Nancy A. Melville

November 07, 2013

ATLANTA — The majority of donor kidneys designated as high risk function well at 30-month follow-up, according to research presented here at Kidney Week 2013.

"In fact, these apparent high-risk organs are safer than most people would assume from an infection perspective," said senior investigator Sumit Mohan, MD, from the Columbia University Medical Center in New York City.

"Our message is that these organs are mislabeled," Dr. Mohan told Medscape Medical News. "They are better designated as identified risk than high risk."

Up to 10% of donor kidneys are considered to be high risk for the transmission of infections such as HIV and hepatitis B and C, according to Centers for Disease Control and Prevention (CDC) criteria.

Traditional serologic testing of organ donors can take weeks or months to detect infection. Nucleic acid testing, however, has significantly improved this situation, and can detect infections acquired up to a matter of days before the test.

These apparent high-risk organs are safer than most people would assume from an infection perspective.

"Whereas traditional testing looks for a reaction from the body indicating the presence of a virus, nucleic acid testing detects evidence of the virus itself, which is faster," Dr. Mohan explained.

Nucleic acid testing is more expensive, however, and the relatively low number of detections raises the issue of cost-benefit for some centers.

To better understand outcomes, Dr. Mohan and his team evaluated the 170 patients who received a kidney that met the CDC high-risk criteria since 2004 at the Columbia University Medical Center.

The deceased kidney donors were predominantly male (72.7%), and mean age was 37 years.

Of the donors designated as high risk, 57.1% had a history of intravenous drug use, 25.9% engaged in high-risk sexual behavior, 11.8% had been incarcerated, 7.1% were men who had sex with men, and 4.7% had received multiple blood transfusions.

The recipients, 69.4% of whom were male, were screened for HIV and hepatitis B and C before transplantation and 6, 12, and 24 weeks after transplantation.

The recipients had waited an average of 1.7 years for a kidney, and 27.7% experienced delayed graft function.

At a median follow-up of 2.4 years, organs were functioning and there were no signs of transmission of infectious seroconversion in 86.5% of the recipients.

Most of the organs, 77.8%, were imported from other organ procurement organizations. "It's hard to prove, but I suspect that's likely because they had this high-risk label," Dr. Mohan speculated.

"We used these kidneys despite their label and they appear to have done just as well as other kidneys with similar characteristics. It makes you wonder if it's only a misunderstanding of what the CDC high-risk label actually means that results in surgeons and transplant professionals or their patients declining them."

Dr. Mohan asserted that a simple label change — from high risk to identified risk — could prevent misunderstandings and allow for more healthy organs to be used.

Telling a patient "I'm going to give you a high-risk organ" has a very different connotation than saying "we know the donor has a risk factor but we've tested the donor," he explained. "That can make a big difference."

This study is valuable because it demonstrates that, despite the high-risk label, such organs show function similar to those without the label, said Anita Mehrotra, MD, from the Mount Sinai School of Medicine in New York City.

HIV and Hepatitis C Transmission

"The study is clinically relevant. A case of HIV and hepatitis C transmission that made national news in 2007 led to a significant decline in the willingness of surgeons to use so-called high-risk organs," Dr. Mehrotra told Medscape Medical News. "By not using them, we are throwing away a significant portion of our organ pool, which is unfortunate, considering how long some people wait for a kidney."

She noted that the rate of graft survival with these high-risk kidneys does not appear to be any higher than with organs not considered to be high risk.

"That rate of graft survival is similar to the overall survival of deceased donor organs as a whole. It is approximately 90% at 1 year and 80% at 5 years for all deceased donor kidneys," Dr. Mehrotra said.

Limitations include the fact that this is a single-center study, and therefore broad generalizations cannot be made. Nevertheless, the findings are useful, she noted.

"These data are in line with previous data that also suggests that using these organs is safe," Dr. Mehrotra said.

Dr. Mohan reports receiving research funding from Pfizer and Gambro. Some of his coauthors report financial relationships with a variety of companies. Dr. Mehrotra has disclosed no relevant financial relationships.

Kidney Week 2013: the American Society of Nephrology 46th Annual Meeting. Abstract TH-PO1152. Presented November 7, 2013.


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