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1/30. Virus-cell interaction in oligodendroglia, astroglia and phagocyte in progressive multifocal leukoencephalopathy. An electron microscopic study.

    A 46-year-old female, with an 11 year history of malignant lymphoreticular disease, developed a neurological illness clinically manifested by a focal mass lesion in the left frontal lobe. In biopsied tissue, immunofluorescence study revealed the presence of JC antigen in the glial cells. Histologically, the lesion was characteristic of PML consisting of PML consisting of focal necrosis in the subcortical white matter, numerous fat laden macrophages and marked hypertrophy of oligodendrocytes and astrocytes. By electron microscopy, hypertrophic astrocytes contained intranuclear viral particles consistent with papova virions and aggregates of intracytoplasmic viral particles consisting of a single to several virions tightly surrounded by a single membrane. The membrane appeared to have been derived from that of the cellular vesicles. Fusion of the virus-associated membrane to the astroglial plasmalemma occurred when the virions appeared to shift towards extracellular space. The virioncontaining astrocytes showed cytoplasmic "fibrillar hypertrophy" similar to the characteristic gigantic astroglias of PML. This fact would provide an additional evidence that these gigantic cells, although lacking identifiable viral structures, were the result of anaplastic transformation by jc virus. Many virus-bearing astroglias were noted to be in the early stage of cellular necrosis, of "edematous degeneration". This further indicates that the jc virus is capable of inducing both lytic and abortive astroglial infections. Many oligodendroglias were hypertrophic due to the presence of intranuclear viral particles and markedly increased numbers of microtubules and free ribosomes in the cytoplasm. Membrane-bound intracytoplasmic viral particles were also noted in the oligodendroglias. Some fat laden macrophages contained large intracytoplasmic viral bodies, presumably originating from phagocytized virus-bearing cells.
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2/30. Progressive multifocal leukoencephalopathy (PML) and cerebral toxoplasmosis in an adult patient, with no symptoms of underlying immunosuppressing illness.

    We present a case of the coincidence of progressive multifocal leukoencephalopathy (PML) and central nervous system (CNS) toxoplasmosis in an adult patient, without a detectable cause of cell-mediated immunity impairment. The proper diagnosis was made postmortem on the basis of histological changes typical of both pathological processes. PML was characterized by the presence of subcortical focal demyelination, containing enlarged, densely basophilic oligodendrocyte nuclei, often with intranuclear inclusion, and bizarre astrocytes, mimicking neoplastic cells. PML was confirmed by detecting numerous papova virus particles in oligo- and astroglial nuclei by thin-section electron microscopy. Cerebral toxoplasmosis was characterized by the presence of multiple well-circumscribed necrotizing abscesses. Numerous toxoplasma gondii (T. gondii) cysts and free, non-encysted protozoan parasites were found among the inflammatory infiltrates. The diagnosis of cerebral toxoplasmosis was further confirmed by immunocytochemistry. In order to detect putative immunosuppressive background underlying both pathological processes, hiv infection was taken into consideration, however, no histopathological changes indicative of AIDS either in the CNS or in the peripheral organs were eventually found. Moreover no hiv provirus genome was identified in the formalin-fixed, paraffin embedded brain tissue by the polymerase chain reaction (PCR). Current view on the selected aspects of the pathogenesis of both disorders were discussed.
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3/30. Progressive multifocal leukoencephalitis (PML) in three patients treated with standard-dose fludarabine (FAMP).

    Since 1990 we have treated 60 patients with standard-dose fludarabine for chronic lymphocytic leukemia (B-CLL), on a compassionate basis. Three patients developed grade IV neurologic complications after treatment, with demyelination of white matter on magnetic resonance imaging (MRI) in patient # 1, diffuse demyelination, abnormal oligodendroglia and enlarged astrocytes at brain biopsy in patient no 2, and progressive multifocal leukoencephalitis (PML) with jc virus on brain biopsy in patient # 3. The neurotoxicity of fludarabine was often observed after administration of high doses (90-120 mg/m2). At standard doses (18-25 mg/m2) neurologic complications were observed in very few cases (0.2%). PML was observed in only 0.52% of patients with chronic lymphocytic leukemia (CLL), particularly those with advanced CLL. Our findings are consistent with the results of published studies and show an increase in neurologic complications in patients with advanced CLL treated with fludarabine. This increased vulnerability is probably multifactorial, but may be secondary to the immunodeficiency.
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4/30. infection with jc virus and possible dysplastic ganglion-like transformation of the cerebral cortical neurons in a case of progressive multifocal leukoencephalopathy.

    infection of the cerebral cortical neurons with jc virus (JCV) with possible dysplastic ganglion-like alteration of the infected neurons found in a case of progressive multifocal leukoencephalopathy (PML) is described. The patient was a 21-year-old man with common variable immunodeficiency who died of PML after a 9-month clinical course. At autopsy, the white matter of the cerebrum, brainstem, cerebellum, and spinal cord exhibited extensive demyelination and necrosis. Numerous inclusion-bearing oligodendrocytes and bizarre astrocytes were found. In the occipital and temporal cortex, thick band-like aggregates of dysplastic ganglion-like cells (DGLCs) were found. These DGLCs showed immunohistochemical properties of neurons, and nuclei of some DGLCs were immunoreactive for large T antigen of SV40/JCV and p53, but not for capsid protein JCV VP1. in situ hybridization for mRNA of JCV large T antigen revealed positive signals in the nuclei of some DGLCs. These results indicate that JCV infected neurons and it is suggested that binding of the large T antigen with cellular proteins could have resulted in the dysplastic, ganglion cell-like change of the infected neurons, although the possibility that the aggregates of DGLCs represent a pre-existent malformative lesion of the cortex cannot be excluded completely.
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5/30. Concomitant progressive multifocal leucoencephalopathy and primary central nervous system lymphoma expressing jc virus oncogenic protein, large T antigen.

    This report describes the concomitant occurrence of the jc virus (JCV) induced demyelinating disease progressive multifocal leucoencephalopathy (PML) and a primary central nervous system lymphoma (PCNS-L) in a patient with AIDS. Postmortem neuropathological examination revealed characteristic features of PML including multiple lesions of demyelination, enlarged oligodendrocytes with hyperchromatic nuclei (many containing eosinophilic intranuclear inclusions), and enlarged astrocytes with bizarre hyperchromatic nuclei. Immunohistochemical analysis demonstrated the expression of the JCV capsid protein VP-1 in the nuclei of infected oligodendrocytes and astrocytes. The PCNS-L lesion located in the basal ganglia was highly cellular, distributed perivascularly, and consisted of large atypical plasmacytoid lymphocytes. Immunohistochemical examination of this neoplasm identified it to be of B cell origin. Moreover, expression of the JCV oncogenic protein, T antigen, was detected in the nuclei of the neoplastic lymphocytes. This study provides the first evidence for a possible association between JCV and PCNS-L.
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6/30. Detection of jc virus type 1 in peripheral lymphocytes, brain and cerebrospinal fluid from two Korean AIDS patients with progressive multifocal leukoencephalopathy.

    The human polyomavirus jc virus (JCV) is the etiologic agent of the fatal demyelinating central nervous system disease progressive multifocal leukoencephalopathy (PML), which occurs in 4-7% of AIDS patients. Two Korean AIDS patients with PML were assayed for JCV, and the virus was genotyped by polymerase chain reaction, DNA sequencing and phylogenetic analysis. Using immunohistochemical analysis, we also examined the distribution of JCV antigen in the brains of the patients. The JCV genome was detected in peripheral lymphocytes, brain and cerebrospinal fluid from these Korean PML patients. Although type 2 is the most common genotype in asia, the genotype of the JCV in these two AIDS patients was characterized as type 1, which is of European origin. We found that JCV antigen was selectively detected in oligodendrocytes and astrocytes of the brains from these patients. Compared to the prototype type 1 (Mad-1), two different nucleotides (G-->C) in the KOR-1 strain identified here were found at positions 2488 and 2490 of the major capsid protein VP1 gene. In summary, this is the first report of PML in Korean AIDS patients; it is also the first isolation of JCV type 1 in PML in East Asians.
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7/30. Progressive multifocal leukoencephalopathy and gliomas in a hiv-negative patient.

    A case of progressive multifocal leukoencephalopathy (PML) is reported, detected at autopsy of a 30-year-old patient. The clinical picture was characterized by a progressive course of mental deterioration and ingravescent neurological symptoms. The patient was hiv-negative. He died of bronchopneumonia, after a clinical course of 13 months. autopsy disclosed pulmonary tuberculosis with involvement of regional lymph nodes. In the brain, besides numerous PML-foci of varying age and structure, a pleomorphic astrocytoma was found in the white matter of the right parietal lobe. In the brain stem glial proliferation resembling diffuse gliomatosis was also present. in situ hybridization revealed Papova-virus (JCV) in oligoglial nuclei, but not in neoplastic astrocytes. This is the third report on the concomitant occurrence of PML and glioma in man.
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8/30. Progressive multifocal leukoencephalopathy complicating treatment with natalizumab and interferon beta-1a for multiple sclerosis.

    A 46-year-old woman with relapsing-remitting multiple sclerosis died from progressive multifocal leukoencephalopathy (PML) after having received 37 doses of natalizumab (300 mg every four weeks) as part of a clinical trial of natalizumab and interferon beta-1a. PML was diagnosed on the basis of the finding of JC viral DNA in cerebrospinal fluid on polymerase-chain-reaction assay and was confirmed at autopsy. Nearly every tissue section from bilateral cerebral hemispheres contained either macroscopic or microscopic PML lesions. There was extensive tissue destruction and cavitation in the left frontoparietal area, large numbers of bizarre astrocytes, and inclusion-bearing oligodendrocytes, which were positive for jc virus DNA on in situ hybridization.
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9/30. Progressive multifocal leukoencephalopathy: investigation of three cases using in situ hybridization with jc virus biotinylated DNA probe.

    Using the technique of in situ DNA-to-DNA hybridization, a jc virus biotinylated DNA probe was developed and applied to formalin-fixed, paraffin-embedded, or fixed, frozen sections of brain tissue from three subjects with progressive multifocal leukoencephalopathy (PML). light microscopy was carried out to correlate the presence of jc virus DNA with the selective infection of oligodendrocytes and astrocytes in PML. Oligodendrocytes (lytically infected) showed the greatest evidence of viral DNA. More astrocytes showing bizarre morphological changes had evidence of viral DNA than did astrocytes that were simply reactive. Viral DNA was not evident in vascular endothelial cells using this technique. Viral dna replication may be an important initial step which produces the bizarre "transformed" astrocytes of PML. Findings in this study do not support the hypothesis that vascular endothelial replication is important in the pathogenesis of jc virus-induced PML. in situ hybridization with biotinylated jc virus probe may be useful in the diagnosis of PML on brain biopsy specimens.
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10/30. Progressive multifocal leukoencephalopathy: jc virus detection by in situ hybridization compared with immunohistochemistry.

    In four cases of progressive multifocal leukoencephalopathy (PML), we compared biotin-labeled DNA:DNA in situ hybridization with peroxidase immunohistochemistry for the detection of jc virus (JCV). The localization of JCV DNA and JCV capsid protein was compared in formalin-fixed, paraffin-embedded brain tissues. Infected oligodendrocytes showed both JCV DNA and JCV protein. However, bizarre astrocytes demonstrated JCV capsid protein less often than JCV DNA. in situ hybridization with a biotinylated probe was as sensitive and specific as immunohistochemistry for diagnosis on formalin-fixed tissue. The presence of both JCV DNA and viral capsid protein in bizarre astrocytes suggests that these cells are neither truly transformed nor permissively infected, but are distinctively altered by JCV.
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