In vitro production of tumour necrosis factor and prostaglandin E2 by peripheral blood mononuclear cells from tuberculosis patients.

We investigated the production of tumour necrosis factor-alpha (TNF-alpha) and prostaglandin E2 (PGE2) by peripheral blood mononuclear cells (PBMC) from tuberculosis patients and healthy controls. PBMC from tuberculosis patients generated constitutively more TNF-alpha than did control PBMC. This production was significantly higher for patients with high-grade fever and cachexia. The increase of TNF-alpha production by PBMC from tuberculosis patients was associated with a comparatively weaker elevation of PGE2 synthesis which did not parallel fever or weight loss. In vitro treatment of control PBMC with the tuberculin purified protein derivative (PPD) promoted an increased TNF-alpha production which was similar to that of untreated PBMC from tuberculosis patients. Thus, the increased TNF-alpha production in tuberculosis could be explained by the in vivo exposure of PBMC to mycobacterial antigens. In contrast, the concentration of PGE2 was weaker in the medium of untreated PBMC from tuberculosis patients than in the medium of PPD-treated control PBMC, suggesting that PGE2 synthesis by PBMC was limited in tuberculosis by unidentified factors.