Leflunomide for Polyomavirus Type BK Nephropathy

Abstract

To the Editor: Polyomavirus type BK nephropathy is an aggressively destructive disease occurring in up to 8 percent of patients with renal allografts,1,2 with rates of graft loss within one year of 30 to 65 percent.3,4 There is no therapy with proven efficacy. Leflunomide (Arava), approved for the treatment of rheumatoid arthritis, is an immunosuppressive drug, yet its active metabolite, A77 1726, has substantial antiviral activity in vitro and in animals.5 From July 2001 to April 2004, we used leflunomide as the initial antiviral therapy in 17 patients with biopsy-proven BK nephropathy. All but one of these patients . . .