Patients with tuberculous
pleural effusions may show cutaneous anergy to
tuberculin purified-
protein derivative (
PPD). This phenomenon has been attributed either to preferential sequestration of
antigen-specific T-lymphocytes to the pleural space or to the presence of suppressor monocytes in the blood. In 2 patients with primary tuberculous
infection involving the pleura and with skin anergy to
PPD, the in vitro proliferation of pleural and peripheral blood T-cells to
PPD was evaluated. Although peripheral blood T-cells were not reactive, pleural T-cells showed a marked proliferative response to
PPD. At least in the first patient, the lack of proliferation of circulating T-cells could not be related to the presence of suppressor monocytes. Interestingly, after 4 to 8 wk of specific
chemotherapy,
PPD skin test became positive and the blood T-lymphocytes responded in vitro to the same
antigen. Pleural T-lymphocytes were used to generate long-term,
PPD-specific T-cell lines and could be maintained in vitro for more than 3 months with repeated cycles of stimulation. The pleural and the blood T-lymphocytes and the T-cell lines were also characterized phenotypically: although the majority of the T-lymphocytes present in the pleural space after
Mycobacterium tuberculosis infection were Leu-3-positive (helper T-cells), T-cell lines proliferating in response to
PPD included high numbers of Leu-2-positive cells (suppressor/cytotoxic T-cells). These data suggest that early skin anergy in
tuberculous pleurisy may be associated with sequestration of
PPD-reactive T-lymphocytes in the pleural spaces involving both Leu-2-and Leu-3-positive T-cells.