Special tests of kidney tissue from deaths

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Johns Hopkins Medicine researchers report the successful and safe transplantation of a kidney from a donor who died of complications from COVID-19. The case, which involved careful harvesting and sensitive molecular testing of the donor organ for the presence of the virus, demonstrates that healthy kidneys from these previously discarded donors can be safely transplanted.

While some kidneys from deceased coronavirus-infected donors have been successfully transplanted in the United States since the start of the pandemic, Johns Hopkins Medicine investigators say their transplant is one of the first documented cases in which samples of Donor tissues were analyzed with sophisticated tools capable of detecting molecular evidence of the virus. A report on the methods used and the results of the transplant was published on January 13 in the American Journal of Transplantation.

Concerns have emerged over the use of these donor kidneys, as the kidneys could be a target for virus infection, based on autopsy results and elevated levels of virus receptors in the kidneys.

“What sets this case apart from others is the fact that we studied the donor kidney using pre-transplant biopsy specimens to investigate the presence of the virus,” said Johns Fellow Kyungho Lee, MD. Hopkins Medicine and first author of the manuscript. “Instead of just doing a nasal swab test on the recipient after the transplant to check for infection afterwards, we obtained kidney tissue from the donor before the transplant and studied it carefully,” he said. declared.

Lee cautioned that large studies are needed to confirm the validity of the molecular analysis he and his team used, and to track the long-term outcomes of recipients of these donor organs. Currently, there are no standardized tissue testing platforms or validated protocols to follow.

To test the donor samples for the virus, the researchers used a standard PCR test, which amplifies the genetic material of the virus, as well as another sensitive technique known as in situ hybridization.

“In this case, surgeon Dr. Desai informed me that an organ was available, but other centers had refused it because the donor had died of complications from COVID-19,” says Hamid Rabb, MD, director. doctor of the Johns Hopkins Kidney Transplant Program. and corresponding author of the published report. Rabb and his team, based on the limited field data, agreed that the organ had a good chance of being used safely for the recipient, but decided to assess the risk using precise molecular methods. to assess infection in the donor organ.

The donor patient, the team reported, was a woman in her early 30s who was otherwise very healthy for her age, but was admitted to hospital in March 2021 with severe COVID pneumonia. -19 and eventually placed on extracorporeal membrane oxygenation (ECMO), which is a blood pump outside the body to deliver oxygen to the body. She developed hypoxic brain injury (when not enough oxygen is supplied to the brain) and progressed to brain death. Her kidney function was stable during her stay in the hospital and she tested negative for the virus by nasal swab three days before the donation.

Tissue samples from the donor kidney and aorta (a blood vessel known to have a high level of receptors for SARS-CoV-2, the virus that causes COVID-19) were taken and tested by PCR and by in situ hybridization. The samples were then compared to a separate positive COVID-19 case for accurate interpretation of the data.

The recipient patient was a 55-year-old man with end-stage renal disease who had been on dialysis for more than five years. The Johns Hopkins Medicine patient had no history of COVID-19, was fully vaccinated and tested negative for the virus on the day of the transplant. Since the procedure, which took place within 24 hours of the donor’s death, the recipient has tested negative for COVID-19 by nasal swab PCR test 20, 30, and 90 days post-transplant, and has not showed no signs or symptoms of the virus.

At the time of publication, the recipient was off dialysis with excellent kidney function since the transplant, says Niraj Desai, MD, surgical director of the kidney and pancreas transplant program at Johns Hopkins Medicine. Desai says there have been about a dozen kidney and liver transplants from COVID-19 positive donors since that case, but this specific case was unique in that sophisticated tissue molecular testing was done to provide data. to justify the use of these organs.

“Part of that was a leap of faith, based on experience over the years with donors who had other viral infections such as hepatitis C,” Desai said. “Although this case was not exactly like the others, we had some confidence in a safe outcome.”

Rabb says decisions about whether to accept organs other than lungs from donors who died of COVID-19-related causes should be made on a case-by-case basis, but the risk of COVID-19 transmission through kidney transplantation appears to be very low based on his team’s cases to date.

“We know that our case may not be representative of many possible COVID-19 donors, especially since the donor was negative for COVID-19 at the time of transplant,” says Rabb. “However, it is a step forward in using highly sensitive molecular tests to show that it can be safe to use organs from deceased COVID-19 donors. Organs can be considered individually for a kidney transplant instead of being systematically discarded.

According to the US Department of Health and Human Services, some 95,000 Americans with kidney failure are waiting for donor organs. As reported by the US Centers for Disease Control and Prevention, nearly 9,000 of these patients drop off the waiting list every year because they can’t get a kidney in time, leading to death. or a deterioration in health that makes transplantation impossible.

In addition to Lee, Rabb and Desai, researchers involved in this case study include Andrew Johanson and Joseph Mankowski from Johns Hopkins University School of Medicine and Jessica Resnick, Maggie Li and Andrew Pekosz from Johns Hopkins Bloomberg School of Public Health.

Funding for this study came from Johns Hopkins University School of Medicine grants HHSN272201400007C and T32AI007417.

None of the authors report any conflicts of interest.


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