Polyomavirus Nephropathy: Ten-Year Experience.

Area of Science:

• Nephrology
• Transplantation Immunology
• Virology

Background:

• BK polyomavirus nephropathy (BKVN) is a significant contributor to chronic allograft dysfunction (CAD).
• Identified risk factors include recipient demographics, deceased donation, intense immunosuppression, diabetes, delayed graft function (DGF), cytomegalovirus infection, and acute rejection (AR).
• Immunosuppression reduction is the primary therapeutic strategy for BKVN.

Purpose of the Study:

• To assess chronic allograft dysfunction (CAD) progression following therapeutic interventions for BKVN.
• To identify risk factors associated with graft loss (GL) in kidney transplant recipients with BKVN.

Main Methods:

• Retrospective analysis of 23 kidney transplant biopsies with histological evidence of BKVN over a 10-year period.
• Patients included those with CAD and BKVN, with 16 having a glomerular filtration rate (GFR) <30 mL/min at diagnosis.
• Therapeutic strategies involved antimetabolite reduction/discontinuation, calcineurin inhibitor (CNI) modification, and antiviral agents.

Main Results:

• BKVN was diagnosed in 23 recipients (19 male, 4 female), predominantly white, with a mean age of 51.2 years.
• Common comorbidities included diabetes (4 patients), DGF (3), cytomegalovirus infection (2), and AR (15).
• One year post-intervention, graft function decreased in 11 patients, stabilized/improved in 10. Graft loss (GL) occurred in 9 patients (39.1%). Older age and DGF emerged as significant risk factors for GL. Lower GFR at diagnosis correlated with increased risk of dialysis initiation.

Conclusions:

• Graft loss occurred in 39.1% of BKVN patients, with DGF being a notable factor.
• Older recipient age and lower GFR at BKVN diagnosis are critical risk factors for graft loss.
• Prompt diagnosis of BKVN is crucial for mitigating graft loss and improving long-term outcomes.