Normal values and membrane markers of theophylline-sensitive and theophylline-resistant human T-lymphocytes.

In 32 healthy adults between 20 and 50 years, the number of theophylline-resistant T-lymphocytes (T-res) was determined to be 51 +/- 4% or 1,161 +/- 326 per microliter, and that of theophylline-sensitive T-lymphocytes (T-sens), 11 +/- 2% or 252 +/- 95.--The decrease in number of rosette-forming cells after incubation with 1 mM theophylline was not caused by reduced vitality (51Cr-release test). The testing of various theophylline concentrations (1, 3, 5, and 10 mM) did not result in a changed count of T-sens. By a variation of the lymphocyte: sheep erythrocyte ratio and of incubation temperature it was found that T-sens possess high-affine and T-res low-affine receptors for sheep erythrocytes. While about 30% of the cells of both subpopulations proved to have Fc-IgM-receptors, among T-sens a significantly higher number of cells carried Fc-IgG-receptors than among T-res (29% vs. 10%).