Ciprofloxacin decreased polyoma BK virus load in patients who underwent allogeneic hematopoietic stem cell transplantation

Background. Polyoma BK virus (BKV) is associated with hemorrhagic cystitis during hematopoietic stem cell transplantation (HSCT). The objective of this study was to test whether standard-dose ciprofloxacin might suppress reactivation of BKV infection during HSCT. Methods. Sixty-eight patients received ciprofloxacin or a cephalosporin as antibiotic prophylaxis after undergoing allogeneic HSCT. Urine samples were collected weekly from day 7 before HSCT to day 50 after HSCT. Laboratory investigations included quantification of BKV load and urinary ciprofloxacin levels and in vitro drug sensitivity of BKV. Results. Twenty-two patients received ciprofloxacin, 21 received cephalosporins, 12 received concomitant corticosteroids and antibiotics (9 received ciprofloxacin, and 3 received cephalosporins), and 13 received interrupted ciprofloxacin therapy. Ciprofloxacin recipients developed a significantly lower peak BKV load, compared with cephalosporin recipients (median, 3 × 10⁵ copies/mL vs.2.6 × 10⁹ copies/mL; P = .021), irrespective of concomitant receipt of corticosteroid therapy. Fewer ciprofloxacin recipients than cephalosporin recipients (P = .013) developed BKV viruria with a ≥3-log increase in BKV load during HSCT, which was associated with significantly more cases of hemorrhagic cystitis (8 of 29 patients with a peak increase of ≥ log vs. 0 of 39 patients without a peak increase of this level; P < .001). Ciprofloxacin recipients excreted ciprofloxacin in urine at a mean 24-h rate of 71.7 μg/mL (range, 23.0-152.9 μg/mL), which was comparable with the in vitro inhibitory concentration of 125-250 μg/mL of ciprofloxacin found for 3 of 7 BKV isolates. Conclusions. Ciprofloxacin decreased urinary BKV reactivation after HSCT.