Polyoma virus infection is a prominent risk factor for bladder carcinoma in immunocompetent individuals

High grade urothelial carcinoma in kidney transplant patients with a history of BK viremia - Just a coincidence?

INTRODUCTION

Kidney transplant recipients (KTR) have a three-to-four-fold increased risk of developing urothelial carcinoma (UC) compared to the general population. BK polyoma virus (BKV) infection is known to affect approximately 15% of KTR. In vitro models support a potential pathogenic role for BKV in the development of UC. We describe a series of UC in kidney transplant recipients.

METHODS

Electronic patient records were searched to identify KTR with UC who had undergone kidney only or simultaneous kidney and pancreas transplantation in a single UK center between 2009 and 2015. Where available, stored pathological samples were retrieved, re-examined and stained for SV40 as a marker of BKV using standard staining protocols for kidney biopsy samples.

RESULTS

Fourteen KTR had developed UC post-transplant. Of these, 10 KTR had a history of BKV infection post-transplant. Six of these 10 KTR developed a rare micropapillary tumor subtype of UC which is typically only found in <1% of UC cases. All six micropapillary tumor samples stained positive for SV40, including samples from metastases. Three tumor samples were available from the four KTR with no history of BKV infection and were not micropapillary subtype and were negative for SV40. Three micropapillary tumors from immunocompetent patients were examined as controls and were negative for SV40.

CONCLUSIONS

These findings would support a pathogenic role for BK virus in the development of rare micropapillary subtype urothelial tumors in the kidney transplant population.

APOBEC3-mediated mutagenesis in cancer: causes, clinical significance and therapeutic potential

Apolipoprotein B mRNA-editing enzyme, catalytic polypeptides (APOBECs) are cytosine deaminases involved in innate and adaptive immunity. However, some APOBEC family members can also deaminate host genomes to generate oncogenic mutations. The resulting mutations, primarily signatures 2 and 13, occur in many tumor types and are among the most common mutational signatures in cancer. This review summarizes the current evidence implicating APOBEC3s as major mutators and outlines the exogenous and endogenous triggers of APOBEC3 expression and mutational activity. The review also discusses how APOBEC3-mediated mutagenesis impacts tumor evolution through both mutagenic and non-mutagenic pathways, including by inducing driver mutations and modulating the tumor immune microenvironment. Moving from molecular biology to clinical outcomes, the review concludes by summarizing the divergent prognostic significance of APOBEC3s across cancer types and their therapeutic potential in the current and future clinical landscapes.

Quantification of APOBEC3 Mutation Rates Affecting the VP1 Gene of BK Polyomavirus In Vivo

Mutations in the BK polyomavirus (BKPyV) capsid accumulate in kidney transplant (KTx) recipients with persistent virus replication. They are associated with neutralization escape and appear to arise as a result of cytosine deamination by host cell APOBEC3A/B enzymes. To study the mutagenic processes occurring in patients, we amplified the typing region of the VP1 gene, sequenced the amplicons to a depth of 5000–10,000×, and identified rare mutations, which were fitted to COSMIC mutational signatures. Background mutations were identified in amplicons from plasmids carrying the BKPyV genome and compared to mutations observed in 148 samples from 23 KTx recipients in France and in Vietnam. Three mutational signatures were consistently observed in urine, serum, and kidney biopsy samples, two of which, SBS2 and SBS13, corresponded to APOBEC3A/B activity. In addition, a third signature with no known etiology, SBS89, was detected both in patient samples, and in cells infected in vitro with BKPyV. Quantitatively, APOBEC3A/B mutation rates in urine samples were strongly correlated with urine viral load, and also appeared to vary between individuals. These results confirm that APOBEC3A/B is a major, but not the only, source of BKPyV genome mutations in patients.

Induction of APOBEC3-mediated genomic damage in urothelium implicates BK polyomavirus (BKPyV) as a hit-and-run driver for bladder cancer

Limited understanding of bladder cancer aetiopathology hampers progress in reducing incidence. Mutational signatures show the anti-viral apolipoprotein B mRNA editing enzyme catalytic polypeptide (APOBEC) enzymes are responsible for the preponderance of mutations in bladder tumour genomes, but no causative viral agent has been identified. BK polyomavirus (BKPyV) is a common childhood infection that remains latent in the adult kidney, where reactivation leads to viruria. This study provides missing mechanistic evidence linking reactivated BKPyV-infection to bladder cancer risk. We used a mitotically-quiescent, functionally-differentiated model of normal human urothelium to examine BKPyV-infection. BKPyV-infection led to significantly elevated APOBEC3A and APOBEC3B protein, increased deaminase activity and greater numbers of apurinic/apyrimidinic sites in the host urothelial genome. BKPyV Large T antigen (LT-Ag) stimulated re-entry from G0 into the cell cycle through inhibition of retinoblastoma protein and activation of EZH2, E2F1 and FOXM1, with cells arresting in G2. The single-stranded DNA displacement loops formed in urothelial cells during BKPyV-infection interacted with LT-Ag to provide a substrate for APOBEC3-activity. Addition of interferon gamma (IFNγ) to infected urothelium suppressed expression of the viral genome. These results support reactivated BKPyV infections in adults as a risk factor for bladder cancer in immune-insufficient populations.

Research progress of BK virus and systemic lupus erythematosus

Background: Systemic lupus erythematosus (SLE) is an autoimmune disease in which patients are often infected by viruses due to deficient immunity or immunosuppressant use. BK virus (BKV)mainly affects the kidney and can also cause multiple organ involvement throughout the body, which is similar to SLE. BKV is mostly a latent infection in vivo. The incidence of virus reactivation is higher in SLE patients. Reactivation of BKV can induce the production of autoantibodies, thereby promoting the occurrence and development of SLE.Purpose: Aim of this article is to review the prevalence and pathegenesis of BKV infection in SLE patients.Method: The literature search was conducted using four different databases including PubMed, Cochrane Library, Scopus and Web of Science.Results: BK virus is higher infection and reactivation in SLE patients. The "hapten carrier" mechanism may lead to the production of autoantibodies. Some immunosuppressive drugs, like leflumide and hydroxychloroquine, may show a protective effect.Conclusions: BKV infection plays a role in the occurrence and development of SLE, and its significance deserves further exploration.

Tissue Pathogens and Cancers: A Review of Commonly Seen Manifestations in Histo- and Cytopathology

Tissue pathogens are commonly encountered in histopathology and cytology practice, where they can present as either benign mimickers of malignancy or true malignancies. The aim of this review is to provide a timely synthesis of our understanding of these tissue pathogens, with an emphasis on pertinent diagnostic conundrums associated with the benign mimickers of malignancy that can be seen with viral infections and those which manifest as granulomas. The oncogenic pathogens, including viruses, bacteria, and parasites, are then discussed with relationship to their associated malignancies. Although not exhaustive, the epidemiology, clinical manifestations, pathogenesis, and histological findings are included, along with a short review of emerging therapies.

BK Virus-Associated Urothelial Carcinoma in a Patient with Peripheral Blood Stem Cell Transplantation for Acute Lymphoblastic Leukemia: A Case Report

Bladder tamponade due to hemorrhagic cystitis caused by BK virus in immunocompetent patients is familiar to urologists. BK virus is an important cause of nephropathy and graft loss in kidney transplant recipients. Although urothelial carcinoma of the bladder in kidney transplant recipients with persistent BK viruria is known, BK virus-associated urothelial carcinoma (BKVUC) in peripheral blood stem cell transplantation recipients is not as well known. A 54-year-old man with acute lymphoblastic leukemia was treated in the Department of Hematology of our hospital. After recurrence 25 months later, he received chemotherapy for half a year and underwent peripheral blood stem cell transplantation. He achieved temporarily complete remission, but he developed hematuria with BK virus-positive result 1 month after peripheral blood stem cell transplantation. One month later, he developed bladder tamponade-diagnosed hemorrhagic cystitis due to BK virus in our Urological Department. We performed transurethral coagulation to manage hemorrhage and removed a bleeding lesion in the bladder wall. Pathological examination of the removed bladder wall revealed pT1 stage BKVUC. We found that bladder tamponade could have led to reactivation of BK virus in this immunocompetent patient. This could be the first report of BKVUC of the bladder found in a peripheral blood stem cell transplantation recipient with close urological follow-up for 24 months. Adequate removal of bleeding lesions from the bladder mucosa with appropriate timing during hemorrhagic cystitis due to BKVUC could be essential to achieve good outcomes.

Pathogenicity of BK virus on the urinary system

Introduction

The polyomaviruses are omnipresent in nature. The major sites of BK virus appearance are the kidney tubular epithelial cells and urinary bladder surface transitional cells.

Material and methods

A literature search according to PRISMA guidelines within the Medline database was conducted in July 2019 for articles presenting data about BK virus in urologic aspect without setting time limits, using the terms ‘BK virus’ in conjunction with transplantation, nephropathy, stenosis, cancer, bladder, prostate, kidney.

Results

The BK virus usually stays latent, however, its replication may become active in various clinical situations of impaired immunocompetence such as solid organ transplantation, bone marrow transplantation, AIDS, pregnancy, multiple sclerosis, administration of chemotherapy or biologic therapy. BK virus is associated with two main complications after transplantation: polyomavirus-associated nephropathy in kidney transplant patients and polyomavirus-associated hemorrhagic cystitis in allogeneic hematopoietic stem cell transplant patients.

Conclusions

The aim of this article was to present available data on urologic aspects of BK virus infection, its detection methods and available treatment.

BK polyomavirus and urothelial carcinoma: Experience at a tertiary care centre in India with review of literature

INTRODUCTION

BK polyomavirus is ubiquitous and remains dormant in the urothelial tract, reactivating and replicating in the immunocompromised state especially in the setting of post-renal transplantation where it is believed to be directly oncogenic based on recent reports. Its oncogenic role in the immunocompetent host is controversial. This study aimed to investigate the association of BK polyomavirus in Urothelial Carcinoma.

MATERIAL AND METHODS

Patients with suspected urothelial carcinoma (UC) admitted under Department of Urology over a period of one year were recruited and transuretheral bladder tumor (TURBT) resection was performed, along with sampling of cystoscopically normal-appearing urothelium away from the tumor. In addition, cystectomy specimens with UC were included, with sampling of grossly normal-appearing urothelium away from the tumor. Immunohistochemistry (IHC) for SV40 T-Antigen and chromogenic in situ hybridization (CISH) using BK polyomavirus specific probe was performed on the paired samples (tumor and normal).

RESULTS

Twenty-three TURBT and 14 cystectomy specimens were assessed. None of the cases showed evidence of BK polyomavirus infection in tumor or in surrounding mucosa by IHC. CISH performed in ten cases were also found to be negative. In comparison, one post-renal transplant urothelial carcinoma in our experience showed diffuse SV40 staining.

CONCLUSIONS

This study suggests that BK polyomavirus infection is not associated with urothelial malignancy in the immunocompetent setting unlike in the immunocompromised setting where it should always be investigated for.

Management of BK Polyomavirus Infection in Kidney and Kidney-Pancreas Transplant Recipients: A Review Article

BK virus (BKV) can cause graft dysfunction or failure in kidney transplant recipients and hemorrhagic cystitis in allogeneic hematopoietic stem cell transplant patients. BKV-associated nephropathy (BKVAN) emerged as a common complication in the late 1990s, probably due to the introduction of potent immunosuppressive agents. BKVAN occurred in up to 5% of kidney transplant recipients, with graft failure in up to 70%. Since universal implementation of effective screening and treatment strategies, BKV is no longer a common cause of graft failure; reported graft loss is only 0% to 5%. This article briefly describes BK virology, epidemiology, diagnosis, and management.

Urologic malignancies in kidney transplantation

With advances in immunosuppression, graft and patient outcomes after kidney transplantation have improved considerably. As a result, long-term complications of transplantation, such as urologic malignancies, have become increasingly important. Kidney transplant recipients, for example, have a 7-fold risk of renal cell carcinoma (RCC) and 3-fold risk of urothelial carcinoma (UC) compared with the general population. While extrapolation of data from the general population suggest that routine cancer screening in transplant recipients would allow for earlier diagnosis and management of these potentially lethal malignancies, currently there is no consensus for posttransplantation RCC or UC screening as supporting data are limited. Further understanding of risk factors, presentation, optimal management of, and screening for urologic malignancies in kidney transplant patients is warranted, and as such, this review will focus on the incidence, surveillance, and treatment of urologic malignancies in kidney transplant recipients.

Human Polyomaviruses: The Battle of Large and Small Tumor Antigens

About 40 years ago, the large and small tumor antigens (LT-Ag and sT-Ag) of the polyomavirus (PyVs) simian vacuolating virus 40 have been identified and characterized. To date, it is well known that all the discovered human PyVs (HPyVs) encode these 2 multifunctional and tumorigenic proteins, expressed at viral replication early stage. The 2 T-Ags are able to transform cells both in vitro and in vivo and seem to play a distinct role in the pathogenesis of some tumors in humans. In addition, they are involved in viral DNA replication, transcription, and virion assembly. This short review focuses on the structural and functional features of the HPyVs’ LT-Ag and sT-Ag, with special attention to their transforming properties.

BK Polyomavirus: Clinical Aspects, Immune Regulation, and Emerging Therapies

BK polyomavirus (BKV) causes frequent infections during childhood and establishes persistent infections within renal tubular cells and the uroepithelium, with minimal clinical implications. However, reactivation of BKV in immunocompromised individuals following renal or hematopoietic stem cell transplantation may cause serious complications, including BKV-associated nephropathy (BKVAN), ureteric stenosis, or hemorrhagic cystitis. Implementation of more potent immunosuppression and increased posttransplant surveillance has resulted in a higher incidence of BKVAN. Antiviral immunity plays a crucial role in controlling BKV replication, and our increasing knowledge about host-virus interactions has led to the development of improved diagnostic tools and clinical management strategies. Currently, there are no effective antiviral agents for BKV infection, and the mainstay of managing reactivation is reduction of immunosuppression. Development of immune-based therapies to combat BKV may provide new and exciting opportunities for the successful treatment of BKV-associated complications.

Archetype and Rearranged Non-coding Control Regions in Urothelial Bladder Carcinoma of Immunocompetent Individuals

BACKGROUND

Polyomaviruses (PyVs) are potential transforming viruses. Despite their involvement in human tumours still being debated, there is evidence to suggest a role for PyVs in bladder carcinoma (BC). Therefore, a possible association between PyVs and BC was investigated.

MATERIALS AND METHODS

Urine, blood and fresh bladder tissue specimens were collected from 29 patients with BC. PyV prevalence, non-coding control region (NCCR) organization and genotypic analysis were assessed.

RESULTS

Data showed a significant prevalence of John Cunningham (JC) PyV in BC tissues and in urine with respect to BKPyV, while simian virus 40 was not revealed. A BKPyV rearranged NCCR sequence was isolated, whereas a JCPyV archetypal structure was consistently retained. A prevalence of European genotypes was observed.

CONCLUSION

Our data would suggest a JCPyV involvement in cancer progression and a BKPyV association with BC pathogenesis in immunocompetent patients. However, further work is necessary to better understand the exact role of PyVs in urothelial carcinogenesis.

BK nephropathy in the native kidneys of patients with organ transplants: Clinical spectrum of BK infection

Nephropathy secondary to BK virus, a member of the Papoviridae family of viruses, has been recognized for some time as an important cause of allograft dysfunction in renal transplant recipients. In recent times, BK nephropathy (BKN) of the native kidneys has being increasingly recognized as a cause of chronic kidney disease in patients with solid organ transplants, bone marrow transplants and in patients with other clinical entities associated with immunosuppression. In such patients renal dysfunction is often attributed to other factors including nephrotoxicity of medications used to prevent rejection of the transplanted organs. Renal biopsy is required for the diagnosis of BKN. Quantitation of the BK viral load in blood and urine are surrogate diagnostic methods. The treatment of BKN is based on reduction of the immunosuppressive medications. Several compounds have shown antiviral activity, but have not consistently shown to have beneficial effects in BKN. In addition to BKN, BK viral infection can cause severe urinary bladder cystitis, ureteritis and urinary tract obstruction as well as manifestations in other organ systems including the central nervous system, the respiratory system, the gastrointestinal system and the hematopoietic system. BK viral infection has also been implicated in tumorigenesis. The spectrum of clinical manifestations from BK infection and infection from other members of the Papoviridae family is widening. Prevention and treatment of BK infection and infections from other Papovaviruses are subjects of intense research.

BK Polyomavirus Infection and Renourinary Tumorigenesis

BK polyomavirus (BKPyV) infection represents a major problem in transplantation, particularly for renal recipients developing polyomavirus-associated nephropathy (PyVAN). The possibility that BKPyV may also be oncogenic is not routinely considered. Twenty high-grade renourinary tumors expressing polyomavirus large T antigen in the entirety of the neoplasm in 19 cases, including the metastases in six, have been reported in transplant recipients with a history of PyVAN or evidence of BKPyV infection. Morphological and phenotypical features consistent with inactivation of the tumor suppressors pRB and p53 were found in the bladder tumors, suggesting a carcinogenesis mechanism involving the BKPyV large tumor oncoprotein/antigen. The pathogenesis of these tumors is unclear, but given the generally long interval between transplantation and tumor development, the risk for neoplasms after BKPyV infections may well be multifactorial. Other elements potentially implicated include exposure to additional exogenous carcinogens, further viral mutations, and cell genomic instability secondary to viral integration, as occurs with the Merkel cell PyV-associated carcinoma. The still scarce but increasingly reported association between longstanding PyVAN and renourinary neoplasms requires a concerted effort from the transplant community to better understand, diagnose, and treat the putative association between the BKPyV and these neoplasms.

MicroRNAs Expressed during Viral Infection: Biomarker Potential and Therapeutic Considerations

MicroRNAs (miRNAs) are short sequences of noncoding single-stranded RNAs that exhibit inhibitory effects on complementary target mRNAs. Recently, it has been discovered that certain viruses express their own miRNAs, while other viruses activate the transcription of cellular miRNAs for their own benefit. This review summarizes the viral and/or cellular miRNAs that are transcribed during infection, with a focus on the biomarker and therapeutic potential of miRNAs (or their antagomirs). Several human viruses of clinical importance are discussed, namely, herpesviruses, polyomaviruses, hepatitis B virus, hepatitis C virus, human papillomavirus, and human immunodeficiency virus.

Malignancies arising in allograft kidneys, with a first reported translocation RCC post-transplantation: A case series

BACKGROUND

The increased risk of malignancy in the post-renal transplant population has been well documented. Renal carcinoma is more common in this population, usually arising in native kidneys. Rarely, tumors arise in the transplanted kidney. Our case series reports four cases of malignancy in allograft kidneys, one of which is a first reported case of translocation RCC in a transplanted kidney.

METHODS

The renal transplantation database (1584 patients) at St. Michael's Hospital was reviewed for malignancies arising in allograft kidneys: reports and pathology slides were reviewed.

RESULTS

Four cases of malignancies arising in the allograft kidney were identified among our kidney transplant population. One patient developed a high grade urothelial carcinoma in the donor kidney post BK virus infection. The other 3 cases were renal cell carcinomas: one clear cell renal cell carcinoma, one translocation renal cell carcinoma, and one papillary renal cell carcinoma. The translocation renal cell cancer had confirmed TFE3 protein over-expression by immunohistochemistry. Molecular testing of the tumors in all 4 cases identified two separate genetic profiles, favored to represent tumors arising from donor tissues along with infiltrating recipient lymphocytes.

DISCUSSION

Previous reports suggested that epithelial malignancies in allograft kidneys are rare. We identified 4 such tumors in 1584 transplant patients. Further, we identified the first reported case of translocation RCC in an allograft kidney. While the rate of malignancy in allograft kidneys is low, screening of the donor kidneys by ultrasound and/or urine cytology may be of use in detecting these lesions.

Outcomes of kidney transplant tourism and risk factors for de novo urothelial carcinoma

BACKGROUND

To date, the outcomes of transplant tourism have not been reported extensively. In addition, data about the accuracy of urine cytology for the detection and the role of the BK virus (BKV) in the carcinogenesis of urothelial carcinoma (UC) after renal transplantation are lacking.

METHODS

Three hundred seven patients who received deceased donor kidney transplants between January 2003 and December 2009 were retrospectively studied. The clinical parameters and outcomes between the domestic and tourist groups were compared. We also investigated the risk factors and role of BKV in the carcinogenesis of de novo UC by quantitative real-time polymerase chain reaction.

RESULTS

The subjects in the tourist group were older at transplantation and had a shorter dialysis time before transplantation. There were significantly higher incidence rates of BKV viruria, Pneumocystis jiroveci pneumonia, and malignancy in the tourist group. Graft and patient survival were superior in the domestic group. A total of 43 cancers were identified, and the most common type of malignancy was UC (23 patients, 53.5%). The tourist group had a significantly higher incidence of tumors. The sensitivity and specificity of urine cytology for detecting UC were 73.9% and 94.7%, respectively. Independent predictors of UC included female sex, use of Chinese herbal medicine, and transplant tourism. Only two patients (8.7%) with UC had detectable BKV.

CONCLUSIONS

Transplant tourism was a risk factor for infection and de novo malignancy. Urothelial carcinoma was the most common malignancy after kidney transplantation. Regular screening for the early detection of UC by urine cytology or periodic sonographic surveys is mandatory, especially for those at high risk.

Polyomavirus BK and prostate cancer: an unworthy scientific effort?

The Polyomavirus BK (BKV) has been proposed to be one of the possible co-factors in the genesis of prostate cancer (PCa) but, so far, the only convincing suggestion is the hypothesis of a “hit and run” carcinogenic mechanism induced by the virus at early stages of this disease. To support this hypothesis we conducted an updated systematic review on previous studies regarding the association between BKV and PCa, in order to interpret the contrasting results and to explore whether there might be a significant virus-disease link. This updated analysis provides evidence for a significant link between BKV expression and PCa development, particularly between the BKV infection and the cancer risk. Forthcoming scientific efforts that take cue from this study might overcome the atavistic and fruitless debate regarding the BKV-PCa association.

Polyoma BK Virus: An Oncogenic Virus?

We report a case of a 65-year-old gentleman with a history of end stage renal disease who underwent a successful cadaveric donor kidney transplant four years ago. He subsequently developed BK virus nephropathy related to chronic immunosuppressant therapy. Three years later, misfortune struck again, and he developed adenocarcinoma of the bladder.

Bladder cancer and seroreactivity to BK, JC and Merkel cell polyomaviruses: the Spanish bladder cancer study

An infectious etiology for bladder cancer has long been suspected. Merkel cell virus (MCV), BKV and JCV polyomaviruses are possible causative agents but data remain scarce. Therefore, we evaluated the seroresponse to these three polyomaviruses in association with bladder cancer risk. 1,135 incident bladder cancer subjects from five Spanish regions and 982 hospital controls matched by sex, age and region were included. 99% of cases were urothelial-cell carcinomas. Antibody response against MCV, BKV and JCV was measured by enzyme immunoassay using Virus-Like-Particles. Our results show a similar seroprevalence in cases and controls: 64/60% for BKV, 83/82% for MCV and 87/83% for JCV. However, among seropositive subjects, higher median seroreactivities were observed in cases compared to controls for BKV (0.84 vs. 0.70, p-value = 0.009) and MCV (1.81 vs. 0.65, p-value < 0.001). Increased bladder cancer risk was observed for BKV (OR = 1.4, 95%CI 1.04-1.8) and for MCV (OR = 1.5, 95%CI 1.2-1.9), when comparing highest to lowest seroreactivity tertiles. The associations of BKV and MCV with bladder cancer were independent of each other and neither smoking status nor disease stage and grade modified them. Furthermore, no association was observed between seroresponse to JCV and bladder cancer. Therefore, we conclude that BKV and MCV polyomavirus infection could be related to an increased bladder cancer risk.

High incidence of potentially virus-induced malignancies in systemic lupus erythematosus: a long-term followup study in a Danish cohort

OBJECTIVE

Patients with systemic lupus erythematosus (SLE) seem to experience an increased prevalence of oncogenic virus infections. The aim of the present study was to investigate whether SLE patients have an increased risk of virus-associated malignancies, defined as malignancies potentially caused by virus infection.

METHODS

A hospital-based cohort of 576 SLE patients was linked to the Danish Cancer Registry. The cohort was followed up for malignancies from the date of SLE diagnosis, and standardized incidence ratios (SIRs) were calculated for various forms of cancer.

RESULTS

The median duration of followup was 13.2 years. Compared to the general population, the patients experienced an increased overall risk of cancer (SIR 1.6 [95% confidence interval (95% CI)] 1.2-2.0). We observed an increased risk of virus-associated cancers combined (SIR 2.9 [95% CI 2.0-4.1]). Among human papillomavirus (HPV)-associated malignant and premalignant conditions, high risk was found for anal cancer (SIR 26.9 [95% CI 8.7-83.4]), vaginal/vulvar cancer (SIR 9.1 [95% CI 2.3-36.5]), epithelial dysplasia/carcinoma in situ of the uterine cervix (SIR 1.8 [95% CI 1.2-2.7]), and nonmelanoma skin cancer (SIR 2.0 [95% CI 1.2-3.6]). Increased SIRs were also found for other potentially virus-induced cancer types (liver cancer SIR 9.9 [95% CI 2.5-39.8], bladder cancer SIR 3.6 [95% CI 1.4-9.7], and non-Hodgkin's lymphoma SIR 5.0 [95% CI 1.9-13.3]).

CONCLUSION

The patients in this SLE cohort experienced an increased risk of HPV-associated tumors and other potentially virus-induced cancers during long-term followup. Our findings call for clinical alertness to oncogenic virus infections in SLE patients.

BK virus-associated urinary bladder carcinoma in transplant recipients: report of 2 cases, review of the literature, and proposed pathogenetic model

Despite strong experimental evidence, BK polyomavirus involvement in human cancers has been controversial. We report 2 cases of kidney ± pancreas transplant recipients with evidence of BK polyomavirus reactivation, who developed aggressive urinary bladder urothelial carcinomas with adenocarcinomatous and/or micropapillary differentiation. Diffuse strong nuclear positivity for viral T antigen, p53, Ki-67, and p16 was observed in both malignancies. The BK polyomavirus role in promoting urothelial neoplasia in transplant recipients may be partly indirect, based on the demonstration by polymerase chain reaction in both tumors of BK polyomavirus with intact open reading frames and close phylogenetic clustering with known replication-competent strains, and viral capsid protein VP1 messenger RNA and intranuclear virions by electron microscopy in 1 tumor. No unique cancer-associated mutations were found, but some viral T antigen mutations were potentially associated with increased rate of viral replication and risk for "rare" carcinogenic events. The BK polyomavirus-induced profound effects on cell activation, cell cycle shift to proliferation, and apoptosis inhibition, in the context of marked immunosuppression, constitute a potentially ideal background for malignant transformation. The long time lapse between transplantation and tumor manifestation, 7 and 11 years, respectively, further supports the concept of multistep carcinogenesis cascade and long-term risk for these patients. We propose a model of changes ranging from viral reactivation to dysplasia to invasive carcinoma. Clinical vigilance is warranted for early diagnosis of BK polyomavirus-related urothelial malignancies in transplant recipients.

Bladder transitional cell carcinoma and BK virus in a young kidney transplant recipient

Kidney transplant recipients have a heightened risk of developing neoplasms. Immunosuppressive treatments decrease the incidence of transplant rejection but increase the risk of infections, including BK virus (BKV). This infection is acquired in childhood and remains latent in the renal and urinary epithelium. In cases of immunodeficiency, BKV has been implicated as a tumor virus, but the role of BKV in cancer is a controversial topic and is difficult to determine. In the tumor cells, it is possible to detect fragments of the viral genome that could alter the control mechanisms of the cell cycle and DNA repair. We report the case of a kidney transplant recipient who developed BKV nephropathy and carcinoma of the bladder, supporting a possible role for BKV in the oncogenic pathway in this clinical setting, but the role of BKV in cancer remains a controversial topic and difficult to determine.

Association of human herpes, papilloma and polyoma virus families with bladder cancer

The aim of the present study was to assess the possible etiologic role of human papillomavirus (HPV), human herpes virus (HHV) and the human polyoma virus families (BKV and JCV) in the tumourigenesis of bladder cancer. Thirty biopsy specimens from patients with different grades and stages of bladder cancer, who underwent transurethral bladder cancer resection, and 30 normal bladder mucosa specimens were analysed using polymerase chain reaction (PCR) for the detection of the above three virus family members. The presence of HPV was determined in all specimens with nested PCR and real-time quantitative PCR. All cancerous specimens, including the control group, were found to be negative both by PCR and real-time qPCR for the presence of HPV DNA, whilst all samples examined by PCR tested negative for the presence of HSV-1,2 Varicella zoster virus and HSV-7 DNA. Cytomegalovirus, HHV-6 and HHV-8 exhibited similar incidence in sample positivity in both cancerous and healthy tissues. EBV showed a higher prevalence in bladder cancer specimens compared to healthy tissue (p = 0.048), whilst BKV and JCV were detected only in tumour samples. The presence of EBV in a significant proportion of bladder tumours indicates the etiological role of this virus in cancer tumourigenesis.

BK virus as a potential oncovirus for bladder cancer in a renal transplant patient

Renal transplant patients have high risk for bladder cancer. The reactivation of BK virus is common in renal transplant patients especially in the urinary tract. There was some evidence suggesting that the reactivation of BK virus (BKV) in renal transplant patients may associate with the development of bladder cancer. Here we demonstrated that a patient that had persistent elevated BKV viruria (urine BKV DNA concentration more than 10(11) copies/ml) after renal transplantation. Then, bladder cancer was found in 13 months after kidney transplantation. The urine BKV DNA concentration was detected by real-time PCR and the BKV DNA in the bladder tumor was detected by PCR. BKV DNA was found in the marginal and central part of the bladder tumor. After removal of the bladder cancer, the urine BKV viral load in this patients dropped dramatically to <10(2) copies/ml. However, the urine viral load had increased modestly to 10(6) copies/ml in 3 months after surgery. Since there is a close correlation between the urine BK viral load and the presence of bladder cancer, we suggested that there might be a causal relationship between the reactivation of BKV and the development of bladder cancer in renal transplant patient.

Differential patterns of large tumor antigen-specific immune responsiveness in patients with BK polyomavirus-positive prostate cancer or benign prostatic hyperplasia

The role of the polyomavirus BK (BKV) large tumor antigen (L-Tag) as a target of immune response in patients with prostate cancer (PCa) has not been investigated thus far. In this study, we comparatively analyzed humoral and cellular L-Tag-specific responsiveness in age-matched patients bearing PCa or benign prostatic hyperplasia, expressing or not expressing BKV L-Tag-specific sequences in their tissue specimens, and in non-age-matched healthy individuals. Furthermore, results from patients with PCa were correlated to 5-year follow-up clinical data focusing on evidence of biochemical recurrence (BR) after surgery (prostate specific antigen level of ≥0.2 ng/ml). In peripheral blood mononuclear cells (PBMC) from patients with PCa with evidence of BR and BKV L-Tag-positive tumors, stimulation with peptides derived from the BKV L-Tag but not those derived from Epstein-Barr virus, influenza virus, or cytomegalovirus induced a peculiar cytokine gene expression profile, characterized by high expression of interleukin-10 (IL-10) and transforming growth factor β1 and low expression of gamma interferon genes. This pattern was confirmed by protein secretion data and correlated with high levels of anti-BKV L-Tag IgG. Furthermore, in PBMC from these PCa-bearing patients, L-Tag-derived peptides significantly expanded an IL-10-secreting CD4(+) CD25(+(high)) CD127(-) FoxP3(+) T cell population with an effector memory phenotype (CD103(+)) capable of inhibiting proliferation of autologous anti-CD3/CD28-triggered CD4(+) CD25(-) T cells. Collectively, our findings indicate that potentially tolerogenic features of L-Tag-specific immune response are significantly associated with tumor progression in patients with BKV(+) PCa.

Urinary human polyomavirus and papillomavirus infection and bladder cancer risk

BACKGROUND

The association of transitional cell carcinomas of the bladder (TCB) with Schistosoma haematobium suggested a possible role of infections in the aetiology of TCB.

METHODS

In all, 114 TCB cases and 140 hospital controls from Pordenone Province were enrolled within an Italian multi-centric case-control study. Urine samples were screened for DNA from five human polyomaviruses (HPyV) (JCV, BKV, MCV, WUV, and KIV); SV40; and 22 mucosal human papillomaviruses (HPV) using highly sensitive PCR assays. Odds ratios (ORs) and corresponding confidence intervals (CIs) were computed for risk of TCB by HPyV- or HPV-positivity using unconditional logistic regression.

RESULTS

Human polyomavirus prevalence was similar in TCB cases (71.7%) and controls (77.7%) (OR for TCB=0.85; 95% CI: 0.45-1.61). JCV was the most frequently detected HPyV type. No individual HPyV showed a significant association. Among cases, HPyV-positivity was not associated with tumour characteristics, but it was significantly lower in women than men and among current and former smokers than never smokers. Human papillomavirus was detected in seven cases and five controls (OR=1.52; 95% CI: 0.42-5.45).

CONCLUSION

The present small study does not support an involvement of HPyV or HPV infection in TCB aetiology in immunocompetent individuals. Differences in HPyV-positivity by sex and smoking may derive from differences in either acquisition or persistence of the infection.

Decoy cells and malignant cells coexisting in the urine from a transplant recipient with BK virus nephropathy and bladder adenocarcinoma

The search for decoy cells (DC) in urine is widely used as screening for BK virus (BKV) reactivation in transplant recipients. BKV cytopathic effect of DC must not be confused with high-grade urothelial carcinoma. This report presents a case of coexistence of DC and malignant cells in the urine from a transplant recipient with BKV-associated nephropathy (BKVN) and bladder adenocarcinoma. A 38-year-old female with type 1 diabetes mellitus and end-stage renal disease underwent a simultaneous pancreas and kidney transplant. Four years post-transplantation, BK virus studies were performed for renal dysfunction. Isolated DC and DC in casts were identified in urine. Also, the tests for BKV DNA were positive in serum and renal allograft biopsy. BKVN was treatment-resistant and the patient returned to hemodialysis. A kidney transplant nephrectomy was performed 2 years later. The next urine cytology showed, in addition to DC, other distinct cells with nuclear atypia highly suggestive of malignancy. Some cells showed both, malignant and DC features. A bladder adenocarcinoma was diagnosed on biopsy and BKV proteins were demonstrated on tumor cells, supporting a possible role for BKV in the oncogenic pathway in this clinical setting. The presence of DC in the urine from a transplant recipient is the hallmark of BKV activation, but it does not exclude the existence of carcinoma. Furthermore, the presence of highly atypical cells should raise, not eliminate, the possibility of neoplastic transformation of the bladder.

Structural evaluation of new human polyomaviruses provides clues to pathobiology

In the past three years, remarkable discoveries have added three new human polyomaviruses (KI virus (KIV), WU virus (WUV) and Merkel cell virus (MCV)) to a class that previously had only two disease-causing members (BK virus (BKV) and JC virus (JCV)) identified. Two monkey polyomaviruses, simian virus (SV)40 and B-cell lymphotropic polyomavirus (LPV) are also present in humans. KIV and WUV lack the agnoprotein coding sequence and regulatory micro (mi)RNA clusters of BKV, JCV and SV40. MCV lacks the agnoprotein sequence but generates miRNAs. KIV, WUV and MCV are all widespread in humans. Although they have distinctive tissue tropisms, all these viruses are probably acquired in childhood. Of these viruses, only MCV has thus far been strongly linked to cancer. Marshalled evidence from diverse sources implicates MCV as an etiological agent of Merkel cell carcinoma. This review compares the structural features of the new and previously known polyomaviruses, with the aim of identifying approaches to molecular pathology.

[Urologic aspects of Polyomavirus infection]

JC virus (JCV) and BK virus (BKV) are human Polyomaviruses of the papovavirus family, which also includes a simian vacuolating virus 40 (SV40). Human Polyomaviruses were first isolated in 1971 from the brain (JCV) and urine (BKV) of two different patients. Human Polyomaviruses have a limited and specific tissue tropism infecting the renal tubular cells, the urothelium, the B cells and the brain cells. The virus infects the majority of the human population with seroconversion occurring during adolescence. The detection of the virus may be cytological, pathological, virological or immunological. Following a typically subclinical primary infection, Polyomavirus establishes a life-long persistent infection, especially in the urinary tract. BKV is known to reactivate and cause severe disease in immunosuppressed patients. The presence of Polyomavirus outside conditions of immunosuppression raises the question of its meaning and its therapeutic management. Given the ubiquitous nature of the virus and its strong association with cancer in animal models, they may play an etiological role in human malignancies. Here, we describe the biology of human Polyomaviruses, review their non-malignant and malignant potentials, and discuss the therapeutic aspect.

High-grade urothelial carcinoma in a kidney transplant recipient with BK virus infection

Bladder malignancy in the kidney transplant recipient is rare and compared with the general population tends to be of high grade and have an aggressive clinical course. In this report, we describe a case of urothelial carcinoma developing in a kidney transplant recipient 6 years after the diagnosis of polyomavirus nephropathy (PVN). BK virus (BKV) DNA was identified in urine and serum by PCR. The diffuse strong staining of SV40 T-antigen and p53 within both the in situ and invasive carcinoma suggest that BKV may play a role in the oncogenic pathway in this clinical setting.

BK virus and human cancer: innocent until proven guilty

BK virus (BKV) is a polyomavirus that ubiquitously infects the human population. Following a typically subclinical primary infection, BKV establishes a life-long persistent infection in the kidney and urinary tract. BKV is known to reactivate and cause severe disease in immunosuppressed patients, particularly renal and bone marrow transplant patients. Infection of BKV in rodent animal models or cells in culture often results in tumor formation or transformation, respectively. When co-expressed with activated oncogenes, BKV large tumor antigen drives the transformation of primary human cells. An etiological role of BKV in human cancer, however, remains controversial. Multiple reports have demonstrated conflicting results in regards to the presence of BKV sequences and/or proteins in various tumor types. This review compiles the most recent findings of BKV detection in a number of human cancers. Due to the lack of conclusive causality data from these studies, there does not appear to be a definitive association between BKV and human cancers.

p53 gene mutational rate, Gleason score, and BK virus infection in prostate adenocarcinoma: Is there a correlation?

Prostate cancer represents the second leading cause of cancer deaths in Western countries. Viral infections could play a role in prostate carcinogenesis. Human polyomavirus BK (BKV) is a possible candidate because of its transforming properties. In this study, BKV sequences in urine, blood, fresh, and paraffin-embedded prostate cancer samples from 26 patients were searched using Q-PCR analysis. T antigen (TAg) and p53 localization in neoplastic cells were evaluated by immunohistochemical analysis. Also, the presence of mutations in 5-9 exons of p53 gene was analyzed. Results showed that BKV-DNA was found in urine (54%), plasma (31%), and in fresh prostate cancer specimens (85%). The analysis of p53 gene evidenced several mutations in high Gleason patients, according to tumor advanced stage. Immunohistochemical analysis results evidenced the localization of p53 and TAg into cytoplasm, whereas in TAg-negative tumors, p53 was nuclear. This study suggests that BKV acts as cofactor in the pathogenesis of prostate cancer. These observations emphasize previous studies regarding the cellular pathways that may be deregulated by BKV.

Polyoma virus infection and urothelial carcinoma of the bladder following renal transplantation

Renal transplant recipients are at increased risk of bladder carcinoma. The aetiology is unknown but a polyoma virus (PV), BK virus (BKV), may play a role; urinary reactivation of this virus is common post-renal transplantation and PV large T-antigen (T-Ag) has transforming activity. In this study, we investigate the potential role of BKV in post-transplant urothelial carcinoma by immunostaining tumour tissue for PV T-Ag. There was no positivity for PV T-Ag in urothelial carcinomas from 20 non-transplant patients. Since 1990, 10 transplant recipients in our unit have developed urothelial carcinoma, and tumour tissue was available in eight recipients. Two patients were transplanted since the first case of PV nephropathy (PVN) was diagnosed in our unit in 2000 and both showed PV reactivation post-transplantation. In one of these patients, there was strong nuclear staining for PV T-Ag in tumour cells, with no staining of non-neoplastic urothelium. We conclude that PV infection is not associated with urothelial carcinoma in non-transplant patients, and is uncommon in transplant-associated tumours. Its presence in all tumour cells in one patient transplanted in the PVN era might suggest a possible role in tumorigenesis in that case.

Hypothesis--ultraviolet-B irradiance and vitamin D reduce the risk of viral infections and thus their sequelae, including autoimmune diseases and some cancers

Many viral infections reach clinical significance in winter, when it is cold, relative humidity is lowest and vitamin D production from solar ultraviolet-B irradiation is at its nadir. Several autoimmune diseases, such as multiple sclerosis, type 1 diabetes mellitus and asthma, are linked to viral infections. Vitamin D, through induction of cathelicidin, which effectively combats both bacterial and viral infections, may reduce the risk of several autoimmune diseases and cancers by reducing the development of viral infections. Some types of cancer are also linked to viral infections. The cancers with seemingly important risk from viral infections important in winter, based on correlations with increasing latitude in the United States, an index of wintertime solar ultraviolet-B dose and vitamin D, are bladder, prostate, testicular and thyroid cancer, Hodgkin's and non-Hodgkin's lymphoma, and, perhaps, gastric cancer. The evidence examined includes the role of viruses in the etiology of these diseases, the geographic and seasonal variation of these diseases, and the time of life when vitamin D is effective in reducing the risk of disease. In general, the evidence supports the hypothesis. However, further work is required to evaluate this hypothesis.

Lack of BK virus DNA sequences in most transitional-cell carcinomas of the bladder

BK virus (BKV), a common human polyomavirus infection latent in the kidneys, can reactivate with immunosuppression to cause renal disease. Some have suggested that BKV may contribute to the development of bladder cancer, and BKV sequences have been reported from bladder tumors. To further examine the role of BKV in human bladder cancer, a series of bladder tumors was investigated for BKV genomic sequences. Fresh-frozen specimens from 76 transitional cell carcinoma tissues and 46 paired adjacent normal urothelial tissues archived at the H. Lee Moffitt Cancer Center were studied. All tissues were histopathologically reviewed. DNA extracted from the tissues was tested by quantitative real-time polymerase chain reaction (QPCR) assays to detect BKV DNA sequences in the VP1 coding region. Amplification of ERV-3 was conducted separately to quantify cell copy number. Conventional PCR targeting the BKV T-antigen (T-Ag) coding region and immunohistochemistry for BKV T-Ag were also conducted on all tissues that tested positive for BKV by QPCR. Seventy-three bladder tumors yielded >/=3,000 copies of ERV-3, 4 (5.5%) of which tested positive for BKV with average copy numbers of 7.9, 15.8, 0.4 and 0.3 per 1,000 cells. Paired normal tissue was available for 2 of these BKV-positive tumors, 1 of which was BKV-positive (14.6 copies/1,000 cells). No other normal tissues were BKV-positive by QPCR. The 6 BKV-positive tissues by QPCR were also positive by conventional PCR, but all stained negative for BKV T-Ag by immunohistochemistry. BKV is unlikely to be involved in the etiology of most bladder tumors.

Expression of p53 in virally infected tubular cells in renal transplant patients with polyomavirus nephropathy

Polyomavirus (PV) infection is associated with ureteral stenosis, hemorrhagic cystitis, and interstitial nephritis in renal transplant patients. The 3 PVs detected in human beings-BK virus, JC virus, and simian virus 40-each encode highly homologous forms of a large T antigen, a transcriptional and replicational regulatory protein. We describe immunohistochemical findings in 5 renal transplant patients who developed PV nephropathy (PVN) and a sixth patient with both PVN and PV infection of the bladder mucosa. Polyomavirus infection was confirmed by immunohistochemical detection of T antigen in kidney and bladder biopsies. We report on the expression of p53 specific to virally infected cells in all biopsies positive for T antigen. Examination of posttransplant biopsies obtained from these 6 patients before they were diagnosed with PVN revealed no expression of T antigen or p53. Accumulation of p53 in PV-infected cells may occur in response to binding of p53 by T antigen, resulting in stabilization of p53. These results provide the first evidence for intracellular actions of PV T antigen in the context of nonneoplastic diseases.

Prevalence of BK virus subtype I in Germany

The primary infection with human polyomavirus BK (BKV) occurs in early childhood and leads to viral latency within the urogenital tract. Up to 90% of the adult population are seropositive. In immunosuppressed patients, the BKV may be reactivated resulting in typical disease patterns like hemorrhagic cystitis and tubulointerstitial nephritis. Based on serological and molecular methods, BKV isolates were classified into four subtypes previously. Sixty specimens obtained from German renal and bone marrow transplant recipients were analyzed to gain data on the prevalence of BKV subtypes in Germany. With 90.9%, BKV subtype I was found to be predominant in both patient groups. 6.1% of BKV strains were classified as subtype IV. This pattern of phylogenetic distribution is similar to that demonstrated previously in England, Tanzania, the United States and Japan. Remarkably, there was one German BKV virus with a sequence which clusters together with strain SB in subtype II. The BKV subtype I was found to consist of at least three subgroups designated as Ia, Ib, and Ic. While the majority of the German sequences represent subgroup Ic, most of the Japanese sequences are clearly distinct. These findings support the hypothesis of distinct geographical prevalence of BKV subgroups. For the genotyping region, a relationship of BKV subgroups to disease patterns like hemorrhagic cystitis or tubulointerstitial nephritis could not be demonstrated.