Study Suggests Unique Way to Prevent Infection after Kidney Transplant

Wednesday, December 10, 2014

Viral infections are a leading cause of disease and death in patients receiving a kidney transplant. But a recent University of Minnesota study suggests a unique way to prevent the transmission of common viruses during kidney transplants.

Published in the journal Transplantation, the study tested whether inhibiting two common viruses in donors by giving them an antiviral drug would reduce the amount of virus transmitted by the donor kidney at transplantation.

“Just as we prevent transmission of HIV to babies by providing pregnant women with antiretroviral medication before child birth, we wanted to test the theory that we could reduce viruses transferred through the organ,” said Priya Verghese, M.D., M.P.H., pediatric nephrologist, University of Minnesota Masonic Children’s Hospital and lead author of the study. “Prevention is so important, especially for children because they have not been exposed to the common viruses carried by adult organ donors.” 

Organ rejection was once the main concern after a kidney transplant. Advances in suppressing the immune system make rejection less commonbut patients are at greater risk for serious infections and cancerous cell growth after transplantation.

Two common herpes viruses cause the greatest burden: Cytomegalovirus, or CMV, and Epstein-Barr virus, or EBV. Both viruses infect most people at some point in their lives. In healthy people, the viruses do not cause serious symptoms. But in a patient whose immune system is suppressed, they can be deadly.

The problem arises when a kidney donor carries CMV or EBV and the person receiving the kidney does not. Called “discordant pairs,” the viruses are believed to be transferred through the kidney. Children are at greatest risk because they frequently do not carry either virus.

Researchers followed 17 pairs of donor-recipients—all discordant pairs. All kidney donors were adults, 11 of 17 recipients were children. In seven pairs, donors took an antiviral medication for 14 days before the kidney transplant. The placebo group included 10 discordant donor-recipients, with donors taking a placebo for 14 days before transplantation.

No patient receiving a kidney from a donor who took the antiviral medication contracted CMV or EBV disease after transplantation. Donors also tolerated the medication well, reporting no side effects and remaining healthy.

In the placebo group, one recipient developed CMV disease and a second recipient had EBV-related cancer (lymphoma) due to post-transplant lymphoproliferative disorder (PTLD), a serious illness often leading to cancer. In the case of the EBV-related PTLD, researchers performed genetic tests on the virus, which led them to believe the PTLD was caused by EBV from the donor kidney.

 “We recognize this is a small sample but the results are encouraging and should be followed up with a larger study,” said Henry Balfour, Jr., M.D., a co-author of the study and director, International Center for Antiviral Research and Epidemiology in the medical school. “If we can find an effective way to prevent transfer of viruses during organ transplants, we can keep patients healthier and avoid the terrible risks of infection.”

“By preventing the transfer of these common viruses, we want to improve the survival of children receiving kidney transplants and hopefully, extend the time before a second transplant is needed,” Verghese said. “The implications are significant if we can reduce the number of people on the waiting list for a kidney.”

The study was funded by grants from the University of Minnesota Foundation and the Amplatz Scholar Medical Research Award.

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