Details

Autor(en) / Beteiligte

• McFadden, J.P.
• Thyssen, J.P.
• Basketter, D.A.
• Puangpet, P.
• Kimber, I.

Titel

T helper cell 2 immune skewing in pregnancy/early life: chemical exposure and the development of atopic disease and allergy

Ist Teil von

• British journal of dermatology (1951), 2015-03, Vol.172 (3), p.584-591

Ort / Verlag

England: Blackwell Publishing Ltd

Erscheinungsjahr

2015

Quelle

Wiley-Blackwell Journals

Beschreibungen/Notizen

• Summary During the last 50 years there has been a significant increase in Western societies of atopic disease and associated allergy. The balance between functional subpopulations of T helper cells (Th) determines the quality of the immune response provoked by antigen. One such subpopulation – Th2 cells – is associated with the production of IgE antibody and atopic allergy, whereas, Th1 cells antagonize IgE responses and the development of allergic disease. In seeking to provide a mechanistic basis for this increased prevalence of allergic disease, one proposal has been the ‘hygiene hypothesis’, which argues that in Westernized societies reduced exposure during early childhood to pathogenic microorganisms favours the development of atopic allergy. Pregnancy is normally associated with Th2 skewing, which persists for some months in the neonate before Th1/Th2 realignment occurs. In this review, we consider the immunophysiology of Th2 immune skewing during pregnancy. In particular, we explore the possibility that altered and increased patterns of exposure to certain chemicals have served to accentuate this normal Th2 skewing and therefore further promote the persistence of a Th2 bias in neonates. Furthermore, we propose that the more marked Th2 skewing observed in first pregnancy may, at least in part, explain the higher prevalence of atopic disease and allergy in the first born. What's already known about this topic? Over the last 50 years there has been an epidemic of atopic disease and associated allergy, the environmental causes of which have not been established. What does this study add? The physiological T helper (Th) 2 cell skewing of pregnancy and early life, and how accentuation of this Th2 skewing is associated with development of atopic disease and allergy is reviewed and highlighted. We postulate that certain types of exposures to chemicals can accentuate this Th2 skewing. We postulate an alternative explanation, which is independent of the hygiene hypothesis, for the inverse association between birth order and atopic allergy.