T gamma and theophylline-sensitive T lymphocytes in allergic contact dermatitis.

Two lymphocyte subpopulations, T cells bearing a receptor for the Fc fragment of IgG (T gamma) and theophylline-sensitive T cells, were investigated in 49 patients with allergic contact dermatitis (ACD) in the acute phase and compared with a control group. Patients with ACD had markedly reduced relative T gamma and theophylline-sensitive T lymphocyte levels, compared with normals (P less than 0.0005). The patients also showed reduced absolute T gamma and theophylline-sensitive T cells with respect to the controls (P less than 0.01). To determine whether decreased levels of T gamma and theophylline-sensitive T cells were related to the activity of ACD, the same T-cell subsets were determined in 10 of 49 patients after the clearing of the contact dermatitis. Both T-cell subpopulations were found within the normal range.