Neutrophil-depleted mice treated with IL-18–neutralizing antiserum are both functionally (a) and histologically (b) protected against ischemic ARF. Mice were injected with the neutrophil-depleting antibody RB6-8C5 24 hours before renal pedicle clamp (neutro^–), followed by anti–IL-18 antiserum (AS) or vehicle 40 minutes before renal pedicle clamp and just before clamp release. (a) In vehicle-treated neutro^– mice with ischemic ARF, there was a significant increase in serum creatinine compared with sham-operated controls. In neutro^– mice treated with AS, the serum creatinine was significantly decreased compared with vehicle-treated mice with ARF. *P < 0.01 vs. sham; **P < 0.01 vs. vehicle-treated ARF, NS vs. sham; n = 8. (b) In vehicle-treated neutro^– mice with ischemic ARF, there was a significant increase in ATN score compared with sham-operated controls. In neutro^– mice treated with AS before induction of ischemic ARF, the ATN score was significantly decreased compared with vehicle-treated neutro^– mice with ARF. *P < 0.001 vs. sham; **P < 0.01 vs. vehicle-treated ARF; n = 4.