Kidney Week

Abstract: SA-PO1143

Concurrent Adenovirus and Polyomavirus Nephritis in a Kidney Transplant Recipient with Positive BK Viremia

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

• Lopez, Yvette Y., Division of Nephrology of Hypertension, Mayo Clinic Arizona, Phoenix, Arizona, United States

Yvette Y. Lopez, MD, MBA

• Mour, Girish K., Division of Transplant Nephrology, Mayo Clinic Arizona, Phoenix, Arizona, United States

Girish K. Mour, MD

• Smith, Maxwell L., Department of Laboratory Medicine and Pathology, Mayo Clinic Arizona, Scottsdale, Arizona, United States

Maxwell L. Smith, MD

• Ryan, Margaret, Department of Laboratory Medicine and Pathology, Mayo Clinic Arizona, Scottsdale, Arizona, United States

Margaret Ryan, MD

• Fu, Liying, Department of Laboratory Medicine and Pathology, Mayo Clinic Arizona, Scottsdale, Arizona, United States

Liying Fu, MD, PhD

Introduction

We report rare concurrent adenovirus and polyomavirus nephritis in a kidney transplant patient on low-dose immunosuppression with BK viremia (BKV DNA 2360 IU/mL) and acute kidney injury at 2 years post-transplant.

Case Description

The renal allograft biopsy tissue noted mixed interstitial inflammation throughout the cortical and medullary tissue, severe tubulitis, tubular epithelial cell necrosis, and without well-formed granulomas. Many tubular epithelial cells show enlarged smudgy nuclei. Simian virus 40 immunohistochemical stain highlighted a few intranuclear polyomavirus inclusions and was negative in many other tubular epithelial cells. Immunohistochemical stain for adenovirus (ADV) highlighted nuclear and cytoplasmic viral inclusions in those tubular epithelial cells. PCR testing on paraffin tissue also confirmed the presence of ADV with subsequent serum PCR was positive for ADV at 29,700 IU/ml. Immunosuppression was further reduced, BK viremia peaked at 138,000 copies/mL. He was treated with intravenous immunoglobulin (IVIG) at 0.5 g/kg weekly. The ADV viral load decreased to 6,580 IU/ml two weeks after, and to 552 IU/ml one month after. At two months post-biopsy,ADV viral load declined to 116 IU/ml, IVIG therapy was transitioned to every two weeks due to persistently positive BK viremia. Four months post biopsy, his BK PCR is down to 9930 IU/mL. His serum creatinine remains elevated.

Discussion

Renal transplant patients with BK viremia and polyomavirus nephritis may also have ADV infection; granulomatous inflammation may be absent. Careful biopsy review and viral studies are essential for appropriate diagnosis and management.

Concurrent adenovirus and polyomavirus nephritis in renal allograft biopsy. A. Low power H&E: dense interstitial inflammation, acute tubular injury, focal tubular epithelial necrosis. B. High power H&E: viral cytopathic changes with enlarged nuclei and smudgy inclusions. C. SV40 IHC: focal nuclear staining in distal tubules. D. ADV IHC: cytoplasmic and nuclear positivity.