T he purpose of these studies was to examine the role of cytokines in the pathogenesis of cisplatin nephrotoxicity. Injection of mice with cisplatin (20 mg/kg) led to severe renal failure. The expression of cytokines, chemokines, and ICAM-1 in kidney was measured by ribonuclease protection assays and RT-PCR. We found significant upregulation of TNF-α, TGF-β, RANTES, MIP-2, MCP-1, TCA3, IL-1β, and ICAM-1 in kidneys from cisplatin-treated animals. In addition, serum, kidney, and urine levels of TNF-α measured by ELISA were increased by cisplatin. Inhibitors of TNF-α production (GM6001, pentoxifylline) and TNF-α Ab’s reduced serum and kidney TNF-α protein levels and also blunted the cisplatin-induced increases in TNF-α, TGF-β, RANTES, MIP-2, MCP-1, and IL-1β, but not ICAM-1, mRNA. In addition, the TNF-α inhibitors also ameliorated cisplatin-induced renal dysfunction and reduced cisplatin-induced structural damage. Likewise, TNF-α–deficient mice were resistant to cisplatin nephrotoxicity. These results indicate cisplatin nephrotoxicity is characterized by activation of proinflammatory cytokines and chemokines. TNF-α appears to play a central role in the activation of this cytokine response and also in the pathogenesis of cisplatin renal injury.