Inflammatory cytokines peak 2 hours posttransfusion. Cytokine analysis using flow cytometry evaluated serological IL-6 (A) and IFN-β (B) levels 2 hours posttransfusion with KEL^lo (green), KEL^med (blue), or KEL^hi (red) RBCs into low (lo), medium (med), or high (hi) αKEL immunized mice. Baseline cytokine levels are represented by the hashed horizontal line in each graph. *IL-6 levels between KEL^hi RBC and KEL^med or KEL^lo RBC transfusion, P < .01. Error bars represent mean ± SEM. n = 5-7 mice per group. Each panel represents data reproduced 2 times.