The Monitoring Interest of BK Virus Load in Renal Allograft Tunisian Recipients: Prospective Study

BK virus (BKV) may cause nephropathy in renal transplant recipients receiving immunosuppressive therapy, resulting in renal dysfunction and, possibly graft loss. However, the positive and negative predictive values of BK viral load are still controversial. In this prospective, single-center study, BKV DNA was measured 1, 3 and 6 months after transplantation. The viral load in urine and plasma was quantified with the real-time Q-PCR (Argen kit) in 73 renal allograft recipients Three of them showed acute rejection. To determine the cutoff value of viral load, 60 sera samples of healthy blood donors, matched for age and sex, were tested. The mean plasmatic viral load one month posttransplantation was statistically higher in renal transplant recipients (17.23 copies/ml) compared to that in controls (2 copies/ml) (p: 0.06). This difference of the distribution of viremia values is more evident in the third and sixth month (p: 0.002 and 0.010 respectively). Furthermore, analysis of the kinetic of viral load revealed an average rise of viremia at 3 months (1589.14 copies/ml) followed by its decrease at 6 months (249.75 copies/ml). However, the difference was not statistically significant. The same is true for the distribution of values of viruria and in all cases the average viral load was statistically higher in urine than in plasma. In addition, this study did not shown significant relationsheep between viremia/viruria and the occurrence of acute rejection, the renal function deterioration, the source of allograft or immunosuppressive therapy protocol. If the results of this study demonstrate the importance of the replication of BKV in renal transplant patients from the first month compared to that in immunocompetent subjects, the screening of the DNA of this virus does not appear to have a prognostic value in the occurrence of acute rejection. However, the plasma and urine monitoring of BKV load beyond 6 months, not appear to exclude the relationsheep between these two biomarkers and the occurrence of chronic graft dysfunction.