JC polyomavirus infection in candidates for kidney transplantation living in the Brazilian Amazon region

Prevalence of JC and BK Polyomavirus Infection in Patients with Chronic Kidney Disease in the State of Pará, Brazil

The polyomaviruses that infect humans, JC virus (JCV) and BK virus (BKV), can establish persistent infections in the cells that make up the renal system, causing nephritis and BKV-associated nephropathy in up to 10% of renal transplant patients, and of these, 90% lose the graft and return for hemodialysis. This study aimed to determine the prevalence of polyomaviruses (PyV) in the population with chronic kidney disease (CKD), classified into three groups (conservative, dialysis, and transplanted) and a control group. Urine samples were collected from 290 individuals, including 202 patients with CKD and 88 from the control group. PyV screening was performed by PCR amplification of a fragment of the VP1 region, and the JCV and BKV species were distinguished through enzymatic digestion with the restriction endonuclease BamHI from the amplification of a TAg region. All amplification products were visualized on a 3% agarose gel. The prevalence of PyV infection was correlated with clinical-epidemiological variables using the chi-squared and Fisher's exact tests. In the group with CKD, the prevalence of PyV was 30.2%, a higher rate being observed in conservative patients (36.66%; 22/60), followed by dialysis patients (30.48%; 25/82), and transplanted patients (20%; 12/60). In the control group, the prevalence was 46.59% (41/88). The differentiation between species revealed that JCV was present in 77.8% and BKV in 22.2% of the group with CKD. The prevalence of infection was higher in male patients (59.32%), whose most common pathology was systemic arterial hypertension (35.59%). In the group of transplanted patients, there was a statistically significant association between infection and the use of the immunosuppressant azathioprine (p = 0.015). The prevalence of PyV infection was higher in the control group than in the group with CKD, being predominant in males and in patients with systemic arterial hypertension.

Database and Statistical Analyses of Transcription Factor Binding Sites in the Non-Coding Control Region of JC Virus

JC virus (JCV), as an archetype, establishes a lifelong latent or persistent infection in many healthy individuals. In immunocompromised patients, prototype JCV with variable mutations in the non-coding control region (NCCR) causes progressive multifocal leukoencephalopathy (PML), a severe demyelinating disease. This study was conducted to create a database of NCCR sequences annotated with transcription factor binding sites (TFBSs) and statistically analyze the mutational pattern of the JCV NCCR. JCV NCCRs were extracted from >1000 sequences registered in GenBank, and TFBSs within each NCCR were identified by computer simulation, followed by examination of their prevalence, multiplicity, and location by statistical analyses. In the NCCRs of the prototype JCV, the limited types of TFBSs, which are mainly present in regions D through F of archetype JCV, were significantly reduced. By contrast, modeling count data revealed that several TFBSs located in regions C and E tended to overlap in the prototype NCCRs. Based on data from the BioGPS database, genes encoding transcription factors that bind to these TFBSs were expressed not only in the brain but also in the peripheral sites. The database and NCCR patterns obtained in this study could be a suitable platform for analyzing JCV mutations and pathogenicity.

BK and JC virus infections in healthy patients compared to kidney transplant recipients in Tunisia

The human polyomaviruses BKPyV and JCPyV are members of Polyomaviridae family and after primary infections they persist as latent infection especially in the kidneys. BKVPy reactivation is mainly related to a renal nephropathy and JCV reactivation can induce the progressive multifocal leukoencephalopathy. The aim of this study was to investigate and to compare the presence of BKPyV and JCPyV in urine and plasma samples from immunocompromised and immunocompetent groups. The viral detection and quantification was done by a real time PCR from 100 healthy individuals and from 72 kidney transplanted patients (KTx) enrolled in a prospective study. Polyomavirus DNA urinary shedding was identified in 19% of healthy person, BKPyV in 6%; JCPyV more frequent in 13%. No individuals in this group developed polyomavirus viremia. BKPyV and JCPyV viruria was seen in 36% and 28% of KTx respectively, and 11% had a concomitant BKPyV and JCPyV viruria. Only BKPy viremia was detected in 5.5% of the KTx. In healthy persons, JCPyV shedding was associated with older individuals. However, in KTx, BKPyV was associated with younger age and male gender. No significant association was found between the patient's origin and BKPyV or JCPyV infection. In conclusion and consisting with previous reports, BKPyV and JCPyV prevalence and urinary loads were significantly higher in immunosuppressed compared to non-immunosuppressed individuals. In Addition and by contrast to KTx, JCPyV was more frequent than BKPyV in healthy individuals. Furthermore, the shedding of both polyomaviruses was differently associated with the age and the sex according to each population.

BK Viremia among Iranian Renal Transplant Candidates

BACKGROUND

Primary infection with BK virus (BKV) is occurred during childhood and usually asymptomatic, but after initial infection, BKV may persist lifelong in the kidney and genitourinary tract. Reactivation may occur in individuals with compromised immunity such as renal transplant recipients. Due to the role of BKV in BK virus-associated nephropathy (BKVAN) and potentially renal allograft rejection, the detection of BKV in renal transplant candidates is very important. The aim of this study was to evaluate the frequency of BK viremia in end stage renal disease cases who were candidates for renal transplantation.

METHODS

In this cross-sectional study, 50 cases with end stage renal disease who were candidates for renal transplantation were recruited from the main dialysis unit in Tehran, Iran. Presence of BK viremia was determined in plasma samples of cases using real time PCR.

RESULTS

A total of 50 renal transplant candidates with mean age 37.8±13 yr were enrolled in the study. Fifty two percent of subjects were male. Forty six (92%) of them were under HD and 4 (8%) were on PD. BK virus was not detected in any plasma samples of renal transplant candidates.

CONCLUSION

This study showed absence of BK viremia in our renal transplant candidates. However, due to the important role of BKV in BKVAN and renal graft failure and rejection, further studies involving larger number of cases are required to elucidate the rate of the BKV in renal transplant candidates.