Prospective Study of BK Virus Disease After Allogeneic Hematopoietic-cell Transplantation: Defining BK Disease's Natural History, Clinical Spectrum, Immunology, and Outcomes

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.

Inclusion Criteria:

- Adult ≥18 years old

- All adult patients who undergo allo-HCT will be eligible for the study, regardless of
age, underlying disease, conditioning regimen, or GVHD prophylaxis regimen

Exclusion Criteria:

- Adults unable to consent

- Individuals who are not yet adults (infants, children, teenagers)

- Pregnant women

- Prisoners