[The role of BK polyomavirus in the development of hemorrhagic cystitis after hematopoietic stem cell transplantation].

OBJECTIVE

To study the role of BK virus (BK polyomavirus) in the development of the hemorrhagic cystitis (HC) after hematopoietic stem cell transplantation (HSCT) and analyze the risk factors for BK viruria and HC.

METHODS

From August 2006 to November 2007, blood and urine samples were collected from 80 patients undergoing HSCT. BK virus DNA was detected with PCR. Cytomegalovirus (CMV) antigen was detected with immunofluorescence histochemical examination. A control group including 20 healthy individuals was established.

RESULTS

Late-onset HC occurred in 15 of the 80 HSCT patients with an incidence of 18.8%. The median onset time of HC was 44 (13 - 150) days after transplantation. BK viruria was detected in 30 of the 80 HSCT patients (37.5%) and the positive rate of viruria in the HC patients was 86.7% (13/15). The median time of BK viruria detection in HC patients was 23 (0 - 56) days after transplantation, being earlier than the onset time of HC. The persistence time of BK viruria was 7 (2 - 14) weeks, being much longer than that of HC (11 days). CMV antigen viremia was detected in 12 of the 80 transplanted patients, with a positive rate of 36.7% in patients with BK viruria and 40.0% in HC patients. Nine of the 30 HC patients developed acute graft versus host disease (aGVHD) of grade II-IV (30.0%). BK virus was not detected in the urine of the remaining two HC patients and the 20 control subjects as well as in all the blood samples. Univariate analysis indicated that CMV viremia and aGVHD of grade II-IV were associated with the occurrence of BK viruria.

CONCLUSIONS

BK viruria is the main cause of the late-onset HC after HSCT. CMV infection and aGVHD may contribute to the occurrence of HC associating with BK virus.