Effect of leflunomide and cidofovir on replication of BK virus in an in vitro culture system

Transplantation. 2005 Jan 15;79(1):116-8. doi: 10.1097/01.tp.0000149338.97084.5f.


Background: Cidofovir and Leflunomide are used empirically in the treatment of BK virus nephropathy. The aim of this study is to quantify the antiviral activity of these drugs.

Methods: BK virus was grown in a cell-culture system. The rate of viral replication in the presence or absence of the drug being tested was assessed using a quantitative polymerase chain reaction assay.

Results: The inhibitory concentration, effective concentration, and selectivity index for Leflunomide are 39.7+/-6.9, 11.3+/-2.8, and 3.8+/-0.8 microg/mL, respectively. For Cidofovir, these indices were, respectively, 63.9+/-17.2, 36.3+/-11.7, and 2.3+/-0.8 microg/mL.

Conclusions: The in vitro activity of Cidofovir and Leflunomide is modest, and the selectivity index is low. There is a need to develop more effective and less toxic anti-BK virus drugs for clinical use.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Antiviral Agents / pharmacology*
  • BK Virus / drug effects*
  • BK Virus / physiology
  • Cidofovir
  • Cytosine / analogs & derivatives*
  • Cytosine / pharmacology*
  • Isoxazoles / pharmacology*
  • Leflunomide
  • Organophosphonates / pharmacology*
  • Virus Replication / drug effects*


  • Antiviral Agents
  • Isoxazoles
  • Organophosphonates
  • Cytosine
  • Leflunomide
  • Cidofovir