Korean J Transplant.  2022 Nov;36(Supple 1):S356. 10.4285/ATW2022.F-4986.

Recurrent atypical hemolytic uremic syndrome after kidney transplantation: a case report

• Park H
• Park HW
• Lee H
• Yang CW
• Chung BH

• KMID: 2535583
• DOI: http://doi.org/10.4285/ATW2022.F-4986

Abstract

The etiology of end-stage kidney disease (ESKD) is uncertain in some patients. Atypical hemolytic uremic syndrome (aHUS) is a rare disease that could cause kidney damage. We herein present a case of recurrent aHUS after kidney transplantation (KT). A 45-year-old man who received KT from deceased donor was hospitalized 1 month after transplantation due to allograft dysfunc-tion. The cause of ESKD was unclear and he underwent hemodialysis for 9 years. He received anti-thymocyte globulin as an in-duction immunosuppression and maintained triple immunosuppressants, including tacrolimus. Allograft biopsy was performed under suspicion of acute rejection and steroid pulse therapy was started. Kidney ultrasound showed no hydronephrosis. There were no signs or symptoms of infection. Additional laboratory test revealed bicytopenia which was not present before and after transplantation. In further evaluation, serum laparoscopic donor hepatectomy level was elevated, haptoglobin level and complement levels were decreased. The presence of schistocytes was confirmed by peripheral blood smear test. Moreover, there was no evidence of rejection in the biopsy result. At this point, we suspected thrombotic microangiopathy (TMA). ADAMTS13 activity, microbiological test for shigatoxin producing bacteria, and DNA sequencing for TMA were conducted. Allograft function continued to deteriorate without responding to the steroid. We decided to start plasmapheresis empirically. Unfortunately, he did not respond to the seven sessions of plasmapheresis and eventually he started hemodialysis. After starting dialysis, genetic testing revealed a mutation in complement factor I, c.119A>C, which was reported to be possibly pathogenic for aHUS. In retrospective review, his past native kidney biopsy presented TMA features. Finally, we diagnosed him with recurrent aHUS after KT and start-ed eculizumab. During induction treatment period of 4 weeks, his urine volume was gradually increased. After he started mainte-nance treatment, he stopped hemodialysis. Laboratory tests reflecting hemolysis and renal function show improvement.