Kidney and urinary tract polyomavirus infection and distribution: molecular biology investigation of 10 consecutive autopsies

BK Polyomavirus in Pediatric Renal Transplantation-What We Know and What We Do Not

BK polyomavirus (BKPyV) is still a real threat in the management of kidney transplantation. Immunosuppressive treatment disrupts the equilibrium between virus replication and immune response, and uncontrolled BKPyV replication leads to nephropathy (BKPyV nephropathy). The first evidence of BKPyV reactivation in transplant recipients is the detection of viral shedding in urine, which appears in 20% to 60% of patients, followed by BKPyV viremia in 10-20% of kidney transplant recipients. BKPyV nephropathy eventually occurs in 1-10% of this population, mainly within the first 2 years post-transplantation, causing graft loss in about half of those patients. Few data exist regarding the pediatric population and we focus on them. In this paper, we review the existing diagnostic methods and summarize the evidence on the role of BKPyV humoral and cellular immunity in modulating the clinical course of BKPyV infection and as potential predictors of the outcome. We look at the known risk factors for BKPyV nephropathy in the immunosuppressed patient. Finally, we propose a sensible clinical attitude in order to screen and manage BKPyV infection in kidney transplant children.

Human herpesvirus 6A and 6B and polyomavirus JC and BK infections in renal cell carcinoma and their relationship with p53, p16INK4a, Ki-67, and nuclear factor-kappa B expression

There are a limited number of studies regarding the involvement of viruses in the development and pathogenesis of renal cell carcinoma (RCC). In this study, we aimed to discover whether human herpesvirus 6A (HHV-6A) and 6B (HHV-6B) and human polyomavirus JC (JCV) and BK (BKV) are associated with RCC and the expression of p53, p16INK4a, Ki-67 and NF-κB in RCC patients. A total of 122 histologically confirmed RCC tissue specimens and 96 specimens of their corresponding peritumoral tissues were included in this prospective study. Nested polymerase chain reaction (nPCR) was performed in order to amplify viral DNA sequences. Restriction endonuclease analysis was carried out to discriminate between HHV-6A and HHV-6B. p53, p16INK4a, Ki-67, and NF-κB immunostaining data of the studied tissue specimens were available from our previous study. Statistical analysis was performed to demonstrate the potential associations. HHV-6B and JCV were detected in 10.7% and 13.9% of RCC patients, respectively. We did not detect HHV-6A and BKV in any of RCC tissue specimens. Moreover, no association was found between either of these viruses and RCC. Our study revealed a significant association between HHV-6B and p53 overexpression. No other associations were found between cellular biomarkers p53, p16INK4a, Ki-67, and NF-κB and the studied viruses. The data of the present study, though very limited, disprove the involvement of HHV-6A, HHV-6B, BKV, and JCV in the initiation or progression of RCC. This article is protected by copyright. All rights reserved.

Routine immunohistochemistry study for polyomavirus BK nephropathy in transplanted kidney biopsies, is it recommended?

BACKGROUND

Early diagnosis and treatment of Polyomavirus BK Nephropathy (PVBKN) is a challenging issue in the management of patients with kidney transplantation. Currently, histopathologic diagnosis is the gold standard method for diagnosis of PVBKN. However, typical viral inclusions may not be found in early stages of the PVBKN and should, instead, be diagnosed using immunohistochemistry (IHC) study. There is no clear consensus about routine IHC tests in the pathologic evaluation of transplanted kidney biopsy samples.

MATERIAL AND METHODS

The current study was conducted on transplanted kidney biopsy samples, since 2016 to 2019. The patients who have presented with new onset of allograft dysfunction, at least 2 weeks after transplantation surgery, were included in our study. All these biopsy samples were evaluated with routine renal biopsy stains as well as IHC for SV40 (Simvian Virus 40) antigen. The identification of typical nuclear virus inclusion body and any nuclear positive staining on IHC (≥1+ positive result) were considered as definite evidence of PVBKN. Sensitivity, specificity, Positive Predictive and Negative Predictive Values (PPV and NPV) of histopathologic assessment without IHC study were evaluated.

RESULTS

Among 275 included cases, 18 (6.5%) patients with PVBKN were diagnosed. In patients with PVBKN, typical viral inclusions were detected in 14 samples (77.7%), on primary histopathological examination. However, virus-infected cells were identified just after IHC study in 4 (22.2%) of patients. Sensitivity, Specifity, PPV and NPV of morphologic histopathological assay without IHC for detection of PVBKN was 77.7, 100, 100 and 98.4% respectively.

CONCLUSION

Routine IHC study for SV40 in all transplanted kidney biopsy samples with new onset of allograft dysfunction, will enhance the diagnostic sensitivity of early stage disease detection.

The Urinary Polyomavirus-Haufen Test: A Highly Predictive Non-Invasive Biomarker to Distinguish "Presumptive" from "Definitive" Polyomavirus Nephropathy: How to Use It-When to Use It-How Does It Compare to PCR Based Assays?

"Definitive" biopsy proven polyomavirus nephropathy (PyVN), usually caused by BK polyomavirus (BKPyV), remains a significant infection of kidney transplants. Diagnosis depends upon an allograft biopsy and outcome depends upon early intervention. Here, we report data on a non-invasive biomarker for PyVN, the urinary PyV-Haufen test. Test results were compared to those of conventional laboratory assays targeting PyV replication, i.e., BKPy-viremia, -viruria and urinary decoy cell shedding. Of 809 kidney transplant recipients, 228 (28%) showed PyV replication with decoy cell shedding and/or BKPy-viremia by quantitative PCR; only a subset of 81/228 (36%) showed "definitive" PyVN. Sensitivity and specificity for identifying patients with PyVN was: 100% and 98%, respectively, urinary PyV-Haufen test; 50% and 54%, respectively, urinary decoy cell shedding; 97% and 32%, respectively, BKPy-viremia with cut-off of ≥250 viral copies/mL; 66% and 80%, respectively, for BKPy-viremia ≥104 viral copies/mL. The PyV-Haufen test showed a very strong correlation with the severity of PyVN (Spearman's ρ = 0.84) and the Banff PyVN disease classes (p < 0.001). In comparison, BKPy-viremia and -viruria levels by PCR displayed modest correlations with PyVN severity (Spearman's ρ = 0.35 and 0.36, respectively) and were not significantly associated with disease classes. No association was found between decoy cell shedding and PyVN severity or disease classes. Pilot data demonstrated that PyVN resolution with decreasing Banff pvl-scores was reflected by a gradual decrease in PyV-Haufen shedding; such a tight association was not noted for BKPy-viremia. In conclusion, urinary PyV-Haufen testing is a highly specific, non-invasive method to accurately diagnose patients with "definitive" PyVN and to optimize patient management. Assay specifics are discussed.

A rare urinary JC virus reactivation after long-term therapy with rituximab

The possible role of JC virus in determining urinary tract involvement has only recently been recognized. The case of a man with laboratory-confirmed JC virus replication in the urine after a maintenance schedule of rituximab administered for a lymphoproliferative disorder is reported herein. The patient developed severe renal and urinary tract impairment, characterized by the onset of nephropathy, bilateral ureteral strictures, and a serious reduction in vesical compliance, ultimately requiring an ileal neobladder configuration. The renal and urinary tract involvement was finally attributed to JC virus reactivation. This observation suggests that renal and urinary tract diseases related to JC virus might be associated with long-term rituximab treatment.

Development of a Nucleic Acid Lateral Flow Immunoassay for the Detection of Human Polyomavirus BK

The BK virus (BKV) is an emerging pathogen in immunocompromised individuals and widespread in the human population. Polymerase chain reaction is a simple and highly sensitive method for detecting BKV, but it is time consuming and requires expensive instruments and expert judgment. The lateral flow assay, a rapid, low-cost, minimal-labor, and easy-to-use diagnostic method, was successfully applied for pathogen detection. In this study, we used oligonucleotide probes to develop a simple and rapid sandwich-type lateral flow immunoassay for detecting BKV DNA within 45 minutes. The detection limit for the synthetic single-stranded DNA was 5 nM. The specificity study showed no cross-reactivity with other polyomaviruses, such as JC virus and simian virus 40. For the Escherichia coli containing BKV plasmid cultured samples, the sensitivity was determined to be 107 copies/mL. The approach offers great potential for BKV detection of various target analytes in point-of-care settings.

Novel 3D organotypic urothelial cell culture model for identification of new therapeutic approaches in urological infections

PURPOSE

3D organotypic cell cultures offer the possibility to study cell growth in a more in vivo like situation. To our knowledge no 3D culture of primary urothelial cells has been established yet. BK Polyomavirus (BKPyV), replicating in urothelial cells, may cause haemorrhagic cystitis in immunocompromised patients.

PRIMARY ENDPOINTS OF THIS STUDY

Establishment of a 3D organotypic cell culture of primary urothelial cells and fibroblasts; use of this model as infection model for archetype BKPyV; description of first parts of viral life cycle with identification of therapeutic targets.

METHODS

This is an experimental study. Primary urothelial cells were purchased from CellnTec, Bern, Switzerland; fibroblasts were isolated from the ureter of patients with no urothelial malignancy in their medical history. As main methods we used quantitative real-time PCR and immunohistochemistry. Outcomes were analysed using SPSS 23.0.

RESULTS

We were able to develop a 3D organotypic culture for primary urothelium. An infection with archetype BKPyV was established in this model with virus replication rates up to 6.41 × 108 copies/ml on day 9 following Infection. Interestingly, proliferation rate of the urothelial cells is significantly (p = 0.049 at day 6 following infection) elevated while cells are losing differentiation under infection. Phosphorylated STAT3 is also significantly elevated (p < 0.0001) during infection.

CONCLUSIONS

The established of urothelial 3D cultures is a new method to study several urothelial diseases. The archetype BKPyV infection model is novel and the first method to study archetype viral life cycle. The STAT3 pathway might be an interesting target for the development of a causal therapy.

Human BK and JC polyomaviruses: Molecular insights and prevalence in Asia

Polyomaviridae family consists of small circular dsDNA viruses. Out of the 14 human polyomaviruses described so far, BKPyV and JCPyV have been studied extensively since their discovery in 1971. Reportedly, both BKPyV and JCPyV are widely distributed across the globe with the frequency of 80-90 % in different populations. The primary infection of these viruses is usually asymptomatic and latent which is activated as a consequence of immunosuppression. Activated BKPyV and JCPyV viruses lead to the development of BK Virus Associated Nephropathy and Progressive Multifocal Leukoencephalopathy, respectively. Immense progress has been made during the last few decades regarding the molecular understanding of polyomaviruses. Epidemiology of polyomaviruses has also been studied extensively. However, most of the epidemiological studies have focused on European and American populations. Therefore, limited data is available regarding the geographical distribution of these potentially oncogenic viruses in Asian countries. In this article, we have presented a compendium of latest advances in the molecular understanding of polyomaviruses and their pathobiology. We also present a comprehensive review of published literature regarding the epidemiology and prevalence of BKPyV and JCPyV in Asian regions. For this purpose, a thorough search of available online resources was performed. As a result, we retrieved 24 studies for BKPyV and 22 studies for JCPyV, that describe their prevalence in Asia. These studies unanimously report high occurrence of both BKPyV and JCPyV in Asian populations. The available data from these studies was categorized into two groups: on the basis of prevalence (low, medium and high) and disease development (healthy and diseased). Altogether, Korean population hasbeen evidenced to possess highest frequency of BKPyV (66.7 %), while JCPyV was found to be most prevalent in Taiwan (88 %). Due to high and ubiquitous distribution of these viruses, frequent studies are required to develop a better understanding regarding the epidemiology and pathobiology of these viruses in Asia.

Impact of human leukocyte antigen and calculated panel reactive antibody on BK viremia in kidney transplant recipients: A single-center experience and literature review

BACKGROUND

The aim of this retrospective analysis was to investigate the effect of human leukocyte antigen (HLA) and calculated panel reactive antibody (cPRA) on BK virus activation as evidenced by BK viremia (BKV).

PATIENTS AND METHODS

At our institution, 649 kidney transplant patients were screened for BKV from 2009 to 2017. Patients were considered to have BKV if they had >10 000 copies/mL of BK DNA in their blood. Donor and recipient HLA and cPRA, demographic, clinical and laboratory data, as well as immunosuppressive medications were collected.

RESULTS

We identified 122 BK positive and 527 BK negative patients. Only 25% of the patients had cPRA of 20% or more, and 64% had more than three HLA-A, -B, and -DR mismatches. In both univariate and multivariate analyses, male gender, age, and maintenance of steroid therapy significantly increased the risk of BKV (P = 0.005, 0.005 and <0.001, respectively). The degree of cPRA and the individual HLA allele and HLA allele matching did not significantly affect BKV.

CONCLUSION

Neither the degree of HLA mismatching nor cPRA appears to affect BKV. Moreover, no specific HLA allele, HLA allele matching, or cPRA were associated with BKV.

Source and Relevance of the BK Polyomavirus Genotype for Infection After Kidney Transplantation

Background

BK polyomavirus (BKPyV)–associated nephropathy (BKPyVAN) is a major threat for kidney transplant recipients (KTRs). The role of specific BKPyV genotypes/serotypes in development of BKPyVAN is poorly understood. Pretransplantation serotyping of kidney donors and recipients and posttransplantation genotyping of viremic recipients, could reveal the clinical relevance of specific BKPyV variants.

Methods

A retrospective cohort of 386 living kidney donor-recipient pairs was serotyped before transplantation against BKPyV genotype I–IV viral capsid protein 1 antigen, using a novel BKPyV serotyping assay. Replicating BKPyV isolates in viremic KTRs after transplantation were genotyped using real-time polymerase chain reaction and confirmed by means of sequencing. BKPyV serotype and genotype data were used to determine the source of infection and analyze the risk of viremia and BKPyVAN.

Results

Donor and recipient BKPyV genotype and serotype distribution was dominated by genotype I (>80%), especially Ib, over II, III and IV. Donor serotype was significantly correlated with the replicating genotype in viremic KTRs (P < .001). Individual donor and recipient serotype, serotype (mis)matching and the recipient replicating BKPyV genotype were not associated with development of viremia or BKPyVAN after transplantation.

Conclusions

BKPyV donor and recipient serotyping and genotyping indicates the donor origin of replicating BKPyV in viremic KTRs but provides no evidence for BKPyV genotype–specific virulence.

Impact of HPyV9 and TSPyV coinfection on the development of BK polyomavirus viremia and associated nephropathy after kidney transplantation

Background

BK polyomavirus (BKPyV) persistently infects the urinary tract and causes viremia and nephropathy in kidney transplantation (KTx), recipients. In a previous study, we observed an increased incidence and load of BKPyV viremia in KTx patients coinfected with human polyomavirus 9 (HPyV9). Here we sought confirmation of this observation and explored whether novel HPyVs that have been detected in urine (HPyV9 and trichodysplasia spinulosa polyomavirus [TSPyV]) potentially aggravate BKPyV infection.

Methods

A well‐characterized cohort of 209 KTx donor‐recipient pairs was serologically and molecularly analyzed for HPyV9 and TSPyV coinfection. These data were correlated with the occurrence of BKPyV viremia and BKPyVAN in the recipients within a year after KTx.

Results

Seropositivity for HPyV9 (19%) and TSPyV (89%) was comparable between donors and recipients and did not correlate with BKPyV viremia and BKPyVAN that developed in 25% and 3% of the recipients, respectively. Two recipients developed TSPyV viremia and none HPyV9 viremia. Modification of the predictive effect of donor BKPyV seroreactivity on recipient BKPyV viremia by HPyV9 and TSPyV was not observed.

Conclusions

Our data provide no evidence for a promoting effect of HPyV9 and TSPyV on BKPyV infection and BKPyVAN in renal allograft patients. Therefore, we do not recommend including HPyV9 and TSPyV screening in KTx patients.

Development and evaluation of a BK polyomavirus serotyping assay using Luminex technology

BACKGROUND

The BK polyomavirus (BKPyV) is subdivided into four genotypes. The consequences of each genotype and of donor-recipient genotype (mis)match for BKPyV-associated nephropathy (BKPyVAN) in kidney transplant recipients (KTRs) are unknown.

OBJECTIVES

To develop and evaluate a genotype-specific IgG antibody-based BKPyV serotyping assay, in order to classify kidney transplant donors and recipients accordingly.

STUDY DESIGN

VP1 antigens of six BKPyV variants (Ib1, Ib2, Ic, II, III and IV) were expressed as recombinant glutathione-s-transferase-fusion proteins and coupled to fluorescent Luminex beads. Sera from 87 healthy blood donors and 39 KTRs were used to analyze seroreactivity and serospecificity against the different BKPyV genotypes. Six sera with marked BKPyV serotype profiles were analyzed further for genotype-specific BKPyV pseudovirus neutralizing capacity.

RESULTS

Seroreactivity was observed against all genotypes, with seropositivity rates above 77% comparable for KTRs and blood donors. Strong cross-reactivity (r > 0.8) was observed among genotype I subtypes, and among genotypes II, III and IV. Seroresponses against genotypes I and IV seemed genuine, while those against II and III could be out(cross)competed. GMT (Luminex) and IC₅₀ (neutralization assay) values showed good agreement in determining the genotype with the strongest seroresponse within an individual.

CONCLUSIONS

Despite some degree of cross-reactivity, this serotyping assay seems a useful tool to identify the main infecting BKPyV genotype within a given individual. This information, which cannot be obtained otherwise from nonviremic/nonviruric individuals, could provide valuable information regarding the prevalent BKPyV genotype in kidney donors and recipients and warrants further study.

BK polyomavirus: a review of the virology, pathogenesis, clinical and laboratory features, and treatment

BK polyomavirus (BKPyV) is a non-enveloped, circular dsDNA virus with a genome of approximately 5100 base pairs. It can be divided into four major genotypes, but the effects of different genotypes on clinical disease are uncertain. Primary BKPyV infection is generally acquired asymptomatically in childhood. It establishes low-level persistence in many tissues, particularly the genitourinary tract. Reactivation can lead to severe disease including BKPyV-associated nephropathy confirmed by renal biopsy, hemorrhagic cystitis and meningoencephalitis. Nucleic acid amplification testing of blood and urine is the main diagnostic and prognostic test for BKPyV infection. The treatment of BKPyV infection has concentrated on reduction in immunosuppressive therapy. Recent studies suggest that antiviral drugs have demonstrated only modest benefit, but adoptive T-cell therapies offer potential advances.

Stability of BK polyomavirus IgG seroreactivity and its correlation with preceding viremia

BACKGROUND

Recently we showed that the level of BK polyomavirus (BKPyV) IgG seroreactivity in kidney donors predicted viremia and BKPyV-associated nephropathy in kidney transplant recipients (KTRs). This observation could be explained by assuming a direct association between BKPyV seroreactivity and the amount of persistent infectious virus in the renal allograft.

OBJECTIVES

Since the renal BKPyV reservoir is probably sowed by viremia during primary BKPyV infection, we systematically analysed the dynamics of BKPyV IgG seroreactivity in relation to preceding BKPyV viremia in KTRs and healthy individuals.

STUDY DESIGN

A cohort of 85 KTRs consisting of BKPyV viremic and nonviremic subjects was analysed for BKPyV IgG seroreactivity at five fixed time points until one year after transplantation. A cohort of 87 healthy blood donors (HBDs) was used as controls.

RESULTS

Baseline BKPyV seropositivity was high in both KTRs and HBDs, and the baseline mean BKPyV IgG level comparable. BKPyV IgG levels in nonviremic KTRs and HBDs remained stable during follow-up, while a considerable increase was observed in viremic KTRs (p=0.015). The increase of BKPyV seroreactivity in viremic KTRs was associated with the duration and peak level of BKPyV viremia.

CONCLUSIONS

BKPyV IgG seroreactivity was stable over time in immunocompetent subjects, which enables the use of this potential pretransplantation biomarker in kidney donors. The observed dose-dependent relationship of BKPyV IgG seroreactivity with preceding BKPyV replication is in agreement with the assumption that BKPyV seroreactivity reflects past BKPyV activity and correlates with the amount of latent BKPyV residing within a kidney allograft.

Pretransplantation Donor-Recipient Pair Seroreactivity Against BK Polyomavirus Predicts Viremia and Nephropathy After Kidney Transplantation

Kidney transplant donors are not currently implicated in predicting BK polyomavirus (BKPyV) infection in kidney transplant recipients. It has been postulated, however, that BKPyV infection originates from the kidney allograft. Because BKPyV seroreactivity correlates with BKPyV replication and thus might mirror the infectious load, we investigated whether BKPyV seroreactivity of the donor predicts viremia and BKPyV-associated nephropathy (BKPyVAN) in the recipient. In a retrospective cohort of 407 living kidney donor-recipient pairs, pretransplantation donor and recipient sera were tested for BKPyV IgG levels and correlated with the occurrence of recipient BKPyV viremia and BKPyVAN within 1 year after transplantation. Donor BKPyV IgG level was strongly associated with BKPyV viremia and BKPyVAN (p < 0.001), whereas recipient BKPyV seroreactivity showed a nonsignificant inverse trend. Pairing of high-BKPyV-seroreactive donors with low-seroreactive recipients resulted in a 10-fold increased risk of BKPyV viremia (hazard ratio 10.1, 95% CI 3.5-29.0, p < 0.001). In multivariate analysis, donor BKPyV seroreactivity was the strongest pretransplantation factor associated with viremia (p < 0.001) and BKPyVAN (p = 0.007). The proportional relationship between donor BKPyV seroreactivity and recipient infection suggests that donor BKPyV seroreactivity reflects the infectious load of the kidney allograft and calls for the use of pretransplantation BKPyV serological testing of (potential) donors and recipients.

Isolation of a novel polyomavirus, related to Japanese eel endothelial cell-infecting virus, from marbled eels, Anguilla marmorata (Quoy & Gaimard)

Marbled eels, Anguilla marmorata (Quoy & Gaimard), cultured in Taiwan exhibited haemorrhage and mortality in January 2012. The severely diseased eels bled from the gills and showed congestion of the central venous sinus of the gill filaments and haemorrhage throughout the body similar to viral endothelial cell necrosis of eel. In this study, a novel polyomavirus (AmPyV) was isolated from the diseased eels using the AMPF cell line established from the pectoral fin of healthy marbled eels. AmPyV was found to encode a long T-antigen orthologous gene. Phylogenetic analysis showed that AmPyV was closely related to Japanese eel endothelial cell-infecting virus. PCR assays revealed AmPyV infection throughout the systemic organs. AmPyV proliferated in the AMPF, EK-1 and EO-2 cells at temperatures 25-30 °C, and the progeny virus yields were 10(7.0) , 10(7.4) and 10(7.7) TCID50  mL(-1) , respectively. The purified virions were icosahedral particles, 70-80 nm in diameter. No clinical signs or mortality was observed among the eels injected with the virus; however, the virus was reisolated from the brain, eyes, kidneys, fins and gills of infected eels 2 month after injection. Our results suggest that AmPyV exhibits a latent infection. Pathogen of the disease needs to study further.

Gene Therapy for Human Lung Adenocarcinoma Using a Suicide Gene Driven by a Lung-Specific Promoter Delivered by JC Virus-Like Particles

Lung adenocarcinoma, the most commonly diagnosed type of lung cancer, has a poor prognosis even with combined surgery, chemotherapy, or molecular targeted therapies. Most patients are diagnosed with an in-operable advanced or metastatic disease, both pointing to the necessity of developing effective therapies for lung adenocarcinoma. Surfactant protein B (SP-B) has been found to be overexpressed in lung adenocarcinoma. In addition, it has also been demonstrated that human lung adenocarcinoma cells are susceptible to the JC polyomavirus (JCPyV) infection. Therefore, we designed that the JCPyV virus-like particle (VLP) packaged with an SP-B promoter-driven thymidine kinase suicide gene (pSPB-tk) for possible gene therapy of human lung adenocarcinoma. Plasmids expressing the GFP (pSPB-gfp) or thymidine kinase gene (pSPB-tk) under the control of the human SP-B promoter were constructed. The promoter's tissue specificity was tested by transfection of pSPB-gfp into A549, CH27, and H460 human lung carcinoma cells and non-lung cells. The JCPyV VLP's gene transfer efficiency and the selective cytotoxicity of pSPB-tk combined with ganciclovir (GCV) were tested in vitro and in a xenograft mouse model. In the current study, we found that SP-B promoter-driven GFP was specifically expressed in human lung adenocarcinoma (A549) and large cell carcinoma (H460) cells. JCPyV VLPs were able to deliver a GFP reporter gene into A549 cells for expression. Selective cytotoxicity was observed in A549 but not non-lung cells that were transfected with pSPB-tk or infected with pSPB-tk-carrying JCPyV VLPs. In mice injected with pSPB-tk-carrying JCPyV VLPs through the tail vein and treated with ganciclovir (GCV), a potent 80% inhibition of growth of human lung adenocarcinoma nodules resulted. The JCPyV VLPs combined with the use of SP-B promoter demonstrates effectiveness as a potential gene therapy against human lung adenocarcinoma.

Detection of Malawi polyomavirus sequences in secondary lymphoid tissues from Italian healthy children: a transient site of infection

Background

The novel Malawi polyomavirus (MWPyV) was initially detected in stool specimens from healthy children and children with gastrointestinal symptoms, mostly diarrhea, indicating that MWPyV might play a role in human gastroenteric diseases. Recently, MWPyV sequences were additionally identified in respiratory secretions from both healthy and acutely ill children suggesting that MWPyV may have a tropism for different human tissues. This study was designed to investigate the possible sites of latency/persistence for MWPyV in a cohort of healthy Italian children.

Methods

Specimens (n° 500) of tonsils, adenoids, blood, urines and feces, from 200 healthy and immunocompetent children (age range: 1–15 years) were tested for the amplification of the MWPyV LT antigen sequence by quantitative real-time PCR. Samples (n° 80) of blood and urines from 40 age-matched children with autoimmune diseases, were screened for comparison. Polyomaviruses JC/BK and Epstein-Barr Virus (EBV) were also tested as markers of infection in all samples using the same molecular technique.

Results

In our series of healthy children, MWPyV was detected only in the lymphoid tissues showing a prevalence of 6 % in tonsils and 1 % in adenoids, although with a low viral load. No JCPyV or BKPyV co-infection was found in MWPyV positive samples, while EBV showed a similar percentage of both in tonsils and adenoids (38 and 37 %).

Conversely, no MWPyV DNA was detected in stool from babies with gastroenteric syndrome. With regards to autoimmune children, neither MWPyV nor BKPyV were detected in blood, while JCPyV viremia was observed in 15 % (6/40) of children treated with Infliximab. Urinary BKPyV shedding was observed in 12.5 % (5/40) while JCPyV in 100 % of the samples.

Conclusions

The detection of MWPyV sequences in tonsils and adenoids of healthy children suggests that secondary lymphoid tissues can harbour MWPyV probably as transient sites of persistence rather than actual sites of latency.

The first case of acute unilateral pan-ureteritis caused by BK polyomavirus in an allogeneic stem cell transplant patient

Several cases of ureteral obstruction have been reported in stem cell transplant (SCT) patients; however, they were bilateral and concomitant with or preceded by hemorrhagic cystitis. We describe, to our knowledge, a first case of acute unilateral pan-ureteritis caused by BK polyomavirus (BKPyV) in an SCT patient. This case may represent an early phase of BKPyV reactivation. BKPyV infection should be considered as a potential cause of acute unilateral ureteritis even among SCT recipients.

BK Polyomavirus Tubulointerstitial Nephritis With Urothelial Hyperplasia in a Kidney Transplant

Polyomavirus nephropathy is characterized histopathologically by evidence of viral replication and acute tubular injury with interstitial inflammation, tubulitis, and intranuclear inclusions. Polyomavirus nephropathy typically develops in the kidney transplant as a combination of the unique nature of the transplanted tissue and the immunomodulated status of the patient. We present a case in which a patient had lingering BK viremia and declining kidney function following receipt of lung and kidney transplants. A kidney biopsy was performed, which demonstrated BK polyomavirus tubulointerstitial nephritis, resultant cytopathic changes and tubular/ductal injury, associated urothelial hyperplasia with foci of squamous metaplasia, suspected membranous glomerulopathy, and moderate arterial/arteriolar sclerosis. There was also evidence of more proximal nephron viral involvement, with glomerular parietal epithelium infection and injury present. This case shows impressive BK polyomavirus-associated urothelial hyperplasia in the kidney, which to our knowledge has not been previously illustrated in the literature. There have been numerous studies attempting to show the association of polyomaviruses with the development of carcinoma, and this case report is significant because it is an example of viral-induced changes that are concerning and hold potential for malignant transformation.

BK polyoma virus infection and renal disease in non-renal solid organ transplantation

BK virus (BKV) is a non-enveloped DNA virus of the polyomaviridae family that causes an interstitial nephritis in immunosuppressed patients. BKV nephropathy is now a leading cause of chronic kidney disease and early allograft failure following kidney transplantation. It is also known to cause renal disease with a progressive decline in kidney function in non-renal solid organ transplant (NRSOT) recipients, although the disease may not be recognized nor its impact appreciated in this patient population. In this report, we review the existing literature to highlight our current understanding of its incidence in NRSOT populations, the approaches to diagnosis and the potential treatment options.

Asymptomatic hematuria associated with urinary polyomavirus infection in immunocompetent patients

Unlike the case for immunodeficient patients, little is known about polyomavirus (PV) infection in immunocompetent patients. PV infection in immunocompetent individuals has been reported sporadically, but little is known about asymptomatic hematuria. To determine the clinical significance and prevalence of urinary PV infection in immunocompetent patients, a total of 95 individuals admitted to Seoul St. Mary's hospital were investigated. Sixty-four patients were enrolled for evaluation of asymptomatic hematuria, and 31 healthy individuals served as controls. Clinical screening for PV infection was performed by urine cytology analysis by liquid-based preparation and urine RT-PCR for BK virus (BKV) and JC virus (JCV), respectively. The average age of the patients in the PV(+) - and PV(-) -groups with asymptomatic hematuria were 60 years and 46 years, respectively. Urine cytology analysis revealed decoy cells in 37/64 hematuria patients (38.9%), but not in healthy controls. They were more prevalent in male patients. Eighty-two patients (86.3%) had PV viruria, viz., 54/64 patients in the hematuria group and 28/31 in the control group. Interestingly, 28/31 (90.3%) cases in the healthy control group were positive for PV viruria, which exceeded the number in the hematuria group (84.4%). PV viruria was associated primarily with JCV, rather than BKV. PV viruria, including JCV viruria, correlated with urine decoy cells and increased age. In conclusion, urinary PV infection is common in immunocompetent patients with asymptomatic hematuria and is age-related. These data may provide an insight into the pathogenesis and future treatment of asymptomatic hematuria associated with urinary PV infection in immunocompetent patients.

Obstructive uropathy is associated with polyomavirus viremia in pediatric kidney transplantation

BKVN leads to allograft dysfunction following kidney transplantation and is preceded by BK viremia. Studies in pediatric kidney transplant recipients reveal an incidence of viruria ranging from 18% to 33%, viremia 6-16%, and BKVN 2-8%. Specific risk factors have not been clearly elucidated. Retrospective chart review of pediatric kidney transplants performed from January 2005 through December 2009; to identify risk factors associated with BK viremia in pediatric kidney transplant recipients from a single center. Of the 93 patients who received kidney transplants in the study period, 22 (24%) developed BK viruria, including 12 (13%) who developed viremia. One patient with viremia (1.6%) had BKVN. Obstructive uropathy was identified as the cause of ESKD in 22 (24%) of all recipients. 27% (n = 6) of these 22 patients developed viremia, while only 8.5% (6/71) with ESKD from another cause had viremia (p = 0.001). No other examined variable differed between the two groups. Although the overall incidence was no higher than other reported series, we identified that BK disease was more frequent in children with OU. A higher index of suspicion for invasive BK disease is necessary in patients with OU who receive kidney allografts. Transplant protocols may need to consider underlying cause of ESKD when designing screening protocols for BK disease in children after kidney transplantation.

Entry tropism of BK and Merkel cell polyomaviruses in cell culture

Merkel Cell Polyomavirus (MCV or MCPyV) was recently discovered in an aggressive form of skin cancer known as Merkel cell carcinoma (MCC). Integration of MCV DNA into the host genome likely contributes to the development of MCC in humans. MCV infection is common and many healthy people shed MCV virions from the surface of their skin. MCV DNA has also been detected in samples from a variety of other tissues. Although MCC tumors serve as a record that MCV can infect the Merkel cell lineage, the true tissue tropism and natural reservoirs of MCV infection in the host are not known. In an effort to gain insight into the tissue tropism of MCV, and to possibly identify cellular factors responsible for mediating infectious entry of the virus, the infection potential of human cells derived from a variety of tissues was evaluated. MCV gene transfer vectors (pseudoviruses) carrying reporter plasmid DNA encoding GFP or luciferase genes were used to transduce keratinocytes and melanocytes, as well as lines derived from MCC tumors and the NCI-60 panel of human tumor cell lines. MCV transduction was compared to transduction with pseudoviruses based on the better-studied human BK polyomavirus (BKV). The efficiency of MCV and BKV transduction of various cell types occasionally overlapped, but often differed greatly, and no clear tissue type preference emerged. Application of native MCV virions to a subset of highly transducible cell types suggested that the lines do not support robust replication of MCV, consistent with recent proposals that the MCV late phase may be governed by cellular differentiation in vivo. The availability of carefully curated gene expression data for the NCI-60 panel should make the MCV and BKV transduction data for these lines a useful reference for future studies aimed at elucidation of the infectious entry pathways of these viruses.

A peptide talk between JC virus and the human host: from silent infection to autoimmunity

Analysis of JC virus (JCV) polyprotein for peptide sharing with the human proteome reveals that the virus has hundreds of pentapeptide sequences in common with the human proteins. The datum is interesting in light of the fundamental role exerted by short amino acid sequences in protein-protein interactions and, consequently, in biochemical reactions and immune recognition. Searching for new approaches to understand the JCV infection scenarios, from the immunoevasion phenomenon underlying the viral asymptomatic stay in the human host to the (re)activation phase and associated pathogenic sequelae, the present study describes the diffuse pentapeptide communication network between JCV and the human host.

Detection of BK virus in urine from renal transplant subjects by mass spectrometry

Background

The diagnosis and management of BK virus (BKV) reactivation following renal transplantation continues to be a significant clinical problem. Following reactivation of latent virus, impaired cellular immunity enables sustained viral replication to occur in urothelial cells, which potentially leads to the development of BKV-associated nephropathy (BKVAN). Current guidelines recommend regular surveillance for BKV reactivation through the detection of infected urothelial cells in urine (decoy cells) or viral nucleic acid in urine or blood. However, these methods have variable sensitivity and cannot routinely distinguish between different viral subtypes. We therefore asked whether mass spectrometry might be able to overcome these limitations and provide an additional non-invasive technique for the surveillance of BKV and identification of recipients at increased risk of BKVAN.

Results

Here we describe a mass spectrometry (MS)-based method for the detection of BKV derived proteins directly isolated from clinical urine samples. Peptides detected by MS derived from Viral Protein 1 (VP1) allowed differentiation between subtypes I and IV. Using this approach, we observed an association between higher decoy cell numbers and the presence of the VP1 subtype Ib-2 in urine samples derived from a cohort of 20 renal transplant recipients, consistent with the hypothesis that certain viral subtypes may be associated with more severe BKVAN.

Conclusions

This is the first study to identify BK virus proteins in clinical samples by MS and that this approach makes it possible to distinguish between different viral subtypes. Further studies are required to establish whether this information could lead to stratification of patients at risk of BKVAN, facilitate distinction between BKVAN and acute rejection (AR), and ultimately improve patient treatment and outcomes.

Neutralization serotyping of BK polyomavirus infection in kidney transplant recipients

BK polyomavirus (BKV or BKPyV) associated nephropathy affects up to 10% of kidney transplant recipients (KTRs). BKV isolates are categorized into four genotypes. It is currently unclear whether the four genotypes are also serotypes. To address this issue, we developed high-throughput serological assays based on antibody-mediated neutralization of BKV genotype I and IV reporter vectors (pseudoviruses). Neutralization-based testing of sera from mice immunized with BKV-I or BKV-IV virus-like particles (VLPs) or sera from naturally infected human subjects revealed that BKV-I specific serum antibodies are poorly neutralizing against BKV-IV and vice versa. The fact that BKV-I and BKV-IV are distinct serotypes was less evident in traditional VLP-based ELISAs. BKV-I and BKV-IV neutralization assays were used to examine BKV type-specific neutralizing antibody responses in KTRs at various time points after transplantation. At study entry, sera from 5% and 49% of KTRs showed no detectable neutralizing activity for BKV-I or BKV-IV neutralization, respectively. By one year after transplantation, all KTRs were neutralization seropositive for BKV-I, and 43% of the initially BKV-IV seronegative subjects showed evidence of acute seroconversion for BKV-IV neutralization. The results suggest a model in which BKV-IV-specific seroconversion reflects a de novo BKV-IV infection in KTRs who initially lack protective antibody responses capable of neutralizing genotype IV BKVs. If this model is correct, it suggests that pre-vaccinating prospective KTRs with a multivalent VLP-based vaccine against all BKV serotypes, or administration of BKV-neutralizing antibodies, might offer protection against graft loss or dysfunction due to BKV associated nephropathy.

JC virus existence in Chinese gastrointestinal carcinomas

The John Cunningham virus (JCV) infects a large proportion of the population worldwide and may cause progressive multifocal leukoencephalopathy upon immunodeficiency. Recent reports provided evidence of its oncogenetic role in malignancies. In this study, JCV was examined by targeting T antigen, viral protein and agnoprotein in paraffin-embedded or frozen gastrointestinal carcinomas and paired non-neoplastic mucosa (NNM) samples by nested-PCR followed by Southern blot analysis. In addition, the expression of JCV T antigen, ki-67, caspase-3, p53, Rb and β-catenin was studied by immunohistochemistry on tissue microarrays. The positive rate of JCV T antigen was higher in paraffin-embedded gastrointestinal carcinomas compared to adjacent NNM by nested-PCR followed by Southern blot analysis (36.9 vs. 16.9%, P<0.05), while there was no difference in other viral oncogenes regardless of whether they were paraffin-embedded or frozen samples. Immunohistochemically, T antigen was detectable in 9.6% (13/135) of carcinoma cases, which was higher than its positive rate in NNM (0.8%, 1/126, P<0.01). However, the genomic JCV DNA existence or its T antigen expression was not correlated with age, gender, tumor size, histological types, lymph node metastasis, expression of ki-67, caspase-3, p53, Rb and β-catenin of gastric carcinomas (P>0.05). In conlusion, JCV T antigen may be involved in gastrointestinal carcinogenesis as an oncogene in China.

Positive correlation between Merkel cell polyomavirus viral load and capsid-specific antibody titer

Merkel cell polyomavirus (MCPyV or MCV) is the first polyomavirus to be clearly implicated as a causal agent underlying a human cancer, Merkel cell carcinoma (MCC). Infection with MCPyV is common in the general population, and a majority of adults shed MCPyV from the surface of their skin. In this study, we quantitated MCPyV DNA in skin swab specimens from healthy volunteers sampled at different anatomical sites over time periods ranging from 3 months to 4 years. The volunteers were also tested using a serological assay that detects antibodies specific for the MCPyV virion. There was a positive correlation between MCPyV virion-specific antibody titers and viral load at all anatomical sites tested (dorsal portion of the hands, forehead, and buttocks) (Spearman’s r 0.644, P < 0.0001). The study results are consistent with previous findings suggesting that the skin is primary site of chronic MCPyV infection in healthy adults and suggest that the magnitude of an individual’s seroresponsiveness against the MCPyV virion generally reflects the overall MCPyV DNA load across wide areas of the skin. In light of previous reports indicating a correlation between MCC and strong MCPyV-specific seroresponsiveness, this model suggests that poorly controlled chronic MCPyV infection might be a risk factor in the development of MCC.

BK virus sequences in specimens from aborted fetuses

Given the conflicting results of the few published studies, the aim of this retrospective molecular-based study of 10 aborted fetuses that underwent complete autopsy and 10 placentas was carried out to determine whether BK polyomavirus (BKV) can be transmitted transplacentally. The interruption of pregnancy was due to a miscarriage (five cases) or a prenatal diagnosis of severe intrauterine malformations (five cases). Samples from the brain, heart, lung, thymus, liver, and kidney were taken from each fetus, and two samples were obtained from all of the placentas. The presence of BKV was investigated by means of PCR using primers specific for the transcription control region (TCR) and viral capsidic protein 1 (VP1) and DNA extracted from formalin-fixed, paraffin-embedded tissue. BKV genome was detected in 22 of 60 samples (36.6%) from seven fetuses (70%), regardless of the cause of abortion: VP1 was amplified in 12 samples (54%), TCR in seven (32%), and both in three (14%). VP1 was also detected in one placental sample. BKV sequences were most frequently detected in heart and lung (five cases), but sequence analyses of TCR and VP1 revealed a high degree of genomic variability among the samples taken from different organs and the placenta. These results indicate that BKV can cross the placenta during pregnancy and become latent in fetal organs other than the kidney and brain (previously considered the main targets of BKV latency). This may happen in early pregnancy and does not seem to be associated with an increased risk of abortion.

John Cunningham virus T-antigen expression in anal carcinoma

BACKGROUND

Anal carcinoma is thought to be driven by human papillomavirus (HPV) infection through interrupting function of cell regulatory proteins such as p53 and pRb. John Cunningham virus (JCV) expresses a T-antigen that causes malignant transformation through development of aneuploidy and interaction with some of the same regulatory proteins as HPV. JCV T-antigen is present in brain, gastric, and colon malignancies, but has not been evaluated in anal cancers. The authors examined a cohort of anal cancers for JCV T-antigen and correlated this with clinicopathologic data.

METHODS

Archived anal carcinomas were analyzed for JCV T-antigen expression. DNA from tumor and normal tissue was sequenced for JCV with viral copies determined by quantitative polymerase chain reaction and Southern blotting. HPV and microsatellite instability (MSI) status was correlated with JCV T-antigen expression.

RESULTS

Of 21 cases of anal cancer (mean age 49 years, 38% female), 12 (57%) were in human immunodeficiency virus (HIV)-positive individuals. All 21 cancers expressed JCV T-antigen, including 9 HPV-negative specimens. More JCV copies were present in cancer versus surrounding normal tissue (mean 32.54 copies/μg DNA vs 2.98 copies/μg DNA, P = .0267). There was no correlation between disease stage and viral copies, nor between viral copies and HIV-positive or -negative status (28.7 vs 36.34 copies/μg DNA, respectively, P = .7804). In subset analysis, no association was found between JCV T-antigen expression and HPV or MSI status.

CONCLUSIONS

Anal carcinomas uniformly express JCV T-antigen and contain more viral copies compared with surrounding normal tissue. JCV and its T-antigen oncogenic protein, presumably through interruption of cell regulatory proteins, may play a role in anal cancer pathogenesis.

Newly discovered KI, WU, and Merkel cell polyomaviruses: no evidence of mother-to-fetus transmission

Background

Three* human polyomaviruses have been discovered recently, KIPyV, WUPyV and MCPyV. These viruses appear to circulate ubiquitously; however, their clinical significance beyond Merkel cell carcinoma is almost completely unknown. In particular, nothing is known about their preponderance in vertical transmission. The aim of this study was to investigate the frequency of fetal infections by these viruses. We sought the three by PCR, and MCPyV also by real-time quantitative PCR (qPCR), from 535 fetal autopsy samples (heart, liver, placenta) from intrauterine fetal deaths (IUFDs) (N = 169), miscarriages (120) or induced abortions (246). We also measured the MCPyV IgG antibodies in the corresponding maternal sera (N = 462) mostly from the first trimester.

Results

No sample showed KIPyV or WUPyV DNA. Interestingly, one placenta was reproducibly PCR positive for MCPyV. Among the 462 corresponding pregnant women, 212 (45.9%) were MCPyV IgG seropositive.

Conclusions

Our data suggest that none of the three emerging polyomaviruses often cause miscarriages or IUFDs, nor are they transmitted to fetuses. Yet, more than half the expectant mothers were susceptible to infection by the MCPyV.

Merkel cell polyomavirus and two previously unknown polyomaviruses are chronically shed from human skin

Mounting evidence indicates that Merkel cell polyomavirus (MCV), a circular double-stranded DNA virus, is a causal factor underlying a highly lethal form of skin cancer known as Merkel cell carcinoma. To explore the possibility that MCV and other polyomaviruses commonly inhabit healthy human skin, we developed an improved rolling circle amplification (RCA) technique to isolate circular DNA viral genomes from human skin swabs. Complete MCV genomes were recovered from 40% of healthy adult volunteers tested, providing full-length, apparently wild-type cloned MCV genomes. RCA analysis also identified two previously unknown polyomavirus species that we name human polyomavirus-6 (HPyV6) and HPyV7. Biochemical experiments show that polyomavirus DNA is shed from the skin in the form of assembled virions. A pilot serological study indicates that infection or coinfection with these three skin-tropic polyomaviruses is very common. Thus, at least three polyomavirus species are constituents of the human skin microbiome.

Investigation of pre-diagnostic virological markers for progressive multifocal leukoencephalopathy in human immunodeficiency virus-infected patients

Progressive multifocal leukoencephalopathy (PML) is a severe neurological disorder due to JC virus (JCV) infection. Pre-diagnostic biological markers and risk factors for PML are not well understood. We conducted a case-control study nested within the Multicenter AIDS Cohort Study to examine the association between JCV viruria and viremia and serum antibody to JCV capsids, in relation to subsequent PML diagnoses, 5 months to 12 years later. Other demographic and immunologic factors were also examined. The study population included 28 incident cases of PML, 26 matched HIV-positive controls, and 50 HIV-negative controls. Prevalence of JCV viruria was 37% in cases, 42% in HIV-positive controls, and 28% in HIV-negative controls (P = 0.43). Among persons with JCV viruria, persistent viruria was more common in cases (89%) than in HIV-positive controls (33%) (P = 0.02). Presence of JCV viruria was not related to the time to PML diagnosis (OR: 1.03, 95% CI: 0.8-1.4); however, the urinary concentration of JCV DNA increased with proximity to the date of PML diagnosis in cases. JCV seropositivity did not differ between cases or controls (P = 0.42). Four cases tested JCV seronegative, including one case only 5 months prior to diagnosis with PML. JCV DNA was detected in the serum of one HIV-positive control. Smoking was the only demographic variable analyzed associated with an increased risk for PML (MOR: 9.0, 95% CI: 1.2-394.5). The results suggest that persistent JCV viruria and increasing urinary concentration of JCV DNA may be predictive of PML for some patients.

Viruses and kidney disease: beyond HIV

SUMMARY

Human immunodeficiency virus (HIV)-infected patients may acquire new viral co-infections; they also may experience the reactivation or worsening of existing viral infections, including active, smoldering, or latent infections. HIV-infected patients may be predisposed to these viral infections owing to immunodeficiency or risk factors common to HIV and other viruses. A number of these affect the kidney, either by direct infection or by deposition of immune complexes. In this review we discuss the renal manifestations and treatment of hepatitis C virus, BK virus, adenovirus, cytomegalovirus, and parvovirus B19 in patients with HIV disease. We also discuss an approach to the identification of new viral renal pathogens, using a viral gene chip to identify viral DNA or RNA.

Epidemiology of BK virus in renal allograft recipients: independent risk factors for BK virus replication

BACKGROUND

Identification of risk factors for BK virus (BKV) replication may improve transplant outcome. We investigated the impact of immunosuppressive drugs on the prevalence of BKV replication in recipients of human renal allografts.

METHODS

One hundred twenty renal allograft recipients were studied prospectively at 1, 3, and 6 months posttransplantation to identify risk factors for BKV replication. BKV replication was quantified by measurement of urinary cell BKV VP1 mRNA levels using BKV specific primers and TaqMan probe in a real-time quantitative polymerase chain reaction assay. Levels of urinary cell mRNA for granzyme B, CD103, and transforming growth factor-beta1 were measured to ascertain whether BKV replication is associated with an inflammatory signature.

RESULTS

The prevalence of BKV replication increased over time and was highest at 6 months compared with 1 or 3 months posttransplantation (P<0.001). A logistic regression model analysis demonstrated that steroid maintenance therapy (odds ratio: 8.3, P=0.003) and induction with rabbit anti-human thymocyte globulin (odds ratio: 5.8, P=0.008) were independent risk factors for BKV replication. Neither mycophenolate mofetil dose nor tacrolimus dose or trough levels were different between those with or without BKV replication. The development of acute rejection or antirejection treatment with methylprednisolone did not increase the risk of BKV replication. BKV replication was associated with heightened levels of urinary cell mRNA for granzyme B (P<0.002), CD103 (P<0.005) but not for transforming growth factor-beta1 (P>0.05).

CONCLUSIONS

Steroid maintenance therapy and induction with antithymocyte globulin are independent risk factors for BKV replication in renal allograft recipients treated with tacrolimus and mycophenolate mofetil.

Internally controlled triplex quantitative PCR assay for human polyomaviruses JC and BK

We have developed a triplex TaqMan-based quantitative PCR assay for the human polyomaviruses JC (JCPyV) and BK (BKPyV). The assay simultaneously detects and quantifies both JCPyV and BKPyV in human clinical samples, and it includes an internal amplification control consisting of murine polyomavirus (MuPyV) plasmid DNA. We developed the assay for the Roche LightCycler 480 platform with the reporter dyes VIC, 6-FAM, and Cy5 for MuPyV, BKPyV, and JCPyV, respectively. The assay had a high specificity for BKPyV and JCPyV when either viral genome was present alone or in mixed samples over a range of 10(1) to 10(7) copy numbers per reaction. The analytical sensitivity was 50 copies for BKPyV and 10 copies for JCPyV. The use of the MuPyV internal control ensured monitoring of the quality of the extraction and of PCR inhibition, even in samples such as cerebrospinal fluid and plasma in which controls based on host genes cannot be effectively used. In addition, we developed a similar assay using a different dye configuration (6-FAM, VIC, and NED) that could be used on an ABI 7500 Fast platform. This assay had sensitivities similar to those of the LightCycler 480 configuration for BKPyV and JCPyV when either viral genome was present alone, but the sensitivity of detection of BKPyV was greatly decreased when an excess of JCPyV (>100-fold) was present in the sample. This internally controlled combined assay offers greater convenience and cost-effectiveness compared to separate assays for each virus and can also detect unexpected PyV activations by testing for both viruses in all samples.

BK virus-associated nephropathy in a patient with AIDS

The BK virus is a ubiquitous member of the group of human polyoma viruses that commonly is reactivated in the setting of immunosuppression related to renal transplantation, which results in tubulointerstitial nephritis and allograft dysfunction. BK virus-associated nephropathy occurring in association with human immunodeficiency virus infection and acquired immunodeficiency syndrome (AIDS) was reported only rarely. We describe the case of a 43-year-old man with AIDS presenting with nonoliguric renal failure. The renal biopsy specimen showed tubulointerstitial nephritis and renal tubular cell changes consistent with BK viral inclusions. Results of in situ hybridization for BK viral DNA were positive and showed tubular cell intranuclear inclusions. To our knowledge, this represents the third case of AIDS-associated BK virus-associated nephropathy diagnosed by means of biopsy.

Complications post renal transplantation: literature focus on BK virus nephropathy and diagnostic tools actually available

Clinical diagnosis of kidney transplants related illnesses is not a simple task. Several studies were conducted to define diseases and complications after renal transplantation, but there are no comprehensive guidelines about diagnostic tools for their prevention and detection.

The Authors of this review looked for the medical literature and pertinent publications in particular to understand the role of Human Polyomavirus BK (BKV) in renal failure and to recognize analytical techniques for BK virus associated nephropathy (BKVAN) detection.

High JC virus load in tongue carcinomas may be a risk factor for tongue tumorigenesis

The John Cunningham virus (JCV) asymptomatically infects a large proportion (approximately 90%) of the population worldwide but may be activated in immunodeficient patients, resulting in progressive multifocal leukoencephalopathy. Recent reports demonstrated its oncogenic role in malignancies. In this paper, the presence of JCV-targeting T antigen was investigated in tongue carcinoma (TC, n = 39), dysplastic tongue epithelium (DTE, n = 15) and glossitis (n = 15) using real-time polymerase chain reaction (PCR) and in situ PCR and immunohistochemistry, and JCV copies were analyzed with the clinicopathological parameters of TCs. The results demonstrated that glossitis and DTEs had significantly lower copies of JCV (410.5 +/- 44.3 and 658.3 +/- 53.3 copies/mug DNA respectively) than TCs (981.5 +/- 14.0, p < 0.05). When they were divided into three groups with 0-200 copies/mug DNA (low), 201-1,000 (moderate) and more than 1001 (high), TCs showed 3 (7.6%) in the low group, 21 (53.8%) in the moderate group and 15 (38.4%) in the high group and glossitis showed 11 (73.3%) in the low group, 0 (0%) in the moderate group and 4 (26.6%) in the high group. The DTEs occupied an intermediate position between them (p < 0.001). In situ PCR demonstrated that the nuclei of TC and DTE cells are sporadically T-antigen positive but not in nasal turbinate epithelial cells. Immunohistochemistry for T-antigen protein revealed four positive cases only in TCs. The existence of JCV T-antigen DNA was not associated with the clinicopathological variables of TCs. In conclusion, the presence of JCV may be a risk factor of tongue carcinogenesis.

BK virus nephropathy and kidney transplantation

Nephropathy from BK virus (BKV) infection is an evolving challenge in kidney transplant recipients. It is the consequence of modern potent immunosuppression aimed at reducing acute rejection and improving allograft survival. Untreated BKV infections lead to kidney allograft dysfunction or loss. Decreased immunosuppression is the principle treatment but predisposes to acute and chronic rejection. Screening protocols for early detection and prevention of symptomatic BKV nephropathy have improved outcomes. Although no approved antiviral drug is available, leflunomide, cidofovir, quinolones, and intravenous Ig have been used. Retransplantation after BKV nephropathy has been successful.