Initial risks high for AAV patients needing a kidney transplant: Study
Infections of particular concern, but survival rates favorable over long term
The risk of poor outcomes after a kidney transplant is considerably higher for ANCA-associated vasculitis (AAV) patients with kidney failure than people without the autoimmune disease, ranging from infections and disease relapse to death, a review study reports.
But long-term survival rates for those who make it through the early post-transplant period are favorable overall, with AAV patients showing a cumulative five-year survival rate similar to other kidney transplant patients.
“Renal [kidney] transplantation remains a vital therapeutic option for AAV patients with [kidney failure],” the researchers wrote. The results “reported by our study may guide clinicians in optimizing care of AAV patients undergoing renal transplantation.”
The review study, “Outcomes of Renal Transplantation in ANCA Associated Vasculitis: A Systematic Review and Meta-Analysis,” was published in the journal Annals of Transplantation.
Kidney failure is estimated to occur in up to 40% of AAV patients
AAV typically is caused by ANCAs, self-reactive antibodies that wrongly bind to neutrophils, a type of immune cell. This ultimately triggers an immune reaction against the cells lining blood vessels, and the disease is characterized by inflammation and damage to small blood vessels.
Although a number of organs can be involved, the kidneys are particularly affected, and kidney failure is estimated to develop in 20-40% of AAV patients. A kidney transplant is considered the optimal treatment option for these people, but the approach “is associated with unique complications in this population,” the researchers wrote.
“While individual studies have explored the outcomes of ANCA-associated renal transplantation, no comprehensive meta-analysis of these outcomes is available to date,” they added.
Researchers in Zhejiang, China, systematically reviewed studies published through September 2023 reporting kidney transplant outcomes in people with and without AAV. A total of 23 retrospective studies were included in the analysis, and outcomes reviewed included mortality, survival, disease relapse, and post-transplant infections.
Available data on AAV types indicated that there were more than 400 patients with microscopic polyangiitis, 255 with granulomatosis with polyangiitis, and five with eosinophilic granulomatosis with polyangiitis. Some patients had kidney-limited AAV.
After a transplant, patients were followed for 1.2 to 9.2 years.
Risk of a post-transplant infection more than 50 times higher with AAV
AAV patients had a six times higher risk of disease relapse and a nearly 12 times higher risk of death after a kidney transplant than those without AAV, results showed. Those with AAV also had a significantly higher risk — about 52 times higher — of infection after a transplant.
According to the researchers, several factors may contribute to this high infection risk, including the use of immunosuppressive therapies to prevent transplant rejection on top of those already used to treat AAV. Immune system suppression can render patients more susceptible to infections and other transplant-related complications.
“The high rate of infections observed in our study further emphasizes the importance of stringent infection control measures in the post-transplantation care of AAV patients,” the scientists wrote.
Nevertheless, survival rates at five or more years after a transplant were similar between AAV patients and those without AAV. This indicates that while AAV patients face grave risks in the initial post-transplant period, including a higher mortality risk, long-term outcomes can be satisfactory.
“Our findings underscore the delicate balance between managing AAV and preventing [transplant] rejection, requiring close post-transplant monitoring and management,” the researchers wrote.
“A comprehensive understanding of the complexities of managing AAV-associated renal transplantation is crucial for providing informed care, mitigating risks, and improving patient outcomes in this population,” the team concluded.
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