Antagonist concentration dependent inhibition of hIgE secretion. A, in vitro; Isolated hPBMC derived from patients suffering from AD (n = 5) and from donors without any history of AD (Non-AD, n = 7) were incubated for 14 days in the presence of 50 ng/ml IL-4 and increasing amounts of antagonist (1:1, 50 ng/ml; 1:2, 100 ng/ml; 1:5, 250 ng/ml; 1:10, 500 ng/ml). At a concentration ratio of 1:2 the difference in the AD group was statistically different from the non-AD group (Kruskall-Wallis test, p = 0.02). B, in vivo; hPBMC derived from patients suffering from AD (n = 4) and from one donor without any history of atopic dermatitis (n = 1) were engrafted and treated with 10 μg IL-4 in 0.5% methylcellulose, 0.05% TWEEN 80 in PBS (1:0) or 10 μg + 100 μg antagonist in 0.5% methylcellulose, 0.05% TWEEN 80 in PBS (1:10). In every cohort (n = 4-5) mean serum hIgE levels were determined. Mean hIgE levels of IL-4 treated animals were defined as 100%. Analysis of the data revealed that the change was not statistically different.