[Polyomavirus BK-associated nephropathy after kidney transplantation]

Area of Science:

• Nephrology
• Virology
• Transplantation Immunology

Background:

• Polyomavirus BK (BKV) infection is a significant cause of renal allograft dysfunction, leading to BKV-related interstitial nephropathy (PVAN).
• PVAN affects 1-10% of renal transplant recipients, often within 6 months post-transplant, with up to 45% experiencing irreversible graft failure.
• Immunosuppression is a key factor in PVAN pathogenesis, highlighting the need for careful management in transplant patients.

Purpose of the Study:

• To review the current understanding of BKV infection and PVAN in renal transplantation.
• To discuss diagnostic approaches, including renal biopsy and plasma BKV-DNA quantification.
• To explore current and potential management strategies for PVAN.

Main Methods:

• Review of existing literature on BKV infection, PVAN diagnosis, and treatment strategies.
• Analysis of diagnostic criteria, including histopathology and molecular methods.
• Evaluation of therapeutic interventions, including immunosuppression modulation and antiviral agents.

Main Results:

• Increased awareness and diagnostic techniques have lowered graft loss rates from PVAN.
• Renal biopsy with immunohistochemistry is standard for PVAN diagnosis, but plasma BKV-DNA quantification is a valuable surrogate marker.
• Evidence suggests reducing immunosuppression, potentially with pulsed steroids for concurrent rejection, improves outcomes.

Conclusions:

• PVAN remains a critical complication of renal transplantation requiring vigilant monitoring and management.
• While no standard treatment exists, a stepwise reduction in immunosuppression is a primary strategy.
• Antiviral therapies and proactive monitoring of viremia represent emerging approaches to prevent graft loss.