Mite-antigen-stimulated cytokine production by peripheral blood mononuclear cells of atopic dermatitis patients with positive mite patch tests.

To investigate possible involvement of Th1-type immunoreaction in the development of skin lesions of atopic dermatitis (AD), we measured mite-antigen-stimulated production of IL-2, IL-4 and IFN-gamma, using peripheral blood mononuclear cells (PBMC) obtained from 23 patients with AD who developed positive patch test reactions to house dust mite antigens extracted from Dermatophagoides pteronyssinus (Dp). Incubation of these PBMC with the Dp antigen for 72 h produced marked secretion of IL-2 and IFN-gamma, but not IL-4, indicating that Dp-specific T cells were found in these patients' circulating peripheral blood and were capable of producing IL-2 and IFN-gamma, known as major mediators of the delayed-type allergic reaction. Our study suggests that Th1-type cells may be involved in the development of skin lesions of AD patients with positive patch test reactions to house dust mite antigen.