Experimental filtration inhibits ALI induced by the supernatant from stored day 42 LR-RBCs. EBD leak is depicted as a function of treatment group. Normal saline (NS) treatment of rats as the first event did not result in ALI regardless of the second event: NS or the heat-treated supernatants from day 1 or day 42 plasma from units that underwent experimental filtration of standard LR. In LPS-treated rats (first event), NS did not cause ALI; however, the heat-treated supernatants from day 42 RBCs that underwent standard LR induced significant EBD leak/ALI. Conversely, none of the heat-treated supernatants from the experimentally filtered units on day 42 induced significant EBD leak/ALI (*P < .05 vs LPS/NS and NS/NS controls, n = 5 for each group).