Polyomavirus infection in pediatric renal transplant recipients: evaluation using a quantitative real-time PCR technique.

Polyomavirus infection and related nephropathy is being increasingly recognized as an important cause of allograft dysfunction in adult renal transplant recipients. We prospectively monitored pediatric renal transplant recipients for the presence of BK and JC polyomavirus in urine and blood using a quantitative PCR assay to evaluate the prevalence and clinical relevance of polyomavirus infection in the pediatric renal transplant population. Of 46 pediatric renal recipients who were evaluated, nine (20%) demonstrated isolated BKV viruria, while five (11%) had concomitant BKV viremia and viruria. JCV viruria was found in eight (17%) patients. BKV viremia was associated with a significantly higher urinary BKV viral load: median urinary viral load 1.9 x 10(9) copies/mL (range 6.7 x 10(2)-1.8 x 10(11)) for the group with concomitant viremia and viruria vs. 1.8 x 10(3) copies/mL (range 2.5 x 10(2)-4.5 x 10(6)) for the group with isolated viruria (p < 0.0001). In children that were followed prospectively since their transplantation, the BKV urinary viral load increased markedly before viremia became detectable a few weeks later. None of the patients with JCV viruria or isolated BKV viruria had renal dysfunction. Among the five patients with BKV in both urine and blood, two developed biopsy-proven BKV nephropathy associated with deterioration of the renal function. Management of the BKV nephropathy consisted of reduction of immunosuppression alone or in combination with antiviral treatment with cidofovir. This study shows that polyomavirus infection and related interstitial nephritis is a relevant clinical issue in the pediatric renal transplant population. Monitoring the polyomaviral load in the urine and the blood of the patients using a quantitative PCR technique is a useful tool in the diagnosis and subsequent management of this infection. Even before viremia is present, an important rise in the urinary viral load should draw the attention of the transplant clinician and raise the issue of adapting the immunosuppression.

Herman J ，Van Ranst M ，Snoeck R ，Beuselinck K ，Lerut E ，Van Damme-Lombaerts R ... -  《PEDIATRIC TRANSPLANTATION》

[Clinical diagnosis and treatment of BK virus infection in renal transplant recipients].

Chen LZ ，Huang G ，Qiu J ，Li J ，Chen GD ，Zeng WT ，Fu Q ，Zhang L ，Ji YL ... -  《-》

Isolated heart and liver transplant recipients are at low risk for polyomavirus BKV nephropathy.

Puliyanda DP ，Amet N ，Dhawan A ，Hilo L ，Radha RK ，Bunnapradist S ，Czer L ，Martin P ，Jordan S ，Toyoda M ... -  《CLINICAL TRANSPLANTATION》

BK viral infection in an Australian pediatric renal transplant population.

BK virus (BKV) is recognized as a significant cause of renal allograft dysfunction in adults, and there is growing awareness of its importance in the pediatric population. Eighteen pediatric renal transplant recipients and 18 age-matched controls were prospectively studied. Anti-BKV immunoglobulin G (IgG) and IgM titres were assayed in all subjects at entry to the study. Polymerase chain reaction (PCR) for BKV DNA was performed on urine and serum at entry, and prospectively tested again at 4, 8 and 12 months. Mean age +/- s.d. of transplant recipients and controls was 14.6 +/- 3.3 and 13.9 +/- 0.33 yr respectively [not significant (NS)]. Transplant patients were studied at a mean time of 5.6 +/- 4.2 yr post-transplant. 56% of transplant patients and 39% of controls were seropositive (+ve BKV IgG) (NS). Plasma BKV PCR was positive in one transplant patient (who also had positive urine PCR) and in none of the controls. The prevalence of positive urine PCR in transplant patients was greater than in controls (33% vs. 0%, p = 0.02). Positive urine BKV PCR was more commonly found in patients treated with mycophenolate than azathioprine (p = 0.04). We conclude that the prevalence of BKV seropositivity and viral activation in this Australian pediatric renal transplant population is similar to that reported in adult and pediatric populations in other countries. BK viruria was more common in children with greater immunosuppression, suggesting that this group is at higher risk of BKV induced nephropathy.

Haysom L ，Rosenberg AR ，Kainer G ，Waliuzzaman ZM ，Roberts J ，Rawlinson WD ，Mackie FE ... -  《PEDIATRIC TRANSPLANTATION》

Cross-sectional study of BK virus infection in pediatric kidney transplant recipients.

Fogeda M ，Muñoz P ，Luque A ，Morales MD ，Bouza E ，BKV Study Group ... -  《PEDIATRIC TRANSPLANTATION》