Any donated human organ or tissue may harbor an unwanted, undiscovered or unrecognized infection, malignancy or other disease. With the transplant, irregardless of the best intentions and most up to date testing, that disease is donated too and may cause serious illness(even death) in a recipient. To minimize this risk, to allow assessment of the risk, and to facilitate informed judgement about whether or not to proceed……in advance of the transplant….. are the objectives. But risk cannot be completely eliminated.
The U.S. Centers for Disease Control and Prevention (CDC) has just issued long awaited guidelines for use in preventing the transmission of Hepatitis B (hep B), Hepatitis C (hep C) and HIV through organ transplantation. They are based on currently available evidence and expert opinions, and formally update guidelines last published in 1994. An essential difference between organ donation and blood or tissue donation led to the restriction of these new guidelines only to the former field. In organ donation transplantation must proceed within hours of the procurement of the donated material that might bear infection. In contrast, both blood and tissue are typically recovered, processed and stored for a longer period of time varying from multiple days to even months or longer. During that interval definitive testing and further risk reduction can clearly be performed.
This rapid time frame within which results of any laboratory testing must be available so that organ procurement and transplantation are not unduly delayed defines different ground rules than in most medical scenarios. For example, only a few labs throughout the country perform the most specialized testing (nucleic acid testing -NAT) for Hep B, Hep C and HIV with 24/7/365 availability and rapid turn around. Blood samples are typically sent by courier to one of these labs when testing of a deceased donor is required. Of course, these steps do increase the cost of transplantation.
A practical approach was, by necessity, taken by the U.S. Public Health Service in developing the guidelines. For example, if one of the test results indicates the presence of Hep B, Hep C or HIV when the virus is really not present (a false positive result), the inappropriate exclusion of the organ donor would be a serious consequence costing one or more lives. The need to balance the potential benefit to be gained from a successful transplant, with the statistical risk of using the possibly infected organ is acknowledged in the guidelines. Thus, it might be reasonable to use a liver from a donor who is suspected of having a false positive test if the liver candidate is at death’s door and no other organs are available. But, it would not be reasonable to use the same donor’s tissue without clarification of the possible infection.
Wisely, these guidelines also delve deeply into the important issue of involving the patient or family (if the patient is unable) through education when transplantation is only a concept, and through full informed consent when the detailed risks and benefits are known. This is a codification of the timing and content of informed consent similar to other approaches in this tightly regulated field.
Behavioral factors that increase the donor’s risk of infection with Hep B, Hep C or HIV include sex with an infected person in the preceding 12 months, male-male sex within the preceding 12 months, people who have had sex with a person in exchange for money or drugs in the preceding 12 months, people who have had sex with a person who injected drugs in the preceding 12 months, a child < 18 months born to an infected or at risk mother, a child who has been breastfed within the preceding 12 months by an infected or at risk mother, people who injected drugs in the preceding 12 months, people in lockup, jail, prison or a juvenile correctional facility > 72 hours in the preceding 12 months, and people newly diagnosed with a sexually transmitted disease in the preceding 12 months.
For any transplant that involved an increased risk of transmission of Hep B, Hep C or HIV, surveillance testing of the recipient for the first year is recommended. If infection does occur, treatment can be initiated as early as possible with the intent of staving off serious illness.
Today, these are the most common severe viral infections that concern transplant recipients. But previously, similar donor transmitted infection with the cytomegalovirus (CMV) and the Epstein Barr virus (EBV) were also highly problematic, at times even causing fatalities. Now these infections are much more manageable because of the anti-viral medications available for use.
If all of these details seem frightening, the real statistic that new (de novo) Hep B, Hep C or HIV infection through transplantation is very rare should be reassuring. The newly available document has simply formalized screening practices that have already become routine at many transplant programs for the protection of patients. Patients are entitled to be familiar with any unusual risks posed by the specific donor whose organ they are being offered (if they are so fortunate). Patients should feel empowered to ask about unusual issues with their donor (if they have not already been informed, which should happen).
Remember that the only way to have no risk at all is to have no transplant. If a transplant does happen, the human donor’s organ has been assessed with a risk/benefit ratio tailored to the specific recipient who should have been informed and should have intentionally opted to proceed. Of course, the transplant team would not typically offer an organ that they did not consider acceptable for that patient. But, in the end, it must be the patient (and/or the family) who agrees to go ahead.