Weighing the risks and benefits of organs donated for transplant
An infectious disease specialist discusses the latest guidelines on using organs from donors once categorized as “increased risk.”
Patients facing end-stage organ failure are often extremely ill. The uncertainty of waiting for a donor organ, and the need to be ready to act quickly when one becomes available, both add to their stress.
As if all of that wasn’t enough, patients awaiting transplants must also grapple with a dilemma they probably never anticipated: whether to accept a compatible organ from a donor who, because of a recent history of intravenous drug use or other behaviors associated with acquisition of a blood-borne virus, may have contracted an infectious disease.
The Michigan Health blog spoke with Daniel Kaul, M.D., director of the Transplant Infectious Disease Service at University of Michigan Health, for an update on research and best practices to safeguard transplant recipients from donor-related infections, and how he approaches this difficult topic with his patients.
Can you describe how the organ donation process is regulated?
Kaul: Organ transplantation is one of the most highly monitored areas of medicine. Multiple organizations provide oversight of every aspect of donation and transplantation to minimize patient risk and maximize the potential for transplant success.
At the national level, oversight of organ procurement organizations and transplant centers is provided by Organ Procurement and Transplantation Network policy, as guided by the U.S. Department of Health and Human Services. In addition, the Public Health Service – which includes the Centers for Disease Control – publishes comprehensive guidelines on the screening and testing of potential organ donors. The Organ Procurement and Transplantation Network develops policies based on those guidelines.
At the local level, transplant centers like University of Michigan Health develop their own safety protocols based on Public Health Service guidelines and Organ Procurement and Transplantation Network policy recommendations.
Talk about the latest Public Health Service guidelines…
Kaul: In June 2020, the Public Health Service issued updated guidelines titled Assessing Solid Organ Donors and Monitoring Transplant Recipients for Human Immunodeficiency Virus (HIV), Hepatitis B Virus (HBV), and Hepatitis C Virus (HCV) Infection. These guidelines, now in effect, are based on the latest research and clinical experience related to the use of organs from donors who are known to have engaged in behaviors that increase their risk of recent infection with these viruses.
This update reflects three major advances in organ transplantation: First, a more advanced type of screening called nucleic acid testing is now used everywhere to test organ donors for HIV, HBV and HCV. Second, we have a better understanding than ever before of the actual risk of an organ donor having an undetected HIV, HBV or HCV infection. Lastly, in the unlikely event that a patient develops one of these infections after transplant, we now have highly effective treatments for HIV and HBV, and a cure for HCV.
This guidance is needed now more than ever because of the impact the opioid epidemic is having on organs available for transplant. Opioid addiction has driven many young, otherwise healthy people to engage in risky behaviors like injecting drugs or having sex for drugs or money. In the all too common but tragic case of overdose, these people may become organ donors.
Today as many as 1 in 4 organ donors may have engaged in one or more of these behaviors, increasing their risk of contracting HIV, HBV or HCV. So we must do a much better job of replacing fear with facts about the safety of donated organs, to help doctors and patients make fully informed decisions about their use in transplant.
How does this update differ from previous Public Health Service guidelines?
Kaul: Several aspects of the previous guidelines, issued in 2013, have been updated:
The criteria for identifying donors at risk for undetected HIV, HBV or HCV have been revised. And it is no longer advised to use any specific terminology to describe donors with HIV, HBV or HCV risk factors. Prior to this, these donors were categorized as “increased risk.”
The time from the risky behavior to the date of procurement of the organ that is felt to create increased risk has been shortened from one year to 30 days to better reflect the ability of testing to recognize recent infection.
The highly accurate nucleic acid testing is now the universal standard for testing organ donors for HIV, HBV and HCV.
Beginning 4 to 6 weeks post-transplant, organ recipients are to be monitored for HIV, HBV and HCV infections, regardless of whether testing revealed the presence of these infections in the organ donor.
It is now required that all transplant centers track and offer HBV vaccinations to people being evaluated to receive transplants.
Does nucleic acid testing identify every potential donor who may have HIV, HBV or HCV?
Kaul: All potential organ donors are tested for HIV, HBV and HCV. But even someone who tests negative may still be at risk of transmitting one of these infections. That’s because when a person becomes infected, it takes some time for it to be detectable. While nucleic acid testing has made that window period as much as ten times shorter than previous tests, it may not pick up an infection contracted in the final few days before a person’s death.
When nucleic acid testing is performed within weeks of a potential donor engaging in a behavior that increases his or her risk, the chance of disease transmission to an organ recipient is extremely low – 1% or less.
Why did Public Health Service drop the “increased risk” designation?
Kaul: Research has shown that the stigma associated with this subset of donors can outweigh the actual risk associated with using their organs. Overestimating their risk, patients, and many doctors, are reluctant to consider them for transplant.
The result is that viable, high quality organs go unused. According to one study, had the increased-risk label not existed, more than 200 additional transplants would have been performed each year in the United States.
Without this designation, how will a transplant candidate know if an available organ carries this risk?
Kaul: While the “increased risk” categorization is no longer used, doctors are still required to disclose all potential risks associated with an offered organ, and patients are still required to give their informed consent before receiving an organ for transplantation.
Just to clarify, doesn’t a positive HIV, HBV or HCV test disqualify someone from donating organs?
Kaul: Not necessarily. When an organ donor tests positive for one of these infections, his or her organ may still be used in certain circumstances. An HIV-positive organ can be transplanted into an HIV-positive patient, or an HCV-positive organ can be transplanted into an HCV-positive recipient. Also, since we have a proven cure for the infection, an HCV-positive organ can be transplanted into a recipient who understands the risk and provides consent.
How do you approach this conversation with your transplant patients?
Kaul: First, we try to make sure it isn’t just one conversation. The education process needs to begin the moment a person becomes a candidate for transplant and continue until the transplant takes place.
We know we are asking patients to take in a great deal of information – from insurance to surgical incisions to the side effects of immunosuppressive drugs. We don’t expect them to remember everything.
Early in the process we begin the conversation about the potential infection risks associated with donated organs. While it may not happen, we need to talk about what we’ll do if it does.
In all my conversations with transplant patients and families, I stress that the goal isn’t to eliminate all risk, but to minimize risk. Not all factors carry the same risks. While there is always a chance of unintended transmission of disease, the risk is quite small, and it is far less of a concern when the resulting disease is treatable.
For the majority of transplant patients, the much riskier choice is to turn down an organ because of fear of contracting an illness. This is not a choice between a risky organ of somewhat more risk and another available organ, but a choice between “a bird in the hand” and an uncertain wait for another organ. Research in kidney transplant patients showed that declining an increased risk kidney significantly increased the risk of death in the following 5 years, largely because the patient will face only about a 1 in 3 chance of getting another organ.
I’m hopeful that these evidence-based guidelines will help guide future doctor-patient conversations across the transplant community, increasing confidence in the organs available for transplant, and decreasing the number of viable organs that go unused.