Oral warfarin affects peripheral blood leukocyte IL-6 and TNF alpha production in rats

Abstract

Warfarin is a Vitamin K (VK) antagonist that affects Vitamin K-dependent (VKD) processes, including blood coagulation, as well as processes unrelated to hemostasis such as bone growth, calcification, and growth of some cell types. In addition, warfarin exerts influence on some non-VKD-related activities, including anti-tumor and immunomodulating activity. With respect to the latter, both immune stimulating and suppressive effects have been noted in different experimental systems. To explore the in vivo immunomodulatory potential of warfarin on one type of activity (i.e., cytokine production) in two different immune cell populations (i.e., mononuclear or polymorphonuclear cells), effects of subchronic oral warfarin intake in rats on pro-inflammatory cytokine (i.e., TNF alpha, IL-6) production by peripheral blood mononuclear and polymorphonuclear cells (granulocytes) was examined. Differential effects of warfarin intake on TNF alpha and IL-6 were noted, depending on the type of peripheral blood leukocytes and on the cytokine examined. Specifically, a lack of effect on TNF alpha and a priming of IL-6 production by mononuclear cells along with a decrease in TNF alpha and a lack of effect on IL-6 in polymorphonuclear cells were seen in warfarin-exposed hosts. The cell-and cytokine-dependent effects from subchronic oral warfarin intake on peripheral blood leukocytes demonstrated in this study could, possibly, differentially affect reactions mediated by these cells. Ultimately, the observed effects in rats might have implications for those humans who are on long-term/prolonged warfarin therapy.