JC Virus PCR Detection Is Not Infallible: A Fulminant Case of Progressive Multifocal Leukoencephalopathy with False-Negative Cerebrospinal Fluid Studies despite Progressive Clinical Course and Radiological Findings

Atypical Presentation of a Patient With Progressive Multifocal Leukoencephalopathy

Progressive multifocal leukoencephalopathy (PML) is a rare, demyelinating infectious disease of the central nervous system, primarily affecting immunosuppressed individuals, such as those with acquired immunodeficiency syndrome (AIDS) or undergoing immunosuppressive therapy. The causative agent is the dormant John Cunningham (JC) polyomavirus, which reactivates in immunocompromised patients. PML is diagnosed through clinical observations, imaging, and polymerase chain reaction (PCR) analysis, detecting JC virus deoxyribonucleic acid (DNA) in the cerebrospinal fluid (CSF). Here, we report a case of a 42-year-old male, recently diagnosed with human immunodeficiency virus (HIV), who presented with slurred speech, difficulty articulating, tingling in both feet, difficulty walking, and significant weight loss. Examination revealed absent reflexes, coordination impairment, and diminished vibration sense. Blood tests showed anemia, elevated D-dimer, and HIV-1 positivity with a low CD4 count. CSF analysis indicated a lymphocytic profile with elevated protein and marginally increased adenosine deaminase (ADA). Autoantibody testing was positive for antinuclear antibodies (ANA), but CSF culture and India ink staining were negative. Magnetic resonance imaging (MRI) of the brain revealed hyperintense lesions on T2-weighted and fluid-attenuated inversion recovery (FLAIR) images in the left peritrigonal and parietal white matter, suggesting demyelination. The diagnosis of PML was confirmed by a positive JC virus PCR result from the CSF. The patient was started on combination antiretroviral therapy (cART) and supportive measures to improve immune status. This case underscores the importance of considering PML in patients with new-onset neurological symptoms and immunosuppression.

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.

Flaccid Brachial Monoplegia As Initial Presentation in a Patient With Progressive Multifocal Leukoencephalopathy

Progressive multifocal leukoencephalopathy (PML) is a demyelinating disease caused by activation of John Cunningham virus (JCV) replication in the setting of impaired cellular immunity. A positive polymerase chain reaction (PCR) assay for JCV DNA in the cerebrospinal fluid (CSF) in conjunction with clinical findings and neuroimaging are diagnostic of PML. A false negative JCV PCR in the CSF may occur, necessitating PML confirmation by brain biopsy. We describe the unique clinical profile of a patient with no prior history of immunocompromise, referred to us for electrodiagnostic evaluation, who initially presented with rapidly progressive weakness of the right upper extremity. The unusual pattern of motor weakness suggested a conduction block or disconnection at the subcortical level. The patient was later diagnosed with atypical small cell lymphocytic lymphoma although not treated with monoclonal antibodies or other forms of chemotherapy. The CSF was negative for JCV, and PML was subsequently confirmed by brain biopsy. This case illustrates an uncommon presentation of PML and highlights the need for a high index of suspicion to diagnose PML.

Progressive multifocal leukoencephalopathy successfully treated with mefloquine and literature review

Progressive multifocal leukoencephalopathy (PML) is an opportunistic infection due to reactivation of John Cunningham virus (JCV). The diagnosis depends on evidence from clinical, imaging, and virologic studies. When the cerebrospinal fluid shows a negative polymerase chain reaction result, brain biopsy is required to confirm the diagnosis. PML has no standard treatment except for immune reconstitution. The anti-JCV effect of mefloquine, however, is supported by some studies, and if brain biopsy is difficult, a mefloquine trial can be considered. We describe a case of possible PML successfully treated with mefloquine.

Early Pathological JC Virus Lesions in a Patient without Any MRI-based Indications

A 70-year-old woman with a human T-cell leukemia virus type 1 infection without any focal neurological symptoms showed age-related atherosclerotic changes in the white matter without any suspicious signal changes suggestive of progressive multifocal leukoencephalopathy (PML) based on the findings of MRI. Viral polymerase chain reaction (PCR) revealed 6,700 copies/mL of the JC virus genome in the cerebrospinal fluid (CSF). An immuno-pathological examination of the autopsied brain revealed JC virus capsid proteins, and in situ hybridization confirmed a JC virus infection, indicating that an active infection begins at the radiologically indistinguishable phase of PML. An early JC virus infection is probably associated with small, scattered demyelinating lesions around the cortico-medullary area of the cortex.

Possible progressive multifocal leukoencephalopathy and active multiple sclerosis under dimethyl fumarate: the central role of MRI in informing therapeutic decisions

Background

Progressive multifocal leukoencephalopathy (PML) can rarely occur in Multiple Sclerosis (MS) patients undergoing dimethyl fumarate (DMF) treatment. Our case stresses the limits of current diagnostic and stratification risk criteria, highlighting the potential role of Magnetic Resonance Imaging (MRI) in advising clinical choices.

Case presentation

A 54 years old MS male patient treated with DMF, after 3 years of clinical stability developed a subacute clinical worsening. He had no severe lymphopenia but MRI signs suggestive of a coexistence of PML and MS activity. Although his viral title was negative, DMF was discontinued, with clinical and radiological improvement.

Conclusions

This case highlights the challenges behind PML diagnosis, especially in patients not fulfilling the risk stratification criteria and that might present with concurrent disease activity, stressing the potential role of MRI in informing therapeutic decisions.

Neuroimaging Insights Into Early Stages of HIV-Progressive Multifocal Leukoencephalopathy: A Case Report

This report aims to enhance the understanding of early longitudinal neuroimaging features of progressive multifocal leukoencephalopathy (PML) in human immunodeficiency virus (HIV). Neuroimaging has become crucial in the diagnosis and early recognition of PML. Recognition of magnetic resonance imaging (MRI) features in the early stages of PML is paramount to avoid misdiagnosis and facilitate the delivery of treatments aimed at reducing disease progression. A 49-year-old white man with HIV presented with 4-month progressive left-sided weakness. Neurological examination revealed mild cognitive impairment, left-sided hemiparesis, and somatosense impairment to all modalities. Brain MRI revealed a punctate pattern with innumerable T2-FLAIR (fluid attenuated inversion recovery) hyperintensities in the cortex, brainstem, cerebellum, subcortical, and periventricular areas. Susceptibility-weighted imaging (SWI) revealed hypointensities involving subcortical U-fibers and cortical architecture. A comprehensive diagnostic evaluation was inconclusive. John Cunningham virus (JCV) PCR in cerebrospinal fluid (CSF) was indeterminate. He was started on antiretroviral therapy. Repeat brain MRI performed 1.5 months later, in the setting of further neurological decline, demonstrated progression of the T2-hyperintensities into a large confluent white matter lesion in the right frontoparietal lobe. Despite an indeterminate JCV PCR, the appearance and characteristic progression of the lesions in successive imaging in the setting of severe immunosuppression, with extensive negative infectious workup, was indicative of PML. This clinical experience illustrates unique neuroimaging features of HIV-PML in early stages and its progression over time. It especially highlights the relevance of the SWI sequence in the diagnosis and features observed with disease evolution. Short-term imaging follow-up may assist with the recognition of MRI features consistent with the biology of the infection.

Improving detection of JC virus by ultrafiltration of cerebrospinal fluid before polymerase chain reaction for the diagnosis of progressive multifocal leukoencephalopathy

Background

Progressive multifocal leukoencephalopathy (PML) is a demyelinating disorder caused by JC virus (JCV). Although detecting JCV DNA in the cerebrospinal fluid (CSF) by real-time polymerase chain reaction (PCR) is useful, diagnosis is difficult when JCV concentrations are low. We therefore aimed to lower the detection limit of real-time PCR testing by enriching JCV in the CSF via ultrafiltration.

Methods

Virus suspensions and CSF specimens from 20 untreated patients with suspected PML were collected and total DNAs were extracted. The JCV large T gene was detected by quantitative real-time PCR under condition with and without prior centrifugal ultrafiltration.

Results

The JCV DNA was reliably detected to a lower limit of 10 copies/mL of virus suspension by real-time PCR with ultrafiltration. When using this method, the quantity of JCV DNA per PCR reaction increased 3.2- to 8.7-fold compared with the standard procedure. Seven patients were positive for JCV when using the standard procedure, and an additional patient was positive when using ultrafiltration. All JCV-positive patients had neurological features and magnetic resonance imaging findings compatible with PML.

Conclusions

The detection limit of JCV DNA by real-time PCR can be lowered by viral enrichment using ultrafiltration. Our simple protocol offers a valuable tool for PML diagnosis when extremely low copy numbers of JCV are released into the CSF or when brain biopsy is not feasible.

Progressive Multifocal Leukoencephalopathy Diagnosed by Brain Biopsy, not by the DNA Test for JC Virus

Progressive multifocal leukoencephalopathy (PML) is a demyelinating disease of the central nervous system caused by a lytic infection of oligodendrocytes due to the presence of JC polyomavirus (JCV). The disease occurs mostly in immunocompromised patients and is associated with a high mortality rate. The diagnosis of PML is based on a polymerase chain reaction (PCR) assay for JC viral DNA in cerebrospinal fluid (CSF). However, case reports of the diagnosis of PML established with brain biopsy despite negative JCV CSF PCR analysis when clinical and neuroimaging features are suggestive of PML have been published. A 44-year-old male with a 6-year history of acquired immunodeficiency syndrome developed mental confusion and memory impairment despite 3 months of highly active antiretroviral therapy. Magnetic resonance imaging revealed multiple subcortical white matter lesions in bilateral hemispheres and subcortical nuclei including the thalamus and basal ganglia. JCV DNA was not detected in CSF study, but a brain biopsy showed a high JCV DNA titer. The diagnosis of PML was established with brain biopsy. An early brain biopsy may be important in the diagnosis of PML in patients with clinical manifestations and neuroimaging findings if JCV DNA is undetectable in the CSF PCR.

Polyomaviruses

Over the last 10 years, the number of identified polyomaviruses has grown to more than 35 subtypes, including 13 in humans. The polyomaviruses have similar genetic makeup, including genes that encode viral capsid proteins VP1, 2, and 3 and large and small T region proteins. The T proteins play a role in viral replication and have been implicated in viral chromosomal integration and possible dysregulation of growth factor genes. In humans, the Merkel cell polyomavirus has been shown to be highly associated with integration and the development of Merkel cell cancers. The first two human polyomaviruses discovered, BKPyV and JCPyV, are the causative agents for transplant-related kidney disease, BK commonly and JC rarely. JC has also been strongly associated with the development of progressive multifocal leukoencephalopathy (PML), a rare but serious infection in untreated HIV-1-infected individuals and in other immunosuppressed patients including those treated with monoclonal antibody therapies for autoimmune diseases systemic lupus erythematosus, rheumatoid arthritis, or multiple sclerosis. The trichodysplasia spinulosa-associated polyomavirus (TSAPyV) may be the causative agent of the rare skin disease trichodysplasia spinulosa. The remaining nine polyomaviruses have not been strongly associated with clinical disease to date. Antiviral therapies for these infections are under development. Antibodies specific for each of the 13 human polyomaviruses have been identified in a high percentage of normal individuals, indicating a high rate of exposure to each of the polyomaviruses in the human population. PCR methods are now available for detection of these viruses in a variety of clinical samples.

Brain Biopsy Is More Reliable than the DNA test for JC Virus in Cerebrospinal Fluid for the Diagnosis of Progressive Multifocal Leukoencephalopathy

The current standard diagnostic approach for progressive multifocal leukoencephalopathy (PML) is to perform a DNA test to identify the presence of the JC virus in cerebrospinal fluid (CSF). A 32-year-old woman with a 5-year history of systemic lupus erythematosus developed right hemiplegia and motor aphasia. MRI revealed a large white matter lesion in the left frontal lobe. JC virus DNA was undetectable in the CSF, but a brain biopsy showed typical histopathology and a high DNA load of the JC virus. The patient was treated with mefloquine and mirtazapine, and is currently alive at 24 months after onset. An early brain biopsy may therefore be important for making a timely diagnosis of PML.

Diagnostic assays for polyomavirus JC and progressive multifocal leukoencephalopathy

Progressive multifocal leukoencephalopathy (PML) is a devastating and often fatal demyelinating disease of the central nervous system for which effective therapies are lacking. It is caused by the replication of polyomavirus JC (JCV) in the oligodendrocytes and astrocytes leading to their cytolytic death and loss of myelin from the subcortical white matter. While the virus is very common in human populations worldwide, the incidence of the disease is very low and confined almost exclusively to individuals with some form of immunological dysfunction. However, the number of people who constitute the at-risk population is growing larger and includes individuals with HIV-1/AIDS and patients receiving immunomodulatory therapies such as multiple sclerosis patients treated with natalizumab. Further adding to the public health significance of this disease are the difficulties encountered in the diagnosis of PML and the lack of useful biomarkers for PML progression. In this review, we examine the diagnostic assays that are available for different aspects of the JCV life cycle, their usefulness and drawbacks, and the prospects for improvements.