Literature review of allograft adenovirus nephritis and a case presenting as mass lesions in a transplanted kidney without symptoms of urinary tract infection or acute kidney injury.

Adenovirus (AdV) infection is a common complication in bone marrow/hematopoietic stem cell transplant and solid organ transplant recipients. AdV infection usually presents as hemorrhagic cystitis, but sometimes it can progress to acute kidney injury showing AdV nephritis (AdVN). We present the case of a 52-year-old Japanese female who had received a living kidney transplantation (KT) from her husband. At 21 months post-KT, the patient presented with a fever, but no renal dysfunction and no abnormal urine findings. A contrast-enhanced computed tomography (CT) scan revealed a few mass lesions with hypoperfusion in the transplanted kidney. An enhanced CT-guided biopsy targeting one of these lesions revealed a necrotizing tubulointerstitial nephritis suggesting AdVN. The polymerase chain reaction tests for ADV were negative in a urine sample but positive in the sera and the frozen kidney biopsy samples. AdVN can manifest as an unusual pattern of acute lobar nephritis/acute focal bacterial nephritis-like localization without symptoms of acute kidney injury or urinary tract infection. Enhanced CT can provide clues for clinical diagnosis.

Kidney transplant patient with immunoglobulin A nephropathy subsequently diagnosed as concurrent autosomal dominant polycystic kidney disease during 17-year follow-up.

A 14-year-old Japanese boy was diagnosed with immunoglobulin A nephropathy resulting in end-stage kidney disease (ESKD). He underwent ABO-compatible living kidney transplantation from his father at the age of 27. In the process of selecting a donor before the transplantation, it turned out that his mother had polycystic kidneys and that her family had a history of hypertension and cerebrovascular diseases. The patient himself also had bilateral multiple kidney cysts, with a normal-sized kidney, confusing us to make the diagnosis of acquired cystic kidney disease (ACKD) or ADPKD difficult at that point. Seventeen years later, his native kidneys showed bilateral swelling with multiple cysts. This, along with the histories of his mother and her relatives and with the existence of multiple liver cysts, led us to confirm the diagnosis of autosomal dominant polycystic kidney disease, not of ACKD. Contrary to previous studies that have suggested the size of cysts both in ADPKD and ACKD reduced with time, the present case showed an increase of 3.0% per year in total kidney volume (TKV) by computed tomography. It suggested the possibility that TKV, after decreasing in the relatively early stage after transplantation, may later increase in the long term after ESKD due to another kidney injury.