In kidney transplant patients, the BK Polyomavirus, when present in urines at a high level ( > 10 exp 7 cp/ ml, by PCR) can allow to reduce the immunosuppressive treatment without risk of rejection, but prudently.
As a consequence, the graft survivals may be prolonged and even patient survival can get better results.
Transpl Infect Dis. 2016 Dec;18(6):872-880. doi: 10.1111/tid.12603. Epub 2016 Oct 20.