Abstract: FR-PO0454
Native BK Virus-Associated Nephropathy in a Lung Transplant Recipient: A Case Report
Session Information
- AKI: Case Reports - TMA, Vasculitis, Immune-Mediated Injury, and Systemic Disease
October 23, 2026 | Location: Exhibit Hall A, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Acute Kidney Injury
- 102 AKI: Clinical, Outcomes, and Trials
Authors
- Gilleo, Michael, University of Minnesota Medical School, Minneapolis, Minnesota, United States
- Alhoshani, Leen Mohammed, American University of Beirut, Beirut, Beirut Governorate, Lebanon
- Koubar, Sahar, University of Minnesota Medical School, Minneapolis, Minnesota, United States
Introduction
Reactivation of BK virus, a ubiquitous polyomavirus, results in BK virus-associated nephropathy (BKVAN) in 10% of kidney transplant recipients, leading to graft loss in 30-50% of cases. In contrast, BKVAN is exceedingly uncommon in non-renal solid organ transplant (NRSOT) recipients. Here, we report a case of BKVAN in a patient following bilateral lung transplant
Case Description
A 74 year old man developed acute kidney injury 13 months after bilateral lung transplant. He had been treated for acute cellular-mediated rejection seven months post-transplant, and continued on increased-dose tacrolimus (trough 12 ug/L), prednisone, and mycophenolic acid (MPA). Serum creatinine increased from 0.8 to a peak of 3.6 mg/dL over two months. Kidney biopsy (Figure 1) showed acute tubular injury, interstitial inflammation, and SV40 staining within tubular epithelial nuclei, consistent with BKVAN. Urine BK DNA level was >100,000,000 copies and serum level was 667,000 IU/mL. MPA was stopped and tacrolimus trough reduced to 6-8 ug/L. He received two doses of IVIG. Two months later, serum BK viral level dropped to 44,700 IU/mL and creatinine improved to 2.3 mg/dL.
Discussion
BKVAN is a rare, but potentially under-recognized, cause of kidney dysfunction in lung transplant recipients, with 12 reported cases and one single-center case series identified to date. Our case adds to the literature and illustrates multiple potential risk factors, including increased immunosuppressants, hypogammaglobulinemia, and advanced age. Prior reports highlighted the variable disease course, with mixed response to cidofovir or leflunamide therapy, and progression to dialysis in several patients. While optimal treatment remains ill-defined, our patient responded to reduction in immunosuppression and administration of IVIG. Our case emphasizes the low index of suspicion needed for BKVAN in unexplained cases of AKI among NRSOT recipients, and raises questions about the role of early screening as the recognized burden of BKVAN increases.
Left panel (PAS) shows interstitial lymphocytic infiltrate. Right panel (SV40 immunohistochemistry) shows positive staining of tubular epithelial nuclei.