECTIVES

This article reinforces the reader's knowledge of the epidemiology of allergy and asthma in eastern versus western European countries and the ability to recognize the different hypotheses formulated to explain the rising trend of allergic asthma in Europe.

DATA SOURCES

Articles in English comparing the epidemiology of allergy in eastern versus western Europe published before December 31, 2000.

RESULTS

Significant higher prevalences of atopy and allergic asthma were observed in the early 1990s among populations living in western compared with eastern European countries. Changes in lifestyle after the fall of the communist system were associated with an increasing trend of atopic sensitization and hay fever in former East Germany after only 6 to 8 years after the Germany reunification. It has been hypothesized that a similar "converging" trend in the prevalence of allergic asthma and of bronchial hyperresponsiveness may take longer periods.

CONCLUSIONS

The prevalence of allergic asthma has increased decades earlier in western Europe with respect to eastern Europe. This is probably attributable to changes in lifestyle that had already occurred rather than to air pollution. The factors of a western lifestyle (diet, hygiene, varied allergen exposure) that have determined the difference in allergic asthma prevalence across Europe have yet to be identified.

Secondhand smoke induces allergic sensitization in mice

Epidemiological studies have suggested increased prevalence of atopy in children of maternal smokers. Although secondhand smoke or environmental tobacco smoke (ETS) has been shown to augment allergic responses, its role in atopic sensitization is still controversial. We studied whether ETS could initiate a Th2 response and thus induce primary allergic sensitization. Mice were exposed for 10 consecutive days to either 1% aerosolized OVA, ETS (5 cigarettes), or both ETS and OVA. C57BL/6 mice receiving both ETS and OVA developed OVA-specific IgE and IgG1, 12, 14, and 25 days after the initial exposure, whereas those receiving OVA alone did not. Thirty days after the initial challenge (20 days after its completion), mice were re-exposed to OVA. Bronchoalveolar lavage performed 24 h later revealed an influx of eosinophils in the group initially challenged with both ETS and OVA, but not in those exposed to ETS alone or OVA alone. Increases in IL-5, GM-CSF, and IL-2 were observed in bronchoalveolar lavage from this OVA/ETS-exposed group, whereas IFN-gamma levels were significantly inhibited. These results suggest that ETS can induce allergic sensitization to a normally harmless Ag, and they may explain why secondhand smoke is a major risk factor for the development of allergy in children.

Trends in bronchial hyperresponsiveness, respiratory symptoms and lung function among adults: West and East Germany. INGA Study Group. Indoor Factors and Genetics in Asthma

Previous studies have shown higher prevalences of bronchial hyperresponsiveness (BHR), respiratory symptoms and atopic sensitization among adults in Western Germany than in Eastern Germany. One of the aims of the joint project INGA (INdoor Factors and Genetics in Asthma) is to assess incidence, prevalence and trends for asthma, BHR and atopic diseases over a time period of 11 years (1990-2001) in the former West (Hamburg) and East Germany (Erfurt), with special reference to indoor exposure. INGA was designed as a case-control study following a cross-sectional study performed from 1990 to 1992 within the European Community Respiratory Health Survey (ECRHS). The database consisted of 1159 subjects in Hamburg and 731 subjects in Erfurt from the ECRHS (age 20-44). In 1995-1996, 107 cases (diagnosed asthma, positive specific serum IgE, positive skin prick or PD20FEV1< or =2.0 mg methacholine at ECRHS) and 106 controls (none of the previous findings) participated in Hamburg (115 cases and 109 controls in Erfurt). The methodology was identical to the ECRHS and dose-response slopes (DRS) of the methacholine challenge were calculated as an index of responsiveness. In the control group, median values of DRS were 0.028% mg(-1) (1990-1992) and 0.044 (1995-1996) (P<0.01) in Erfurt. Corresponding values for Hamburg were 0.028 and 0.022 (NS). Corresponding values within the case groups were 0.041 and 0.049 (NS) for Erfurt, and 0.069 and 0.052 (P<0.05) for Hamburg. Thus, 4 years after the first survey, we found an increased BHR in the Erfurt control group while the bronchial responsiveness remained unchanged for the Hamburg group. These trends in BHR, which indicate the expected converging tendency between East and West Germany, have to be confirmed within the next INGA-survey in 2000-2001.