To analyse whether there is a general defect in T or B cell function in atopic individuals we have measured cytokine and IgE production by peripheral blood lymphocytes, isolated from 19 atopic donors (17 asthma/rhinitis and two dermatitis patients) in comparison with 19 non-atopic controls. After stimulation of lymphocytes with anti-CD2 and anti-CD28, we found no significant difference in IL-2, IL-4 and interferon-gamma (IEN-γ) production. To examine the correlation between the production of IgE and IL-4, we stimulated lymphocytes with anti-CD2 and rIL-2. Under this condition both T cell IL-4 and B cell IgE production can be measured. No significant difference was found for the amount of IgE and IL-4 produced between the two groups (P > 0.05). The non-atopic donors showed a good correlation between IL-4 and IgE production (r= 0.70). Surprisingly, within the atopic group there was no correlation between IgE and IL-4 production at all (r= M-0.04). The ratio of IgE to IL-4 was higher (although not significantly) in the atopic group. Our data suggest that in atopic donors IgE production is less dependent on IL-4, and that other cytokines are involved.