title: Risk factors and interventional strategies for BK polyomavirus infection after renal transplantation.
abstract: OBJECTIVE
  BK virus (BKV)-induced viraemia after renal transplantation can be associated with severe impairment of graft function. This study evaluated possible risk factors for BKV replication and examined the outcomes following various currently used treatment approaches.
  
  
  METHODS
  Fifty-seven renal transplant recipients with BKV viraemia were retrospectively compared with 71 BKV-negative recipients to identify risk factors for BKV viraemia. Furthermore, outcome and graft function in 14 patients with BKV replication, in whom mycophenolate mofetil (MMF) was discontinued with a dose reduction of the remaining immunosuppressants, were compared with 32 patients in whom both MMF and the additional immunosuppressants were reduced.
  
  
  RESULTS
  Patients with BKV viraemia received MMF (p < 0.01) and triple immunosuppression (p < 0.01) significantly more often, and displayed tacrolimus (p = 0.034) at higher blood concentrations (p = 0.002), a lower lymphocyte count (p = 0.006) and a longer warm ischaemic time (p = 0.019), and were more often male (p = 0.026). Patients in whom MMF was stopped had a higher chance of clearance of BKV viraemia (p = 0.022), which was achieved more rapidly (p = 0.048). Graft function improved during treatment and no graft losses occurred, compared with eight graft losses in the MMF-treated group (p = 0.04).
  
  
  CONCLUSIONS
  MMF and tacrolimus could promote BKV viraemia after renal transplantation. Discontinuation of MMF together with a reduction of calcineurin inhibitors and glucocorticoids could be an option to reduce BKV replication after renal transplantation.
authors.affiliation: Abteilung für Nephrologie, Klinikum rechts der Isar der Technischen Universität München, München, Germany. dominik.steubl@lrz.tum.de
authors.forename: Dominik
authors.initials: D
authors.lastname: Steubl
authors.forename: Marcus
authors.initials: M
authors.lastname: Baumann
authors.forename: Tibor
authors.initials: T
authors.lastname: Schuster
authors.forename: Michael
authors.initials: M
authors.lastname: Fischereder
authors.forename: Bernhard K
authors.initials: BK
authors.lastname: Krämer
authors.forename: Uwe
authors.initials: U
authors.lastname: Heemann
authors.forename: Jens
authors.initials: J
authors.lastname: Lutz
mesh_terms: D000328:Adult; D000893:Anti-Inflammatory Agents / Q000008:administration & dosage; D001739:BK Virus / Q000502:physiology; D016001:Confidence Intervals; D016572:Cyclosporine / Q000009:adverse effects; D004359:Drug Therapy, Combination; D005260:Female; D006085:Graft Survival; D006801:Humans; D007166:Immunosuppressive Agents / Q000008:administration & dosage / Q000009:adverse effects*; D053208:Kaplan-Meier Estimate; D016030:Kidney Transplantation / Q000009:adverse effects*; D018655:Lymphocyte Count; D008297:Male; D008875:Middle Aged; D009173:Mycophenolic Acid / Q000008:administration & dosage / Q000009:adverse effects / Q000031:analogs & derivatives*; D016017:Odds Ratio; D027601:Polyomavirus Infections / Q000821:virology*; D011239:Prednisolone / Q000008:administration & dosage; D012189:Retrospective Studies; D012307:Risk Factors; D016559:Tacrolimus / Q000009:adverse effects; D014412:Tumor Virus Infections / Q000821:virology*; D019562:Viral Load; D014779:Virus Replication; D052096:Warm Ischemia
chemical_list: D000893:Anti-Inflammatory Agents; D007166:Immunosuppressive Agents; D016572:Cyclosporine; D011239:Prednisolone; D009173:Mycophenolic Acid; D016559:Tacrolimus