Drotrecogin Alfa (Activated) Does Not Affect Intracellular Production of Interleukin-6 and Tumor Necrosis Factor-?? in Endotoxin-Stimulated Human Monocytes

Abstract

In this ex vivo laboratory study, we investigated the effects of drotrecogin alfa (activated) (DA(a)), a recombinant form of human activated protein C, on the intracellular expression of interleukin (IL)-6 and tumor necrosis factor (TNF)-alpha on lipopolysaccharide (LPS)-stimulated human monocytes in a whole blood system. Whole blood samples from 10 healthy volunteers were stimulated with LPS (0.2 ng/mL) and incubated with 0.01, 0.1, 1, 10, and 100 nM of (final concentration) DA(a) for 3 h at 37 degrees C and 5% CO2. Intracellular expression of IL-6 and TNF-alpha was assessed by flow cytometry. Our investigation showed that DA(a), at any of the concentrations tested, did not affect intracellular IL-6 and TNF-alpha production in LPS-stimulated human monocytes after 3 h of incubation. The results of this investigation led us to conclude that any antiinflammatory activity of DA(a), if present, does not occur via detectible decreases in the production of proinflammatory cytokines IL-6 and TNF-alpha in human monocytes.

Up-regulation interleukin-6 and interleukin-8 by activated protein C in lipopolysaccharide-treated human umbilical vein endothelial cells

“…Czeslick showed that even in monocyte model, APC cannot affect intracellular production of IL-6 and TNF-α. Conclusion is drawn that the possible anti-inflammatory activity of APC may not occur via the production of pro-inflammatory cytokines in human monocytes (Czeslick et al, 2005). The recently published result is contrary to that of White. It seems that the exact mechanism of the APC benefit in human being is intricate.…”

Activated protein C inhibits chemotaxis and interleukin-6 release by human neutrophils without affecting other neutrophil functions

“…In THP-1 cells, LPS-induced IL-8 was decreased by APC in vitro. 17 However, in a study of isolated human monocytes, APC had no effect on IL-8 20 and in endothelial cells APC was reported to up-regulate both IL-6 and IL-8. 23 Thus, there are clear cell-specific differences.…”

“…17 Our findings also confirm the lower plasma IL-6 concentrations in patients treated with APC in the PROWESS study. 2 However, a study using isolated human monocytes failed to show any effect of APC on low-dose LPS-induced IL-6, 20 and a recent study reported no effect of APC on IL-6 in pigs treated with LPS. 21 IL-6 has important roles in the host response mechanisms to sepsis.…”

Time-course of neopterin levels in patients suffering from severe sepsis treated with and without Drotrecogin-alpha (activated)

“…This study was primarily aimed to investigate the influence of Drotrecogin-alpha (activated) on neopterin levels as a pro-inflammatory marker. Several preliminary studies have shown that Drotrecogin-alpha (activated) does not affect levels of pro-inflammatory markers such as interleukin-6 or tumour necrosis factor-a [21]. Dhainaut et al [16,17] measured cytokine levels (TNF-a, IL-1, IL-8 IL-10 and IL-6) in patients treated with or without Drotrecogin-alpha (activated) in the 'Prowess' study population and found no significant differences between the treatment groups.…”