Abstract
Background: There is no effective therapy for BK virus nephropathy (BKVN). Cyclosporine A (CsA) has a lower immunosuppressive effect than tacrolimus. In vitro studies have shown that CsA inhibits BK virus (BKV) replication. This study aimed to evaluate the effectiveness of switching from tacrolimus to low-dose CsA in renal transplant recipients with BKVN.
Methods: Twenty-four patients diagnosed with BKVN between January 2015 and December 2016 were included. Tacrolimus was switched to low-dose CsA, and patients were followed for 24 months. Primary endpoints were BKV clearance in blood and graft. Secondary endpoints were urine specific gravity, serum creatinine, and graft loss.
Results: The viremia in all patients cleared at a mean of 2.7±2.0 months after switching to CsA. Urine specific gravity at 3 months after switching to CsA increased significantly compared to that at diagnosis ( P = 0.002). The timing and trend of urine specific gravity increase was consistent with the timing and trend of blood and urine viral load decrease. Repeated biopsies at a median of 11.2 months (range, 9.1-12.5 months) after switching to CsA showed that 8 patients (42.1%) were negative for BKV, and 11 patients (58.9%) had a decrease in BKV load ( P < 0.001). There was no statistical difference in the serum creatinine level between the time of diagnosis and 24 months of CsA therapy ( P = 0.963). The graft survival rate was 100%. Only 2 patients (8.3%) suffered from acute rejection.
Conclusions: Switching from tacrolimus to low-dose CsA may be an effective therapy for BKVN.
- BK virus
- BK virus nephropathy
- cyclosporine A
- tacrolimus
- conversion of immunosuppression
- ©2019 The Author(s)
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