BK Virus Infection in Thai Kidney Transplant Recipients: A Single-Center Experience

BK virus-associated nephropathy (BKVAN) is a significant cause of allograft dysfunction and failure in kidney transplant recipients. Early detection and proper adjustment of immunosuppression is the best method for treatment of this condition and to improve long-term allograft outcome. Here, we reported the prevalence and risk factors of BK virus (BKV) infection in our population.

We retrospectively reviewed kidney transplant recipients at Siriraj Hospital between January 2012 and December 2015 who had been investigated using real-time polymerase chain reaction BK viral load. BKV infection including BK viruria, BK viremia, and BKVAN had been reported.

In all, 173 patients were enrolled. Fifty-three patients (30.6%) were diagnosed with BKV infection. The median time to diagnosis of BKV infection was 10.9 months after transplantation. There were 11 cases of BKVAN. Mycophenolic acid (MPA) more than 1 g/d was the only significant risk factor for developing BKV infection (odds ratio = 2.35, 95% confidence interval 1.07-5.14). The high level of BK viral load in urine (>1.7 × 10⁷ copies/mL) could predict BK viremia.

Protocol screening of BKV following with adjusted immunosuppressive regimens should be established for preventing allograft loss in BKVAN especially in the first year after transplantation and in patients who receive more than 1 g of MPA per day. Urinary BK viral load is the early marker for prediction of BK viremia, which leads to BKVAN.