Immunological changes after hyposensitization in house-dust-sensitive asthmatic children: a review

Patients with allergic diseases are characterized by the presence of elevated total serum IgE and specific IgE antibodies against a variety of environmental allergens. To explore the causes for augmented IgE antibody production and the working mechanisms of hyposensitization (HS), a series of studies has been conducted on house-dust-sensitive, newly diagnosed, and hyposensitized asthmatic children and normals. The specific IgE and IgG antibodies were measured by radioallergosorbent test; the lymphoproliferative capability was measured by 3H-thymidine incorporation; the allergen-specific suppressor activity was determined by the extent of house-dust-activated, interleukin-2 (IL-2)-expanded lymphocytes to suppress the allergen-induced proliferation of autologous mononuclear cells (MNC); and IL-2 was produced by stimulating MNC with allergen or phytohemagglutinin (PHA) and quantitated by its capability to support the proliferation of mouse IL-2-dependent cytotoxic T-cell line. The results showed: 1) HS was effective in 90% of patients in terms of decreased attacks and medication taken; 2) the patients were defective in suppressor T-cell function for IgE production; 3) HS was able to restore the regulatory T-cell function and increase the production of IgG-blocking antibody; and 4) IL-2 production may be used as an indicator for initiation and discontinuation of HS. Therefore, hyposensitization is an effective and specific treatment for allergic bronchial asthma and can partially correct an immunoregulatory aberration in atopic individuals.