Resolvin D2 restores monocyte anisocytosis and mediates a shift toward classical monocytes ex vivo in blood samples from patients after major burns.

Circulating monocytes contribute to the defense against pathogens and play a crucial role in maintaining immune homeostasis. While there is substantial evidence regarding the triggers of monocyte activation, our understanding of how monocyte function is restored toward homeostasis after activation remains limited. Here, we assessed the changes in monocyte anisocytosis upon activation in blood, measured by monocyte distribution width (MDW), a biomarker for sepsis. We determined that the increase in MDW post-lipopolysaccharide (LPS) stimulation in the blood can be reversed promptly by adding resolvin D2 (RvD2), and we measured a decrease in interleukin-1 beta (IL-1β) in blood, and a decrease in the size of the population of intermediate monocyte subsets. Moreover, the ex vivo addition of RvD2 to blood samples from burn patients with high MDW restored normal MDW values. Further studies are needed to probe the potential therapeutic role of RvD2 in the context of burn injuries.