[Alpha tumor necrosis factor in the serum of patients with sarcoidosis, tuberculosis or bronchial cancer].

Tumor-necrosis-factor-alpha (TNF-alpha), which is secreted by cells of the macrophage/phagocytic system, interact in a variety of different ways with other cytokines and immunologically active substances. To investigate a possible role of TNF-alpha in granulomatous lung diseases and to determine whether sarcoidosis can be differentiated from tuberculosis on the basis of serum TNF-alpha levels, we studied sera from patients with sarcoidosis and active tuberculosis. Ninety-one percent of the patients with sarcoidosis and 83% of the patients with tuberculosis exhibited significantly elevated TNF-alpha levels as compered with controls. Since these levels remained elevated irrespective of clinical stage and even under therapy, it is believed that patients with sarcoidosis and tuberculosis experience continuous activation of TNF-2-alpha-producing cells of the myelomonocytic system. In addition, determination of serum TNF-alpha levels does not permit differentiation between sarcoidosis, tuberculosis or malignant disease.