[Role of T lymphocytes in systemic lupus erythematosus]

In very active systemic lupus erythematosus (SLE), the serum levels of interleukin-2 (IL-2) are increased, indicating activation of T lymphocytes in the organism. The peripheral blood, however, contains T cells with a strongly reduced functional capacity, which results from a post-activation/refractory state; this hypofunction is reversible. Thus, the activity of the T lymphocytes in the circulating pool is the "mirror image" of the activity of these cells at the level of the whole organism. The B lymphocyte hyperactivity in SLE is T-dependent. A highly specific mechanism is involved in the activation of the B cells producing anti-native DNA antibodies. The investigation of lymphocyte functions enables one to follow the effect of immunosuppressive therapy.