Advances in Virus-Specific T Cell Therapy for Polyomavirus Infections: A Comprehensive Review.

Polyomaviruses are a group of small, non-enveloped, double-stranded DNA viruses that can infect various hosts, including humans. BKPyV is known to cause conditions such as human polyomavirus-associated nephropathy (HPyVAN), human polyomavirus-associated hemorrhagic cystitis (HPyVHC), and human polyomavirus-associated urothelial cancer (HPyVUC). JCPyV, on the other hand, is responsible for progressive multifocal leukoencephalopathy (PML), a severe demyelinating disease of the central nervous system. PML primarily affects immunocompromised individuals, including those with HIV, recipients of certain immunosuppressive therapies, and transplant patients. The treatment options for HPyV infections have been limited, but recent developments in virus-specific T cell (VST) therapy have shown promise. While VST therapy has shown promise in treating both BKPyV and JCPyV infections, several challenges remain. These include the time-consuming and costly preparation of VSTs, the need for sophisticated production facilities, and uncertainties regarding the optimal cell type and infusion frequency. To the best of our knowledge, 85 patients with hemorrhagic cystitis, 27 patients with BKPyV viremia, 2 patients with BKPyV nephritis, 14 patients with hemorrhagic cystitis and BKPyV viremia, 32 patients with PML were treated with VST in the literature. The overall response was 82, 33, 35, and 10 complete, partial, non-response, and no-outcome-reported (NA), respectively. In conclusion, this review underscores the importance of VST therapy as a promising treatment approach for polyomavirus infections, emphasizing the need for continued research and clinical trials to refine and expand this innovative immunotherapeutic strategy.

Mapping of Human Polyomavirus in Renal Cell Carcinoma Tissues.

Worldwide, the incidence of renal cell carcinoma (RCC) is rising, accounting for approximately 2% of all cancer diagnoses and deaths. The etiology of RCC is still obscure. Here, we assessed the presence of HPyVs in paraffin-embedded tissue (FFPE) resected tissue from patients with RCC by using different molecular techniques. Fifty-five FFPE tissues from 11 RCC patients were included in this study. Consensus and HPyV-specific primers were used to screen for HPyVs. Both PCR approaches revealed that HPyV is frequently detected in the tissues of RCC kidney resections. A total of 78% (43/55) of the tissues tested were positive for at least one HPyV (i.e., MCPyV, HPyV6, HPyV7, BKPyV, JCPyV, or WUyV). Additionally, 25 tissues (45%) were positive for only one HPyV, 14 (25%) for two HPyVs, 3 (5%) for three HPyVs, and 1 one (1%) tissue specimen was positive for four HPyVs. Eleven (20%) RCC specimens were completely devoid of HPyV sequences. MCPyV was found in 24/55 RCC tissues, HPyV7 in 19, and HPyV6 in 8. The presence of MCPyV and HPyV6 was confirmed by specific FISH or RNA-ISH. In addition, we aimed to confirm HPyV gene expression by IHC. Our results strongly indicate that these HPyVs infect RCC and nontumor tissues, possibly indicating that kidney tissues serve as a reservoir for HPyV latency. Whether HPyVs possibly contribute to the etiopathogenesis of RCC remains to be elucidated.

Detection of JC and BK polyomaviruses in patients with colorectal cancer (CRC) by PCR.

BACKGROUND: Overall, 20-30% of all cancers are estimated to be linked to infectious agents. Polyomaviruses are oncogenic cause in rodent models, readily transform their cells, and cause chromosomal instability in animal and human cells in-vitro. Some reports have indicated the presence of JCPyV and BKPyV in some human tumors. The JCPyV and BKPyV genome encodes some transforming proteins such as LT-Ag. Thus, these viruses could cause or promote some neoplasia, such as lymphomas, pancreatic, prostate, and colorectal cancers. Colorectal cancer (CRC) is the third most common cancer in the world. Risk factors for developing CRC are associated with personal features or habits, such as age, lifestyle, and gut microbiota. MATERIALS AND METHODS: In this study, we examined the prevalence of JCPyV and BKPyV in the 23 fecal samples of CRC patients and 24 healthy samples (control group). Virus DNA was extracted by a Favorgen DNA extraction kit. The large T antigen of JCPyV and VP1 of BKPyV were investigated by optimized multiplex PCR. RESULTS: One of the samples was positive for the JCPyV (4.3%), while in the samples of healthy individuals, the JCPyV was negative. Also, positive results for BKPyV PCR were obtained for five cases (21.7%) in the samples of the CRC group and one case (4.1%) in healthy individuals. CONCLUSION: The result showed no direct correlation between tumorigenesis and polyomavirus infections in CRC development. However, the exact role of BKPyV and JCPyV is still controversial and needs further study with larger sample size.

Nonclinical and clinical characterization of MAU868, a novel human-derived monoclonal neutralizing antibody targeting BK polyomavirus VP1.

Reactivation of BK polyomavirus (BKPyV) can cause significant kidney and bladder disease in immunocompromised patients. There are currently no effective, BKPyV-specific therapies. MAU868 is a novel, human immunoglobulin (Ig) G1 monoclonal antibody that binds the major capsid protein, VP1, of BKPyV with picomolar affinity, neutralizes infection by the 4 major BKPyV genotypes (EC50 ranging from 0.009-0.093 µg/mL; EC90 ranging from 0.102-4.160 µg/mL), and has comparable activity against variants with highly prevalent VP1 polymorphisms. No resistance-associated variants were identified in long-term selection studies, indicating a high in vitro barrier-to-resistance. The high-resolution crystal structure of MAU868 in complex with VP1 pentamer identified 3 key contact residues in VP1 (Y169, R170, and K172). A first-in-human study was conducted to assess the safety, tolerability, and pharmacokinetics of MAU868 following intravenous and subcutaneous administration to healthy adults in a randomized, placebo-controlled, double-blinded, single ascending dose design. MAU868 was safe and well-tolerated. All adverse events were grade 1 and resolved. The pharmacokinetics of MAU868 was typical of a human IgG, with dose-proportional systemic exposure and an elimination half-life ranging between 23 and 30 days. These results demonstrate the potential of MAU868 as a first-in-class therapeutic agent for the treatment or prevention of BKPyV disease.

John Cunningham Virus and Progressive Multifocal Leukoencephalopathy: A Falsely Played Diagnosis.

Progressive Multifocal Leukoencephalopathy (PML) is a possibly fatal demyelinating disease and John Cunningham Polyomavirus (JCPyV) is believed to cause this condition. The so-called JCPyV was initially reported in lymphoma and Human Immunodeficiency Virus (HIV) cases, whereas nowadays, its incidence is increasing in Multiple Sclerosis (MS) cases treated with natalizumab (Tysabri). However, there are conflicting literature data on its pathology and diagnosis, whereas some misdiagnosed reports exist, giving rise to further questions towards the topic. In reality, the so-called PML and the supposed JCPyV are not what they seem to be. In addition, novel and more frequent PML-like conditions may be reported, especially after the Coronavirus Disease 2019 (COVID-19) pandemic.

Absence of JC polyomavirus in stool samples of patients with multiple sclerosis despite high anti-JCV antibodies in serum.

BACKGROUND: Natalizumab is an effective treatment for relapsing multiple sclerosis (MS). During therapy, individuals are at increased risk of developing progressive multifocal leukoencephalopathy (PML). So far, the relevant reservoir for PML-type JC polyomavirus (JCV) remains elusive. We here tested if the detection of JCV-DNA in stool of persons with MS treated with natalizumab could be a future tool for PML risk assessment. METHODS: The presence of JCV-DNA in stool, urine, and whole blood of MS patients treated with natalizumab and known serum anti-JCV antibodies index values (IV) was studied. Different DNA extraction methods, real-time (RT) and droplet digital (dd) PCR techniques were compared. JCV isolates were screened for PML-associated variants by sequencing. RESULTS: Thirty MS patients treated with natalizumab were screened. For 21 patients, blood, stool, and urine samples were available. These patients were stratified according to their serum anti-JCV antibody IV (high (>1.5, n = 12); medium (1.5-0.9, n = 2); low (<0.9, n = 1); negative (n = 6)). JCV-DNA could not be detected in the whole blood or stool samples. Four urine samples had measurable JCV-DNA, ranging from 1.71×104-1.07×108 international units (IU)/mL detected by RT-PCR, corresponding to 4.62×104-9.85×106 copies/mL measured by ddPCR. All JCV variants were wild-type and derived from patients with high antibody IV. CONCLUSION: Stool-specific DNA extraction methods provided the highest quality of DNA, while the sensitivity of ddPCR and RT- PCR was comparable. Our findings do not support assessing stool samples for PML risk stratification in persons with MS. Further studies are needed to explore where PML-associated viral variants arise.

A Study of Alternative TrkA Splicing Identifies TrkAIII as a Novel Potentially Targetable Participant in PitNET Progression.

Pituitary neuroendocrine tumors (PitNETs) are generally benign but comprise an aggressive, invasive, therapy-resistant, metastatic subset, underpinning a need for novel therapeutic targets. PitNETs exhibit low mutation rates but are associated with conditions linked to alternative splicing, an alternative oncogene pathway activation mechanism. PitNETs express the neurotrophin receptor TrkA, which exhibits oncogenic alternative TrkAIII splicing in other neuroendocrine tumors. We, therefore, assessed whether TrkAIII splicing represents a potential oncogenic participant in PitNETs. TrkAIII splicing was RT-PCR assessed in 53 PitNETs and TrkA isoform(s) expression and activation were assessed by confocal immunofluorescence. TrkAIII splicing was also compared to HIF1α, HIF2α, SF3B1, SRSF2, U2AF1, and JCPyV large T antigen mRNA expression, Xbp1 splicing, and SF3B1 mutation. TrkAIII splicing was detected in all invasive and most non-invasive PitNETs and was significantly elevated in invasive cases. In PitNET lineages, TrkAIII splicing was significantly elevated in invasive PIT1 PitNETs and high in invasive and non-invasive SF1 and TPIT lineages. Immunoreactivity consistent with TrkAIII activation characterized PitNET expressing TrkAIII mRNA, and invasive Pit1 PitNETs exhibited elevated HIF2α expression. TrkAIII splicing did not associate with SF3B1 mutations, altered SF3B1, SRSF2, and U2AF1 or JCPyV large T antigen expression, or Xbp1 splicing. Therefore, TrkAIII splicing is common in PitNETs, is elevated in invasive, especially PIT1 tumors, can result in intracellular TrkAIII activation, and may involve hypoxia. The data support a role for TrkAIII splicing in PitNET pathogenesis and progression and identify TrkAIII as a novel potential target in refractory PitNETs.

Exploring JC Polyomavirus Sequences and Human Gene Expression in Brain Tissue of Patients With Progressive Multifocal Leukoencephalopathy.

Progressive multifocal leukoencephalopathy (PML) is a rare neurological condition associated with reactivation of dormant JC polyomavirus (JCPyV). In this study, we characterized gene expression and JCPyV rearrangements in PML brain tissue. Infection of white matter astrocytes and oligodendrocytes as well as occasional brain cortex neurons was shown. PML brain harbored exclusively rearranged JCPyV variants. Viral transcripts covered the whole genome on both strands. Strong differential expression of human genes associated with neuroinflammation, blood-brain barrier permeability, and neurodegenerative diseases was shown. Pathway analysis revealed wide immune activation in PML brain. The study provides novel insights into the pathogenesis of PML.

Longitudinal study of human polyomaviruses viruria in kidney transplant recipients.

INTRODUCTION: Immunosuppression after kidney transplantation (KTx) exposes recipients to Human Polyomaviruses (HPyVs) infections, whose natural history is still misunderstood. METHODS: Allograft biopsies, and urine from 58 donor-recipient pairs were collected before KTx (T0) and 1 (T1), 15 (T2), 30 (T3), 60 (T4), 90 (T5), 180 (T6), 270 (T7), 360 (T8), and 540 (T9) days after transplant. Specimens were tested for JC (JCPyV) and BK (BKPyV), by quantitative Real-Time PCR. The course of post-KTx HPyVs viruria, and the association between JCPyV viruria in recipients and donors, were evaluated. RESULTS: HPyVs were detected in 3/58 (5.2%) allograft biopsies. HPyVs viruria was present in 29/58 (50%) donors and 41/58 (70.7%) recipients. JCPyV DNA was detected in 26/58 (44.8%) donors and 25/58 recipients (43.1%), 19 of whom received kidney from JCPyV positive donor, whereas BKPyV genome was detected in 3 (5.2%) donors and 22 (37.9%) recipients. The median time of JCPyV, and BKPyV first episode of replication was 1, and 171 days post KTx, respectively. At T0, JCPyV viruria of donors was associated with increased risk of JCPyV replication post-KTx; recipients with JCPyV positive donors showed lower risk of BKPyV replication post-KTx. CONCLUSIONS: The results suggested that JCPyV may be transmitted by allograft, and that its replication post KTx might prevent BKPyV reactivation. Future investigation regarding correlation between chronic exposure to immunosuppressive agents and HPyVs urinary replication are warranted.

Polyomavirus Wakes Up and Chooses Neurovirulence.

JC polyomavirus (JCPyV) is a human-specific polyomavirus that establishes a silent lifelong infection in multiple peripheral organs, predominantly those of the urinary tract, of immunocompetent individuals. In immunocompromised settings, however, JCPyV can infiltrate the central nervous system (CNS), where it causes several encephalopathies of high morbidity and mortality. JCPyV-induced progressive multifocal leukoencephalopathy (PML), a devastating demyelinating brain disease, was an AIDS-defining illness before antiretroviral therapy that has "reemerged" as a complication of immunomodulating and chemotherapeutic agents. No effective anti-polyomavirus therapeutics are currently available. How depressed immune status sets the stage for JCPyV resurgence in the urinary tract, how the virus evades pre-existing antiviral antibodies to become viremic, and where/how it enters the CNS are incompletely understood. Addressing these questions requires a tractable animal model of JCPyV CNS infection. Although no animal model can replicate all aspects of any human disease, mouse polyomavirus (MuPyV) in mice and JCPyV in humans share key features of peripheral and CNS infection and antiviral immunity. In this review, we discuss the evidence suggesting how JCPyV migrates from the periphery to the CNS, innate and adaptive immune responses to polyomavirus infection, and how the MuPyV-mouse model provides insights into the pathogenesis of JCPyV CNS disease.

Comprehensive proteomic analysis of JC polyomavirus-infected human astrocytes and their extracellular vesicles.

IMPORTANCE: Progressive multifocal leukoencephalopathy is a crimpling demyelinating disease of the central nervous system caused by JC polyomavirus (JCPyV). Much about JCPyV propagation in the brain remains obscure because of a lack of proper animal models to study the virus in the context of the disease, thus hampering efforts toward the development of new antiviral strategies. Here, having established a robust and representative model of JCPyV infection in human-induced pluripotent stem cell-derived astrocytes, we are able to fully characterize the effect of JCPyV on the biology of the cells and show that the proteomic signature observed for JCPyV-infected astrocytes is extended to extracellular vesicles (EVs). These data suggest that astrocyte-derived EVs found in body fluids might serve as a rich source of information relevant to JCPyV infection in the brain, opening avenues toward better understanding the pathogenesis of the virus and, ultimately, the identification of new antiviral targets.

Detection of BK and JC polyomaviruses in sewage water of the urban areas of Lahore, Pakistan.

The surveillance of sewage water has become an extremely essential tool to trace the circulation of viruses in a population and to predict the outbreak of viral diseases. Sewage monitoring is important for those viruses which cause subclinical infections since it is difficult to determine their prevalence. Polyomaviruses are ubiquitously present, circular double-stranded DNA viruses that can infect humans as well. Among all human polyomaviruses, BK polyomavirus and JC polyomavirus associated with the development of aggressive diseases in immunocompromised individuals, are highly prevalent. This study aimed to investigate the presence and the quantitative prevalence of these two disease-associated human polyomaviruses in sewage water collected from six drains of Lahore, Pakistan. The viruses present in the environmental samples were concentrated by PEG method before isolating viral nucleic acids. Conventional PCR amplifications were performed for molecular detection of BK polyomavirus and JC polyomavirus targeting their large tumor antigen genetic region. The presence of BK polyomavirus and JC polyomavirus was confirmed in the DNA extracted from concentrated sewage samples of each drain by performing both qualitative and quantitative PCR. Our data shows that the viral load ranged from 1278 to 178368 copies per µg of environmental DNA for BK polyomavirus and 5173 to 79129 copies per µg of environmental DNA for JC polyomavirus. In conclusion, here we report first time the detection of BK polyomavirus and JC polyomavirus in sewage water collected from six main drains in urban areas of Lahore, Pakistan showing the high prevalence of these viruses in the Pakistani population. This assay could be used as a proxy to determine the prevalence of these viruses in the Pakistani population.

Infection by human polyomaviruses JCPyV and BKPyV in blood donors of Argentina.

BACKGROUND AND OBJECTIVES: A spectrum of blood-borne infectious agents may be transmitted through transfusion of blood components from asymptomatic donors. Despite the persistence of polyomaviruses in blood cells, no studies have been conducted in Argentina to assess the risk of transfusion infection. MATERIALS AND METHODS: We investigated BKPyV and JCPyV in 720 blood donors, using polymerase chain reaction (PCR) for a region of T antigen common to both viruses. Positive T-antigen samples were subjected to two additional PCR assays targeting the VP1 region. Viral genotypes were characterized by phylogenetic analysis. RESULTS: Polyomaviruses were detected in 1.25% (9/720) of the blood samples selected; JCPyV was identified in 0.97% (7/720) and BKPyV in 0.28% (2/720) of them. Phylogenetic analysis showed that the JCPyV sequences clustered with 2A genotype and Ia of BKPyV. CONCLUSION: This study describes for the first time the prevalence of polyomavirus DNA in blood donors of Córdoba, Argentina. The polyomavirus DNAemia in healthy populations suggests that those viruses are present in blood components eligible for transfusion. Therefore, the epidemiological surveillance of polyomavirus in blood banks might be incorporated into haemovigilance programmes, to determine the infectious risk and implement newer interventions to ensure the safety of blood supplies, if required.

Detection of human neurotropic JCPyV DNA sequence in pediatric anaplastic xanthoastrocytoma.

Due to its peculiar histopathological findings, pleomorphic xanthoastrocytoma (PXA), a rare cerebral tumor of young adults with a slow growth and a good prognosis, resembles to the lytic phase of progressive multifocal leukoencephalopathy, a fatal neurodegenerative disease caused by JC polyomavirus (JCPyV). Therefore, the presence of JCPyV DNA was examined in an 11-year-old child with xanthoastrocytoma, WHO grade 3, by quantitative PCR (qPCR) and nested PCR (nPCR) using primers amplifying sequences encoding the N- and C-terminal region of large T antigen (LTAg), the non-coding control region (NCCR), and viral protein 1 (VP1) DNA. The expression of transcripts from LTAg and VP1 genes was also evaluated. In addition, viral microRNAs' (miRNAs) expression was investigated. Cellular p53 was also searched at both DNA and RNA level. qPCR revealed the presence of JCPyV DNA with a mean value of 6.0 × 104 gEq/mL. nPCR gave a positive result for the 5' region of the LTAg gene and the NCCR, whereas 3' end LTAg and VP1 DNA sequences were not amplifiable. Only LTAg transcripts of 5' end were found whereas VP1 gene transcript was undetectable. Although in most cases, either Mad-1 or Mad-4 NCCRs have been identified in association with JCPyV-positive human brain neoplasms, the archetype NCCR structure was observed in the patient's sample. Neither viral miRNA miR-J1-5p nor p53 DNA and RNA were detected. Although the expression of LTAg supports the possible role of JCPyV in PXA, further studies are warranted to better understand whether the genesis of xanthoastrocytoma could depend on the transformation capacity of LTAg by Rb sequestration.

Co-Detection of EBV and Human Polyomavirus JCPyV in a Case of AIDS-Related Multifocal Primary Central Nervous System Diffuse Large B-Cell Lymphoma.

The human neurotropic Polyomavirus JCPyV is the widespread opportunistic causative pathogen of the fatal demyelinating disease progressive multifocal leukoencephalopathy; however, it has also been implicated in the oncogenesis of several types of cancers. It causes brain tumors when intracerebrally inoculated into rodents, and genomic sequences of different strains and expression of the viral protein large T-Antigen have been detected in a wide variety of glial brain tumors and CNS lymphomas. Here, we present a case of an AIDS-related multifocal primary CNS lymphoma in which JCPyV genomic sequences of the three regions of JCPyV and expression of T-Antigen were detected by PCR and immunohistochemistry, respectively. No capsid proteins were detected, ruling out active JCPyV replication. Sequencing of the control region revealed that Mad-4 was the strain of JCPyV present in tumor cells. In addition, expression of viral proteins LMP and EBNA-1 from another ubiquitous oncogenic virus, Epstein-Barr, was also detected in the same lymphocytic neoplastic cells, co-localizing with JCPyV T-Antigen, suggesting a potential collaboration between these two viruses in the process of malignant transformation of B-lymphocytes, which are the site of latency and reactivation for both viruses.

JC Polyomavirus Modifies the Expression of Human microRNAs in Progressive Multifocal Leukoencephalopathy Brain.

Progressive multifocal leukoencephalopathy (PML) is a severe neurological condition caused by reactivation of JC polyomavirus (JCPyV) in immunosuppression. Asymptomatic JCPyV persists in peripheral tissues. Upon reactivation, neurotropic rearrangements may emerge, and the virus gains access to the brain. To assess the mechanisms of PML pathogenesis, brain tissue material from PML patients was collected for small RNA sequencing. Upregulation of 8 microRNAs (miRNAs) in PML brain was validated using quantitative microRNA polymerase chain reaction (PCR). Bioinformatics tools were utilized to identify major associations of the upregulated miRNAs: neuroinflammation and blood-brain barrier disruption. The results indicate involvement of human miRNA regulation in PML pathogenesis.

JC polyomavirus: a short review of its biology, its association with progressive multifocal leukoencephalopathy, and the diagnostic value of different methods to manifest its activity or presence.

INTRODUCTION: JC polyomavirus is the causative agent of progressive multifocal leukoencephalopathy (PML), a demyelinating disease resulting from the lytic infection of oligodendrocytes that may develop in immunosuppressed individuals: HIV1 infected or individuals under immunosuppressive therapies. Understanding the biology of JCPyV is necessary for a proper patient management, the development of diagnostic tests, and risk stratification. AREAS COVERED: The review covers different areas of expertise including the genomic characterization of JCPyV strains detected in different body compartments (urine, plasma, and cerebrospinal fluid) of PML patients, viral mutations, molecular diagnostics, viral miRNAs, and disease. EXPERT OPINION: The implementation of molecular biology techniques improved our understanding of JCPyV biology. Deep sequencing analysis of viral genomes revealed the presence of viral quasispecies in the cerebrospinal fluid of PML patients characterized by noncoding control region rearrangements and VP1 mutations. These neurotropic JCPyV variants present enhanced replication and an altered cell tropism that contribute to PML development. Monitoring these variants may be relevant for the identification of patients at risk of PML. Multiplex realtime PCR targeting both the LTAg and the archetype NCCR could be used to identify them. Failure to amplify NCCR should indicate the presence of a JCPyV prototype speeding up the diagnostic process.

Rapid-progressing progressive multifocal leukoencephalopathy in two patients newly diagnosed with HIV: case series and review of literature.

The JC Polyomavirus (JCPyV) is a virus of global distribution and is usually kept under control by the immune system. In patients with AIDS, a latent JCPyV infection can reactivate and develop into progressive multifocal leukoencephalopathy (PML). Around half of the patients with PML die within 2 years since the diagnosis, yet in rare cases, the disease advances significantly quicker and seems to be insusceptible to any medical actions. In our clinic, we observed two cases of such course in HIV-positive patients in the AIDS stage. On admission, both patients had mild neurological symptoms such as dizziness, vision disturbances, and muscle weakness. Both had extremely low CD4 lymphocyte count (7 cells/µL, 40 cells/µL) and high HIV-1 viral load (VL) (50,324 copies/ml, 78,334 copies/ml). PML was confirmed by PCR for JCPyV DNA in cerebrospinal fluid (CSF) coupled with clinical and radiological features. Despite receiving though antiretroviral (ARV) treatment paired with intra-venous (IV) steroids, the disease progressed rapidly with neurological manifestations exacerbating throughout the few weeks following the admission. Eventually, both patients developed respiratory failure and died within less than 3 months after the onset of the neurological symptoms. Even though such curse of the disease is not common, it should be a warning to all how deadly both PML and AIDS can be and remind doctors to offer testing even to asymptomatic patients.

Prevalence of JC Polyomavirus in Patients with Neuroinvasive Disease of Unknown Etiology in Croatia.

Background and Objectives: John Cunningham polyomavirus (JCPyV) is a highly prevalent virus in the human population. The prevalence of JCPyV in patients with central nervous system disorders has not been examined extensively. The aim of this study was to analyze the prevalence of JCPyV DNA/antibodies in patients with neuroinvasive diseases (NID) of unknown etiology. Materials and Methods: The study included 132 patients with NID (febrile headache, meningitis, encephalitis) tested from January 2021 to December 2022. The control group consisted of 47 asymptomatic individuals. In patients with NID, serum and cerebrospinal fluid (CSF) samples were collected in the acute phase of the disease. CSF samples were tested for JCPyV DNA (PCR), while serum samples were tested for JCPyV IgG antibodies (ELISA). In controls, serum samples were tested for JCPyV IgG antibodies (ELISA). Results: JCPyV DNA was not detected in any of the CSF samples from patients with NID. JCPyV IgG antibodies were detected in 88.6% of patients and 74.5% of controls (p < 0.001). In the patients' group, a significant difference in the IgG prevalence was observed between males (94.6%) and females (81.0%). In addition, significant differences in the seropositivity between age groups were found. The lowest seroprevalence (28.6%) was in patients less than 20 years, followed by a sharp increase in the 20-29-year group (69.2%), after which the seroprevalence remained stable (90.0-94.1%) in patients up to 69 years. All patients older than 70 years were JCPyV IgG-seropositive. No significant difference in the seroprevalence was found in patients presenting with febrile headache (81.6%), meningitis (93.3%), or meningoencephalitis (91.3%). No difference in the seropositivity between genders was found in controls. Although the seropositivity steadily increased in older participants, these differences were not significant. Analyzing the JCPyV antibody levels in patients with NID, the median antibody titers differed significantly between groups, ranging from 248 AU/mL (younger age groups) to 400 AU/mL (older age groups). Conclusions: Higher seroprevalence in the patients' group highlights the need to further investigate the possible association of JCPyV and NID.

Human polyomaviruses JCPyV and MCPyV in urothelial cell carcinoma: a single institution experience.

Objective: Urothelial cell carcinoma (UCC) is the most common type of urinary bladder. JCPyV and BKPyV have been detected in the urine and tissue of urothelial cell carcinomas (UCC) in immunocompetent patients. Here, we investigated the presence of several HPyVs in UCC samples using diverse molecular techniques to study the prevalence of HPyVs in UCC. Methods: A large single-institution database of urine cytology specimens (UCS; n = 22.867 UCS) has previously been searched for decoy cells (n = 30), suggesting polyomavirus infection. The available urine sediments and formalin-fixed paraffin-embedded (FFPE) tissue samples of UCC patients were tested for the presence of JCPyV-LTAg expression by immunohistochemistry (IHC) labeled with SV40-LTAg antibody (clone: PAb416) and subsequent PCR followed by sequencing. In addition, the presence of the oncogenic Merkel cell polyomavirus (MCPyV) and the presence of human polyomavirus 6 (HPyV6) and 7 (HPyV7) DNA were tested with DNA PCR or IHC. Results: Of the 30 patients harboring decoy cells, 14 were diagnosed with UCC of the urinary bladder (14/30; 46.6%) before presenting with decoy cells in the urine. The SV40-LTAg IHC was positive in all 14 UCC urine sediments and negative in the FFPE tissues. JCPyV-DNA was identified in all five available UCS and in three FFPE samples of UCC (three of 14; 21.4%). Two UCC cases were positive for MCPyV-DNA (two of 14; 14.3%), and one of them showed protein expression by IHC (one of 14; 7.1%). All specimens were HPyV6 and HPyV7 negative. Conclusion: Our findings show the presence of JCPyV in the urine and UCC of immunocompetent patients. Moreover, MCPyV was detected in two UCC cases. In total, five UCC cases showed the presence of either JCPyV or MCPyV. The evidence here supports the hypothesis that these viruses might sporadically be associated with UCC. Further studies are needed to confirm the relevance of JCPyV or MCPyV as a possible risk factor for UCC development.