Intrauterine sensitization of allergen-specific IgE analyzed by a highly sensitive new allergen microarray

Background To design a rational allergy prevention program, it is important to determine whether allergic sensitization starts in utero under the maternal immune system. Objective To investigate the origin of allergen-specific IgE antibodies in cord blood (CB) and maternofetal transfer of immunoglobulins. Methods The levels of food and inhalant allergen-specific IgE, IgA, IgG, and IgG4 antibodies in CB and maternal blood (MB) from 92 paired neonates and mothers were measured by using a novel allergen microarray of diamond-like-carbon–coated chip, with high-sensitivity detection of allergen-specific antibodies and allergen profiles. Results The levels of allergen-specific IgE antibodies against food and inhalant allergens and allergen profiles were identical in CB and newborn blood, but the levels and profiles, specifically against inhalant allergens, were different from those in MB. The level of allergen-specific IgA antibodies was below the detection levels in CB despite clear detection in MB. Therefore, contamination with MB in CB was excluded on the basis of extremely low levels of IgA antibodies in CB and the obvious mismatch of the allergen-specific IgE and IgA profiles between CB and MB. However, the levels of allergen-specific IgG and IgG4 antibodies and their allergen profiles were almost identical in both MB and CB. Conclusion Allergen-specific levels of IgE and IgA antibodies and their allergen profiles analyzed by the diamond-like-carbon allergen chip indicate that IgE antibodies in CB are of fetal origin. Food-allergen specific IgE antibodies were detected more often than inhalant-allergen specific IgE antibodies in CB, the reason of which remains unclarified.