Neonatal total IgE and respiratory tract infections in children with intrauterine smoke exposure.
BACKGROUND
Exposure to environmental tobacco smoke (ETS) is known to increase the risk of respiratory tract infections (RTI). Some children, however, may be more susceptible to the harmful effects of ETS than others. We examined whether early atopic status (defined by elevated neonatal total IgE (tIgE) or symptoms of atopic dermatitis) modified the association between ETS exposure and RTI.


METHODS
The data of 2863 children from the Prevention and Incidence of Asthma and Mite Allergy birth cohort were collected to the age of 4 years. Neonatal tIgE was collected from a subset of 914 children, and clinical information by yearly parental questionnaires. The effect of pre- and/or postnatal ETS exposure, early atopic status and interaction between these factors was studied for various RTI.


RESULTS
Children with elevated tIgE or atopic dermatitis and prenatal ETS exposure have a strongly increased risk of frequent RTI (aOR 6.18 (95% CI 1.45 to 26.34) and 5.69 (2.01 to 16.04), respectively; interaction p=0.006 and p=0.14, respectively) compared to non-atopic children without prenatal ETS exposure. Similar results were seen for lower RTI and otitis. This effect was less evident for postnatal ETS.


CONCLUSIONS
Early atopic status enhances the risk of RTI in children with prenatal ETS exposure. This suggests that host factors modify the association between ETS and RTI.
Ruskamp
Jopje
J
Department of Paediatrics, Wilhelmina Children's Hospital, University Medical Centre Utrecht, Utrecht, the Netherlands. j.ruskamp@umcutrecht.nl
Smit
Henriette
H
Rovers
Maroeska
M
Hoekstra
Maarten
M
Schilder
Anne
A
Brunekreef
Bert
B
Wijga
Alet
A
Kerkhof
Marjan
M
de Jongste
Johan
J
Sanders
Elisabeth
E
D002675:Child, Preschool; D015331:Cohort Studies; D003876:Dermatitis, Atopic / Q000150:complications / Q000453:epidemiology; D005260:Female; D006801:Humans; D007073:Immunoglobulin E / Q000097:blood*; D007231:Infant, Newborn; D009426:Netherlands / Q000453:epidemiology; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects / Q000453:epidemiology*; D012141:Respiratory Tract Infections / Q000453:epidemiology / Q000209:etiology* / Q000276:immunology; D014028:Tobacco Smoke Pollution / Q000009:adverse effects* / Q000032:analysis
D014028:Tobacco Smoke Pollution; D007073:Immunoglobulin E