A PRELIMINARY-STUDY OF INTERLEUKIN-4 DETECTION IN ATOPIC PEDIATRIC AND ADULT PATIENTS - EFFECT OF DIETARY MODIFICATION

The heterogeneity of clinical atopic symptoms complicates the simultan eous detection and therapy of food hypersensitivity. Interleukin 4 (IL -4) produced by activated T lymphocytes can increase mast cell numbers or IgE production. Fifteen patients (11 children and 4 adults), ages 20 months to 42 years,with atopic dermatitis, asthma, or rhinitis were evaluated for atopic disease and food hypersensitivity for eventual e ntry into a double-blind controlled food challenge by a careful histor y, physical examination, prick skin tests, or specific IgE to inhalant and food allergens. Gastrointestinal symptoms and coexistence of atop ic dermatitis with house dust sensitivity was observed in 7 patients. Serum IL-4 was assayed in duplicate by a sensitive monoclonal ELISA. L evels before dietary elimination ranged from 3 to 21 ng/ml, with mean levels of 9.8 +/- 2.3 ng/ml, and levels after dietary elimination rang ed from <0.1 to 6 ng/ml, with mean levels of 2.5 +/- 0.86 ng/ml in 6 p atients. Levels in 4 of 6 normal controls were undetectable, and the m ean level was 0.73 +/- 0.56 ng/ml. Dietary modification in 11 patients (6 pediatric and 5 adults) improved cutaneous and gastrointestinal sy mptoms, and all patients had decreased IL-4 levels after dietary elimi nation. The mean percentage of IL-4 decreased in 67%, correlating with clinical scores. Cytokine production from food antigen-stimulated T c ells showed an inverse correlation with serum IL-4. Lymphocyte prolife rative responses in all patients tested postdietary elimination for T cell cytokine production were inhibited by anti-IL-4.