Allogeneic red blood cell transfusion can induce transfusion-related immunomodulation while correcting anemia and improving oxygenation,and thus may be associated with the increased risk of postoperative infections.However,the available studies have conflicting conclusions.Preclinical studies demonstrate transfusion-related immunomodulation is associated with transfusion amounts.Stored red blood cells can cause more significant immunosuppression than fresh blood products,while leukoreduction alleviates the negative effect on immune system.However,clinical studies do not reach agreements on these issues.Recently,accumulating multi-center,large-sample-size,real-world studies have reported significant associations of all ogeneic red blood cell transfusion in cardiac,orthopedic,hepatic,pancreatic,gastrointestinal,and vesical surgeries with postoperative infections.Considering the limitations of previous studies,future research should focus on multiple operations,prolong the time interval between transfusion and surgery,include different infections into outcomes,and define the postoperative infections accurately in the premise of adequate samples.High-quality clinical evidence could help to optimize the utilization of blood products and improve the postoperative outcomes.
Keywords: allogeneic red blood cell transfusion; leukoreduction; postoperative infection; red blood cell storage time; transfusion-related immunomodulation.