Environmental allergens
Prenatal exposure to a farm environment modifies atopic sensitization at birth

https://doi.org/10.1016/j.jaci.2008.06.011Get rights and content

Background

Previous cross-sectional surveys have suggested that maternal exposure to animal sheds during pregnancy exerted a protective effect on atopic sensitization in children lasting until school age.

Objective

We sought to evaluate the effects of maternal exposure to animal sheds and other farm-related exposures during pregnancy on cord blood IgE levels in a prospective birth cohort.

Methods

Pregnant women living in rural areas in Austria, Finland, France, Germany, and Switzerland were recruited in the third trimester of pregnancy. Information on maternal farm-related exposures, nutrition, and health during pregnancy was obtained by means of interviews. Specific IgE levels for food and common inhalant allergens were assessed in cord blood of 922 children and peripheral blood samples of their mothers.

Results

Different sensitization patterns in cord blood of farm and nonfarm children were observed. In multivariable analysis consumption of boiled, but not unboiled, farm milk during pregnancy was positively associated with specific IgE to cow's milk independently from maternal IgE. In contrast, there was an inverse relationship between maternal exposure to animal sheds and cord blood IgE levels against seasonal allergens (adjusted odds ratio, 0.38; 95% CI, 0.21-0.70). This association was not confounded by maternal IgE levels. Maternal contact with hay enhanced the protective effect of exposure to animal sheds on IgE levels to grass pollen in cord blood.

Conclusions

Maternal exposure during pregnancy influences atopic sensitization patterns in cord blood. The (microbial) context of allergen contact possibly modifies the risk of atopic sensitization.

Section snippets

Study design and population

The PASTURE study is a prospective birth cohort study involving children from rural areas in 5 European countries: Austria, Finland, France, Germany, and Switzerland.7 Pregnant women living in these rural areas were recruited in the third trimester of pregnancy. Women who lived on family-run farms where any kind of livestock was kept were assigned to the farm group. For the reference group, women from the same rural areas but not living on a farm were recruited. Exclusion criteria were living

Results

The study population comprised 1133 newborns, 47% of them born to farm families (Fig 1). Table E1 (available in the article's Online Repository at www.jacionline.org) shows general population characteristics for the 922 (81%) farm and reference children who had complete values for both maternal and cord blood IgE and were subject to this analysis.

The specific IgE levels to the various allergens were consistently less than 3.5 IU/mL, and the 95th percentiles were less than 0.35 IU/mL. At a

Discussion

In the PASTURE birth cohort specific IgE antibodies to various allergens were detected at low levels in cord blood. Intriguingly, a clear distinction of the sensitization patterns of farm and reference children emerged.

References (27)

  • R.J. Boyle et al.

    Can allergic diseases be prevented prenatally?

    Allergy

    (2006)
  • P. Holt et al.

    Early immunological influences

    Chem Immunol Allergy

    (2004)
  • J.O. Warner

    The early life origins of asthma and related allergic disorders

    Arch Dis Child

    (2004)
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    Supported by the European Union (research grant QLK4-CT-2001-00250).

    Disclosure of potential conflict of interest: M. J. Ege has received research support from the German Research Fund (DFG) TR22 and European Union Food-CT-2004-506378. R. P. Lauener has received research support from the Swiss National Research Foundation, the European Commission, and the Kuhne Foundation and has served as an expert witness in allergy diagnosis and allergy treatment litigation. A. Hyvärinen has received research support from the Finnish Academy and the European Union and has served as an expert witness in mold damage problematics litigation. D. A. Vuitton has received research support from the National French Research Agency and National Research Projects and has served as an expert witness for the European Commission and the French Research Institute for Development. J. Pekkanen has received research support from the European Union, the farmer's pension fund, and rhe government of Finland (EVO). E. von Mutius has consulting arrangements with GlaxoSmithKline, UCB, and Protectimmun and has received research support from the European Commission and the Bavarian Ministry for Environment, Health and Consumer Protection. The rest of the authors have declared that they have no conflict of interest.

    The Protection Against Allergy Study in Rural Environments (PASTURE) study group: Gertraud Weiß, Ellen Üblagger, Claudia Humer, and Manuela Rußegger (Austria); Raija Juntunen, Reetta Tiihonen, Pekka Tiittanen, Maija-Riitta Hirvonen, Kati Huttunen, Suvi Virtanen, Timo Kauppila, Aino Nevalainen, Sami Remes, Tomi-Pekka Tuomainen, and Anne Karvonen (Finland); Marie-Laure Dalphin, Renaud Piarroux, Gabriel Reboux, Sandrine Roussel, and Bertrand Sudre (France); Susanne Schmid, Sabina Illi, Nicola Korherr, Jon Genuneit, Richard Peter, Serdar Sel, Nicole Blümer, and Petra Pfefferle (Germany); Ulrike Gehring (The Netherlands); Sondhja Bitter, Felix H. Sennhauser, Susanne Loeliger, Johanna Steinle, and Remo Frei (Switzerland).

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