Every year, more than 25,000 patients worldwide receive lifesaving bone marrow transplantations with hematopoietic-cells from another person. It is estimated that over 75% of these patients will develop an infectious complication, of which approximately one third can be life-threatening. A significant proportion of these infections are caused by opportunistic viruses, such as BK virus.~This virus establishes latent infection in most individuals, but does not normally cause disease. It can reactivate after hematopoietic-cell transplantation and represents the second most common viral infection in this patient population. BK virus is associated with kidney failure and a decreased chance of survival after hematopoietic-cell transplantation. There are no effective antiviral treatments for this disease.~Despite being the second most common cause of clinical disease hematopoietic-cell transplantation, very little is known about this virus. To address this knowledge gap, the investigators aim to study patients with confirmed BK virus disease post allogeneic hematopoietic-cell transplantation.~As part of this study, regular urine and blood tests will be done to understand how the virus behaves over time and which organs it affects. Blood and urine samples will also be obtained to study how the immune system rebuilds itself after hematopoietic-cell transplantation. Finally, an ultrasound of the kidneys and the bladder will be done to evaluate for any presence of disease in these organs.
This research study is evaluating the reactivation of BK virus in patients who have undergone allogeneic hematopoietic-cell transplantation.