Copyright ©The Author(s) 2017. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Transplant. Dec 24, 2017; 7(6): 329-338
Published online Dec 24, 2017. doi: 10.5500/wjt.v7.i6.329
Polyoma virus nephropathy in kidney transplantation
Jacob RW Scadden, Adnan Sharif, Kassi Skordilis, Richard Borrows
Jacob RW Scadden, University of Birmingham, Edgbaston, Birmingham B15 2TH, United Kingdom
Adnan Sharif, Richard Borrows, Department of Kidney Transplantation, Queen Elizabeth Hospital Birmingham, Birmingham B15 2TH, United Kingdom
Kassi Skordilis, Department of Renal Histopathology, Queen Elizabeth Hospital Birmingham, Birmingham B15 2TH, United Kingdom
Author contributions: Scadden JRW, Sharif A and Borrows R devised, wrote and edited manuscript; Skordilis K edited manuscript and provided histology.
Conflict-of-interest statement: Dr. Borrows has nothing to disclose.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See:
Correspondence to: Richard Borrows, Consultant Nephrologist, Department of Kidney Transplantation, Queen Elizabeth Hospital Birmingham, Edgbaston, Birmingham B15 2TH, United Kingdom.
Telephone: +44-121-3716099 Fax: +44-121-3716098
Received: January 18, 2017
Peer-review started: January 19, 2017
First decision: February 15, 2017
Revised: November 17, 2017
Accepted: December 1, 2017
Article in press: December 4, 2017
Published online: December 24, 2017

BK virus (BKV) is a polyomavirus that is able to cause renal dysfunction in transplanted grafts via BK virus-associated nephritis (BKVAN). This condition was mis-diagnosed in the past due to clinical and histopthological similarities with acute rejection. Due to the prevalence of the virus in the population, it is an important pathogen in this context, and so it is important to understand how this virus functions and its’ relationship with the pathogenesis of BKVN. Screening for BKV often reveals viruria and/or viremia, which then manifests as BKVN, which can be asymptomatic or result in clinical features namely renal dysfunction. The pathogenesis of BKV infection is still unclear and needs to be further investigated; nevertheless there are a variety of hypotheses that indicate that there are a host of factors that play important roles. Treatments for BKVAN include a reduction in immunosuppression, the use of antiviral therapy or the combination of both treatment options.

Keywords: Polyoma, Kidney, Transplant, Infection, Virus

Core tip: Prior to its recognition as a separate entity, kidney transplant infection with the polyoma virus, BK virus (BKV), and the ensuing viral nephropathy (BKVN) portended a poor prognosis. But with the advent of heightened clinical suspicion and improved diagnostics the prognosis has improved considerably. Blood and urine polymerase chain reaction testing allows invasive investigation (i.e., transplant biopsy) to be selective and appropriate. Peripheral blood assays of anti-BKV cell mediated immunity offers potential for refining risk stratification. While conventional antiviral agents have failed to show utility to date, reduction of immunosuppression currently represents the most effective and proven treatment for BKVN.