RT Journal Article
SR Electronic
T1 Can early infection explain the sibling effect in adult atopy?
JF European Respiratory Journal
JO Eur Respir J
FD European Respiratory Society
SP 956
OP 961
DO 10.1183/09031936.03.00039102
VO 22
IS 6
A1 P. Cullinan
A1 J.M. Harris
A1 A.J. Newman Taylor
A1 M. Jones
A1 P. Taylor
A1 J.R. Dave
A1 P. Mills
A1 S.A. Moffat
A1 C.W. White
A1 J.K. Figg
A1 A.M. Moon
A1 M.C. Barnes
YR 2003
UL http://erj.ersjournals.com/content/22/6/956.abstract
AB Atopy is strongly and inversely related to family size, a pattern which is plausibly assumed to reflect a protective effect of early infection. The current study tested this hypothesis by case-referent analysis of an adult cohort in the UK. The study established that atopy, defined by prick tests to common aeroallergens, was less common among those from larger families after adjustment for potentially confounding factors. In particular, a higher number of brothers appeared to offer protection. The current authors attempted to explain this distribution by examining contemporary family-doctor records of early childhood infections; and by a number of other indirect indices of early-life “hygiene”. The sibling effect was unexplained by evidence of infection with either hepatitis A or Helicobacter pylori, or by counts of infections or antibiotic prescriptions in early life. There was a significant and independent negative association between the number of gastrointestinal infections before the age of 5 yrs and the odds of atopy. Dog ownership and home moving in early life also displayed potentially protective associations. Although the current study replicates the finding that atopy is inversely associated with family size this could not be explained by documentary or serological evidence of early infection. The findings support the suggestion that the “sibling effect” in atopy may not simply reflect protection by early infection. The study was supported by the Colt Foundation.