Can IgE-mediated allergic diseases be prevented by using allergen-specific IgG antibodies?

The prevalence of allergic disease has increased significantly over the past few decades, especially in children. Prenatal period may represent an ideal time for the implementation of interventions to prevent allergy and allergic diseases. In this hypothesis, allergen-specific immunoglobulin G (IgG) antibodies may combine with maternal allergens as blocking antibodies with immunoglobulin E (IgE) or mask antigenic determinants in their binding to prevent the sensitization of the fetus. It may also modify fetal immune response to prevent the production of allergen-specific IgE antibodies and the further development of allergic diseases. Recent epidemiological, immunological and intervention studies supporting the hypothesis were summarized. Anti-mite human IgG Fabs (antigen binding fragments) were prepared from two immunoglobulin genes libraries and they were confirmed to have a specific binding blocking property by an in vitro mastocyte degranulation inhibition test. Allergen-specific human IgG antibodies may have a potential use in the prenatal immunoprophylaxis or the prevention of allergic diseases after birth.