SEASONAL-VARIATIONS OF INTERLEUKIN-4 AND INTERFERON-GAMMA RELEASE BY PERIPHERAL-BLOOD MONONUCLEAR-CELLS FROM ATOPIC SUBJECTS STIMULATED BY POLYCLONAL ACTIVATORS

IgE synthesis is controlled by interleukin (IL)-4 and interferon (IFN) -gamma, but there is heterogeneity in the IL-4 response depending on t he sensitization of patients and natural allergen exposure. In patient s sensitized to various allergens, we studied the synthesis of IL-4 IF N-gamma, and IgE to determine to what extent their in vitro immune res ponse may be influenced by pollen season, depending on their sensitiza tion. We studied 12 nonallergic individuals, seven patients sensitized to cypress pollen, 12 sensitized to grass pollen, 14 sensitized to se veral pollens, and 42 patients with polysensitization. The release of IL-4 and IFN-gamma from peripheral blood mononuclear cells stimulated by polyclonal agents (calcium ionophore A23187 and phorbol myristate a cetate) was measured by ELISA. The spontaneous and IL-4-induced releas e of IgE was measured by ELISA. In patients with cypress pollen allerg y, IL-4 and IgE release were significantly lower than in patients with other allergies. In the pollen-sensitized group, IL-4 and IgE release were significantly higher during the pollen season than out of it. No variation in IL-4 ol IgE release was observed in the polysensitized g roup. IFN-gamma production was not affected by the pollen season. Thes e data show that the seasonal variations of IL-4 and IgE synthesis dif fer according to the sensitization of patients.