EFFECT OF XANTHINE DERIVATES AND DEXAMETHASONE ON STREPTOCOCCUS PNEUMONIAE-STIMULATED PRODUCTION OF TUMOR-NECROSIS-FACTOR-ALPHA, INTERLEUKIN-1-BETA (IL-1-BETA), AND IL-10 BY HUMAN-LEUKOCYTES

The present study concerns the release of the proinflammatory cytokine s interleukin 1 beta (IL-1 beta) and tumor necrosis factor alpha and o f the anti-inflammatory cytokine IL-10 by human leukocytes in whole bl ood during stimulation with Streptococcus pneumoniae and the effects o f various xanthine derivates, i.e., pentoxifylline (PTX), caffeine, an d theofylline, and of dexamethasone (DXM). All three xanthine derivate s and DXM inhibited the release of tumor necrosis factor alpha, PTX be ing the most effective. PTX, theofylline, and DXM inhibited the releas e of IL-1 beta, but caffeine did not affect IL-1 beta release. The rel ease of IL-10 was significantly reduced by PTX at 24 h and by caffeine at 48 h, but DXM increased the release of this cytokine. In sum, the results of this study demonstrate that DXM inhibits only the release o f proinflammatory cytokines but not of the anti-inflammatory cytokine IL-10 by human leukocytes, while PTX is the most potent inhibitor of b oth proinflammatory and anti-inflammatory cytokines.