Serial Donor-derived Cell-free DNA Monitoring in a Kidney Transplant Recipient With Adenovirus Nephritis

Opportunistic infection is one of the most common complications in solid organ transplantation. In particular, viral infections of the renal allograft pose a diagnostic and management dilemma because the histopathologic differences between viral allograft nephritis and acute rejection can be subtle yet critical to recognize, given the fundamentally contradictory treatment strategies. Although noninvasive tests, such as viral polymerase chain reaction, can aid in the diagnosis of viral allograft involvement, a definitive diagnosis requires a kidney biopsy. Donor-derived cell-free DNA (dd-cfDNA) has been validated for detecting both acute cellular rejection and antibody-mediated rejection, but its utility as a test for renal allograft infection remains to be defined and has largely been restricted to cases of BK polyomavirus nephropathy. Here, we described a case of acute kidney injury that developed shortly after kidney transplantation. dd-cfDNA was elevated, and biopsy revealed findings characteristic of adenovirus infection. We examined the differential diagnosis of viral infections in renal allografts and explored the role of dd-cfDNA in managing these cases.