Innate immunity recovers earlier than acquired immunity during severe postoperative immunosuppression

Background: Postoperative immune suppression, particularly a loss of cell-mediated immunity, is commonly seen after surgery and is associated with worse outcome, i.e. delayed wound healing, infections, sepsis, multiple-organ failure and cancer recurrence.However, the recovery of immune cells focusing on differences between innate and acquired immunity during severe postoperative immunosuppression is not investigated.Methods: In this retrospective randomized controlled trial (RCT) subgroup analysis, 10 postoperatively immune suppressed patients after esophageal or pancreatic resection were analyzed.Innate and acquired immune cells, the expression of human leukocyte antigen-D related on monocytes (mHLA-DR), lipopolysaccharide (LPS)-induced monocytic TNF-α and IL-10 secretion ex vivo, Concanavalin A (Con A)-induced IFN-γ, TNF-α, IL-2, IL-4, IL-5 and IL-10 release were measured preoperatively (od) until day 5 after surgery (pod5).Recovery of immune cells was defined by a significant decrease respectively increase after a significant postoperative alteration.Statistical analyses were performed using nonparametric statistical procedures.Results: Postoperative alterations of innate immune cells recovered on pod2 (eosinophils), pod3 (neutrophils) and pod5 (mHLA-DR, monocytic TNF-α and IL-10 secretion), whereas alterations of acquired immune cells (lymphocytes, T cells, T helper cells, and cytotoxic T cells) did not recover until pod5.Peripheral blood T cells showed an impaired production of the T helper (Th) 1 cytokine IFN-γ upon Con A stimulation on pod1, while Th2 specific cytokine release did not change until pod5.Conclusions: Innate immunity recovered earlier than acquired immunity during severe postoperative immunosuppression.Furthermore, we found a more anti-than pro-inflammatory T cell function on the first day after surgery, while T cell counts decreased.