Abstract: TH-PO0167
Native Kidney BK Polyoma Virus Nephropathy Treated with Intravenous Immunoglobulin (IVIg) and Leflunomide in a Patient on Bispecific T Cell Engager Therapy
Session Information
- Onconephrology: Anticancer Therapies, PTLD, Paraneoplastic Diseases, and More
November 06, 2025 | Location: Exhibit Hall, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Onconephrology
- 1700 Onconephrology
Authors
- Pendyala, Megha Eshani, Williamsville East High School, East Amherst, New York, United States
- Pendyala, Reshub R., Johns Hopkins University, Baltimore, Maryland, United States
- Pendyala, Prashant, Buffalo General Medical Center, Buffalo, New York, United States
Introduction
BK Nephropathy is an infection usually described in Renal transplant kidneys. There have been case reports of BK Nephropathy in native kidneys in patients with mainly lung transplants and bone marrow transplants.
The management has usually been decreasing the doses of immunosuppression.
We describe a patient with BK nephropathy in a native kidney in a non-transplant patient that has been receiving immunotherapy with Bispecific T-Cell engager (BiTE) agents. He was managed with IV immunoglobulin (IVIg) and Leflunomide.
Case Description
78yr old male initially diagnosed with rectal cell high grade plasmacytoma and Oligo-secretory Multiple Myeloma 5 yrs prior. He was being managed with Carfilzomib, lenalidomide and dexamethasone.
Two years ago treatment was changed to Teclistimab a BiTE agent due to an increase in disease activity. He did well till 3 mo prior to the presentation. For the prior 3 months his creatinine has been worsening and went from 1.3mg/dl at baseline to 4.1 (GFR 11). His immunotherapy was stopped, and patient was referred for Nephrology evaluation.
Patient has been receiving IV immunoglobulin therapy along with BiTE therapy when IgG levels were less then 600mg/dl
Patient underwent kidney biopsy that revealed chronic active Interstitial Nephritis with medium to marked chronicity, medium activity with focal tubular cytopathic effects that were SV-40 positive
The BK virus DNA PCR showed 24650 copies.
His IViG treatment was restarted at q 4week interval, and he was placed on Leflunomide at 40mg/day after loading dose.
His BK virus load decreased to 2450 four weeks later.
His CR improved to 2.9 with a GFR of 21 in 8 weeks
BiTE therapy was restarted with Talquetamab for 3 months now. His CR has remained at 2.9 and BK virus load around 2500. He is continuing with monthly IvIg and Leflunomide.
Discussion
This case is unique that BK nephropathy is described in a native kidney in a non-transplant setting. BiTE therapy is known to cause viral infections due to decrease in immunoglobulin levels. However, BK nephropathy has not been described. The treatment in this setting is not clear. We have extrapolated from the transplant patients and have used IvIg and leflunomide with good outcome.
With the usage of new immunotherapy agents, one has to have a high suspicion for unusual causes of renal failure and we describe an unique one here.