Vaccines were safe in transplant recipients, but their efficacy was affected by immunosuppressive therapies.
People who undergo kidney transplantation appear to have better outcomes from COVID-19 compared with those waiting for transplants, according to a new review.
However, the report also found that the immunosuppressive regimens associated with the procedure can complicate efforts to protect patients from the virus. The report was published in Cureus.
Study investigators noted that although anyone can become ill with COVID-19, immunocompromised patients, such as those undergoing kidney transplants, are at an increased risk of severe disease.
“COVID-19 has been infecting kidney transplant recipients, affecting their treatment protocols, and threatening their survival,” the authors wrote.
To better understand the risks associated with COVID-19 for people undergoing kidney transplants, they conducted a scoping review to identify and summarize existing literature on the impact of the pandemic on this patient population.
The investigators found more than 1000 articles in online databases, and after excluding duplicates and studies that did not meet the review’s inclusion criteria, they were left with 16 papers to examine.
One area of focus was the potential impact of COVID-19 on performing kidney transplants. Two studies addressed this topic. One compared outcomes of patients on transplant waitlists with those who underwent the procedure and found that the latter group had better outcomes. The second postoperatively tracked people who underwent transplants to gauge COVID-19 risk, but none of the patients followed became infected with SARS-CoV-2.
“These studies demonstrated a benefit to transplantation, as kidney transplant recipients were less likely to require hospitalization and ultimately fared better than the patients who were awaiting a transplantation operation,” the study authors wrote.
The authors also looked at the impact of COVID-19 vaccines on people who undergo transplants. In both studies reviewed, vaccines were well tolerated and did not result in adverse effects. However, the studies also suggested patients undergoing transplants had an inhibited vaccine response. The investigators said this appears to depend on which immunosuppressive therapies patients receive.
“Adolescent patients receiving either lower doses of mycophenolate or an immunosuppressant regimen that did not contain mycophenolate recorded a stronger immune response compared to patients who were nonresponsive to the vaccination who received higher doses of mycophenolate,” they wrote.
The investigators said more research needs to be done to better understand the ideal treatment regimens for people undergoing transplants in the COVID-19 era, but they said an individualized approach is important.
“The concept of removing patients from immunosuppression altogether does not seem to prove effective,” they said, “and a reduction in pharmacology might be a better approach.”
When investigators looked at studies examining mortality rates in transplant recipients with COVID-19, they found that markers of acute kidney injury were linked with higher mortality, a finding they expected. However, they also found immunosuppressive drug regimens may be associated with a higher risk of severe COVID-19, highlighting the importance of an individualized approach.
Overall, they found hospitalization, graft dysfunction, acute kidney injury, and respiratory failure were the most common risk factors for mortality in transplant recipients.
Karas M, Bernal I, Diaz O, et al. A scoping review of the impact of COVID-19 on kidney transplant patients in the United States. Cureus. 2023;15(3):e35725. Published online March 3, 2023. doi:10.7759/cureus.35725