JC virus spread is potentiated by glial replication and demyelination-linked glial proliferation.

Progressive multifocal leukoencephalopathy (PML) is a demyelinating infection of the immunosuppressed brain, mediated by the gliotropic polyomavirus JCV. JCV replicates in human glial progenitor cells and astrocytes, which undergo viral T antigen-triggered mitosis, enabling viral replication. We asked if JCV spread might therefore be accelerated by glial proliferation. Using both in vitro analysis and a human glial chimeric mouse model of JCV infection, we found that dividing human astrocytes supported JCV propagation to a substantially greater degree than did mitotically quiescent cells. Accordingly, bulk and single cell RNA-sequence analysis revealed that JCV-infected glia differentially manifested cell cycle-linked disruption of both DNA damage response and transcriptional regulatory pathways. In vivo, JCV infection of humanized glial chimeras was greatly accentuated by cuprizone-induced demyelination and its associated mobilization of GPCs. Importantly, in vivo infection triggered the death of uninfected as well as infected glia, reflecting significant bystander death. Together, these data suggest that JCV propagation in PML may be accelerated by glial cell division. As such, the accentuated glial proliferation attending disease-associated demyelination may provide an especially favorable environment for JCV propagation, thus potentiating oligodendrocytic bystander death and further accelerating demyelination in susceptible hosts.

Progressive multifocal leukoencephalopathy in patients with chronic kidney disease.

Progressive multifocal leukoencephalopathy (PML) is an opportunistic central nervous system infection caused by the human polyomavirus 2, leading to demyelination from oligodendrocyte death and rapid neurologic decline. Most commonly, PML affects patients in immunocompromised states. However, rare reports of PML in an immunocompetent host exist. Here, we report two cases of PML in older individuals with chronic kidney disease (CKD). CKD can ultimately lead to immune system dysfunction and place patients in a relatively immunosuppressed state. Testing for JC virus should remain a consideration for rapid, unexplained neurologic decline even without known immunocompromised status in the appropriate clinical setting.

Pathology for severe inflammatory PML with PD1/PD-L1 expression of favorable prognosis: What's a prognostic factor for PML-IRIS?

A 72-year-old woman with dermatomyositis (DM) developed neurological manifestation, and magnetic resonance imaging (MRI) revealed multiple T2/fluid-attenuated inversion recovery (FLAIR)-hyperintense lesions predominantly in the deep white matter of the cerebral hemisphere. Punctate or linear contrast enhancement was observed surrounding the T1-hypointense area. Multiple T2/FLAIR-hyperintense lesions were aligned along with the corona radiata. Malignant lymphoma was first suspected, and a brain biopsy was performed. Pathological investigation suggested the provisional diagnosis of "suspicious of malignant lymphoma." Owing to emergent clinical conditions, high-dose methotrexate (MTX) therapy was conducted, and then T2/FLAIR-hyperintense lesions were dramatically reduced. However, the diagnosis of malignant lymphoma was concerning since multiplex PCR demonstrated clonal restriction of the Ig H gene for B cells and TCR beta genes for T cells. Histopathology revealed the infiltration of both CD4+ and CD8+ T cells, and the CD4+ /CD8+ ratio was 4.0. Moreover, prominent plasma cells were observed, in addition to CD20+ B cells. Atypical cells with enlarged nuclei were present, and they were not hematopoietic but found as glial cells. JC virus (JCV) infection was verified with both immunohistochemistry and in situ hybridization; the final diagnosis was progressive multifocal leukoencephalopathy (PML). The patient was treated with mefloquine and discharged. This case is informative in understanding the host anti-viral response. Variable inflammatory cells were observed, including CD4+ and CD8+ T cells, plasma cells, and a small amount of perivascular CD20+ B cells. PD-1 and PD-L1 expression was observed in lymphoid cells and macrophages, respectively. PML with inflammatory reactions was thought fatal, and autopsy cases of PML with immune reconstitution inflammatory syndrome (IRIS) demonstrated excessive infiltration of only CD8+ T cells. However, this case revealed infiltration of variable inflammatory cells, and a favorable prognosis would be expected under PD-1/PD-L1 immune-checkpoint regulation.

A human T-lymphotropic virus-1 carrier who developed progressive multifocal leukoencephalopathy following immunotherapy for sarcoidosis: a case report.

BACKGROUND: Progressive multifocal leukoencephalopathy (PML) is a devastating demyelinating disorder of the central nervous system caused by opportunistic infection of the JC virus (JCV). CASE PRESENTATION: A 58-year-old Japanese woman was admitted to our hospital for aphasia. She had a 5-year history of untreated sarcoidosis and was a human T cell lymphotropic virus-1 (HTLV-1) carrier. Serum angiotensin-converting enzyme, soluble interleukin-2 receptor, lysozyme, and calcium levels were elevated. JCV-DNA was not detected in cerebrospinal fluid by PCR testing. Skin biopsy revealed noncaseating granuloma formation. Bilateral multiple nodular lesions were present on chest X-ray. Brain magnetic resonance imaging showed left frontal and temporal lesions without gadolinium enhancement. As we suspected that systemic sarcoidosis had developed into neurosarcoidosis, we started steroid and infliximab administration. After treatment, the chest X-ray and serum abnormalities ameliorated, but the neurological deficits remained. At 1 month after immunotherapy, she developed right hemiparesis. Cerebrospinal fluid was positive for prototype (PML-type) JCV on repeated PCR testing. Brain biopsy revealed demyelinating lesions with macrophage infiltration, atypical astrocytes, and JCV antigen-positive cells. We diagnosed her with PML and started mefloquine, leading to partial remission. CONCLUSIONS: Sarcoidosis and HTLV-1 infection both affect T cell function, especially CD4+ T cells, and may developped the patient's PML. The comorbidity of sarcoidosis, PML, and HTLV-1 infection has not been reported, and this is the world's first report of PML associated with HTLV-1 infection and sarcoidosis.

Progressive multifocal leukoencephalopathy in multiple myeloma: a case report of a patient with SARS-CoV-2 infection and an updated systematic literature review.

BACKGROUND: Progressive multifocal leukoencephalopathy (PML) is a demyelinating disease of the central nervous system caused by a reactivation of the human polyomavirus 2 (HPyV-2, previously known as JCV) in immunosuppressed individuals. Few cases of PML have been described in multiple myeloma (MM) patients. METHODS: We described a case of PML in a patient with MM with fatal worsening that occurred during SARS-CoV-2 infection. We also performed a literature review to update the 16 cases series of MM patients with PML already collected until April 2020. RESULTS: A 79-year-old female patient with refractory IgA lambda MM in Pomalidomide- Cyclophosphamide-Dexamethasone regimen developed gradual lower limbs and left arm paresis along with a decreased consciousness 3.5 years after the MM diagnosis. Symptoms developed shortly after the recognition of hypogammaglobulinemia. After SARS-CoV-2 infection, her neurological status quickly worsened until she deceased. MRI features and JCV-positive PCR on CSF confirmed the PML diagnosis. Our literature review adds sixteen clinical cases of PML in MM published between May 2020 and March 2023 to the 16 cases already collected in the previously published review by Koutsavlis. DISCUSSION: PML has been increasingly described in MM patients. It remains questionable if the HPyV-2 reactivation is determined by the severity of MM itself, by the effect of drugs or by a combination of both. SARS-CoV-2 infection may have a role in worsening PML in affected patients.

A case of progressive multifocal leukoencephalopathy with hypogammaglobulinemia and a TCF3 mutation.

Progressive multifocal leukoencephalopathy (PML) is a rare and potentially fatal demyelinating disease of the central nervous system (CNS) caused by JC virus; it was previously seen predominantly in immunocompromised patients and those under intense immune suppression. Here, we report the case of a patient with PML with hypogammaglobulinemia and a heterozygous mutation in the TCF3 gene. As the TCF3 gene has been demonstrated to play an important role in the B cell differentiation process and the patient had no other medical history of the immune system, he was diagnosed with common variable immunodeficiency (CVID). To our knowledge, this is the first case of patient with a TCF3 gene deficiency and hypogammaglobulinemia who developed PML.

Early reduction of the splicing factor2/alternative splicing factor: a cellular inhibitor of the JC polyomavirus in natalizumab-treated MS patients long before developing progressive multifocal leukoencephalopathy.

Natalizumab is effective against relapsing-remitting multiple sclerosis (MS) but increases the risk of progressive multifocal leukoencephalopathy (PML), which is caused by the activation of the JCV polyomavirus. SF2/ASF (splicing factor2/alternative splicing factor) is a potent cellular inhibitor of JCV replication and large T-antigen (T-Ag) expression. We reported that SF2/ASF levels in blood cells increase during the first year of natalizumab therapy and decrease thereafter, inversely related to T-Ag expression, and suggested a correlation with JCV reactivation. Here, we report SF2/ASF levels of longitudinal blood samples of two patients undergoing natalizumab therapy, who developed PML while monitored, in comparison to natalizumab-treated controls and to one-off PML samples. After 6 months of therapy, SF2/ASF levels of the two cases were reduced, instead of increased, and their overall SF2/ASF levels were lower than those from natalizumab controls. Since SF2/ASF inhibits JCV, its early reduction might have a role in subsequent PML. We are aware of the limitations of the study, but the uniqueness of serial blood samples collected before and after PML onset in natalizumab-treated patients must be stressed. If confirmed in other patients, SF2/ASF evaluation could be a new and early biomarker of natalizumab-associated PML risk, allowing an 18-24-month interval before PML onset (presently ~ 5 months), in which clinicians could evaluate other risk factors and change therapy.

A case of immune reconstitution syndrome complicating progressive multifocal leukoencephalopathy after kidney transplant: Clinical, pathological, and radiographic features.

Progressive multifocal leukoencephalopathy (PML) is a life-threatening central nervous system (CNS) disorder, most commonly described in patients infected with the human immunodeficiency virus (HIV). Limited data exist on its natural history and treatment in solid organ transplant (SOT) recipients. A complication of PML is the immune reconstitution inflammatory syndrome (IRIS), which develops after T cell reconstitution and can have severe consequences when it occurs in the CNS. While well described in HIV-infected individuals, its clinical features, diagnosis, and treatment after SOT are largely unknown. We report a case of a kidney transplant recipient who was diagnosed with PML and developed significant worsening of her symptoms upon reduction of immunosuppression. Thallium SPECT showed avid uptake suggestive of lymphoma, but the diagnosis of PML-IRIS was ultimately established by brain biopsy. She survived with nearly complete restoration of her functional status after a prolonged steroid taper.

Development of demyelinating lesions in progressive multifocal leukoencephalopathy (PML): Comparison of magnetic resonance images and neuropathology of post-mortem brain.

Progressive multifocal leukoencephalopathy (PML) is a demyelinating disorder caused by opportunistic infection of JC polyomavirus (JCV). Today, increased attention has been focused on PML development in multiple sclerosis (MS) patients under disease-modifying therapies (DMT). Although in the acquired immunodeficiency syndrome (AIDS) era, PML was thought to be a rapidly progressive disease with poor prognosis, drug-associated PML is relatively slow in progress, and a favorable outcome may be expected with early diagnosis. However, early PML diagnosis on magnetic resonance imaging (MRI) is frequently difficult, and JCV DNA copy number in cerebrospinal fluid (CSF) is usually low. To facilitate early PML diagnosis on MRI, the pre-mortem images were compared with neuropathology of the post-mortem brain, and underlying pathology corresponding to the MRI findings was evaluated. As a result, PML lesions of the autopsied brain were divided into three parts, based on the disease extension patterns: (A) Progressive white matter lesion in the right frontoparietal lobe including the precentral gyrus. Huge demyelinated lesions were formed with fusions of numerous small lesions. (B) Central lesion including deep gray matters, such as the putamen and thalamus. The left thalamic lesion was contiguous with the pontine tegmentum. (C) Infratentorial lesion of brainstem and cerebellum. Demyelination in the pontine basilar region and in cerebellar white matter was contiguous via middle cerebellar peduncles (MCPs). In addition, (D) satellite lesions were scattered all over the brain. These observations indicate that PML lesions likely evolve with three steps in a tract-dependent manner: (1) initiation; (2) extension/expansion of demyelinating lesions; and (3) fusion. Understanding of the PML disease evolution patterns would enable confident early diagnosis on MRI, which is essential for favorable prognosis with good functional outcome.

A Chronic Lymphocytic Leukemia Patient with Progressive Multifocal Leukoencephalopathy Caused by John Cunningham Virus.

Progressive multifocal leukoencephalopathy (PML) is a rare but fatal disease leading to severe neurological impairments. PML is a clinical manifestation, which is usually associated with John Cunningham virus (JCV) infection. It is also correlated to malignancies that mainly include hematologic malignancies such as chronic lymphocytic leukemia (CLL). Until now, no specific treatment has been established for JCV-induced PML; therefore, the prognosis of this disease is poor.We present a case of a 67-year-old woman who suffered from CLL with a chief complaint of seizure. Her clinical symptoms, results of brain MRI and biopsy were suggestive for the JCV-induced PML. The patient had received treatment using mefloquine at dose of 250 mg/day with no clinical improvement.

Evaluation of RAG1 mutations in an adult with combined immunodeficiency and progressive multifocal leukoencephalopathy.

Here we describe novel mutations in recombination activation gene 1 (RAG1) in a compound heterozygous male patient with combined T and B cell immunodeficiency (CID). Clinical manifestations besides antibody deficiency included airway infections, granulomatosis and autoimmune features. He died at the age of 37 due to PML caused by JC virus infection. By targeted next-generation sequencing we detected post mortem in this patient three mutations in RAG1. One allele harbored two novel mutations (c.1123C>G, p.H375D and c.1430delC, p.F478Sfs*14), namely a missense variant and a frameshift deletion, of which the latter leads to a truncated RAG1 protein. The other allele revealed a previously described missense mutation (c.1420C>T, p.R474C, rs199474678). Functional analysis of the p.R474C variant in an in vitro V(D)J recombination assay exhibited reduced recombination activity compared to a wild-type control. Our findings suggest that mutations in RAG1, specifically the p.R474C variant, can be associated with relatively mild clinical symptoms or delayed occurrence of T cell and B cell deficiencies but may predispose to PML.

Progressive multifocal leukoencephalopathy in a patient with lymphoma and presumptive hyper IgE syndrome.

We, herein, report a 23-year-old male with a rare inherited immunodeficiency disease, hyperimmunoglobulin IgE syndrome (HIES), who developed progressive multifocal leukoencephalopathy (PML) and lymphoma simultaneously. Primary immunodeficiency of the patient has remained undiagnosed until adulthood. PML is a severe demyelinating disease of the central nervous system caused by John Cunningham virus. HIES is a rare, inherited immunodeficiency characterized by high serum levels of IgE, recurrent staphylococcal infection, eczema, and hypereosinophilia. PML may accompany primary immunodeficiency syndromes, but the association with HIES is exceedingly rare. We discuss the imaging findings, medical management, and a review of related literature on primary immunodeficiency cases complicating with PML.

Reassessing the risk of natalizumab-associated PML.

The risk algorithm for natalizumab-associated PML was first established in 2012 using the observations that JC virus antibody status, prolonged duration of natalizumab therapy (>2 years), and prior exposure to immunosuppressive therapy increased the risk for the disease. Prior to the publication of Biogen's algorithm, a risk algorithm was created by Fox and Rudick using an Excel spreadsheet in order to address the concerns of their patients. Applying the most recently available data regarding natalizumab-associated PML, the risk assessments for PML were recalculated. The current numbers indicate substantially higher risks for PML in 2015 than in 2012. Our calculations suggest that an individual having all three risk factors has an approximately 1 in 44 chance of developing PML.

Natalizumab-treated patients at high risk for PML persistently excrete JC polyomavirus.

Sixty-three natalizumab-treated patients with relapsing multiple sclerosis were screened for JC polyomavirus (JCV) viruria. Urinary-positive patients were longitudinally sampled for up to 24 weeks. Using methods that distinguish encapsidated virus from naked viral DNA, 17.5 % of patients were found to excrete virus, consistent with the prevalence of urinary excretion in the general population. Unexpectedly, urinary excretion was predominantly seen (>73 %) in patients with high JC antibody index (≥2.0). Active JCV infection, therefore, tends to occur in natalizumab patients that carry a high risk factor for the development of disease, directly linking JC infection to the risk factors for PML development.

Diagnostic performance of brain MRI in pharmacovigilance of natalizumab-treated MS patients.

BACKGROUND: In natalizumab-treated multiple sclerosis (MS) patients, magnetic resonance imaging (MRI) is considered as a sensitive tool in detecting both MS disease activity and progressive multifocal leukoencephalopathy (PML). OBJECTIVE: To investigate the performance of neuroradiologists using brain MRI in detecting new MS lesions and asymptomatic PML lesions and in differentiating between MS and PML lesions in natalizumab-treated MS patients. The secondary aim was to investigate interrater variability. METHODS: In this retrospective diagnostic study, four blinded neuroradiologists assessed reference and follow-up brain MRI scans of 48 natalizumab-treated MS patients with new asymptomatic PML lesions (n = 21) or new MS lesions (n = 20) or no new lesions (n = 7). Sensitivity and specificity for detection of new lesions in general (MS and PML lesions), MS and PML lesion differentiation, and PML detection were determined. Interrater agreement was calculated. RESULTS: Overall sensitivity and specificity for the detection of new lesions, regardless of the nature of the lesions, were 77.4% and 89.3%, respectively; for PML-MS lesion differentiation, 74.2% and 84.7%, respectively; and for asymptomatic PML lesion detection, 59.5% and 91.7%, respectively. Interrater agreement for the tested categories was fair to moderate. CONCLUSION: The diagnostic performance of trained neuroradiologists using brain MRI in pharmacovigilance of natalizumab-treated MS patients is moderately good. Interrater agreement among trained readers is fair to moderate.

Whole Genome Sequencing Reveals a Chromosome 9p Deletion Causing DOCK8 Deficiency in an Adult Diagnosed with Hyper IgE Syndrome Who Developed Progressive Multifocal Leukoencephalopathy.

PURPOSE: A 30 year-old man with a history of recurrent skin infections as well as elevated serum IgE and eosinophils developed neurological symptoms and had T2-hyperintense lesions observed in cerebral MRI. The immune symptoms were attributed to Hyper IgE syndrome (HIES) and the neurological symptoms with presence of JC virus in cerebrospinal fluid were diagnosed as Progressive Multifocal Leukoencephalopathy (PML). The patient was negative for STAT3 mutations. To determine if other mutations explain HIES and/or PML in this subject, his DNA was analyzed by whole genome sequencing. METHODS: Whole genome sequencing was completed to 30X coverage, and whole genome SNP typing was used to complement these data. The methods revealed single nucleotide variants, structural variants, and copy number variants across the genome. Genome-wide data were analyzed for homozygous or compound heterozygous null mutations for all protein coding genes. Mutations were confirmed by PCR and/or Sanger sequencing. RESULTS: Whole genome analysis revealed deletions near the telomere of both copies of chromosome 9p. Several genes, including DOCK8, were impacted by the deletions but it was unclear whether each chromosome had identical or distinct deletions. PCR across the impacted region combined with Sanger sequencing of selected fragments confirmed a homozygous deletion from position 10,211 to 586,751. CONCLUSION: While several genes are impacted by the deletion, DOCK8 deficiency is the most probable cause of HIES in this patient. DOCK8 deficiency may have also predisposed the patient to develop PML.

Longitudinal JCV serology in multiple sclerosis patients preceding natalizumab-associated progressive multifocal leukoencephalopathy.

The presence of anti-John Cunningham Virus (JCV) antibodies is a risk factor for the development of progressive multifocal leukoencephalopathy (PML) in MS patients treated with natalizumab. It has been suggested that an increase in serum anti-JCV antibody index precedes the development of PML. We here describe extensive longitudinal serum anti-JCV antibody indexes of four MS patients who developed PML. Anti-JCV antibodies were measured using the STRATIFY JCV™DxSelect™ test. All four patients had rather stable high anti-JCV antibody indexes in all samples obtained before developing PML. Possibly caused by reaching the saturation level of the assay, no increase in anti-JCV antibody indexes was seen just before the diagnosis of PML. This study confirms that high serum anti-JCV antibody indexes precede natalizumab-associated PML.

Unveiling the Enigma: John Cunningham Virus-Associated Progressive Multifocal Leukoencephalopathy in an Immunocompetent Individual.

Progressive multifocal leukoencephalopathy (PML) is considered an often fatal, demon-leading disease primarily associated with immunosuppression. Immunocompromised individuals predominantly exhibit this manifestation, while immunocompatible patients rarely encounter it. We present a unique case of PML in an immunocompetent individual who initially presented with stroke-like symptoms, received management, and was subsequently discharged. He returned to our hospital a few days later with similar complaints, prompting further investigations that revealed PML, a condition often overlooked, especially in individuals with an intact immune system. Although he received successful treatment with mefloquine and other anti-malarial medications and followed up on an outpatient basis, his subsequent outcome was unfavourable. As a result, this case emphasises the importance of having PML as a significant differential and therapeutic option.

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.

Association of B-cell activating factor gene variants with serum anti-JCV antibody positivity in male patients with multiple sclerosis under natalizumab treatment: Implications for progressive multifocal leukoencephalopathy risk stratification.

INTRODUCTION: Progressive multifocal leukoencephalopathy (PML) is a potentially life-threatening complication among Multiple Sclerosis (MS) patients under natalizumab treatment, with serum anti-JCV antibody titers being used for stratification risk. Given the critical role of interferon (IFN)/B-cell activating factor (BAFF) axis in humoral immune responses against viruses, we explored whether it is involved in the generation of serum anti-JCV antibodies among these patients. METHODS: 162 consecutive patients with relapsing-remitting MS under natalizumab treatment were included. Serum anti-JCV antibodies were measured at baseline, as well as 12 and 24 months after treatment initiation. Type I and II IFN-inducible genes and BAFF expression were quantitated in peripheral blood by qRT-PCR. Moreover, BAFF rs9514828, rs1041569, and rs9514827 gene variants were assessed by RFLP-PCR. RESULTS: While type I and II IFN inducible gene expression were not associated with anti-JCV serum titers, the latter were significantly correlated with BAFF gene expression. Of interest, the TTT haplotype of the studied BAFF variants was more frequently detected in male, but not female anti-JCV (+) MS patients compared to anti-JCV (-) counterparts at baseline, as well as at 12 months and 24 months of natalizumab treatment. Measures of clinical validity/utility for the BAFF TTT haplotype showed 88% specificity, 45%, positive predictive value, and sensitivity of 70% for the discrimination of anti-JCV (+) male MS patients after 24 months of treatment. CONCLUSIONS: Our study suggests an implication of the BAFF axis in the production of serum anti-JCV antibodies. Additionally, the BAFF TTT haplotype derived from the rs9514828, rs1041569, and rs9514827 variants may represent a novel risk factor for anti-JCV seropositivity and indirectly for PML development among male MS patients treated with natalizumab.