Published online: December 10, 2016
Atopic dermatitis (AD), also known as eczema, affects 17-24% of the pediatric population. Eighty-five percent of cases present before the age of five years old. AD is commonly associated with the subsequent development of food allergy, asthma and hay fever, together comprising the ‘atopic march’. B cells and T cells are crucial component of the immune system, but their relative role in AD and the atopic march initiation has not been studied.
In an original manuscript recently published in The Journal of Allergy & Clinical Immunology (JACI), Czarnowicki and colleagues defined the profile of B-cells, major players in allergy development, and their interactions with other components of the immune system in the skin and in blood of 27 children with recent-onset moderate-to-severe AD (in the previous 6 months), 34 adults with moderate-to-severe AD, and their age-matched controls. Levels of specific IgE antibodies were measured in the pediatric population to assess sensitization to a diverse group of food and environmental factors.
The lesional skin in recent-onset AD showed a predominance of T cells and a paucity of B cells, although circulating B cells in these children prematurely developed markers of adult AD. IgE allergen sensitization increased with age and severity in pediatric AD. Multiple associations were documented between B cells, T cells and allergen sensitization in blood.
In the current clinical view of the atopic march, other atopic disorders develop during the years after the onset of AD, suggesting the later occurrence of an allergic “switch”. This study, however, reminds that the onset of B-cell activation with antibodies to food or environmental antigens is also within the first 6 months of AD onset. The demonstration in this paper that B- and T-cell activation is correlated, and clusters with IgE sensitization and disease severity, supports the possibility that early introduction of immune targeted therapeutics may be needed to avert the development of the atopic march.
The Journal of Allergy and Clinical Immunology (JACI) is the official scientific journal of the AAAAI, and is the most-cited journal in the field of allergy and clinical immunology.