Lymphocyte transformation tests and subpopulations of lymphocytes in a population-based material of atopic dermatitis in twins.

Lymphocyte function and lymphocyte subpopulations in the peripheral blood have been studied in a population-based material of 47 twins with atopic dermatitis (AD) (31 with a history of AD, 10 with mild AD, and 6 with moderate AD) and in 47 age- and sex-matched non-atopic control twins. Lymphocyte transformations to phytohaemagglutinin, concanavalin A (Con A), pokeweed mitogen, and purified protein derivative of tuberculin were investigated. Lymphocyte subpopulations were characterized by EAET rosettes and the monoclonal antibodies OKT3, OKT4, and OKT8. None of these in vitro tests showed any statistically significant differences between patients and controls. In the rather few individuals with moderate AD there was a statistically insignificant tendency to a decreased Con A stimulation in suboptimal concentration and a reduction of the OKT8+ cells. However, there were definitely no alterations in the immunological variables between patients with a history of AD and controls. Our results indicate that the investigated variables could be related to disease activity. We suggest that they represent epiphenomena rather than pathogenetic mechanisms of importance for the development of AD.