JCV granule cell neuronopathy: A rare case manifestation.

Granule cell neuronopathy (GCN) caused by John Cunningham virus (JCV) is a rare yet significant neurological complication, particularly in immunocompromised individuals such as those with AIDS. We present a case of a 34-year-old HIV-positive male exhibiting classical symptoms of cerebellar dysfunction. Magnetic resonance imaging revealed demyelination suggestive of progressive multifocal leukoencephalopathy (PML). Histopathological examination confirmed JCV-GCN, characterized by lytic infection of cerebellar granule cell neurons. Among the 41 reported cases of JCV-GCN, histopathological data were available for only 10 cases. Ours is the 11th case with available histopathology. This case underscores the importance of considering JCV infection in the differential diagnosis of progressive cerebellar syndromes in immunocompromised patients. Early recognition and diagnosis are crucial for appropriate management and prognosis.

Chemokine-mediated cell migration into the central nervous system in progressive multifocal leukoencephalopathy.

Progressive multifocal leukoencephalopathy (PML) has been associated with different forms of immune compromise. This study analyzes the chemokine signals and attracted immune cells in cerebrospinal fluid (CSF) during PML to define immune cell subpopulations relevant for the PML immune response. In addition to chemokines that indicate a general state of inflammation, like CCL5 and CXCL10, the CSF of PML patients specifically contains CCL2 and CCL4. Single-cell transcriptomics of CSF cells suggests an enrichment of distinct CD4+ and CD8+ T cells expressing chemokine receptors CCR2, CCR5, and CXCR3, in addition to ITGA4 and the genetic PML risk genes STXBP2 and LY9. This suggests that specific immune cell subpopulations migrate into the central nervous system to mitigate PML, and their absence might coincide with PML development. Monitoring them might hold clues for PML risk, and boosting their recruitment or function before therapeutic immune reconstitution might improve its risk-benefit ratio.

Progressive multifocal leukoencephalopathy with a benign prognosis in an immunocompetent patient - A case report.

John Cunningham virus (JCV) is most commonly acquired in childhood and is often asymptomatic throughout life. However, in the case of primary or secondary immunosuppression, it is known to cause progressive multifocal leukoencephalopathy (PML) in the central nervous system. Hereby, we describe a rare case of PML in a patient without known factors of immunosuppression or use of immunomodulation. A 53-year-old female patient was presented with progressive left-side weakness and tremors in the left hand over a period of two months. The patient was diagnosed with PML based on history, examination, cerebrospinal fluid markers, histopathology, and brain magnetic resonance imaging at presentation. Despite detailed examination, nothing was found in the patient to cause an immunosuppressed state. Therapy was started with mirtazapine with significant neurological improvement.To our knowledge, PML in immunocompetent patient with bening prognosis is a very rare condition. There is also no effective treatment. Our case is a complicated example of this condition.

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.

Successful epilepsy surgery in two cases with multiple sclerosis.

Brain surgery is the only curative treatment for people with focal epilepsy, but it is unclear whether this induces active disease in multiple sclerosis (MS). This creates a barrier to evaluate MS patients for epilepsy surgery. We present two cases of successful epilepsy surgery in patients with pharmacoresistant epilepsy and stable MS and give an overview of the existing literature. (1) a 28-year-old woman with seizures arising from a right basal temporo-occipital ganglioglioma was seizure-free after surgery, without MS relapse but with one new MS lesion postsurgically. (2) a 46-year-old woman with seizures arising from a natalizumab-associated progressive multifocal leukoencephalopathy (PML) lesion in the right frontal lobe was seizure-free after surgery preceded by extraoperative subdural electrocorticography, with new subclinical MS lesions. We are the first to report brain surgery in a PML survivor. Both patients stabilized radiologically after initiating second-line therapies. Successful epilepsy surgery can substantially increase the quality of life in patients with pharmacoresistant epilepsy and MS. With increasing survival rates of brain tumors and PML, the risk-benefit ratio of epilepsy surgery compared to a potential MS relapse after surgery becomes critically important. Shared decision-making is valuable for balancing the risks related to both diseases.

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.

An autopsy case of progressive multifocal leukoencephalopathy with massive iron deposition in juxtacortical lesions.

Progressive multifocal leukoencephalopathy (PML) is a severe demyelinating disease caused by JC virus infection of oligodendrocytes. Little has been reported on iron deposits in patients with PML. Herein, we report a case of PML with massive iron deposition in the juxtacortical regions attaching white matter lesions in a 71-year-old woman who developed bilateral visual disturbance and progressive aphasia after 16 months of rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisolone treatment for follicular lymphoma. Magnetic resonance imaging revealed white matter lesions in the left parietal and other lobes with massive iron deposition in the juxtacortical lesions. A PCR test for JC virus was positive, confirming the diagnosis of PML. Despite treatment with mefloquine and mirtazapine, the patient died six months later. At autopsy, demyelination was found dominantly in the left parietal lobe. Moreover, hemosiderin-laden macrophages and reactive astrocytes containing ferritin were abundant in the juxtacortical regions adjacent to the white matter lesions. This is a previously unreported case of PML after lymphoma, in which iron deposition was confirmed both radiologically and pathologically.

Changes in Brain Volumes Are Relevant during Natalizumab-Associated Progressive Multifocal Leukoencephalopathy: Lessons from a Case Report.

This is a case report concerning a Natalizumab-associated Progressive Multifocal Leukoencephalopathy (PML) with cerebellar localization and wakefulness disturbances. Awakening and clinical improvement dramatically occurred as soon as the immune reconstitution inflammatory syndrome (IRIS) took place, being it mild in nature and colocalizing with the PML lesion. In these ideal experimental conditions, we applied brain magnetic resonance imaging post-analysis in order to know changes in brain volumes underlying the pathological process over the infection period. White matter volume increased with a decrease in grey matter during IRIS. Conversely, we found a constant increase in cerebrospinal fluid volume throughout the duration of PML, suggesting a widespread abiotrophic effect, far from the lesion. Furthermore, brain parenchymal fraction significantly decreased as expected while the total brain volume remained stable at all times. Neurodegeneration is the main contributor to the steady disability in Natalizumab-associated PML. This process is thought to be widespread and inflammatory in nature as well as sustained by IRIS and humoral factors derived from the PML lesion.

[The phenomenon of pseudotumorous cross immunohistochemical reactivity of glia in progressive multifocal leukoencephalopathy]. / Fenomen psevdotumoroznoi perekrestnoi immunogistokhimicheskoi reaktivnosti glii pri progressiruyushchei mul'tifokal'noi leikoentsefalopatii.

Progressive multifocal leukoencephalopathy (PML) is a subacute demyelinating brain damage caused by infection of oligodendrocytes and astrocytes with the lytic JC virus on the background of immunosuppression. A case report of PML with a tumor-like course is presented. Morphological diagnostics revealed non-specific staining of antibodies to Ki-67, p53, IDH1, NF and Vim in the nuclei of gliocytes affected by the JC virus. Histological examination and microscopic evaluation of the changes in the brain for the diagnosis of PML is a priority. The recommended intravital biopsy does not always help in clear verification of PML due to the limited volume of tissue fragments presented for research. For the correct interpretation of changes during an intravital pathological examination and verification of PML, it is important to take material during a stereotaxic biopsy, not only from the center, but from the edges and perifocal zone of the altered tissues for the possibility of a spatial histological assessment of the pathological process.

Progressive multifocal leukoencephalopathy in a patient with occult hypogammaglobulinemia experiencing bilateral visual impairment.

INTRODUCTION: Progressive multifocal leukoencephalopathy (PML) is a rare, lethal, demyelinating disease classically seen in profoundly immunosuppressed individuals. It is caused by intracerebral infection by John Cunningham polyomavirus (JCV). We report a rare case of PML in a man with presumed immunocompetence at presentation experiencing bilateral painless visual impairment. CASE DESCRIPTION: A 60-year-old man with a 3-week history of bilateral painless visual impairment attended our ophthalmology department. Unusually, he navigated around the room well and was able to read 4 of 13 Ishihara test plates in spite of a best-corrected visual acuity of counting fingers at 1 m bilaterally. Slit lamp examination, routine blood tests and optical coherence tomography (OCT) of the maculae and discs were unremarkable. Diffuse hyperintense white matter lesions on T2-weighted magnetic resonance imaging of the brain and detection of JCV within the parietal lobe tissue obtained by biopsy confirmed PML. Additional investigations identified an underlying hypogammaglobulinaemia, which may have initiated PML. He received intravenous immunoglobulin but passed away 2 months after diagnosis. CONCLUSIONS: To our knowledge this case is one of only a handful worldwide to describe PML developing in a patient with presumed immunocompetence at presentation - there was no previous history of recurrent, chronic, or atypical infections. There has only been one other report of visual symptoms presenting as the primary complaint. The case illustrates the importance of ruling out organic, central nervous system pathology in patients presenting with visual loss and normal objective visual function tests such as slit lamp examination and OCT.

Teriflunomide Inhibits JCPyV Infection and Spread in Glial Cells and Choroid Plexus Epithelial Cells.

Several classes of immunomodulators are used for treating relapsing-remitting multiple sclerosis (RRMS). Most of these disease-modifying therapies, except teriflunomide, carry the risk of progressive multifocal leukoencephalopathy (PML), a severely debilitating, often fatal virus-induced demyelinating disease. Because teriflunomide has been shown to have antiviral activity against DNA viruses, we investigated whether treatment of cells with teriflunomide inhibits infection and spread of JC polyomavirus (JCPyV), the causative agent of PML. Treatment of choroid plexus epithelial cells and astrocytes with teriflunomide reduced JCPyV infection and spread. We also used droplet digital PCR to quantify JCPyV DNA associated with extracellular vesicles isolated from RRMS patients. We detected JCPyV DNA in all patients with confirmed PML diagnosis (n = 2), and in six natalizumab-treated (n = 12), two teriflunomide-treated (n = 7), and two nonimmunomodulated (n = 2) patients. Of the 21 patients, 12 (57%) had detectable JCPyV in either plasma or serum. CSF was uniformly negative for JCPyV. Isolation of extracellular vesicles did not increase the level of detection of JCPyV DNA versus bulk unprocessed biofluid. Overall, our study demonstrated an effect of teriflunomide inhibiting JCPyV infection and spread in glial and choroid plexus epithelial cells. Larger studies using patient samples are needed to correlate these in vitro findings with patient data.

Biopsy-proven PML in an HIV-negative patient with discoid lupus: Failure to detect JC virus in CSF.

We present a case of a 58-year-old man with a history of severe discoid lupus erythematosus and acute encephalopathy and incoordination. Antinuclear antibody testing was weakly positive but all other laboratory tests for systemic lupus erythematosus were negative and serum quantitative immunoglobulins and lymphocytes were normal. MRI brain showed T2/FLAIR hyperintensities within the bilateral parietal and temporal lobes with involvement of subcortical U fibers. CSF PCR was negative for varicella-zoster virus, herpes simplex, JCV and BK virus. However, JCV antibody index was elevated (3.88; reference: < 0.2). Right parietal brain biopsy was consistent with JCV infection and diagnostic of progressive multifocal leukoencephalopathy (PML). To the best of our knowledge, this is the first reported case of PML in a patient with discoid lupus without other traditional risk factors for the disease and highlights the need for clinical vigilance in this patient population.

Progressive multifocal leukoencephalopathy in patients treated with rituximab: a 20-year review from the Southern Network on Adverse Reactions.

Progressive multifocal leukoencephalopathy (PML) is a serious and usually fatal CNS infection caused by the John Cunningham virus. CD4+ and CD8+ T-cell lymphopenia, resulting from HIV infection, chemotherapy, or immunosuppressive therapy, are primary risk factors for PML. Following its introduction in 1997, the immunomodulatory anti-CD20 monoclonal antibody, rituximab, has received regulatory approval worldwide for treatment of non-Hodgkin lymphoma, rheumatoid arthritis, chronic lymphocytic leukaemia, granulomatosis with polyangiitis, microscopic polyangiitis, and pemphigus vulagris. Rituximab leads to prolonged B-lymphocyte depletion, potentially allowing John Cunningham viral infection to occur. Six unexpected cases of PML infection developing in rituximab-treated patients were first reported in 2002. We review 20 years of information on clinical findings, pathology, epidemiology, proposed pathogenesis, and risk-management issues associated with PML infection developing after rituximab treatment. Since the first case series report of 52 cases of rituximab-associated PML among patients with non-Hodgkin lymphoma or chronic lymphocytic leukaemia in 2009, updated and diligent pharmacovigilance efforts have provided reassurance that this fatal toxicity is a rare clinical event with concurring causal factors. International harmonisation of safety warnings around rituximab-associated PML should be considered, with these notifications listing rituximab-associated PML under a section titled warnings and precautions as is the case in most countries, rather than a boxed warning as is the case in the USA.

CNS inflammation after natalizumab therapy for multiple sclerosis: A retrospective histopathological and CSF cohort study.

Natalizumab, a recombinant humanized monoclonal antibody directed against the α4 subunit of the integrins α4ß1 and α4ß7, has been approved for the treatment of active relapsing-remitting MS. Although natalizumab is a highly beneficial drug that effectively reduces the risk of sustained disability progression and the rate of clinical relapses, some patients do not respond to it, and some are at higher risk of developing progressive multifocal leukoencephalopathy (PML). The histopathological effects after natalizumab therapy are still unknown. We, therefore, performed a detailed histological characterization of the CNS inflammatory cell infiltrate of 24 brain specimens from natalizumab treated patients, consisting of 20 biopsies and 4 autopsies and 21 MS controls. To complement the analysis, immune cells in blood and cerebrospinal fluid (CSF) of 30 natalizumab-treated patients and 42 MS controls were quantified by flow cytometry. Inflammatory infiltrates within lesions were mainly composed of T cells and macrophages, some B cells, plasma cells, and dendritic cells. There was no significant difference in the numbers of T cells or macrophages and microglial cells in lesions of natalizumab-treated patients as compared to controls. A shift towards cytotoxic T cells of a memory phenotype was observed in the CSF. Plasma cells were significantly increased in active demyelinating lesions of natalizumab-treated patients, but no correlation to clinical disability was observed. Dendritic cells within lesions were found to be reduced with longer ongoing therapy duration. Our findings suggest that natalizumab does not completely prevent immune cells from entering the CNS and is associated with an accumulation of plasma cells, the pathogenic and clinical significance of which is not known. As B cells are considered to serve as a reservoir of the JC virus, the observed plasma cell accumulation and reduction in dendritic cells in the CNS of natalizumab-treated patients may potentially play a role in PML development.

Isolated cerebellar progressive multifocal leukoencephalopathy after allogeneic bone marrow transplantation: focus on imaging.

INTRODUCTION: Progressive multifocal leukoencephalopathy (PML) is caused by JC virus opportunistic infection in the setting of immunodeficiency. Typical imaging features are multifocal and asymmetric lesions within supratentorial subcortical white matter in parieto-occipital regions. CASE DESCRIPTION: A 47-year-old patient experienced a relapse of acute myeloid leukemia 21 months after hematopoietic stem cell transplantation. He also had visual impairment and magnetic resonance imaging showed an isolated cerebellar lesion without mass effect or enhancement. Common opportunistic infections and leukemic central nervous system involvement were excluded by cerebrospinal fluid (CSF) analysis. Given the worsening clinical and radiologic scenario, PML was suspected, and CSF protein chain reaction analysis was positive for JC virus. CONCLUSIONS: Given its potential curability, PML should be thoroughly investigated in patients with hematologic neoplasms and atypical isolated cerebellar presentation.

Induction of Brain Tumors by the Archetype Strain of Human Neurotropic JCPyV in a Transgenic Mouse Model.

JC Virus (JCPyV), a member of the Polyomaviridiæ family, is a human neurotropic virus with world-wide distribution. JCPyV is the established opportunistic infectious agent of progressive multifocal leukoencephalopathy, a fatal demyelinating disease, which results from the cytolytic infection of oligodendrocytes. Mutations in the regulatory region of JCPyV determine the different viral strains. Mad-1 the strain associated with PML contains two 98 base pair repeats, whereas the archetype strain (CY), which is the transmissible form of JCPyV, contains only one 98 tandem with two insertions of 62 and 23 base pairs respectively. The oncogenicity of JCPyV has been suspected since direct inoculation into the brain of rodents and primates resulted in the development of brain tumors and has been attributed to the viral protein, T-Antigen. To further understand the oncogenicity of JCPyV, a transgenic mouse colony containing the early region of the archetype strain (CY), under the regulation of its own promoter was generated. These transgenic animals developed tumors of neural crest origin, including: primitive neuroectodermal tumors, medulloblastomas, adrenal neuroblastomas, pituitary tumors, malignant peripheral nerve sheath tumors, and glioblastomas. Neoplastic cells from all different phenotypes express T-Antigen. The close parallels between the tumors developed by these transgenic animals and human CNS tumors make this animal model an excellent tool for the study of viral oncogenesis.

Inadequate Immune Humoral Response against JC Virus in Progressive Multifocal Leukoencephalopathy Non-Survivors.

JC virus (JCV) causes progressive multifocal leukoencephalopathy (PML) in immunosuppressed patients. There is currently no effective specific antiviral treatment and PML management relies on immune restoration. Prognosis markers are crucially needed in this disease because of its high mortality rate. In this work, we investigated the compartmentalization of JCV strains as well as the humoral neutralizing response in various matrices to further understand the pathophysiology of PML and define markers of survival. Four patients were included, of which three died in the few months following PML onset. Cerebrospinal fluid (CSF) viral loads were the highest, with plasma samples having lower viral loads and urine samples being mostly negative. Whether at PML onset or during follow-up, neutralizing antibody (NAb) titers directed against the same autologous strain (genotype or mutant) were the highest in plasma, with CSF titers being on average 430-fold lower and urine titers 500-fold lower at the same timepoint. Plasma NAb titers against autologous genotype or mutant were lower in non-survivor patients, though no neutralization "blind spot" was observed. The surviving patient was followed up until nine months after PML onset and presented, at that time, an increase in neutralizing titers, from 38-fold against the autologous genotype to around 200-fold against PML mutants. Our results suggest that patients' humoral neutralizing response against their autologous strain may play a role in PML outcome, with survivors developing high NAb titers in both plasma and CSF.