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Absence of imune deficiencies in a case of progressive multifocal leukoencephalopathy.

Progressive multifocal leukoencephalopathy (PML) is a rare disease related to a slow virus infection of the central nervous system; it is usually seen in patients who have impaired immunologic function. The present patient with biopsy-proved PML was found to have no demonstrable defects in either cellular or humoral immunity as assessed by multiple parameters. Thus, it appears that PML may occur in the presence of intact immune responses.

Biopsy

Molecular characterization of a JC virus (Sap-1) clone derived from a cerebellar form of progressive multifocal leukoencephalopathy.

Progressive multifocal leukoencephalopathy (PML) is a demyelinating disease caused by polyomavirus JC (JCV). In the majority of cases of PML the cerebrum is mainly affected (cerebral PML) but on rare occasions lesions are restricted to the cerebellum and brain stem (cerebellar PML). We report a rare cerebellar PML case which occurred in a Japanese patient undergoing prolonged hemodialysis treatment. To understand the molecular basis of the viral tissue tropism, we molecularly cloned JCV DNA and compared it with those of cerebral PML. Of ten clones analyzed nine showed identical fragment patterns after digestion with various restriction endonucleases, and we designated these clones Sap-1. It could be shown that the basic structures of the regulatory regions are similar between Sap-1 and isolates from cerebral PML. Restriction endonuclease mapping analysis was used to examine the genetic relationship between Sap-1 and urine-derived isolates containing the archetypal regulatory sequence. We found that Sap-1 was genetically related to an archetypal JCV isolate in Japan.

Base Sequence

Detection of JC virus DNA in peripheral lymphocytes from patients with and without progressive multifocal leukoencephalopathy.

Progressive multifocal leukoencephalopathy (PML) results from lytic infection of oligodendrocytes by JC virus (JCV). Although JCV has been identified in mononuclear cells in bone marrow and hematogenous dissemination of the virus to the central nervous system has been suspected, JCV has never been clearly demonstrated in the peripheral circulation. Using polymerase chain reaction technology, we examined peripheral lymphocytes of 19 patients with brain biopsy-proven PML for the JCV genome. Two non-PML control groups, consisting of 26 patients seopositive for human immunodeficiency virus type 1 (HIV-1) and 30 immunocompetent patients with Parkinson's disease, were also examined for the presence of the JCV genome in lymphocytes. Cerebrospinal fluid from 10 patients with PML was examined for the presence of the JCV genome as well. The JCV genome was detected in the lymphocytes of 89% (17) of the patients with PML, 38% (10) of the HIV-1-seropositive patients without PML, and none of the patients with Parkinson's disease. Sequencing of the JCV regulatory region from the lymphocytes of three patients revealed the prototype MAD-1 strain of JCV in one patient with PML, a MAD-4 strain in a second patient with PML, and a slightly modified MAD-4 strain in an HIV-1-positive patient without PML. Only 3 of 10 patients with PML who had JCV detected in lymphocytes had the JCV genome in their cerebrospinal fluid. These results demonstrate that the JCV genome can be found in circulating lymphocytes from patients with PML and suggest that lymphocytes are an important vector for hematogenous dissemination of JCV to the central nervous system.(ABSTRACT TRUNCATED AT 250 WORDS)

Base Sequence

Expression of major histocompatibility complex antigens in the brains of patients with progressive multifocal leukoencephalopathy.

Progressive multifocal leukoencephalopathy (PML) is caused by JC virus (JCV) infection of the central nervous system (CNS) in immunosuppressed patients. The immunopathogenesis of this chronic encephalitis is unknown. Because major histocompatibility (MHC) class I and class II antigens are important in modulating the immune response and viral clearance, we examined the tissue expression of MHC molecules in relation to CNS damage and presence of virus. By immunocytochemical staining, both MHC class I and class II antigens were expressed at high levels within PML lesions. Beta-2 microglobulin (beta-2m) was present on endothelial cells and JCV-infected oligodendroglia within the lesions. Also, many astrocytes with bizarre morphology expressed MHC class I antigens. In histologically normal regions of PML brains expression of beta-2m was noted only on endothelial cells. Expression of MHC class II also was focused within demyelinating lesions and was restricted to macrophages/microglia and occasional endothelial cells. When compared to other viral encephalitides (e.g. human immunodeficiency virus) these findings suggest that intra-CNS immune response to JCV is appropriate for antigenic presentation; however, the absence of responsive systemic T-cells may lead to chronic viral infection with progressive neuropathology.

Acquired Immunodeficiency Syndrome

Alpha-interferon therapy in a case of probable progressive multifocal leukoencephalopathy.

Probable progressive multifocal leukoencephalopathy (PML) was diagnosed on the basis of clinical picture and magnetic resonance imaging in a 63-year-old man with a complete remission of a non-Hodgkin's lymphoma. After the introduction of intramuscular alpha-interferon therapy, his neurological state and MRI findings showed a clear improvement. Eighteen months after the onset of first symptoms the patient has significantly recovered from both aphasia and motor impairment, and shows only a mild attentional deficit.

Antineoplastic Combined Chemotherapy Protocols

Molecular characterization of JC virus in progressive multifocal leukoencephalopathy cases from India.

Progressive Multifocal Leukoencephalopathy (PML) is a rare, often fatal demyelinating disease of the central nervous system caused by reactivation of the John Cunningham virus (JCV) in immunocompromised individuals. Despite an estimated 2.4 million people living with HIV in India, the reported incidence of PML remains lower than in Western countries, likely due to underdiagnosis, underreporting, and distinct host genetic and viral factors. The rising number of individuals on immunosuppressive therapies, including organ transplant recipients and those with autoimmune disorders, further emphasizes the need to study JC virus diversity in the Indian context. This study aimed to characterize the genetic diversity of JCV in India by sequencing the VP1 and non-coding control region (NCCR) from cerebrospinal fluid (n=30) of confirmed PML cases using Sanger sequencing. VP1 sequencing (n=23) revealed a predominance of genotypes 2 (subtypes 2D, 2A, 2B) and 3A. NCCR analysis (n=17) showed extensive rearrangements relative to the archetype form, with most sequences classified as Type II-R. Structural variations, including deletions, duplications, and insertions were common, particularly in blocks D, C, and F. Transcription factor binding sites (TFBS) were identified for TATA box, Tst-1, SP-1, p53, CEBPB, AP-1, NF-1, EGR-1, GF-1, CRE-TAR and NFkB. Additional TFBS were created due to rearrangements, often spanning two blocks. These findings underscore the genomic diversity of JCV in India and highlight the need for continued molecular surveillance to better understand its implications for high-risk populations.

Leukoencephalopathy, Progressive Multifocal

Diagnosis of progressive multifocal leukoencephalopathy by computed tomography.

Progressive multifocal leukoencephalopathy (PML) is a demyelinating disease of the central nervous system which predominantly affects immunologically compromised hosts. The distinctive CT appearance in three documented cases includes low-density lesions of central and convolutional white matter with scalloped lateral borders. Lesions demonstrate no mass effect or contrast material enhancement. Findings are discussed with reference to other entities which may produce a similar CT appearance.

Adult

Progressive multifocal leukoencephalopathy in renal transplant recipients.

Progressive multifocal leukoencephalopathy, a slowly progressive papovavirus infection of the CNS, has been reported in more than 110 patients to date, over half of whom have had either leukemia or lymphoma. Our patient is the fourth case of PML occurring after long-term immunosuppression for renal transplantation. We believe that PML is emerging as a potentially serious problem in renal transplant recipients.

Adult

[The multifocal progressive leukoencephalopathy--a papova-virus-encephalitis (author's transl)].

Two cases of multifocal progressive leukoencephalopathy are reported. A 62 years old patient suffering from lymphosarcomatosis for more than 5 years developed neurological symptoms and died 7 weeks after their onset. In a 44 years old patient a kidney transplantation was performed. 6 months after that operation he developed a disorder of the central nervous system and died 3 weeks later. Post-mortem examinations revealed the characteristic morphological findings of multifocal leukoencephalopathy in both the cases. Electron microscopic examination of the brain tissue obtained at autopsy demonstrated virions in paracristalline arrangement within the nuclei of oligodendrocytes. These findings are identical with those reported in literature, that were regarded as papova-viruses. Therefore, it is suggested to name the disease a papova-virus-encephalitis.

Adult

Cerebellar form of progressive multifocal leukoencephalopathy (PML).

A case of progressive multifocal leukoencephalopathy (PML) with selective involvement of cerebellum and brain stem is compared with nine other published cases. Recognition of PML presenting with ataxia before cerebral manifestations is stressed especially, since promising results with some antiviral drugs have been claimed.

Ataxia

JC Papovavirus in progressive multifocal leukoencephalopathy.

Brain tissue from seven patients with progressive multifocal leukoencephalopathy was tested for the presence of papovaviruses. JC virus, ahuman papovavirus, was identified in all seven cases. Virus was isolated in tissue culture from extracts from each of four patients and was detected by immunofluorescence in sections from the other three. The new osolates were indistinguishable from the prototypical JC strain serologically and in all biological characteristics examined. Thus JC virus has, to date, been associated with 20 cases of progressive multifocal leukoencephalopathy.

Adult

Atypical progressive multifocal leukoencephalopathy and primary cerebral malignant lymphoma.

Atypical progressive multifocal leukoencephalopathy occurred in an 82-year-old man with long-standing chronic lymphocytic leukemia. The multifocal white matter lesions revealed demyelination and gliosis, relative preservation of axons and a prominent plasma cell infiltrate. Bizarre astrocytes were uncommon. There were no changes in the oligodendroglial nuclei and no inclusion bodies. Electron and immunohistofluorescence microscopy for papova virus were negative. In addition to this leukoencephalopathy a small primary cerebral lymphoma was present in the right occipital lobe. The tumor cells were plasmacytoid in appearance and their cytoplasm stained well with pyronin. They contained IgG by immunohistofluorescence microscopy. The neoplasm was considered an immunoblastic sarcoma (reticulum cell sarcoma) and thought to arise directly within foci of demyelination. Both disease processes, leukoencephalopathy and lymphoma, may have occurred on a background of immunosuppression.

Aged

Macrophage association of polyomavirus in progressive multifocal leukoencephalopathy: an immunohistochemical and ultrastructural study. Case report.

Progressive multifocal leukoencephalopathy (PML) in a patient following autologous bone marrow transplantation for a non-Hodgkin's centroblastic lymphoma was studied by immunohistochemistry and transmission electron microscopy. Our observations indicate that a large amount of polyomavirus, most probably JC virus, is taken up and segregated within vacuoles of macrophages by phagocytosis. A relevant role of macrophages in the pathogenesis of PML is emphasized.

Brain

Cerebellar form of progressive multifocal leukoencephalopathy in a patient with chronic renal failure.

Progressive multifocal leukoencephalopathy (PML) developed in a 64-year-old woman who had undergone hemodialysis treatment due to chronic renal failure (CRF) for 6 yr. Her initial symptom was ataxia, and computed tomographic (CT) scan and magnetic resonance imaging (MRI) suggested a demyelinating disease of the cerebellum. Her cell-mediated immunity was impaired. At autopsy, the cerebellar disease was confirmed as PML by ultrastructural and immunohistochemical studies. Moreover, the JC type of papova virus infection was verified by Southern blot analysis.

Cerebellar Diseases

Progressive multifocal leukoencephalopathy.

The radionuclide, radiographic and pathologic findings in a patient with progressive multifocal leukoencephalopathy were correlated. Radionuclide imaging demonstrated the largest two of the many lesions observed at pathology. On repeated studies, one of the lesions developed a "doughnut" sign due to central necrosis. Cerebral angiography disclosed only one lesion which was initially suggestive of tumor encasement, but four weeks later, this deteriorated into an avascular zone. There were no characteristic features of the lesions demonstrated by radionuclide imaging and cerebral angiography that could be specifically attributed to progressive multifocal leukoencephalopathy.

Carotid Arteries

Multiple central nervous system infections in progressive multifocal leukoencephalopathy.

Clinical, pathologic, and immunologic features of two patients with progressive multifocal leukoencephalopathy and multiple coexisting central nervous system infections are presented. Both showed impaired cell-mediated immunity whereas immunoglobulins were normal, suggesting that defective cellular rather than humoral immunity predisposes to progressive multifocal leukoencephalopathy. Continued neurologic deterioration might be due not only to progression of the condition but also to simultaneous opportunistic bacterial and fungal infections that may be amenable to treatment. Unusual features in case 1 included striking neurologic remission for 8 months and a positive brain scan corresponding to a large demyelinated lesion in the frontal lobe.

Brain Diseases