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Category: Viruses and Viral Pathogenesis
Pathological Features of Encephalitis in Humans, Page 1 of 2
< Previous page | Next page > /docserver/preview/fulltext/10.1128/9781555817831/9781555812409_Chap01-1.gif /docserver/preview/fulltext/10.1128/9781555817831/9781555812409_Chap01-2.gifAbstract:
This chapter provides an overview of the pathology of human encephalitis. It describes procedures that are of value in examining central nervous system (CNS) tissues from cases of suspected encephalitis, and histopathological features common to most forms of viral encephalitis. The chapter discusses factors that confer specificity in the case of particular viral infections of the CNS, such as selectivity with regard to a host cell type that a virus may show, the character of the immune response, and the tempo of the disease. The association of a virus with its natural host species is generally a very close and specific one, and it is therefore only with caution that findings in animals can be applied to humans. Naked-eye examination and light microscopy are the classical techniques of pathological examination that formed the basis of the early studies of encephalitis. A variety of techniques is available to search in histological material for specific viral antigens. Immunofluorescence was the first of these to be developed and has been in routine use for many years. The appearance of the characteristic inflammatory infiltrate in encephalitis is dependent on the presence of an intact immune response. The relative contributions of cellular and humoral immunity, both in eliminating virus and in contributing to the damage produced, remain relatively ill-defined in human encephalitis. In recent decades, the autopsy rates in most hospitals have dropped dramatically. There are few conditions for which the autopsy is more important than viral encephalitis.
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Summary chart of recommended procedures when dealing with autopsy or biopsy specimens from a case of suspected encephalitis. IPX, immunoperoxidase; ISH, in situ hybridization; EM, electron microscopy; HE, hematoxylin and eosin.
Summary chart of recommended procedures when dealing with autopsy or biopsy specimens from a case of suspected encephalitis. IPX, immunoperoxidase; ISH, in situ hybridization; EM, electron microscopy; HE, hematoxylin and eosin.
Astrocytic reaction in white matter demonstrated by GFAP immunostaining in a case of HIV encephalitis.
Astrocytic reaction in white matter demonstrated by GFAP immunostaining in a case of HIV encephalitis.
(a) Plasma cells immunostained by an antibody to immunoglobulin G in a case of herpes simplex encephalitis, (b) Macrophages immunostained by an antibody to CD68 surrounding a small vein in acute hemorrhage leukoencephalitis.
(a) Plasma cells immunostained by an antibody to immunoglobulin G in a case of herpes simplex encephalitis, (b) Macrophages immunostained by an antibody to CD68 surrounding a small vein in acute hemorrhage leukoencephalitis.
Examples of immunostaining for viral antigens in formalin-fixed paraffin-embedded tissue, (a) HIV in the processes of a multinucleated macrophage in HIV encephalitis (arrows), (b) Herpes simplex virus in the hippocampus in herpes simplex encephalitis, (c) Cytomegalovirus in ependymal and subependymal cells in a case of necrotizing ventriculo-encephalitis with AIDS, (d) Rabies virus in negri bodies of hippocampal neurons (arrows). (Courtesy of G. Gosztonyi.)
Examples of immunostaining for viral antigens in formalin-fixed paraffin-embedded tissue, (a) HIV in the processes of a multinucleated macrophage in HIV encephalitis (arrows), (b) Herpes simplex virus in the hippocampus in herpes simplex encephalitis, (c) Cytomegalovirus in ependymal and subependymal cells in a case of necrotizing ventriculo-encephalitis with AIDS, (d) Rabies virus in negri bodies of hippocampal neurons (arrows). (Courtesy of G. Gosztonyi.)
Demonstration of JC virus DNA using in situ hybridization in a case of progressive multifocal leukoencephalopathy. The positively reacting nuclei (arrows) mainly surround a small locus of demyelination indicated by the dashed line.
Demonstration of JC virus DNA using in situ hybridization in a case of progressive multifocal leukoencephalopathy. The positively reacting nuclei (arrows) mainly surround a small locus of demyelination indicated by the dashed line.
Foci of neuronophagia seen at low power in (a) and (b) and at higher power in (c). In (c), there is a central degenerate neuron in the dentate nucleus of the cerebellum. The neuron contains an intranuclear inclusion body suggestive of cytomegalovirus infection. Sample was collected from a patient with encephalitis with microglial nodules following renal transplantation. Panels (a) and (c) hematoxylin and eosin stain; (b) immunostain for macrophages using Ricinus communis agglutinin.
Foci of neuronophagia seen at low power in (a) and (b) and at higher power in (c). In (c), there is a central degenerate neuron in the dentate nucleus of the cerebellum. The neuron contains an intranuclear inclusion body suggestive of cytomegalovirus infection. Sample was collected from a patient with encephalitis with microglial nodules following renal transplantation. Panels (a) and (c) hematoxylin and eosin stain; (b) immunostain for macrophages using Ricinus communis agglutinin.
Neurofibrillary tangle in a substantia nigra neuron from a case of postencephalitic parkinsonism. Congo red stain.
Neurofibrillary tangle in a substantia nigra neuron from a case of postencephalitic parkinsonism. Congo red stain.
Bizarre multinucleated astrocytes in the cerebellum of a young man with progressive multifocal leukoen cephalopathy complicating a severe congenital immunodeficiency syndrome. Hematoxylin and eosin stain.
Bizarre multinucleated astrocytes in the cerebellum of a young man with progressive multifocal leukoen cephalopathy complicating a severe congenital immunodeficiency syndrome. Hematoxylin and eosin stain.
Typical perivascular cuffs of mononuclear inflammatory cells surrounding a small vein in a case of brain stem encephalitis resembling encephalitis lethargica.
Typical perivascular cuffs of mononuclear inflammatory cells surrounding a small vein in a case of brain stem encephalitis resembling encephalitis lethargica.
(a) CD68+ cells extending into parenchyma from small veins in a case of brain stem encephalitis. In contrast, (b) immunostained B cells (arrows) remain in perivascular spaces. Both panels counterstained with hematoxylin.
(a) CD68+ cells extending into parenchyma from small veins in a case of brain stem encephalitis. In contrast, (b) immunostained B cells (arrows) remain in perivascular spaces. Both panels counterstained with hematoxylin.
(a) Negri bodies (arrows) in the cytoplasm of cortical pyramidal neurons in rabies, (b) Cowdry type A inclusion bodies (arrows) in neuronal nuclei in a case of immunosuppressive measles encephalitis. Both panels, hematoxylin and eosin stain.
(a) Negri bodies (arrows) in the cytoplasm of cortical pyramidal neurons in rabies, (b) Cowdry type A inclusion bodies (arrows) in neuronal nuclei in a case of immunosuppressive measles encephalitis. Both panels, hematoxylin and eosin stain.
Examples of diffetences in topographical location of damage found in different forms of viral encephalitis (ventricular system stippled).
Examples of diffetences in topographical location of damage found in different forms of viral encephalitis (ventricular system stippled).
Acute hemorrhagic leukoencephalitis showing a small vein at the center surrounded by leukocytes. Beyond these, there is a zone of red blood cells and demyelinated white matter parenchyma. Luxol fast blue stain.
Acute hemorrhagic leukoencephalitis showing a small vein at the center surrounded by leukocytes. Beyond these, there is a zone of red blood cells and demyelinated white matter parenchyma. Luxol fast blue stain.
Cerebral white matter from a case of perivenous encephalitis. Venules are surrounded by an intense inflammatory cell infiltrate. Nissl stain.
Cerebral white matter from a case of perivenous encephalitis. Venules are surrounded by an intense inflammatory cell infiltrate. Nissl stain.
Adjacent section to that shown in Fig. 1.14, stained for myelin and showing perivenous myelin pallor. Weil's stain.
Adjacent section to that shown in Fig. 1.14, stained for myelin and showing perivenous myelin pallor. Weil's stain.
Cerebellar tonsillar herniation, particularly marked on the right side (left side in photograph).
Cerebellar tonsillar herniation, particularly marked on the right side (left side in photograph).
Venous infarction secondary to sagittal sinus thrombosis in a case of encephalitis of undiagnosed cause.
Venous infarction secondary to sagittal sinus thrombosis in a case of encephalitis of undiagnosed cause.