- Last Update On : 2012-12-24
BK is a type of polyomavirus that is ubiquitous in nature and infects most people in early childhood. Seroprevalence is 60-100% in epidemiologic studies. Following primary infection, the virus becomes latent in lymphocytes and renal epithelium. Intermittent viral shedding may occur in immunocompetent individuals (up to 20% incidence) and more frequently in immuno-compromised individuals (up to 60% incidence). BK is so-named from the initials of the patient from whom the virus was first isolated. A related polyomavirus that infects humans is JC virus, which is associated with progressive multifocal leukoencephalpathy.
BK virus reactivation is a major concern for renal transplant and bone marrow transplant recipients. Following reactivation, BK virus either clears spontaneously, perisists in urine, or progresses to viremia. Reactivation has been linked to tubulointerstitial nephritis and nephropathy as well as ureteral stenosis in renal transplant patients, while bone marrow t