Seraph 100 Microbind Affinity Blood Filter for Persistent Pediatric BK Virus Nephropathy.

Background: Resolution of BK viremia is almost universally required before kidney transplant. Unfortunately, proven anti-BK viral therapies are limited. The Seraph 100 mimics the action of the natural glycocalyx, which binds pathogens via heparin sulfate proteoglycans. In this case report, we describe the use of this filter to facilitate the clearance of BK viremia.

Methods: Our patient was a 14-year-old cardiac transplant recipient secondary to familial dilated cardiomyopathy. She developed BK nephropathy resulting in end stage kidney disease (ESKD). After failed medical management and immunoreduction over 4 years, the Seraph 100 Microbind Affinity Blood Filter was utilized extracorporeally in line with continuous renal replacement therapy (CRRT) for 48 h to eliminate detectable BK viral replication.

Results: The patient's BK titers initially increased negligibly but cleared within 2 months of Seraph 100 treatment, and she successfully underwent kidney transplantation without recurrence of BK viremia. There were no adverse events other than one episode of emesis at the initiation of CRRT.

Conclusion: Our case provides proof of concept and feasibility for studying the Seraph 100 as a potential therapeutic option for the clearance of BK viral titers, especially in ESKD patients who already have dialysis access.