IN-VITRO EFFECT OF DEXAMETHASONE, PENTOXIFYLLINE, AND ANTIENDOTOXIN MONOCLONAL-ANTIBODY ON THE RELEASE OF PROINFLAMMATORY MEDIATORS BY HUMAN-LEUKOCYTES STIMULATED WITH HAEMOPHILUS-INFLUENZAE TYPE-B

The effects of dexamethasone, pentoxifylline, and MAb against endotoxi n (HA-1A) on the release of various proinflammatory mediators, i.e. tu mor necrosis factor-alpha (TNF), IL-1 beta, IL-8, and prostaglandin(2) , by human leukocytes during stimulation with Haemophilus influenzae t ype B were studied. The results show that only monocytes, and thus nei ther lymphocytes nor granulocytes, release these mediators in response to H. influenzae. Dexamethasone inhibited the release of all of these mediators, whereas pentoxifylline only inhibited the release of TNF. HA-1A only reduced the release of IL-8 from adherent monocytes signifi cantly and had no significant effect on the release of TNF, IL-1 beta, and prostaglandin E(2). In whole blood, no significant effect of HA-1 A on the release of TNF, IL-1 beta, IL-8, and prostaglandin E(2) was f ound. In summary, the results of this study demonstrate that dexametha sone is the most potent inhibitor of the release of proinflammatory me diators by monocytes induced by H. influenzae type B.