Epidemiology of BK virus in renal allograft recipients: independent risk factors for BK virus replication.
BACKGROUND
Identification of risk factors for BK virus (BKV) replication may improve transplant outcome. We investigated the impact of immunosuppressive drugs on the prevalence of BKV replication in recipients of human renal allografts.


METHODS
One hundred twenty renal allograft recipients were studied prospectively at 1, 3, and 6 months posttransplantation to identify risk factors for BKV replication. BKV replication was quantified by measurement of urinary cell BKV VP1 mRNA levels using BKV specific primers and TaqMan probe in a real-time quantitative polymerase chain reaction assay. Levels of urinary cell mRNA for granzyme B, CD103, and transforming growth factor-beta1 were measured to ascertain whether BKV replication is associated with an inflammatory signature.


RESULTS
The prevalence of BKV replication increased over time and was highest at 6 months compared with 1 or 3 months posttransplantation (P<0.001). A logistic regression model analysis demonstrated that steroid maintenance therapy (odds ratio: 8.3, P=0.003) and induction with rabbit anti-human thymocyte globulin (odds ratio: 5.8, P=0.008) were independent risk factors for BKV replication. Neither mycophenolate mofetil dose nor tacrolimus dose or trough levels were different between those with or without BKV replication. The development of acute rejection or antirejection treatment with methylprednisolone did not increase the risk of BKV replication. BKV replication was associated with heightened levels of urinary cell mRNA for granzyme B (P<0.002), CD103 (P<0.005) but not for transforming growth factor-beta1 (P>0.05).


CONCLUSIONS
Steroid maintenance therapy and induction with antithymocyte globulin are independent risk factors for BKV replication in renal allograft recipients treated with tacrolimus and mycophenolate mofetil.
Dadhania
Darshana
D
Division of Nephrology and Hypertension, Department of Medicine, New York Presbyterian-Weill Cornell Medical Center, New York, NY, USA. dmd2001@med.cornell.edu
Snopkowski
Catherine
C
Ding
Ruchuang
R
Muthukumar
Thangamani
T
Chang
Christina
C
Aull
Meredith
M
Lee
Jun
J
Sharma
Vijay K
VK
Kapur
Sandip
S
Suthanthiran
Manikkam
M
D000328:Adult; D000368:Aged; D001739:BK Virus / Q000502:physiology; D005260:Female; D005500:Follow-Up Studies; D006650:Histocompatibility Testing; D006801:Humans; D007166:Immunosuppressive Agents / Q000627:therapeutic use; D016030:Kidney Transplantation / Q000009:adverse effects* / Q000276:immunology; D008297:Male; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D027601:Polyomavirus Infections / Q000453:epidemiology*; D011183:Postoperative Complications / Q000453:epidemiology* / Q000821:virology*; D011446:Prospective Studies; D012333:RNA, Messenger / Q000235:genetics / Q000302:isolation & purification; D012307:Risk Factors; D013997:Time Factors; D014184:Transplantation, Homologous; D014779:Virus Replication
D007166:Immunosuppressive Agents; D012333:RNA, Messenger