Kidney Week

Abstract: SA-PO1138

Between a Virus and a Hard Place: Managing BK Virus Nephropathy, Cytomegalovirus Infection, and Rejection After Kidney Transplantation

Session Information

• Transplantation: Clinical - Infectious Diseases
  October 24, 2026 | Location: Exhibit Hall A, Convention Center
  Abstract Time: 10:00 AM - 12:00 PM

Category: Transplantation

• 2002 Transplantation: Clinical

Authors

• Elattma, Ahmed, Alameda Health System, Oakland, California, United States

Ahmed Elattma, MD

• Ahearn, Patrick, Stanford University, Palo Alto, California, United States

Patrick Ahearn, MD

• Odunaiya, Adetokunbo A., Stanford University, Palo Alto, California, United States

Adetokunbo A. Odunaiya, MD, MS

• Jain, Neha, Alameda Health System, Oakland, California, United States

Neha Jain, MD

Introduction

BK Virus Nephropathy (BKVN) affects 3 – 5% of kidney transplant patients and complicates transplant management when there are concurrent infections and rejection episodes. We present a complex case of a kidney transplant recipient with ANCA vasculitis who developed BKVN, fungal pneumonia, cytomegalovirus (CMV) infection and borderline acute cellular rejection, highlighting the intricate immunological tightrope in transplant medicine.

Case Description

A 58-year-old female with end-stage kidney disease from ANCA-associated vasculitis who underwent living related kidney transplant presented with fatigue and cough two months post-transplant. She was found to have aspergillus pneumonia, acute kidney injury (baseline creatinine 0.96 mg/dL to 4.2 mg/dL), BK viremia at 4260 IU/ml and BK nephropathy on allograft biopsy. Mycophenolate mofetil (MMF) was stopped and she was initiated on Cresemba with clinical and renal improvement. She restarted MMF when her BKV titers decreased and continued Tacrolimus and prednisone. However, soon enough after a period of 6-8 weeks, her creatinine increased again with proteinuria. Transplant biopsy was repeated and now showed acute T-cell mediated rejection without active BK nephropathy (SV-40 negative) or ANCA vasculitis. She still had positive BKV titers. She was treated with a short course of high-dose oral prednisone followed by rapid taper to minimize BK virus flare up. Soon after the treatment of rejection, she developed CMV rhinosinusitis necessitating treatment with Valcyte. She is improved now with low BKV titers, negative CMV, and stable renal function with Cr 1.8 mg/dl and no proteinuria.

Discussion

This case highlights the complexity in managing kidney transplant patients that develop competing complications that require opposing treatment approaches. Guidelines recommend immunosuppression reduction for BK viremia. However, this increases rejection risk, creating a therapeutic dilemma. Additionally, the fungal pneumonia and CMV increases her mortality risk. The management of borderline rejection with recurrent infections represents a particular challenge. The decision to treat with short, high-dose oral steroid pulse rather than traditional methylprednisolone or lymphocyte-depleting agents reflects an individualized approach balancing rejection treatment against infection risk.