title: BK viremia surveillance after kidney transplant: single-center experience during a change from cyclosporine-to lower-dose tacrolimus-based primary immunosuppression regimen.
abstract: BACKGROUND
  The aim was to report our experience of BK viremia surveillance after kidney transplant during a period of change from cyclosporine (CyA)-to lower-dose tacrolimus (Tac)-based primary immunosuppression regimens.
  
  
  METHODS
  In a prospective single-center observational cohort study, 68 consecutive patients received renal transplant during the period when we used a CyA-based primary immunosuppression regimen and 66 after we changed to a lower-dose Tac-based regimen. Testing for BK viremia by quantitative polymerase chain reaction assay was performed at least monthly for a minimum of 1 year.
  
  
  RESULTS
  Thirty-nine (29.1%) patients developed BK viremia and 2 (1.5%) developed BK nephropathy. The actuarial time to BK viremia was shorter in patients receiving CyA/mycophenolate mofetil (MMF)/prednisolone (Pred) compared with Tac/MMF/Pred (P=0.04) and primary immunosuppression with CyA/MMF/Pred was the only independent predictor of BK viremia (hazard ratio 1.95; P=0.047). Comparing patients who experienced BK viremia and those who did not, there was no difference in incidence of acute rejection (20.5% vs. 25.3%; P=0.56) or estimated glomerular filtration rate at 12 months (48.8 vs. 49.9 mL/min/1.73 m(2)), but the incidence of ureteric stenosis was higher (10.3% vs. 1.1%; P=0.01).
  
  
  CONCLUSIONS
  Our data demonstrate a lower incidence of BK viremia in patients on lower-dose Tac compared with CyA-based primary immunosuppression in contrast to previous studies, and provide further support for the association between BK virus and ureteric complications.
authors: Renal Unit, Western Infirmary, Glasgow, UK. colin.geddes@ggc.scot.nhs.uk
authors: C C
authors: CC
authors: Geddes
authors: R
authors: R
authors: Gunson
authors: E
authors: E
authors: Mazonakis
authors: R
authors: R
authors: Wan
authors: L
authors: L
authors: Thomson
authors: M
authors: M
authors: Clancy
authors: W F
authors: WF
authors: Carman
mesh_terms: D001739:BK Virus / Q000302:isolation & purification*; D016572:Cyclosporine / Q000008:administration & dosage / Q000627:therapeutic use*; D006801:Humans; D007165:Immunosuppression Therapy; D007166:Immunosuppressive Agents / Q000008:administration & dosage / Q000627:therapeutic use; D007674:Kidney Diseases / Q000097:blood / Q000517:prevention & control / Q000821:virology; D016030:Kidney Transplantation / Q000009:adverse effects*; D009173:Mycophenolic Acid / Q000008:administration & dosage / Q000031:analogs & derivatives / Q000627:therapeutic use; D027601:Polyomavirus Infections / Q000097:blood / Q000150:complications / Q000517:prevention & control* / Q000821:virology; D011239:Prednisolone / Q000008:administration & dosage / Q000627:therapeutic use; D016559:Tacrolimus / Q000008:administration & dosage / Q000627:therapeutic use*; D013997:Time Factors; D014412:Tumor Virus Infections / Q000097:blood / Q000150:complications / Q000517:prevention & control* / Q000821:virology; D014766:Viremia / Q000097:blood
chemical_list: D007166:Immunosuppressive Agents; D016572:Cyclosporine; D011239:Prednisolone; D009173:Mycophenolic Acid; D016559:Tacrolimus