H2(W)
NATIVE BK VIRUS NEPHROPATHY IN A PATIENT WITH CHRONIC
LYMPHOCYTIC LEUKAEMIA
McCrory, R1, Gray, M2, Smyth, J1, Leonard, N1, Woodman, A1
1
Ulster Hospital Renal Unit, Belfast, 2Royal Group Hospitals Pathology Department,
Belfast
BACKGROUND: BK Virus Nephropathy (BKVN) is a well recognised complication after
renal allograft transplantation and an increased incidence has been observed following the
introduction of more potent immunosuppressive regimens. Cases of BKVN affecting the native
kidneys of other solid organ and bone marrow transplant (BMT) recipients have also been
reported.
CASE REPORT: We describe a patient with chronic lymphocytic leukaemia, resulting in
immunoglobulin deficiency, who presented with deteriorating renal function. There was no
history of solid organ or bone marrow transplantation. Ultrasound renal tracts noted normal
sized kidneys and urinalysis was negative for blood and protein. Renal biopsy demonstrated
tubular injury characteristic of viral infection. Immunohistochemistry indicated tubular staining
strongly positive for BK virus. Serum BK viral titres were elevated at 4.8 million copies/ml and
urine microscopy confirmed the presence of decoy cells. 12 months of treatment with
leflunomide reduced serum viral titres to negligible levels and stabilised renal function.
COMMENT: To our knowledge, this is the first case of native kidney BKVN to be reported in
a patient without a history of previous solid organ or bone marrow transplantation. BKVN is a
differential diagnosis to be considered in selected groups of immunosuppressed patients
presenting with deteriorating renal function. This case indicates a role for leflunomide in aiding
viral clearance and renal recovery beyond its use in renal allograft recipients.