CMV and organ transplants

Ganciclovir-resistant cytomegalovirus (CMV) is an important cause of illness among certain types of transplant recipients who have had prolonged exposure to ganciclovir (the main drug used for preventing and treating CMV disease), according to a UW study published in the Aug. 17 issue of The Lancet.

Ganciclovir-resistant CMV disease is well known among HIV-1-infected patients who have received the drug for long periods, but has been rarely reported among recipients of solid-organ transplants. Dr. Ajit Limaye, UW acting assistant professor of medicine and laboratory medicine, and colleagues studied 240 recipients of liver, kidney, or pancreas transplants for signs of ganciclovir-resistant CMV disease. They concentrated their study on patients testing positive for CMV, and recipients of transplants from seropositive donors.

Ganciclovir-resistant disease was diagnosed in five of 67 (7%) patients who received transplants from positive donors, compared with none of 173 patients who tested positive for CMV before transplant. The investigators also noted that ganciclovir-resistant disease was more common among patients who received the most potent immunosuppression, and led to serious clinical complications.

Limaye commented: “Although CMV is a common viral infection among organ transplant recipients, it has generally been treatable with the drug ganciclovir. This study suggests that resistance to this main drug used to treat CMV is an emerging problem. Resistance seems to preferentially affect patients who have received the most potent immunosuppression and oral ganciclovir for prolonged periods. Clinicians who care for transplant patients should be aware of this complication and test for it accordingly,” he said. “Because alternative treatments are limited and toxic, new antiviral medications for treating CMV are urgently needed.”

A commentary in the same issue supports concerns that the problem of ganciclovir-resistant disease is likely to increase in this era of routine viral prophylaxis and highly potent immunosuppression.