Role of Cytomegalovirus Reinfection in Acute Rejection and CMV Disease After Renal Transplantation

Renal transplantation is a most valuable treatment for patients with end-stage renal disease as it offers improved survival and quality-of-life benefits compared with dialysis (Evans, Manninen et al. 1985; Port, Wolfe et al. 1993). However, there has been no satisfactory increase in long-term graft survival despite significant advances in the field of renal transplantation (Meier-Kriesche, Schold et al. 2004). Long-term graft failure is generally due to death despite a functioning graft, chronic rejection, or recurrent kidney disease (Valente, Hariharan et al. 1997). Among these, chronic rejection is the most important cause of longterm graft failure (Jindal and Hariharan 1999). Graft failure owing to chronic rejection is a common reason for retransplantation, and the most important predictor of chronic rejection is a previous episode of acute rejection (Almond, Matas et al. 1993; Hariharan, Alexander et al. 1996; Cosio, Pelletier et al. 1997). Clinical acute rejection within the first year after transplantation has been reported to have a detrimental effect on long-term graft survival (Hariharan, Johnson et al. 2000). The projected half-life for cadaveric transplants in patients who did not have an episode of clinical acute rejection in the first year after transplantation was 17.9 years in 1995, compared with that of 8.8 years for patients who had an episode of clinical acute rejection (Hariharan, Johnson et al. 2000). This reduction in the relative risk of graft failure was significant among patients without acute rejection, whereas no reduction in the relative risk of graft failure was observed among those with acute rejection. Thus, the main issue asociated with renal transplantation is the suppression of allograft rejection.