Induction immunosuppression has provided great advances in reducing the incidence of acute rejection (AR) following kidney transplantation. Despite this success, there has been recent concern over possible increased rates of viral complications when such powerful immunosuppressive therapy is used. This study was undertaken to determine the incidence of BK viral infection following kidney transplantation under alemtuzumab induction therapy.
With institutional review board approval, a retrospective study was performed of all patients undergoing kidney transplantation under alemtuzumab induction at a single center. The incidence of BK viremia was determined, and univariate analysis was performed to determine factors associated with the development of BK viremia. Further analysis was undertaken, using standard statistical methods, to determine the rates of graft survival and hazard ratio (HR) for AR in patients with and without BK viremia.
There were 456 patients in the current study, with a mean age of 51 years. The majority of these (61.8%) were male, and 73.5% were Caucasian. The overall incidence of BK viremia identified on routine screening was 6.6%. Univariate analysis failed to identify any significant predictors of BK viremia. One-, 3-, and 5-year graft survival for patients who developed BK viremia was 96.6%, 91.7%, and 91.7%, respectively, compared with 94.1%, 87.8%, and 80.2% for patients without BK viremia (P = 0.860). BK viremia was associated with a significantly increased risk for AR (HR 3.48, 95% confidence interval 1.24–9.76; P = 0.018).
The incidence of BK viremia following alemtuzumab induction appears to be in concordance with the published literature, with satisfactory graft survival rates. BK viremia is, however, associated with an increased risk for AR.