Fig. 1.

Older, stored RBC transfusions exacerbate sepsis and decrease survival in S. typhimurium–infected mice. Transfusion recipients were male C57BL/6 mice. (A) Mice were infected intraperitoneally with 1000 CFUs of S. typhimurium strain LT2 and infused with saline (n = 35; black circles); fresh syngeneic RBCs (<24-hr storage; n = 39; blue squares); or older, stored RBCs (2 weeks of storage; n = 28; red triangles). Kaplan-Meier survival estimates of mice are shown. (B–D) Salmonella infected mice (n = 10 per group) were infused with saline, fresh RBCs, or old RBCs, as above, and euthanized 5 days later. Bacterial load was measured by plate dilution in (B) blood, (C) liver, and (D) spleen. Results are presented as mean ± SEM; no bacteria were detected in the blood of mice infused with saline or transfused fresh RBCs. (E) Representative images of hematoxylin and eosin–stained histologic sections of the liver and spleen, 5 days after transfusion of S. typhimurium –infected mice with fresh or old RBCs or mice transfused old RBCs without infection. The arrow denotes tissue necrosis; the arrowhead denotes a blood vessel. Original magnification was 400× (liver) and 40× (spleen). ***p < 0.001 compared to fresh RBC transfusions.