Beneficial effect of transfusion with low-affinity red blood cells in endotoxemia.

Sepsis caused by endotoxins such as lipopolysaccharide (LPS) impairs the microcirculation, diminishing tissue blood supply and aggravates systemic hypoxia. A novel lower-affinity hemoglobin (Hb) variant, Hb Presbyterian, enhances oxygen release to peripheral tissues and may improve tissue oxygen supply during sepsis. This study investigated the effectiveness of Presbyterian Hb in transfusion therapy with LPS-challenged sepsis mouse model. Septic wild-type mice were transfused with RBCs from Presbyterian Hb-carrying mutant mice and wild-type mice. Their survival rates were assessed, and apoptosis of hepatocytes was evaluated. Survival rates of septic Presbyterian mutant mice and the wild-type littermates were also studied. The Presbyterian mutant RBC-transfused septic group survived longer than the wild-type RBC-transfused group. Apoptosis was reduced in the hepatocytes of the former group. Presbyterian mutant mice themselves, however, did not have stronger resistance to LPS-induced sepsis. Transfusion of low-affinity Hb-containing RBCs has beneficial effects in septic mice.