Impact of IL-4 and antagonist on T-cells in vitro and in vivo. A, Relevance of the immunological background on IL-4 induced proliferation of T-cells and differentiation of CD4 cells in vitro (AD, n = 7; non-AD, n = 4). Isolated hPBMC were incubated in the absence (No) or presence of 50 ng/ ml IL-4 (IL-4) or 50 ng IL-4 + 500 ng/ml antagonist (IL-4 + Antagonist). B, Comparison of individual CD4 : CD8 ratios in response to IL-4 and antagonist in vitro and in vivo. Non-AD; No treatment (No), n = 6; IL-4, n = 11, IL4 + Antagonist, n = 5), AD1 (No treatment, n = 3; IL-4, n = 4, IL4 + Antagonist, n = 4) and AD2 (IL-4, n = 7; IL4 + Antagonist, n = 5). Dotted lines indicate respective in vitro ratios at day 14.