Tuberculous pleural effusions.

Tuberculosis is the most frequent cause of death due to infectious diseases. In Europe, it is one of the most frequent types of pleural effusions in young patients. Tuberculosis is caused by the rupture of a pulmonary subpleural caseous focus, which releases mycobacterium into the pleural cavity, thereby triggering an immune response involving mainly macrophages, CD4+ T lymphocytes, and the cytokines released by these cells (especially interleukin 1, interleukin 2, and ?-interferon).