The human polyomavirus BK (BKPyV): virological background and clinical implications
Article first published online: 19 JUN 2013
© 2013 APMIS. Published by John Wiley & Sons Ltd
Volume 121, Issue 8, pages 728–745, August 2013
How to Cite
The human polyomavirus BK (BKPyV): virological background and clinical implications. APMIS 2013; 121: 728–45., , .
- Issue published online: 9 JUL 2013
- Article first published online: 19 JUN 2013
- Manuscript Accepted: 27 APR 2013
- Manuscript Received: 18 APR 2013
- Polyomavirus BK;
- polyomavirus-associated nephropathy;
- polyomavirus-associated haemorrhagic cyctitis;
- kidney transplantation;
- hematopoietic stem cell transplantation;
Polyomavirus BK (BKPyV) infects most people subclinically during childhood and establishes a lifelong infection in the renourinary tract. In most immunocompetent individuals, the infection is completely asymptomatic, despite frequent episodes of viral reactivation with shedding into the urine. In immunocompromised patients, reactivation followed by high-level viral replication can lead to severe disease: 1–10% of kidney transplant patients develop polyomavirus-associated nephropathy (PyVAN) and 5–15% of allogenic hematopoietic stem cell transplant patients develop polyomavirus-associated haemorrhagic cystitis (PyVHC). Other conditions such as ureteric stenosis, encephalitis, meningoencephalitis, pneumonia and vasculopathy have also been associated with BKPyV infection in immunocompromised individuals. Although BKPyV has been associated with cancer development, especially in the bladder, definitive evidence of a role in human malignancy is lacking. Diagnosis of PyVAN and PyVHC is mainly achieved by quantitative PCR of urine and plasma, but also by cytology, immunohistology and electron microscopy. Despite more than 40 years of research on BKPyV, there is still no effective antiviral therapy. The current treatment strategy for PyVAN is to allow reconstitution of immune function by reducing or changing the immunosuppressive medication. For PyVHC, treatment is purely supportive. Here, we present a summary of the accrued knowledge regarding BKPyV.