THE PROFILES OF INTERLEUKIN (IL)-2, IL-6, AND INTERFERON-GAMMA PRODUCTION BY PERIPHERAL-BLOOD MONONUCLEAR-CELLS FROM HOUSE-DUST-MITE-ALLERGIC PATIENTS - A ROLE FOR IL-6 IN ALLERGIC DISEASE

We have developed a model to measure cytokine production by peripheral blood mononuclear cells (PBMC) in vitro. In this report, we examine t he production of interleukin-2 (IL-2), IL-6, and interferon-gamma (IFN -gamma) by PBMC of house-dust-mite (Dermatophagoides pteronyssinus)-al lergic subjects. When stimulated with specific allergen (D. pteronyssi nus), PBMC of patients produced significant levels of IL-2 and high le vels of IL-6, but little or no IFN-gamma. Nonatopic control PBMC also produced IL-6, although at lower levels, but no IL-2 or IFN-gamma. A u biquitous antigen, streptokinase/streptodornase (SKSD), induced high l evels of IL-2 in patients, but only low levels of IFN-gamma and IL-6. Nonatopic controls produced similar levels of IL-2 and IL-6, but high levels of IFN-gamma to SKSD. IL-2 and IFN-gamma levels induced by the T-cell mitogen phytohaemagglutinin (PHA) were similar in patient and c ontrol groups, but IL-6 levels were significantly lower in the patient s. IgE synthesis in vitro was shown only in atopic PBMC cultures stimu lated with specific allergen. The major points can be summarized as 1) IL-2 production by atopic patients in response to allergen; 2) IL-6 pr oduction to allergen by both atopic and nonatopic patients, but signif icantly increased in atopic patients; and 3) defective IFN-gamma produ ction by atopic patients to both allergen and antigen. These findings suggest that IL-6 may be important in the immune response to inhalent allergens such as D. pteronyssinus, possibly by creating a cytokine en vironment favourable to a T(H)2 response, and that atopic patients exh ibit a generalized defect of IFN-gamma production, not related to the response to allergen.