[Flow cytometric analysis of helper T cell subsets (Th1 and Th2) in healthy adults].

To estimate frequency of T helper (Th) 1, Th2, and other related subsets in T cells among healthy Japanese, we determined the frequencies of interferon (IFN)-gamma- and/or interleukin (IL)-4-producing cells in stimulated peripheral blood lymphocytes (PBL) from 51 healthy adults of various ages by three-color flow cytometry using FITC-labeled anti-IFN-gamma, PE-conjugated anti-IL-4, and peridinin chlorophyll protein (PerCP)-labeled anti-CD4 or anti-CD3 antibody. As a result, proportions (mean +/- SD) of IFN-gamma-single positive (conveniently called Th1), IL-4-single positive (Th2), and double-positive cells (Th0) in CD4+ PBL, and homologous cell populations in CD3+ PBL (Th1 type, Th2 type, and Th0 type cells) were 21.3 +/- 8.2%, 2.7 +/- 1.1%, 1.9 +/- 1.0%, 39.5 +/- 13.5%, 1.7 +/- 0.8%, and 1.8 +/- 1.0%, respectively. Percentages of Th1 and Th2 were roughly consistent with those reported previously. Proportions of Th1, Th2, Th1 type, and Th2 type cells were found to increase with the age, whereas there were no significant difference in sex at least in 20s. Furthermore, positive correlation was seen between Th1 and Th1 type (r = 0.79), Th2 and Th2 type (r = 0.87), and Th0 and Th0 type (r = 0.86). Frequencies of these subsets in each donor were maintained at substantially the same levels for at least 3 months, suggesting existence of particular and stable Th1/Th2 balance among healthy individuals. As reported, 6 patients with atopic dermatitis examined in this study showed significantly lower frequencies of Th1 (11.0 +/- 2.5%) as compared with healthy donors (p < 0.01), implying usefulness of the immune test.