Detection of JC virus in cerebrospinal fluid (CSF) samples from patients with progressive multifocal leukoencephalopathy but not in CSF samples from patients with herpes simplex encephalitis, enteroviral meningitis, or multiple sclerosis

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.

Viruses Causing Aseptic Meningitis: A Tertiary Medical Center Experience With a Multiplex PCR Assay

Background: Central nervous system (CNS) infection is associated with high rates of morbidity and mortality, and despite advancements in molecular testing, aseptic meningitis remains challenging to diagnose. Aseptic meningitis cases are often underreported worldwide, which impacts the quality of patient care. Therefore, we aimed to assess the results of BioFire® FilmArray® meningitis/encephalitis (ME) PCR panel, clinical characteristics, and etiologies of aseptic meningitis patients.

Methods: From January 2018 to January 2020, all pediatric and adult patients in a large tertiary medical center who underwent lumbar puncture and cerebrospinal fluid (CSF) testing by a ME multiplex PCR panel and who fit the aseptic meningitis definition were retrospectively reviewed.

Results: Data were reviewed from 1,607 patients; 240 met the inclusion criteria (54.6% males; 68.8% <4 years of age). The rate of detected viral causes of aseptic meningitis was 40.4%; therefore, 59.6% of the patients remained with unidentified etiology. Among the identified viral meningitis, enterovirus and human herpesvirus 6 (HHV-6) were the most common (25 and 7.9%, respectively). The median length of hospital stay was 6 days, and it was longer in patients with unidentifiable aseptic meningitis (p < 0.0001).

Conclusion: Aseptic meningitis is common among suspected meningitis patients, but most cases remained of unknown etiology. The most common identified viruses were enterovirus followed by HHV-6, and there is predominance in males and the pediatric age group. These results highlight that further research is needed to identify other etiologies and possible additional viral pathogens for aseptic meningitis in the current diagnostic methods.

A globally applicable PCR-based detection and discrimination of BK and JC polyomaviruses

BKV and JCV belong to the Polyomaviridae family and are opportunistic agents associated with complications in immunocompromised individuals. Although a single screening assay for both viruses would be convenient, the diversity of BKV and JCV serotypes and genotypes is a methodological challenge. In this paper, we developed a PCR method able to detect and segregate BKV and JCV, despite these genetic discrepancies. A duplex semi-nested PCR (duplex snPCR) was designed to target a conserved region (639nt-1516nt) within the VP2 gene. In the first PCR, a primer set common to all BKV and JCV serotypes/ genotypes was used, followed by a semi-nested PCR with internal primers for BKV and JCV segregation. The limit of detection of the duplex snPCR was as low as 10 copies of BKV or JCV plasmids/μL. Specific products were observed when JCV and BKV plasmids were mixed in the same reaction. In field sample testing, the duplex snPCR detected and distinguished both viruses in different biological samples. Results were confirmed by Sanger's sequencing. The geographical complexity of BKV and JCV serotypes and genotypes imposes limits to a simple and universal method that could detect each virus. However, we describe here a sensitive and reliable PCR technique for BKV and JCV diagnosis that overcomes these limitations and could be universally applied.

An observational comparison of natalizumab vs. fingolimod using JCV serology to determine therapy

Background:

The lack of prospective trial data comparing certain multiple sclerosis (MS) therapies could be addressed with observational research.

Objective:

The objective of this paper is to investigate outcomes of natalizumab versus fingolimod treatment in an MS cohort using a novel method of patient selection.

Methods:

We reviewed entries from our clinic’s database for all relapsing–remitting MS patients started on fingolimod and natalizumab where JCV serology was used to determine treatment. We analyzed each group for time to first relapse and in a second analysis, time to first relapse or gadolinium-enhancing lesion.

Results:

Sixty-nine patients on natalizumab and 36 on fingolimod met our inclusion criteria and had adequate follow-up for analysis. The baseline clinical characteristics at the time of treatment switch were similar. With a mean follow-up of 1.5 years for both treatment groups, there was a trend favoring natalizumab in time to first relapse, although this was not statistically significant (2.20 (0.87, 5.55) p = 0.095). There was a significant difference in the secondary outcome, time to relapse or gadolinium-enhancing lesion (2.31 (1.03, 5.17) p = 0.041), favoring natalizumab. Adjusted analyses favored natalizumab for both outcomes ( p < 0.05).

Conclusion:

This work employed an observational study design where treatment allocation by JCV serology allowed for treatment groups with well-balanced characteristics.

The long and evolving relationship between viruses and multiple sclerosis

Multiple sclerosis (MS) is a demyelinating disorder of unknown etiology, possibly caused by a virus or is virus-triggered. Several viruses, including herpesviruses, were suggested as etiologic agents or risk factors for exacerbation in the course of illness but none have been shown to be irrefutably linked. Recently the interest of researchers and clinicians in the association between viruses and MS was reawakened by the development of progressive multifocal leukoencephalopathy, a demyelinating and fatal disease caused by JC polyomavirus replication, in natalizumab-treated MS patients. In this review, we will illustrate the evidence underlying the viral hypothesis for MS pathogenesis and will review the main features of the potential viral candidates. We will also describe the risks associated with newer MS therapies and with viral/bacterial vaccinations.

Progressive multifocal leukoencephalopathy

Progressive multifocal leukoencephalopathy (PML) is a disease of the central nervous system (CNS) with destructive infection of oligodendrocytes by JC virus. PML belongs to the opportunistic infections. It is observed in patients with HIV infection, lymphoid malignancies, after organ- and stem cell transplantations and more recently in the context of modern immune-therapies with monoclonal antibodies (mAb) like natalizumab, rituximab, infliximab and efalizumab. The natural course of PML is fatal within months. More recently, the Immune Reconstitution Inflammatory Syndrome (IRIS) has been observed in patients with HIV infection treated with combination antiretroviral therapy (cART) as well as patients in whom the PML-inducing immune therapy has been terminated. In PML-IRIS the immune system contributes to the elimination of JC virus from the CNS and if PML-IRIS emerges, PML can be survived but can lead as well to catastrophic outcomes with brain herniation and death. Therefore the management of IRIS requires special knowledge in JC virus biology and patient care. JC virus infection is possibly involved in a variety of additional neurological conditions and cancer. Much will be learned within the next years that could change our view on the understanding of JC virus and human disease.

Polyomavirus shedding in the stool of healthy adults

We recently reported the frequent detection of polyomaviruses (BK virus [BKV] or simian virus 40 [SV40]) in 46% of stool samples from hospitalized children. In order to determine if adults exhibit fecal shedding of polyomavirus, single stool specimens from healthy adults were evaluated by PCR. Overall, 20 (18.2%) of 110 specimens were positive for human polyomaviruses: 9 with BKV, 9 with JC virus (JCV), 1 with SV40, and 1 with both JCV and SV40. Among the 94 subjects without immune compromise, 17 (18.1%) were excreting polyomaviruses. This shedding frequency in adults was significantly lower than that observed in children (P < 0.001). These findings support the hypothesis that the gastrointestinal tract may be a site of polyomavirus persistence, and they suggest a fecal-oral route of viral transmission.

Progressive multifocal leukoencephalopathy, a review and an extended report of five patients with different immune compromised states

Progressive multifocal leukoencephalopathy (PML) is an opportunistic infection of the brain caused by the JC-virus. Both a decreased cellular or humoral immune response can increase the susceptibility for JC-virus induced PML. Not only HIV infected people are at risk, a wide range of otherwise immune compromised patients are a potential target for this virus. This report of five PML patients shows the importance of a clinician's familiarity with this disease and it's presenting symptoms. The presenting symptoms of PML can sometimes mimic worsening of the underlying disease. Although different therapeutic strategies have been tried, the outcomes remain very poor. In this series, treatment with cidofovir appears not to be effective in treating PML, neither in HIV positive nor HIV negative patients. Experimental therapy with leflunomide, after tapering of the immunosuppressive medication, did change the natural course of PML in one patient.

A progressive neurologic disorder with multiple CNS lesions: a neuroimaging clinicopathologic correlation. Progressive multifocal leukoencephalopathy (PML)

A 51-year-old man with a diagnosis of myelodysplasia and non-Hodgkin's lymphoma underwent an unmatched allogenic bone marrow transplantation and was treated posttransplant with chronic immunosuppressive medication. Eight months following transplantation, he presented with progressive dysarthria, cognitive and visual decline. Evaluation included brain magnetic resonance (MR) imaging demonstrating multifocal areas of increased T2 and FLAIR (fluid attenuated inversion recovery) signals involving the left frontal, parietal, and occipital lobes. The MR lesions demonstrated diffuse increased signal on DWI (diffusion-weighted images) and normal to low signal on ADC (apparent diffusion coefficients). Contrast-enhanced T1 images were unremarkable. Lumbar puncture revealed a mild elevation in cerebrospinal fluid (CSF) protein. CSF PCR assay for viral DNA fragments were negative on two occasions. Serum serology for HIV was negative as well. A brain biopsy was subsequently performed. The clinical and neuroimaging differential diagnoses as well as neuropathologic correlation are presented.

The role of polyomaviruses in human disease

The human polyomaviruses, BK virus and JC virus, have long been associated with serious diseases including polyomavirus nephropathy and progressive multifocal leukoencephalopathy. Both viruses establish ubiquitous, persistent infections in healthy individuals. Reactivation can occur when the immune system is impaired, leading to disease progression. Recently, the human polyomavirus family has expanded with the identification of three new viruses (KI, WU and Merkel cell polyomavirus), all of which may prove to be involved in human disease. This review describes the general aspects of human polyomavirus infections and pathogenicity. Current topics of investigation and future directions in the field are also discussed.

Analysis of cerebrospinal fluid and cerebrospinal fluid cells from patients with multiple sclerosis for detection of JC virus DNA

OBJECTIVE

1) To determine whether JC virus (JCV) DNA was present in the cerebrospinal fluid (CSF) and blood from patients with multiple sclerosis (MS) in comparison with controls and 2) to find out if our clinical material, based on presence of JCV DNA, included any patient at risk for progressive multifocal leukoencephalopathy (PML).

METHODS

The prevalence of JCV DNA was analyzed in CSF and plasma from 217 patients with MS, 86 patients with clinically isolated syndrome (CIS), and 212 patients with other neurological diseases (OND). In addition, we analyzed CSF cells, the first report of JCV DNA in CSF cells in a single sample, and peripheral blood cells in a subgroup of MS (n = 49), CIS (n = 14) and OND (n = 53).

RESULTS

A low copy number of JCV DNA was detected in one MS cell free CSF sample and in one MS CSF cell samples. None of these had any signs of PML or developed this disease during follow-up. In addition, two OND plasma samples were JCV DNA positive, whereas all the other samples had no detectable virus.

CONCLUSION

A low copy number of JCV DNA may occasionally be observed both in MS and other diseases and may occur as part of the normal biology of JC virus in humans. This study does not support the hypothesis that patients with MS would be at increased risk to develop PML, and consequently screening of CSF as a measurable risk for PML is not useful.

Induction of experimental autoimmune encephalomyelitis in Lewis rats by a viral peptide with limited homology to myelin basic protein

Viral infections are thought to play an important role in the pathogenesis of multiple sclerosis potentially through molecular mimicry, but direct evidence from humans and animal models remains inadequate. Based on the fact that amino acid homology has been found between viral and host encephalitogenic protein, we designed four viral peptides (peptides of HBV polymerase protein, large T protein of JC virus, EB virus DNA polymerase and alkaline exonuclease of Human herpesvirus 6) with limited homology to myelin basic protein and explored their clinical, immunological and histological characteristics in Lewis rats. The immunization with JC virus peptide induced slight clinical signs of EAE in Lewis rats. Immunological examination indicated that rats immunized with JC virus peptide triggered T-cell cross-reactivity against MBP68-86, but failed to induce antibody cross-reactivity with MBP68-86. Histological staining exhibited the infiltration of inflammatory T cells and the activation of microglia in spinal cords of rats immunized with MBP68-86 and JC virus peptide. Other three peptides had negative findings in Lewis rats. These results suggested that molecular mimicry could be an important factor in the pathogenesis of EAE induced with JC virus peptide by expanding a population of reactive T cells that recognize MBP68-86 in Lewis rats inferring a possible pathogenesis for molecular mimicry in MS.

Human demyelinating disease and the polyomavirus JCV

Many human neurological diseases involve demyelination of the central and/or peripheral nervous systems. These include the hereditary leukodystrophies--which have a genetic basis; multiple sclerosis (MS)--where the underlying cause of demyelination remains unknown; and progressive multifocal leukoencephalopathy (PML)--where the etiology is well-established as being viral. The human neurotropic polyomavirus--JC virus (JCV)--is the etiologic agent of PML, a fatal demyelinating disease of the central nervous system that occurs mainly in immunosuppressed patients, especially those with HIV/AIDS. JCV belongs to the polyomavirus family of tumor viruses that are characterized by non-enveloped icosahedral capsids containing small, circular, double-stranded DNA genomes. Serological studies have shown that JCV is widespread throughout the human population, but infections are usually restricted by the immune system, particularly cell-mediated immunity, causing the virus to enter a latent phase. An important corollary of this is that situations of severe immunosuppression may permit JCV to replicate and are thus a risk factor for PML.

Quantitative real-time PCR assay for detection of human polyomavirus infection

The human polyomaviruses BK (BKV) and JC (JCV) affect immunosuppressed patients and are associated with urogenital tract (BKV) and CNS disorders (JCV) and in humans, the pathogenic role of the rhesus monkey virus, Simian virus 40 (SV40), is uncertain. These three viruses have somewhat overlapping tissue pathogenicity and detection of all three polyomaviruses is desirable. A broadly targeted, simple, single tube real-time degenerated quantitative PCR (QPCR) technique for detection of JCV, BKV and SV40 DNA was developed. To avoid false positive results, due to contamination with commonly used SV40 T-antigen plasmids, a conserved region of the VP2 gene was targeted. Down to 1-10 copies of target DNA per PCR reaction were detected. The QPCR was compared with a nested PCR on 41 clinical samples (urine, serum and plasma): 24 (58.5%) tested positive by nested PCR, whereas 31 (75.6%) were positive with QPCR. One CSF sample, from a patient with progressive multifocal leukoencephalopathy, was negative with the nested PCR but determined as positive by QPCR. Sera from 24 blood donors were negative with QPCR. The QPCR described had a high sensitivity. Its specificity was confirmed sequencing. The QPCR is simple to perform and is valuable for diagnosis of polyomavirus infection.

Progressive multifocal leukoencephalopathy: lessons from AIDS and natalizumab

The dramatic increase in the incidence of progressive multifocal leukoencephalopathy (PML) that occurred as a consequence of the AIDS pandemic and the recent association of PML with the administration of natalizumab, a monoclonal antibody to alpha4 integrin that blocks inflammatory cell entry into the brain, has stimulated a great deal of interest in this previously obscure viral demyelinating disease. The etiology of this disorder is JC virus (JCV), a polyoma virus, observed in 80% of the population worldwide. Seroepidemiological studies indicate that infection with this virus typically occurs before the age of 20 years. No primary illness owing to JCV infection has been recognized and the means of spread from person to person remains obscure. Following infection, the virus becomes latent in bone marrow, spleen, tonsils and other tissues. Periodically the virus reactivates during which time it can be demonstrated in circulating peripheral lymphocytes. The latter is significantly more commonly observed in immunosuppressed populations than that in normal subjects. Despite the large pool of people infected with JCV, PML remains a relatively rare disease. It is seldom observed in the absence of an underlying predisposing illness, typically one that results in impaired cellular immunity. A variety of factors are likely responsible for the unique increase in frequency of PML in HIV infection relative to other underling immunosuppressive disorders. Preliminary data suggests that natalizumab appears to distinctively predispose recipients to PML relative to other infectious complications. Studies in these populations will be invaluable in understanding the mechanisms of disease pathogenesis.

Bk virus: a clinical review

We present a review of the clinically oriented literature about BK virus, a relative of JC virus, which is the etiologic agent of progressive multifocal leukoencephalopathy (PML). The kidney, lung, eye, liver, and brain have been proposed as sites of BK virus-associated disease, both primary and reactivated. BK virus has also been detected in tissue specimens from a variety of neoplasms. We believe that BK virus is most often permissively present in sites of disease in immunosuppressed patients, rather than being an etiologic agent that causes symptoms or pathologic findings. There is, however, strong evidence for BK virus-associated hemorrhagic cystitis and nephritis, especially in recipients of solid organ or bone marrow transplants. Now that BK virus can be identified by use of specific and sensitive techniques, careful evaluation of the clinical and pathologic presentations of patients with BK virus will allow us to form a clearer picture of viral-associated pathophysiology in many organ systems.