Aggressive immunosuppression minimization reduces graft loss following diagnosis of BK virus-associated nephropathy: a comparison of two reduction strategies.
OBJECTIVE
BK virus-associated nephropathy (BKVAN) has emerged as a leading cause of kidney graft loss, with no known predictors for graft loss and no consensus regarding treatment other than reduction of immunosuppression.


METHODS
A single-center retrospective analysis was performed of all cases of BKVAN from 1999 to 2005 for clinical predictors of graft loss, with evaluation of the impact of immunosuppression withdrawal (3-drug to 2-drug immunosuppression) within the first month versus reduction of immunosuppression.


RESULTS
Of 910 kidney transplants, 35 (3.8%) cases of BKVAN were diagnosed at a median of 15 months after transplant (range, 5.5 to 90 months after transplant), 16 (46%) of which progressed to graft failure at a median of 11 months (range, 2 to 36 months) after diagnosis. Depleting antibody induction was a significant risk factor for graft loss on univariate analysis, whereas early drug withdrawal (<1 mo following diagnosis) protected against graft loss. On multivariate analysis, these findings were independent predictors of graft outcomes. Additionally, when patients were comanaged by referring nephrologists and the transplant center before the diagnosis of BKVAN, the risk of graft loss was 11-fold higher (P = 0.03) than if patients were managed solely by the transplant center.


CONCLUSIONS
Increased awareness and early diagnosis of BKVAN, with aggressive tapering of immunosuppression once established, is critical to preserve kidney graft function. Early drug withdrawal to low-dose two-drug therapy maintenance may be preferable to a general reduction of agents.
Weiss
Andrew S
AS
Division of Renal Diseases and Hypertension, University of Colorado at Denver and Health Sciences Center, Denver, Colorado, USA.
Gralla
Jane
J
Chan
Larry
L
Klem
Patrick
P
Wiseman
Alexander C
AC
D000328:Adult; D000368:Aged; D000998:Antiviral Agents / Q000627:therapeutic use*; D001739:BK Virus / Q000472:pathogenicity*; D004334:Drug Administration Schedule; D005260:Female; D006084:Graft Rejection / Q000517:prevention & control* / Q000821:virology; D006085:Graft Survival / Q000187:drug effects*; D006801:Humans; D007166:Immunosuppressive Agents / Q000008:administration & dosage*; D016030:Kidney Transplantation / Q000009:adverse effects*; D008297:Male; D008875:Middle Aged; D009393:Nephritis / Q000188:drug therapy* / Q000821:virology; D027601:Polyomavirus Infections / Q000188:drug therapy* / Q000821:virology; D012189:Retrospective Studies; D013997:Time Factors; D016896:Treatment Outcome
D000998:Antiviral Agents; D007166:Immunosuppressive Agents