Efficacy of Levofloxacin in the Treatment of BK Viremia: A Multicenter, Double-Blinded, Randomized, Placebo-Controlled Trial; Lee B, Gabardi S, Grafals M, Hofmann R, Akalin E, Aljanabi A, Mandelbrot D, Adey D, Heher E, Fan P, Conte S, Dyer-Ward C, Chandraker A; Clinical Journal of the American Society Nephrology, CJASN (Jan 2014)

BACKGROUND AND OBJECTIVES BK virus reactivation in kidney transplant recipients can lead to progressive allograft injury. Reduction of immunosuppression remains the cornerstone of treatment for active BK infection. Fluoroquinolone antibiotics are known to have in vitro antiviral properties, but the evidence for their use in patients with BK viremia is inconclusive. The objective of the study was to determine the efficacy of levofloxacin in the treatment of BK viremia.
DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS Enrollment in this prospective, multicenter, double-blinded, placebo-controlled trial occurred from July 2009 to March 2012. Thirty-nine kidney transplant recipients with BK viremia were randomly assigned to receive levofloxacin, 500 mg daily, or placebo for 30 days. Immunosuppression in all patients was adjusted on the basis of standard clinical practices at each institution. Plasma BK viral load and serum creatinine were measured monthly for 3 months and at 6 months.
RESULTS At the 3-month follow-up, the percentage reductions in BK viral load were 70.3% and 69.1% in the levofloxacin group and the placebo group, respectively (P=0.93). The percentage reductions in BK viral load were also equivalent at 1 month (58% versus and 67.1%; P=0.47) and 6 months (82.1% versus 90.5%; P=0.38). Linear regression analysis of serum creatinine versus time showed no difference in allograft function between the two study groups during the follow-up period.
CONCLUSIONS A 30-day course of levofloxacin does not significantly improve BK viral load reduction or allograft function when used in addition to overall reduction of immunosuppression.

The BK virus is a member of the polyomavirus family. Past infection with the BK virus is widespread, but significant consequences of infection are uncommon, with the exception of the immunocompromised and the immunosuppressed. The BK virus was first isolated in 1971 from the urine of a renal transplant patient, initials B.K.[1] The BK virus is similar to another virus called the JC virus (JCV), since their genomes share 75% sequence similarity. Both of these viruses can be identified and differentiated from each other by carrying out serological tests using specific antibodies or by using a PCR based genotyping approach.