Does paternal antigen-induced secretion of interleukin-10 by T regulatory cells mediate the birth order effect?
Bernsen RM; Nagelkerke NJ; al-Ramadi BK United Arab Emirates University, Faculty of Medicine and Health Sciences, Department of Community Medicine, P.O. Box 17666, Al Ain, United Arab Emirates. roos.bernsen@uaeu.ac.ae Childhood allergy constitutes a significant burden of disease in the Western world. The prevalence of this condition is highest in first born children, an as yet unresolved phenomenon called the “birth order effect”. The hygiene hypothesis attempted to explain this differential risk by stating that less exposure to microbial agents at an early age of first born children would result in reduced activation of the immune system and subsequent polarization towards a Th2 phenotype. However, no conclusive evidence for or against the hygiene hypothesis has been found so far. Another, not necessarily conflicting, theory states that the birth order effect is already established during prenatal life and that the fetal-maternal interaction changes during successive pregnancies. Comb
