Cytomegalovirus (CMV) is one of the most important infections in renal transplant recipients [1-5]. Exposure to the virus, as indicated by the presence of detectable immunoglobulin G (IgG) anti-CMV antibodies in the plasma, increases with age in the general population and is present in more than two-thirds of donors and recipients prior to transplantation . It is therefore common for the donor and/or recipient to be CMV-positive at the time of transplantation.
CMV can be transmitted from the donor either by blood transfusion or by the transplanted kidney; the concurrent administration of immunosuppressive drugs to prevent rejection further increases the risk of clinically relevant CMV disease, with induction therapy principally being associated with an increased risk of disease [6,7]. Thus, both the recipient and the donor are routinely tested for anti-CMV antibodies prior to transplantation. (See "Evaluation for infection before solid organ transplantation".)
CMV is also a significant underlying cause of morbidity and mortality in the renal transplant setting:
●This was shown in a study using data from the United States Renal Data System in which donor and recipient CMV serostatus was available for over 17,000 deceased-donor renal transplant recipients . Based upon a multivariate analysis, CMV-positive patients had significantly higher incidence of CMV disease, allograft loss, and overall costs, compared with CMV-negative recipients.
●The impact of CMV on overall mortality was examined in a prospective, single-center study of almost 500 patients who did not receive induction therapy or CMV prophylaxis . Patients were monitored by weekly CMV pp65 antigenemia for 100 days and followed for a median length of time of 66 months. Despite the absence of induction therapy and maintenance immunosuppressive therapy with cyclosporine, mycophenolate mofetil (MMF), and low-dose prednisone, CMV-antigenemia was detectable in over 60 percent of patients in the first 100 days after transplant. Compared with those without CMV, CMV disease was associated with a relative risk of overall mortality of 2.5, and, importantly, asymptomatic CMV infection was associated with a relative risk of overall mortality of 2.9.