Cytomegalovirus-mediated upregulation of chemokine expression correlates with the acceleration of chronic rejection in rat heart transplants.

Cytomegalovirus (CMV) infections have been shown to dramatically affect solid organ transplant graft survival in both human and animal models. Recently, it was demonstrated that rat CMV (RCMV) infection accelerates the development of transplant vascular sclerosis (TVS) in both rat heart and small bowel graft transplants. However, the mechanisms involved in this process are still unclear. In the present study, we determined the kinetics of RCMV-accelerated TVS in a rat heart transplant model. Acute RCMV infection enhances the development of TVS in rat heart allografts, and this process is initiated between 21 and 24 days posttransplantation. The virus is consistently detected in the heart grafts from day 7 until day 35 posttransplantation but is rarely found at the time of graft rejection (day 45 posttransplantation). Grafts from RCMV-infected recipients had upregulation of chemokine expression compared to uninfected controls, and the timing of this increased expression paralleled that of RCMV-accelerated neointimal formation. In addition, graft vessels from RCMV-infected grafts demonstrate the increased infiltration of T cells and macrophages during periods of highest chemokine expression. These results suggest that CMV-induced acceleration of TVS involves the increased graft vascular infiltration of inflammatory cells through enhanced chemokine expression.

Late mortality after orthotopic liver transplantation.

BACKGROUND: Mortality within the first year after orthotopic liver transplantation (OLTx) is usually due to infection or allograft failure. Late complications leading to death after OLTx have not been extensively evaluated. The aim of this study was to determine the incidence of late mortality and to identify the most common causes and risk factors associated with late mortality after OLTx. METHODS: A total of 479 OLTx were performed in 459 patients (320 males, 139 females; mean age 47 years, range 13 to 69) between September 1991 and April 2000. All patient deaths among liver transplant recipients who survived more than 1 year after transplantation (follow-up mean 3.4 years, median 3, range 1 to 8.6) were reviewed. RESULTS: In all, 122 allografts (24%) were lost in 109 patients during the study period (24%). Seventy-five allografts were lost in 69 patients by 1 year (15%). Forty-seven allografts were lost in 40 patients who survived at least 1 year (9.6%). Actuarial survivals at 2 years, 5 years, and 9 years were 95%, 85%, and 80%, respectively (based on 100% survival at 1 year). The causes of the late mortality were malignancy (9 patients), disease recurrence (8), late infection (6), renal failure complications (5), cardiovascular complications (4), chronic rejection (3), gastrointestinal hemorrhage (2), medication noncompliance (1), and unknown (2). CONCLUSIONS: Malignancy and disease recurrence are the major causes of late mortality among adult OLTx recipients. Pharmacologic immunosuppression is associated with many of the causes of late mortality. Advances in immunosuppression with less toxicity may improve long-term survival after OLTx.