Biologics in the treatment of transplant rejection and ischemia/reperfusion injury: new applications for TNFalpha inhibitors?
Tumor necrosis factor (TNF)-alpha inhibitors have proven efficacy in various autoimmune diseases such as Crohn disease, rheumatoid arthritis, psoriasis, and ankylosing spondylitis. Indeed, some TNFalpha inhibitors have already been approved for the management of the inflammatory manifestations associated with Crohn disease and rheumatoid arthritis. These agents are increasingly used for treatment of corticosteroid-resistant graft-versus-host disease after bone marrow transplantation, and case reports have documented their efficacy in treating corticosteroid- and muromonab-resistant rejection after intestinal transplantation. Thus, the potential role of TNFalpha inhibitors in transplantation of other vascularized solid organs is worthy of investigation. Experimental evidence indicates that TNFalpha plays a key role in mediating ischemia/reperfusion (IR) injury after liver, kidney, intestine, heart, lung, and pancreas transplantation. TNFalpha was also identified as a marker cytokine during organ rejection. Single-center studies evaluating the role of TNFalpha inhibitors in kidney transplantation have been initiated but the results are not yet available. TNFalpha is known to be a contributing factor in kidney allograft rejection, and may have value in predicting the onset of steroid-resistant acute rejection after liver transplantation. Experimental and preliminary clinical data have shown that circulating levels of TNFalpha are increased during cardiac graft rejection, and indicate that TNFalpha plays a role in the pathogenesis of acute cardiac allograft rejection. Anti-TNFalpha therapy was shown to prolong cardiac allograft survival when used alone or in combination with other drugs. TNFalpha genotype has been strongly associated with mortality in humans due to acute cell-mediated heart transplant rejection. In addition, there is evidence for a genetic predisposition toward acute rejection after kidney and simultaneous kidney-pancreas transplantation. TNFalpha inhibition has been used successfully as part of an induction therapy for pancreatic islet cell transplantation. Apart from IR injury and acute rejection after lung transplantation, TNFalpha was also found to be involved in the pathoimmunology of obliterative bronchiolitis. In conclusion, a substantial body of experimental evidence and preliminary clinical data suggest that TNFalpha inhibitors may play an important role in solid-organ transplantation, both in the amelioration of IR injury and in the treatment and prevention of acute rejection. Pharmacodynamic monitoring and pharmacogenetic screening may help to identify patients most likely to benefit from TNFalpha blockade. Randomized controlled trials in patients undergoing solid-organ transplantation are needed to further elucidate the clinical value of TNFalpha inhibition.
Pascher
Andreas
A
Department of Visceral and Transplantation Surgery, Charité-Universitaetsmedizin Berlin, Campus Virchow Klinikum, Berlin, Germany. andreas.pascher@charite.de
Klupp
Jochen
J
D000818:Animals; D000893:Anti-Inflammatory Agents / Q000009:adverse effects / Q000627:therapeutic use*; D000911:Antibodies, Monoclonal / Q000009:adverse effects / Q000627:therapeutic use*; D001688:Biological Products / Q000627:therapeutic use*; D002986:Clinical Trials as Topic; D006084:Graft Rejection / Q000378:metabolism / Q000628:therapy*; D006801:Humans; D015427:Reperfusion Injury / Q000378:metabolism / Q000628:therapy*; D014409:Tumor Necrosis Factor-alpha / Q000037:antagonists & inhibitors*
D000893:Anti-Inflammatory Agents; D000911:Antibodies, Monoclonal; D001688:Biological Products; D014409:Tumor Necrosis Factor-alpha