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Progressive multifocal leukoencephalopathy occurred in two homosexual men affected with acquired immune deficiency syndrome (AIDS). Both patients received HLA-matched platelet transfusions in an attempt to increase their immune status, but we were unsuccessful in altering their fatal clinical course.
Progressive multifocal leukoencephalopathy developed in a patient with rheumatoid arthritis after treatment with an immunosuppressive agent (chlorambucil). We fell that this case lends further support to the concept that an altered immunologic state is important in the appearance of this infection, which is probably viral in origin.
The MR imaging appearance of progressive multifocal leukoencephalopathy is described in four cases that were confirmed by brain biopsy. Characteristic aspects are long T1 and long T2 lesions limited to white matter. At first the lesions are round or oval, then confluent and large. There is no mass effect. The involvement is most often asymmetric and distant from the periventricular region. The differential diagnosis includes other diseases affecting white matter: demyelination, infarction, infection, and tumors.
Since the initial description of progressive multifocal leukoencephalopathy (PML) in 1958, clinical and basic science investigators have demonstrated a growing interest in the area of neurovirology, with a recent focus on polyomaviruses. In this review, the authors present an overview of the biological properties of the human polyomavirus, JC virus (JCV), and its association with PML as the etiologic agent. Additionally, the authors provide a discussion of the current understanding of JCV molecular pathogenesis and therapeutic strategies.
Seizures are not expected in progressive multifocal leukoencephalopathy (PML), a condition considered to be restricted to the white matter. Review of medical records of 89 patients with possible or proven PML showed an 18% prevalence of seizures. Seizures usually responded well to treatment and did not affect survival. The presence of PML lesions immediately adjacent to the hemispheric cortex was the only risk factor associated with seizures in this population.
Six weeks after liver transplantation, a 51-year-old man developed a slowly progressive hemiparesis with deteriorating mental status and seizures. Successive computed tomography (CT) scans of the brain revealed unilateral nonenhancing white matter lucencies that gradually coalesced and progressed to both hemispheres. Brain biopsy results were consistent with progressive multifocal leukoencephalopathy (PML). We believe this is the first antemortem description of PML after liver transplantation. Herein, we describe the case and review the literature on PML after solid organ transplantation. Early recognition of this central nervous system disease may be important with new advances in therapy of this viral infection of the immunocompromised patient.
To evaluate the benefit of combined antiretroviral therapy including protease inhibitors (CART) on survival time and neurological progression in patients with AIDS-related progressive multifocal leukoencephalopathy (PML), 81 consecutive PML cases, collected between January 1990 and June 1998, were reviewed. Fifteen patients were neuropathologically proven. JC virus detection in CSF was positive in 59 patients. At PML diagnosis, median CD4 cell count was low (median, 35 cells/microL) and plasma HIV load, determined in 41 patients, was high (median, 4.8 log10 copies/ml). Following PML diagnosis, there was a significant difference (P<10(-4)) in survival between patients who were untreated or treated with nucleoside analogs (n=50, median: 80 days) and patients who were started early on CART (n=23, median: 246 days). A third group of eight patients who received CART late during the course of PML was considered separately. At the study endpoint, 18 of all the CART-treated patients (n=31) were still alive. Plasma HIV load was undetectable in 67% of them. The median increase in CD4 cell count was 112 cells/microL from CART onset. In contrast, no significant improvement in neurological status was observed. Our results demonstrate a benefit of CART on survival of AIDS-related PML patients and suggest the need for an early, specific anti-JC virus treatment to limit the neurological deterioration.
Atypical forms of progressive multifocal leukoencephalopathy (PML) may simulate other disorders. A previously healthy 70-year-old female developed unsteadiness of gait, dysarthria, dementia and weakness leading to inanition and death from bronchopneumonia over a 43 month period. The diagnosis of PML was not suspected prior to death. Neuropathologic examination of the brain disclosed characteristic findings of PML-deep bilateral cerebral demyelinative foci with enlarged gemistocytic astrocytes and swollen oligodendrocytes containing intranuclear inclusions. Electron microscopy identified papova virus particles within these inclusions. An underlying source of immunosuppression was not identified either premortem nor at the time of autopsy. The prolonged clinical course, simulating that of a primary degenerative disease, and the lack of apparent immunocompromise are unusual features of PML and lend credence to the suggestions that variations in its expression and course are to be expected.
Progressive multifocal leukoencephalopathy (PML) is a demyelinating infectious disease caused by the JC virus. It was originally described in patients with chronic lymphocytic leukemia (CLL). Richter's syndrome, or transformation to large cell Lymphoma, occurs in approximately 3% of patients with CLL, and carries a poor prognosis. We report a patient with documented PML and concurrent Richter's transformation outside the central nervous system. Before establishing a definitive diagnosis of PML, radiation therapy to the presumed lymphomatous brain lesion had been considered, raising the issue of whether stereotactic brain biopsy should be considered in every patient in a similar situation. Although this is likely a rare occurrence, patients with Richter's transformation documented at an extra-neural site and a brain lesion may benefit from the establishment of an infectious diagnosis which would influence therapy.
Tissues from 10 patients with progressive multifocal leukoencephalopathy (PML) and 14 patients without PML who were serologically positive for JC papovavirus were examined by molecular hybridization for human polyomavirus DNA sequences. Although viral proteins were not identified by fluorescent antibody methods, viral DNA was found in the kidneys of seven of nine patients with PML by hybridization, at 0.2-10 viral genome copies per cell genome equivalent, compared with 0.6-4 X 10(3) copies per cell in diseased areas of the brain. Examination of viral DNA from brains and kidneys of patients with PML by blot hybridization yielded no evidence of integration into the host cell genome. In three of the patients with PML, viral DNA was also found in liver, lung, lymph node, and spleen. Two of these patients, with widely disseminated JC virus, were children. In tissues from patients without PML, no evidence of JC virus infection was found, but BK papovavirus DNA was detected in two of 14 kidneys tested.
Progressive multifocal leukoencephalopathy (PML) due to JC virus can be the initial manifestation of AIDS. A 40-year-old man seropositive for HIV-1 presented with aphasia, hemiparesis, and hemianopsia, and with magnetic resonance imaging of the brain typical of PML. He quickly became bed bound, incontinent, and mute. The diagnosis of PML was established by histopathology in a brain biopsy with positive immunocytochemistry for polyomavirus capsid proteins, and detection of JCV DNA by polymerase chain reaction using JCV-specific primers. High dose zidovudine therapy was initiated (1200 mg/day). Within two weeks the patient began to respond, and after three months he was able to walk and care for himself and was discharged. He lived for two years from the onset of PML. While cytarabine has been the drug most widely used for PML treatment, this is the second confirmed case with apparent response to zidovudine. High dose zidovudine may benefit some previously untreated AIDS patients with onset as PML.
Progressive multifocal leukoencephalopathy (PML) is an uncommon opportunistic infection that causes focal or multifocal demyelination predominantly in the subcortical white matter. The authors describe the clinical and radiographic features in 2 unusual cases of PML that were initially isolated to the pons. One patient presented clinically with only an isolated sixth cranial nerve palsy.
Progressive multifocal leukoencephalopathy (PML) is a subacute demyelinating slow-virus encephalitis caused by the JC polyomavirus in 2-5% of patients with AIDS. MRI typically shows multiple lesions in the cerebral hemispheres. We present a rare case of rapidly evolving and lethal PML with a severe bulbar syndrome and spastic tetraparesis in a patient with AIDS. MRI showed high-signal lesions on T2-weighted images confined to the brain stem, extending from the medulla oblongata to the midbrain. JC virus polymerase chain reaction in cerebrospinal fluid was positive, and neuropathology showed the findings of PML. This case was also notable because of the rapid progression despite improved immune status with antiretroviral therapy.
Progressive multifocal leukoencephalopathy (PML), a formerly rare disease, is estimated to occur in up to 5% of all patients with AIDS. The high prevalence of PML in AIDS patients currently enables a comprehensive evaluation of this disorder. We evaluated the clinical and radiographic features of PML in a large cohort of AIDS patients identified by retrospective chart review from 1981 to 1994. Two hundred and five patients were diagnosed with PML of which 154 met the inclusion criteria. Seventy-two (47%) were pathologically confirmed and the remaining 82 (53%) met clinical and radiographic criteria. There was a 12-fold increase in the frequency of PML between 1981-1984 and 1991-1994. PML affected 136 men and 18 women with AIDS. Eighty-four percent of cases were 20-50 years old (range 5 to 68 years). The most common AIDS risk factors were homosexuality (57%) among men and heterosexual transmission (28%) and intravenous drug abuse (28%) among women. In 27% of patients, PML heralded AIDS. Common manifestations included weakness, gait abnormalities, speech disturbance, cognitive disorders, headache, and visual impairment. The CD4 lymphocyte counts exceeded 200 cells in 11% at the time of presentation. Involvement of posterior fossa structures was evident in 48% of cranial magnetic resonance imaging (MRI) studies, but in only 11% of computed tomographies (CT) of the brain. Contrast enhancement, typically faint and peripheral, was seen in 10% of CT scans and 15% of MRIs. The median survival was 6 months and survival exceeded 1 year in 9%. PML is no longer a rare disease. It often heralds AIDS and may occur in the absence of significant decline in CD4 lymphocytes. Survival is generally poor, although prolonged survival beyond 1 year is not unusual.
Progressive multifocal leukoencephalopathy (PML) is a demyelinating disease which occurs in immunodepressed subjects and is particularly frequent in AIDS. Some authors having drawn attention to the protean aspect of the disease and claimed that AIDS may lose its basic characteristics and affect the grey matter as well as the white matter, we reviewed a series of 8 patients who had been biopsied and/or autopsied and had been examined at least once by MRI. In this series, contrary to what is regularly observed in toxoplasmic abscesses we did not find any lesion of the grey matter or any mass effect. On the other hand, we confirmed that PLM is not multifocal in all cases and that it course may be interrupted by prolonged remissions. The MRI criteria for PML therefore are reliable, provided multiple T2-weighted slices in coronal plane are performed, clearly showing the anatomy of the white fibres affected. However, it must be borne in mind that HIV-infected patients often have other associated brain pathologies, especially when the immune deficiency increases.
Most immunosuppressed individuals who develop progressive multifocal leukoencephalopathy (PML) have a rapid fatal outcome, whereas some become long-term survivors. We explored the impact of the cellular immune response against JC virus (JCV) on the clinical outcome of 7 HIV+ and 3 HIV- individuals with PML. Of the 4 HIV+/PML survivors, all had detectable cytotoxic T lymphocytes (CTL) specific for JCV T or VP 1 proteins compared to none of the 3 HIV+/PML progressors tested. Of the 3 HIV-/PML patients, 1 was recently diagnosed with PML and showed evidence of neurologic improvement without any treatment. This patient had CTL specific for the VP1 protein of JCV. The other 2 HIV-/PML survivors were stable 3-8 years after the diagnosis of PML. They did not have any detectable CTL against JCV. These findings suggest that JCV-specific immune response is associated with favorable outcome in HIV+ individuals with PML. The lack of detectable JCV-specific CTL in 2 HIV-/PML survivors might indicate a burnt-out disease without sufficient antigenic stimulation to maintain the cellular immune response. The detection of JCV-specific CTL in an HIV- patient recently diagnosed with PML, who was showing evidence of neurological improvement without any treatment, indicates that this finding may be used as a favorable prognostic marker of disease evolution in the clinical management of patients with PML. As the quest for an effective treatment of PML continues, JCV-specific cellular immune response deserves further attention because it appears to play a crucial role in the prevention of disease progression.
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.
In order to obtain a useful and readily applicable in situ hybridization (ISH) protocol for progressive central nervous system (CNS) diseases of unknown etiology that are possibly due to persistent viral infection, known and well described diseases were studied, namely, progressive multifocal leukoencephalopathy (PML) and subacute sclerosing panencephalitis (SSPE). The procedures described were validated by confirming results obtained by other investigators using histology, immunocytochemistry, electron microscopy, and ISH. A number of frequently encountered problems of tissue preparation are addressed as well as techniques to reduce autoradiography exposure times. A multi-staged specific, sensitive, reliable, and valid procedure for detection of viral genomes, mRNA and proteins is approached. Formalin-fixed and paraffin-embedded (FFPE) brain material from six patients who died with PML and one patient who died from SSPE were studied using ISH with a tritium-labeled cloned JC virus DNA probe and a measles-cloned nucleocapsid (NC) gene cDNA probe, respectively. This report constitutes a methodological framework as well as a detailed neuropathological analysis of identified brain cell populations within which in situ hybridization was detected. In early PML lesions, swollen nuclei or oligodendrocytes were the predominant cells labeled, whereas older lesions revealed increased numbers of reactive and bizarre hypertrophic astrocytes hybridized at the outer periphery of the demyelinated lesions. The hybridization varied greatly in intensity in different cells. Intense hybridization was noted very rarely in microglial cells, including rod cells and rarely in venular pericytes, intravascular mononuclear cells, or in vascular endothelial cells. These results, considered together with previous findings, indicate that in PML the viral infection runs different courses in the various cells: in astrocytes the viral genome persists for a long time inducing pathological changes in some cells. In oligodendrocytes the infection rapidly lyses the cells. There was a good correlation between chromatic changes observable in routinely stained sections and virus presence. In addition, in situ hybridization using a measles-NP-cloned probe in white matter from FFPE SSPE brain is presented confirming earlier results in SSPE cryopreserved brain.