Production of Tumor Necrosis Factor/Cachectin by Peripheral Blood Mononuclear Cells in Patients with Systemic Lupus erythematosus

Levels of tumor necrosis factor/cachectin (TNFα) assessed by ELISA were similar in the supernatant of cultures from peripheral blood mononuclear cells (PBMC) from either active or inactive systemic lupus erythematosus (SLE) patients and controls stimulated with mitogen alone. When PBMC were stimulated with mitogen plus phorbol 12-myristate-13-acetate (PMA), the amount of TNFα was significantly decreased in culture supernatants from active patients or from the entire group of SLE patients studied. However, spontaneous synthesis of TNFα in nonstimulated cultures was increased in the SLE patients. Interferon-γ (IFN-γ) enhanced TNFα synthesis in cultures from either SLE patients or controls stimulated by concanavalin A (Con A) alone, but depressed the high production of TNFα by normal PBMC stimulated with Con A plus PMA. IFN-γ enhanced TNFα production in response to Con A plus PMA in 2 of 3 SLE patients.