[Bronchiolitis obliterans with organized pneumonia associated with measles virus]

Bronchiolitis obliterans with organizing pneumonia (BOOP) is a nonspecific form of pulmonary injury related to different etiologic agents. The disorder is not only limited to the alveoli but also affects to the alveolar ducts and distal bronchioles. This fact may differentiate this disorder of others with chronic inflammatory diffuse alveolar lesion as chronic eosinophilic pneumonia (CEP), extrinsic allergic alveolitis (EAA) or diffuse alveolar damage (DAD). It has been described an idiopathic form and other associated with connective tissue diseases, infections, organ's transplantation, drug or chemical induced reactions, irradiation pneumonitis and aspiration pneumonitis, among others. Their extremely variable clinical presentation and course, etiology, and histologic appearance and, in some way, the considerable confusion as a result to the different terminologies applied, has made difficult a clear understanding of this disease. We present two cases of BOOP related to infection by measles virus, whose diagnostic was obtained through pulmonary thoracoscopic biopsy and serological study respectively. Patients were treated with steroids (6 months) with a favorable outcome in terms of clinical symptoms, radiological findings, and a normalization of the pulmonary function tests. We suggest that in each patient with clinic and radiological study suspicious of BOOP, it seem to be useful to include measles virus in serologic study. This investigation may contribute to reduce the number of cases classified as idiopathic BOOP.

Measles virus suppresses cell-mediated immunity by interfering with the survival and functions of dendritic and T cells

Secondary infections due to a marked immunosuppression have long been recognized as a major cause of the high morbidity and mortality rate associated with acute measles. The mechanisms underlying the inhibition of cell-mediated immunity are not clearly understood but dysfunctions of monocytes as antigen-presenting cells (APC) are implicated. In this report, we demonstrate that measles virus (MV) replicates weakly in the resting dendritic cells (DC) as in lipopolysaccharide-activated monocytes, but intensively in CD40-activated DC. The interaction of MV-infected DC with T cells not only induces syncytia formation where MV undergoes massive replication, but also leads to an impairment of DC and T cell function and cell death. CD40-activated DC decrease their capacity to produce interleukin (IL) 12, and T cells are unable to proliferate in response to MV-infected DC stimulation. A massive apoptosis of both DC and T cells is observed in the MV pulsed DC-T cell cocultures. This study suggests that DC represent a major target of MV. The enhanced MV replication during DC-T cell interaction, leading to an IL-12 production decrease and the deletion of DC and T cells, may be the essential mechanism of immunosuppression induced by MV.

Measles virus infects human dendritic cells and blocks their allostimulatory properties for CD4+ T cells

Measles causes a profound immune suppression which is responsible for the high morbidity and mortality induced by secondary infections. Dendritic cells (DC) are professional antigen-presenting cells required for initiation of primary immune responses. To determine whether infection of DC by measles virus (MV) may play a role in virus-induced suppression of cell-mediated immunity, we examined the ability of CD1a+ DC derived from cord blood CD34+ progenitors and Langerhans cells isolated from human epidermis to support MV replication. Here we show that both cultured CD1a+ DC and epidermal Langerhans cells can be infected in vitro by both vaccine and wild type strains of MV. DC infection with MV resulted within 24-48 h in cell-cell fusion, cell surface expression of hemagglutinin, and virus budding associated with production of infectious virus. MV infection of DC completely abrogated the ability of the cells to stimulate the proliferation of naive allogeneic CD4+ T cell as early as day 2 of mixed leukocyte reaction (MLR) (i.e., on day 4 of DC infection). Mannose receptor-mediated endocytosis and viability studies indicated that the loss of DC stimulatory function could not be attributed to the death or apoptosis of DC. This total loss of DC stimulatory function required viral replication in the DC since ultraviolet (UV)-inactivated MV or UV-treated supernatant from MV-infected DC did not alter the allostimulatory capacity of DC. As few as 10 MV- infected DC could block the stimulatory function of 10(4) uninfected DC. More importantly, MV-infected DC, in which production of infectious virus was blocked by UV treatment or paraformaldehyde fixation, actively suppressed allogeneic MLR upon transfer to uninfected DC-T-cultures. Thus, the mechanisms which contribute to the loss of the allostimulatory function of DC include both virus release and active suppression mediated by MV-infected DC, independent of virus production. These data suggest that carriage of MV by DC may facilitate virus spreading to secondary lymphoid organs and that MV replication in DC may play a central role in the general immune suppression observed during measles.

Spread of measles virus through axonal pathways into limbic structures in the brain of TAP1 -/- mice

The spread of measles virus into the brain was studied exploiting the olfactory pathway, which represents an important route of neuroinvasion by viruses. The virus was injected into the main olfactory bulb of wild-type mice and mice with disrupted TAP1 gene (TAP refers to the Transporter associated with Antigen Presentation), which codes for products essential for the cell-mediated immune response. Virus invasion was monitored for 4 weeks by immunohistochemistry. The distribution of measles virus was found to be restricted to brain areas connected with the olfactory bulbs. However, in the wild-type mice there was a marked infiltration of lymphocytes in the infected brain structures, and the virus did not pass beyond the piriform cortex. In the TAP1 -/- mice the virus spread more extensively along olfactory projections into the limbic system and monoaminergic brainstem neurons. Infected mice of both types developed seizures, which may have been focally evoked from the piriform cortex. This study provides evidence that measles virus can spread through axonal pathways in the brain. The findings obtained in the gene-manipulated mice point out that a compromised immune state of the host may potentiate targeting of virus to the limbic system through olfactory projections.

Experimental measles. I. Pathogenesis in the normal and the immunized host

An animal model to study measles pathogenesis and the correlates of protective immunity was established using rhesus monkeys. A measles isolate, obtained during an epidemic of measles in the primate colony at the University of California, Davis, was passaged through rhesus monkeys and amplified in rhesus mononuclear cells to create a pathogenic virus stock. Sequence analysis of the nucleoprotein and hemagglutinin genes of this isolate revealed strong homology with the Chicago 89 strain of measles virus. Conjunctival/intranasal inoculation of juvenile rhesus monkeys with this virus resulted in skin rash, pneumonia, and systemic infection with dissemination to other mucosal sites and to the lymphoid tissues. Inflammation and necrosis occurred in the lungs and lymphoid tissues and many cell types were infected with measles virus on Day 7 postinoculation (p.i.). The most commonly infected cell type was the B lymphocyte in lymphoid follicles. Measles antigen was found in follicular dendritic cells on Day 14 p.i. In contrast to naive monkeys infected with measles virus, animals vaccinated with the attenuated Moraten strain did not develop clinical or pathologic signs of measles after challenge. However, moderate to marked hyperplasia occurred in the lymph nodes and spleen of a vaccinated animal on Day 7 after pathogenic virus challenge, suggesting that an effective measles vaccine limits but does not prevent infection with wild-type measles virus.

Apoptosis in measles virus-infected human central nervous system tissues

The extent of apoptotic cell death was examined in central nervous system (CNS) tissues from three cases of subacute sclerosing panencephalitis (SSPE). Apoptosis was demonstrated by in situ end-labelling of DNA in formalin-fixed, paraffin-embedded tissue sections. Measles virus and cell types were labelled by immunohistochemistry and/or in situ hybridization. Furthermore, bcl-2 expression in SSPE was examined by immunohistochemistry. All three cases exhibited varying degrees of apoptosis in all CNS areas studied. Brain tissue from a non-neurological control case did not show any significant apoptosis. Characterization of cell types demonstrated neurons, oligodendrocytes, lymphocytes and microglia undergoing apoptosis. A linear relationship could not be established between virus burden and the extent of apoptosis in any particular area. Virus-negative cells were observed which were undergoing apoptosis. Bcl-2 immunoreactivity in SSPE was confined to the infiltrating cell population. These results suggest that apoptosis of various cell types may contribute to the neuropathogenesis of measles virus infection in the human CNS, either as a direct effect of viral infection or by cytokine-mediated responses.

Changes in intracellular cytokine levels in lymphocytes induced by measles virus

We investigated the changes in intracellular cytokine levels in different lymphocyte populations induced by measles virus (MV). MV-infected and uninfected peripheral blood mononuclear cells were cultured with phorbol 2-myristate 13-acetate plus ionomycin in the presence of monensin for 10 hr. Surface antigen and intracellular cytokines, interleukin (IL)-2, interferon (IFN)-gamma, and IL-4, were stained simultaneously and analyzed by flow cytometry. The percentage of cells that expressed IL-2 and IFN-gamma was significantly increased in MV-infected CD3+, CD4+, and CD8+ lymphocytes and alphabeta T lymphocytes compared with that in uninfected lymphocytes. In gammadelta T lymphocytes, expression of IFN-gamma, not IL-2, was increased in MV-infected cells compared with that in uninfected cells. IL-2 was increased mainly in MV-infected CD4+ lymphocytes and alphabeta T lymphocytes, whereas IFN-gamma was increased mainly in MV-infected CD8+ lymphocytes and gammadelta T lymphocytes. Expression of IL-4 was unaffected by MV infection. These results demonstrate that MV enhances intracellular levels of type 1 cytokines during the acute phase of measles.

Subacute sclerosing panencephalitis manifesting as viral retinitis: clinical and histopathologic findings

PURPOSE AND METHODS

To describe the clinical and histopathologic features of a patient with viral retinitis secondary to subacute sclerosing panencephalitis.

RESULTS

The patient was a human immunodeficiency virus-negative intravenous drug abuser with an acute retinitis that later progressed to encephalitis despite aggressive treatment for possible viral, protozoal, bacterial, and rickettsial infections. The patient had many of the characteristic findings of subacute sclerosing panencephalitis, including a history of measles in early childhood, myoclonus, periodic complexes on electroencephalographic testing, persistently elevated serum and cerebrospinal fluid antimeasles immunoglobulin G (IgG) titers, and a cerebrospinal fluid oligoclonal IgG gammopathy. Ultrastructural examination demonstrated numerous filamentous microtubular intranuclear viral inclusions in the nuclear layers of the retina consistent with the measles virus. This case is unusual in that our patient developed subacute sclerosing panencephalitis later in life and because there was an 8-year period between presumed viral infections in the two eyes.

CONCLUSIONS

An acute retinitis in an intravenous drug abuser is not always caused by human immunodeficiency virus-related infections; not all viral retinitis responds to therapy; and mortality as well as the usual morbidity may be associated with viral retinitis. One might consider the diagnosis of subacute sclerosing panencephalitis in a young person with an acute retinitis with little or no vitreal inflammation and lack of response to anticytomegalovirus and antitoxoplasmosis therapy.

In situ immune responses in Crohn's disease: a comparison with acute and persistent measles virus infection

The implied aetiological association of measles virus with Crohn's disease would be supported by detection of an immune response to infected cells in affected tissues. This study sought to detect and characterise in situ immune responses to measles virus in both acutely and persistently infected tissues, and in particular, Crohn's granulomata. Tissue sections from patients with Crohn's disease (n = 17), tuberculosis (n = 9), acute intestinal ischaemia (n = 5), acute measles pneumonitis (n = 2), acute measles appendicitis (n = 1), subacute sclerosing panencephalitis (SSPE; n = 1), and measles inclusion body encephalitis (MIBE; n = 1), were examined. Single and double immunohistochemical labelling was performed to identify both cytotoxic lymphocytes (CD8, TIA, perforin, Leu 7, CD45RO, CD45RA) and macrophages (KP1). The relationship of these cells to measles infected cells was examined by double immunolabelling with antimeasles virus nucleoprotein antibody. In both acute measles appendicitis and SSPE, CD8+/TIA cytotoxic lymphocytes (CTL) targeted infected cells. In the cases of Crohn's disease (13/17), MIBE, fatal pneumonitis, and one tuberculous granuloma, that were positive for measles virus, infected cells appeared to be targeted by macrophages rather than CTL. CTL in both tuberculous and Crohn's granulomata were similar in their peripheral distribution, number, and phenotype. The data suggest that measles-specific CTL responses may be attenuated in Crohn's disease compared with acute measles appendicitis and SSPE, and secondly, that an abnormal macrophage response to persistent measles virus infection of the intestine may result in granulomatous inflammation.

Giant cell pneumonia: light microscopy, immunohistochemical, and ultrastructural study of an autopsy case

An autopsy case of measles giant cell pneumonia with intranuclear inclusion bodies is reported. This case of giant cell pneumonia was studied by light microscopy and immunohistochemistry using monoclonal and polyclonal antibody to measles and by electron microscopy (EM). Light microscopic examination showed multinucleated epithelial giant cells with intranuclear and intracytoplasmic inclusions. The giant cells contained prominent, sharply marginated, eosinophilic intranuclear inclusions typical of classic measles pneumonia. Presence of measles antigen was confirmed using both monoclonal and polyclonal antibodies by peroxidase antiperoxidase method. Monoclonal antibody stained positively for intracytoplasmic and intranuclear inclusions. Electron microscopic examination of lung tissue showed intranuclear inclusions of filamentous or worm like nucleocapsid materials in multinucleated epithelial giant cells. The results suggest that this is a case of measles giant cell pneumonia and the intranuclear inclusion bodies are measles viral particles.

The effect on chick osteoclasts of infection with paramyxoviruses

The detection of virus in osteoclasts from Pagetic patients is now well known, but it has yet to be shown convincingly that the presence of virus in Pagetic osteoclasts influences their behaviour. In this study, osteoclasts from embryonic chick tibiae were infected with canine distemper virus or measles virus and compared with mock-infected controls. Infection was confirmed using virus-specific fluorescent antibodies. It was found that virus infection did not alter osteoclast morphology or tartrate-resistant acid phosphatase (TRAP) activity. Both infected and mock-infected osteoclasts produced resorption pits on bovine bone slices; these could be divided into two distinct size classes with a computer-based measuring system. Virus infection significantly increased the proportion of the larger size class of resorption pit. These results suggest that virus infection can increase bone resorption by osteoclasts, lending further support to the hypothesis that viruses play a role in Paget's disease of bone.

Clinical features of measles in immunocompromised children

Measles is often fatal for immunocompromised hosts. Protective immunity against measles has been studied but is still not completely understood. Recently, five cases of measles were encountered in immunocompromised children. Two of these were allogeneic bone marrow transplanted cases (one common variable immunodeficiency and one severe aplastic anemia) in remission, one Wilms' tumor case in remission, one hepatoblastoma case after cytotoxic therapy at disease onset and one exaggerating hemophagocytic syndrome case with suppressed natural killer cell activity. Clinical symptoms, laboratory findings and the immunologic backgrounds of these five patients were investigated. One of the patients, an 8 year old boy with hemophagocytic syndrome, died of giant cell pneumonia which was confirmed in the section of necropsy lung specimen. Two other patients who received allogeneic bone marrow transplants were not immune to measles, despite their own and their donors' immunizations. Their clinical symptoms were rather severe but both patients recovered and have remained seropositive for as long as 13 months. This fatality from measles is the first reported in a patient with hemophagocytic syndrome. Suppressed natural killer cell activity may be a poor prognostic factor. Also, secondary immunization failure for measles can occur in bone marrow transplanted patients with rather severe clinical symptoms.

Nonhuman primate models of measles

Wild measles virus isolated in a marmoset lymphoblastoid B95a cell line induced rashes and Koplik's spots when inoculated parenterally in cynomolgus and squirrel monkeys. Marked leukopenia. associated with transient decrease in the CD4(+)-to-CD8+ T-cell ratio also was induced. Virus growth, as well as histologic lesions of necrosis and giant cell formation, was observed in the lymphoid tissues. Thus clinical signs of acute measles were successfully induced in monkeys by inoculation with cell-culture-grown measles virus. These nonhuman primate models of measles will be useful for study of the pathogenesis of acute measles virus infection in terms of generalized clinical signs of disease, leukopenia, and changes in the lymphocyte subsets.

Major histocompatibility complex class I expression on neurons in subacute sclerosing panencephalitis and experimental subacute measles encephalitis

Lack of major histocompatibility class I antigens on neurons has been implicated as a possible mechanism for viral persistence in the brain since these antigens are required for cytotoxic T-lymphocyte recognition of infected cells. In subacute sclerosing panencephalitis (SSPE), measles virus (MV) persists in neurons, resulting in a fatal chronic infection. MHC class I mRNA expression was examined in formalin-fixed brain tissue from 6 SSPE patients by in situ hybridization. In addition MHC class I protein expression in MV-infected neurons was examined in experimental Subacute Measles Encephalitis (SME) by double immunohistochemistry. MHC class I mRNA expression was found to be upregulated in SSPE tissues studied, and in 5 out of 6 cases the expression was definitively seen on neurons. The percentage of neurons expressing MHC class I mRNA ranged between 20 to 84% in infected areas. There was no correlation between the degree of infection and expression of MHC class I molecules on neurons. Importantly, the number of neurons co-expressing MHC class I and MV antigens was markedly low, varying between 2 to 8%. Similar results were obtained in SME where 20 to 30% of the neurons expressed MHC class I but <8% co-expressed MHC class I and MV antigens. Perivascular infiltrating cells in the infected regions in SME expressed IFNgamma immunoreactivity. The results suggest that MV may not be directly involved in the induction of MHC class I on neurons and that cytokines such as IFNgamma may play an important role. Furthermore, the paucity of neurons co-expressing MHC class I and MV antigens in SSPE and SME suggests that such cells are either rapidly cleared by cytotoxic T lymphocytes (CTL), or, alternatively, lack of co-expression of MHC class I on MV infected neurons favors MV persistence in these cells by escaping CTL recognition.

[Pathogenesis of otosclerosis. "State of the art"]

Women suffer from otosclerosis 1.6 times more often than males. Histologically, otosclerotic foci can be found in temporal bones of females 1.9 times more often than in those of males. Characteristic topographic regions are the oval window, round window niche and promontory. Otosclerosis can also occur principally in any area of the enchondral/periosteal layer of the otic capsule. Evidence is presented that otosclerosis is an inflammatory tissue reaction associated with macrophages, T- and B-lymphocytes, HLA-DR positive cells and plasma cells. Dependent on the stage of the osteolytic bone disease present deposits of complement and immunoglobulins (IgG, IgA) can be found. These immunoglobulins have been identified as antibodies to measles virus proteins. Using the polymerase chain reaction we were successful in demonstrating RNA sequences of measles viruses in otosclerotic bone from footplates removed during stapes surgery. Since most of the otosclerotic lesions were in direct contact to the perilymphatic space, it may be expected that the endolymphatic sac--as the immune competent organ of the inner ear--specifically reacts to antigens delivered from the otosclerosis focus into the perilymph. Perilymph samples from patients were collected during stapes surgery and their antibody titers against measles were compared with that in corresponding blood serum. All samples revealed a significantly elevated-specific anti-measles IgG amount which was significantly higher than in the corresponding serum. In contrast, antibody titer in the perilymph against herpes simplex or cytomegalo viruses did not differ from that of the serum. These findings indicate that otosclerosis is a measles virus associated inflammatory osteolytic disease of the temporal bone. Since women suffer from severe measles virus infections more often than males, it can be hypothesized that females have a higher susceptibility of their cochleo-vestibular tissues to these infections (organotropism). In addition, estrogens are well-known stimulators of osteocytic activity and may play a dominant role during ossification of an otospongeotic bone lesion. This may explain the onset of a conductive hearing loss due to otosclerosis during pregnancy.

Widespread, restricted low-level measles virus infection of brain in a case of subacute sclerosing panencephalitis

In situ reverse transcriptase-polymerase chain reaction amplification with labeled-probe hybridization (in situ RT-PCR/LPH) was used to detect measles virus RNA within formalin-fixed, paraffin-embedded brain tissue sections from a patient who died with subacute sclerosing panencephalitis (SSPE). Many more infected neurons and oligodendrocytes were detected by in situ RT-PCR/LPH than by immunohistochemistry or by in situ hybridization alone. In addition, infection of vascular endothelial cells was demonstrated only by in situ RT-PCR/LPH. The observation that many cells contained only a few copies of viral RNA without detectable antigen is consistent with a persistent viral infection of the central nervous system. In situ RT-PCR/LPH, combining the sensitivity of PCR with the tissue localization of in situ hybridization, should prove useful in further studies to detect nucleic acids in situ in the central nervous system.

Immunohistochemical study of cellular events in lesional skin during common virus infections

Determination was made of epidermal Langerhans cell (LC) distribution and infiltrating cellular events in lesional skin during varicella zoster virus (VZV) infection, and the results were compared with those for herpes simplex (HS), measles, and rubella by immunohistochemical staining with cell surface markers. CD1a positive epidermal LCs increased in number, particularly in measles and rubella. The number of LCs was within the normal range or slightly increased in the epidermis of VZV infection. In herpes zoster (HZ) and varicella, HLA-DR positive epidermal cells were present in the basal part of the epidermis. In measles, HLA-DR positive cells aggregated in papular lesions. In measles and rubella, the number of HLA-DQ positive epidermal cells appeared to increase. In HS cases, CD11b (OKM1) positivity of the upper epidermal keratinocytes was quite pronounced, but not in the basal layer. CD8 positive suppressor/cytotoxic cells extensively infiltrated the dermis of HZ and varicella. Dermal infiltrates were identified as CD8 positive cell dominant in measles, HZ, and varicella. These results provide a partial explanation as to why cellular events in skin lesions act immunosuppressively.

Detection and comparison of viral antigens in measles and rubella rashes

Measles and rubella skin lesions were immunocytochemically compared by the avidin-biotin-peroxidase complex method for detecting viral antigens. Cryostat sections of biopsied specimens of the skin were stained with mouse monoclonal antibodies to P protein of measles virus and to E1 protein of rubella virus. The measles virus antigen was concentrated in the corneal layer and the keratinocytes of the epidermis and in the surface part of the dermis in the biopsy secimens taken within 6 days after the onset of rash. On the other hand, the rubella virus antigen was dispersed in all parts of the dermis and the subcutaneous layer but not in the epidermis in the biopsy specimens taken within 2 days after the onset of rash. The differences in the distribution and density of the viral antigen and in the times of its detection suggest distinct patterns of spread of infection with each virus in the skin.

Persistent measles virus infection of the intestine: confirmation by immunogold electron microscopy

This study sought to investigate persistent measles virus infection of the intestine: a novel protocol for immunogold electron microscopy was developed using a polyclonal anti-measles nucleoprotein antibody on reprocessed, formalin fixed paraffin wax embedded tissue sections. Antibody binding was detected using both immunoperoxidase and light microscopy on tissue sections, and 10 nm gold conjugated secondary antibody and electron microscopy on ultrathin sections. The techniques were validated using both measles infected vero cells and human tissues with established measles infection: these included brain affected by subacute sclerosing panencephalitis and acute measles appendicitis. The technique was applied subsequently to six untreated cases of granulomatous Crohn's disease, and two cases of ileocaecal tuberculosis, a granulomatous control. Mumps primary antibody--applied to both mumps infected vero cells, and measles infected vero cells and tissues studied by immunoperoxidase, and measles antibody on mumps infected cells studied by immunoperoxidase and immunogold--were used as specificity controls: the primary antibodies identified their respective target antigen and there was no antibody cross reactivity. Measles virus nucleocapsids labelled with gold conjugated antibody in both infected cells and tissues, including foci of granulomatous inflammation in five of six cases of Crohn's disease: in the fifth case, the granuloma could not be identified in ultrathin section. In one of the tuberculosis cases, a low level of signal was noted while the second case was negative. Labelling adopted a characteristic pattern in all infected tissues, strengthening the specificity of these findings. This study provides the first direct confirmation of persistent measles virus infection of the intestine.

Blocking measles virus infection with a recombinant soluble form of, or monoclonal antibodies against, membrane cofactor protein of complement (CD46)

Human membrane cofactor protein (MCP, CD46) functions as an inhibitor of the complement (C) cascade to protect host cells from C attack, and as a receptor for measles virus (MV). Normal human sera contains 10-60 ng/ml of naturally produced soluble forms of MCP, which is also a cofactor for the factor I-mediated inactivation of C3b. We produced monoclonal antibodies (mAb) against MCP and a recombinant soluble form of MCP similar to the natural soluble forms, and tested their ability to block MV infection. Vero cells and CHO cells expressing human MCP were the targets. Of the antibodies tested, M75 and M177, which blocked the C regulatory activity of MCP, efficiently blocked MV infection. More than 50 micrograms/ml of the soluble form moderately blocked MV infection of CHO cells expressing MCP, but barely blocked that of Vero cells. The two mAb and the soluble form also inhibited MV H protein-mediated green monkey erythrocyte rosette formation. A quantitative analysis suggested that 30 micrograms/ml of the soluble form functionally corresponded to 0.2 microgram/ml of M177 or M75. These data established that the C regulatory function and the MV receptor function of MCP were blocked simultaneously by the individual mAb, and that soluble forms of MCP could inhibit MV infection in cells expressing human MCP, although doses far higher than the natural concentration of soluble MCP were required.

[Morphologic characteristics of digestive tract mucosa in virus infections]

Biopsies of mucous membranes of the alimentary canal in widespread viral infections (measles, chicken pox, HIV infection) in 17 to 40-year-old patients of both sexes were examined. Intracellular oedema and viral particles are found in the epithelial cells. The presence of membrane-granular structures in HIV-infection and their absence in other viral infections is of a different diagnostic importance.

Acute encephalopathy with bilateral thalamotegmental involvement in infants and children: imaging and pathology findings

PURPOSE

To investigate the imaging and pathologic characteristics of acute encephalopathy with bilateral thalamotegmental involvement in infants and children.

METHODS

Five Japanese children ranging in age from 11 to 29 months were studied. We performed CT imaging in all patients, 10 MR examinations in four patients, and an autopsy in one patient.

RESULTS

The encephalopathy affected the thalami, brain stem tegmenta, and cerebral and cerebellar white matter. The brain of the autopsied case showed fresh necrosis and brain edema without inflammatory cell infiltration. Petechiae and congestion were demonstrated mainly in the thalamus. CT and MR images showed symmetric focal lesions in the same areas in the early phase. These lesions became more demarcated and smaller in the intermediate phase. The ventricles and cortical sulci enlarged. MR images demonstrated T1 shortening in the thalami. The prognosis was generally poor; one patient died, three patients were left with severe sequelae, and only one patient improved.

CONCLUSIONS

The encephalopathy might be a postviral or postinfectious brain disorder. T1 shortening in the thalami indicated the presence of petechiae.

[Some features of measles virus morphogenesis in highly differentiated human astrocyte cultures]

Astrocyte cultures of adult human brain were used to study the morphogenesis of measles virus at different multiplicity of infection. High-dose (1 to 10 TCD50/ml) inoculation of the culture was found to give rise to an acute infection with cytolysis on days 10-12 postinfection and formation of extracellular mature virions. Low multiplicity of infection (0.01-0.1 TCD50/ml) caused the persistence of virus. During a persistent infection the virus in titers 1.7 to 2.4 lg TCD50/ml was detected as long as up to the 3rd passage. Ultrastructural studies of such cultures revealed some features which were not observed in an acute infection: (1) the diameter of intracytoplasmic RNP increased by 1.5 times vs. that in other cell cultures because of coarse thickening of the envelope; (2) numerous immature virions in which nucleocapsids were completely or partially absent; and (3) uncommonly low number of mature virions. Moreover, alterations in the spatial orientation of cytoskeleton components, such as intermediate and thin (actin) filaments were observed. A conclusion is made that astrocytes as a reservoir for measles virus accumulation serve as the source of immature envelope virus production, which may be one of the possible causes of sclerosing panencephalitis. The causes of disturbances in RNP transport from the site of assembly to cell membrane are discussed.

Central nervous system virion detection in acute measles: histopathological, ultrastructural and pathogenetic aspects

Histopathological and ultrastructural studies of 23 patients who died with clinical diagnosis of measles were carried out. In 12 cases viral nucleocapsids were searched by electron microscopy and detected in 100% of the cases in the lungs and in 50% of the cases in the central nervous system. They were mostly intranuclear. Histopathological changes associated to neurological alterations and the detection of virion are discussed in relation to acute and delayed clinical manifestations.

Replication-incompetent adenoviruses as vectors for protective immunization against measles virus infection

Despite the availability of an efficient live-attenuated measles virus vaccine about 1.5 million annual deaths from measles infections and their complications are recorded worldwide. Particularly in developing countries measles remains an unsolved problem and a new vaccine seems necessary. In our animal model of measles virus infection in rats we studied a candidate vaccine based on infectious replication incompetent (E1A-) adenovirus (RAd) where measles virus genes are expressed under the control of the cytomegalovirus immediate early promoter. The aim of the study was to characterize the cell mediated and humoral immunity after immunization with RAd and its protective effect. After challenge with a lethal dose of measles virus no signs of disease or histopathological changes were detected in RAd68-immunized rats. The elimination of measles virus was successful within a few days. The results demonstrate that defective recombinant adenovirus vectors can induce complete protection from experimental measles infection in rats.

The rash of measles is caused by a viral infection in the cells of the skin: a case report

Measles skin rash was immunohistochemically examined in an effort to detect virus antigen in skin samples taken from a 15-year-old girl with measles. A sectioned specimen obtained by punch biopsy from a 2nd-day skin lesion showed localized parakeratosis and acanthosis with multinucleated giant cells in the epidermis, thickening and cellular edema of epithelia in the hair follicles, and vascular dilation in the papillary plexus. Measles virus antigen was detected by ABC immunoperoxidase in the epidermis, follicular epithelia, and lympho-histiocytic cell infiltrates in the upper of the dermis. This rash deemed to be caused in part by direct viral infection of the epidermal cells.

Immunosuppressive measles encephalitis

A case of immunosuppressive measles (rubeola) encephalitis in a 12-year-old boy in remission from acute lymphoblastic leukemia is described. The patient presented with focal seizures which led to epilepsia partialis continua and then progressive obtundation. Magnetic resonance imaging revealed focal abnormalities, predominantly in the cortex, that on light and electron microscopic examination were demonstrated to be highly localized areas of neuronal loss, gliosis, and secondary Wallerian degeneration with paramyxovirus inclusions in the oligodendrocytes and surviving neurons.

An immunohistochemical study of Warthin-Finkeldey cells in measles

An autopsy case of an 18 month old male infant with measles infection is reported. An autopsy revealed generalized lymphadenopathy, splenomegaly and hyperplastic thymus. Histologically, there were many Warthin-Finkeldey cells (WFC) in hyperplastic lymphoid tissues. Although viral particles and inclusions were not detected electronmicroscopically, the infection of measles virus was detected in WFC by immunofluorescent technique using anti-measles antibody. Warthin-Finkeldey cells were morphologically and immunohistochemically divided into two groups. The first type was WFC appearing in the germinal centers of lymphoid tissue, revealing many large nuclei and B cell markers. The second type was WFC appearing in the interfollicular areas and thymus, showing many small hyperchromatic nuclei and T cell markers. The data indicate that there might be a morphologic and immunophenotypic heterogeneity in WFC.

Cytologic diagnosis of measles pneumonia in a bronchoalveolar lavage specimen. A case report

An immunocompromised employee of our medical center contracted measles during an epidemic and subsequently died of giant cell pneumonia. In this report we discuss the cytologic diagnosis of measles pneumonia and the differential diagnosis of multinucleate giant cells in lung cytology specimens. In the appropriate clinical setting, inclusion-bearing syncytial epithelial giant cells in lung are virtually pathognomonic of measles infection. Cytologic specimens can provide an important early diagnosis.

[A morphological and immunofluorescent study of the measles vaccinal process in an experiment on monkeys]

A correlation between localization of morphological lesions and the presence of viral antigen in the CNS was established. Dissemination of the infectious process in the CNS depended on both topography of the inoculated areas and more so on traumatic injury of the ventricular system. Viral antigen could be detected in the reticuloendothelial system and epithelial cells of the respiratory tract without inducing specific cytopathic changes. Simultaneous morphological and immunofluorescent examination allowed the safety of live measles vaccine to be established more accurately.

Disseminated measles infection after vaccination in a child with a congenital immunodeficiency

An infant boy with a congenital immunodeficiency had fatal disseminated measles after administration of a live attenuated measles vaccine. This rare complication was confirmed with molecular virologic techniques. Although efforts to expand availability of vaccinations are critically important, caution is warranted in children with potentially severe immunologic dysfunction.

Acute measles infection in the hamster cochlea

Measles virus has been implicated in sudden sensorineural hearing loss (SNHL) in adults as well as in children. Furthermore, sensorineural hearing loss following live measles virus vaccination has been reported. As of yet, however, there has been only few reports on human temporal bone pathology due to measles, and on experimental animal models of measles infection. This study was undertaken to examine acute measles infection in adult hamster cochlea morphologically and immunohistochemically for precise understanding of this viral infection. Atrophy of the stria vascularis, loss of the organ of Corti, "rolled-up" tectorial membrane, and cell infiltration with a positive immunofluorescent reaction primarily within the scale media indicating endolymphatic labyrinthitis were the principal findings. These results were generally consistent with previous ones on human temporal bone pathology not only due to measles but also to SNHL. We consider measles virus to be one of the possible pathogens, even if low in frequency, causing profound and irreversible hearing loss, including SNHL. Completion of measles vaccination without complication and selective or mass revaccination may be necessary to prevent such hearing loss.

Measles encephalitis during immunosuppressive treatment for acute lymphoblastic leukaemia

Between 1971 and 1989 measles encephalitis was identified in five children receiving chemotherapy for acute lymphoblastic leukaemia. Review of these and previously reported cases of measles encephalitis in immunosuppressed patients failed to identify any pathognomonic features in the history, the clinical presentation, or the results of electroencephalography or computed tomography. Detection of measles virus antigen in nasopharyngeal secretions or intrathecal synthesis of specific antibody was not possible in all instances. Early diagnosis by direct detection of viral antigen in the brain was confounded by difficulties in identifying areas of the brain suitable for biopsy. Increasing herd immunity to measles in the general population by vaccination is the only effective intervention against measles encephalitis in immunosuppressed children. Measles encephalitis must be remembered as a possible explanation of encephalopathy in the immunocompromised child: the benefits of early use of antiviral agents need to be evaluated.

Measles virus-induced hippocampal neurodegeneration in the mouse: a novel, subacute model for testing neuroprotective agents

The hamster neurotropic (HNT) strain of measles virus causes non-inflammatory encephalopathy in Balb/c mice, associated with neurodegeneration in hippocampal CA1 and CA3 regions. This loss of pyramidal cells can be prevented by twice daily systemic treatment with 1 mg/kg dizocilpine (5-methyl-10,11-dihydro-5H-dibenzo(a,d)cyclo-hepten-5,10-imine maleate; MK-801) for 7 days. By varying the MK-801 treatment protocol, we now found that drug administration during the last 4 days prior to sacrifice (i.e. days 4-7 post inoculation, p.i.) is essential for neuroprotection. In contrast, MK-801 treatment during the first days (days 0-4 p.i.) did not prevent the neuronal necrosis. These data suggest that the concentration of an excitotoxic factor in the mouse brain increases after virus inoculation, reaching toxic levels by days 4-5 p.i. This novel 'subacute' mouse model of neurodegeneration therefore constitutes an attractive tool for mechanistic and interventional studies in excitotoxicity research.

Patterns of measles pneumonitis

As a result of the enlarging pool of unvaccinated children and young adults, there has been an increase in serious measles pneumonitis in our areas. We recently examined autopsy and/or lung biopsy material from five children with fatal measles pneumonitis. Two patients were immunocompromised because of either prematurity or acute leukemia and died 13-16 days following onset of symptoms. Both had classic giant cell pneumonitis, with readily demonstrable intranuclear inclusions. Three other children without known immunocompromise had a more prolonged course. The lungs of these patients lacked the classic pattern and displayed instead a spectrum of less specific findings ranging from organizing diffuse alveolar damage to interstitial pneumonia with giant cells, but without viral inclusions. An accompanying necrotizing bronchiolitis was also present. Electron microscopy and/or detection of elevated measles-specific immunoglobulin M was necessary to confirm the diagnosis in these apparently immunocompetent patients. We conclude that the histologic features of fatal or serious measles pneumonitis are variable and depend to some extent on the immunocompetence of the host as well as the duration and tempo of the disease. Ancillary studies may be necessary to establish the diagnosis in cases lacking classic histopathologic features.

Measles cervicitis. Report of a case with cytologic and molecular biologic analysis

We report on a 20-year-old woman who, in her third month of pregnancy, presented with a morbilliform rash, fever and diarrhea. Many multinucleate superficial, intermediate and metaplastic cells were noted in the cervical cytologic preparation. The presence of the measles virus in cells from the cervix was confirmed by the amplification of measles complementary DNA (cDNA) by the polymerase chain reaction. The patient's cervical Papanicolaou smear was unremarkable on reexamination four months after the onset of the disease. To our knowledge, this is the first verified reported case of infection of the uterine cervix by the measles virus.

Cutaneous manifestations of measles in AIDS

In immunocompetent patients, infection by the measles (rubeola) paramyxovirus produces fever, cough, coryza, Koplik's spots, and, on the skin, a macular erythema that can become confluent. The erythema has a striking cephalocaudal spread and clearing. The diagnosis of measles on a skin biopsy and the distinction from an erythema multiforme type of drug eruption can be difficult. We studied a skin biopsy from a patient with the acquired immunodeficiency syndrome (AIDS) who presented with measles. In contrast to erythema multiforme, the measles biopsy has necrosis of clusters of keratinocytes in the high spinous layer and granular layer of the epidermis, whereas erythema multiforme has necrosis of basal keratinocytes. Multinucleated keratinocytes may or may not be prominent in the measles biopsy. Cytoplasmic swelling of the keratinocytes in the granular layer may be present even when multinucleated cells are sparse. Immunoperoxidase reactivity for measles virus protein is present in intranuclear inclusions and in the cytoplasm of infected upper spinous keratinocytes. There were more cells with positive staining in the biopsy from the AIDS patient than in another biopsy from an immunocompetent patient with measles. The AIDS patient was seronegative for measles throughout the course of the illness. The examination of the skin biopsy can be very important in the diagnosis of measles in AIDS patients or immunocompromised patients who may not develop the usual diagnostic serology.

Acute measles encephalitis of the delayed type: neuroradiological and immunological findings

A case of delayed acute measles encephalitis in an immunosuppressed child is reported. Detailed immunological studies have shown defective humoral immunity (defective IgA, IgG2 and IgG3) and decreased natural killer activity. Neuroradiological examination by magnetic resonance imaging revealed several high signal lesions on T2-weighted images in the gray matter without clinical or pathological correlation. The implications of these findings are discussed.

Sputum cytology in measles infection. A case report

A resurgence of measles, a highly infectious viral infection, has occurred in the United States. In this report the sputum cytology from a case of measles pneumonia is described and discussed. Only a few recent reports have described the cytopathologic changes of measles. Familiarity with the typical cytologic changes of measles will assist in the diagnosis of this infection.

Do measles early giant cells result from fusion of non-infected cells? An immunohistochemical and in situ hybridization study in a case of morbillous appendicitis

A case of acute appendicitis with features of measles inflammatory reaction is studied. Two types of lymphoid polykaryons are seen: Warthin Finkeldey cells inside germinal centres (LN1 ++, LN2 +, L26 +, MB1 +, MB2 +/-) and multinucleate plasma cells in the lamina propria (mu +, alpha ++, kappa +, lambda +). Both types of polykaryon are devoid of inclusions. The search for viral genetic information by in situ hybridization was negative in these cells. A positive signal was observed in interfollicular mononuclear cells and rare enterocytes. A possible mechanism of fusion from without, acting at the beginning of the disease to induce the appearance of polykaryons, is discussed.

[The isolation of the morbilli virus from the Baikal seal Phoca sibirica and its preliminary characterization]

A morbillivirus was isolated from the organs of a seal (Phoca sibirica) which had died during 1987-1988 epizootic in Baikal. This Baikal seal morbillivirus (BSM) was adapted to Vero cell cultures in which it induced a cytopathic effect developing to complete destruction of the monolayer. Typing of BSM was done by indirect immunofluorescence test and enzyme immunoassay using antibodies to distemper and measles viruses. A method for virus concentration and purification was developed. According to electron microscopic examinations, the virus virions were spherical particles of heterogeneous sizes over 100 nm in diameter. The clinical picture of seal infection, pathological anatomy and histopathology are described. A possible role of BSM in the epizootics of Baikal seals is discussed.

Isolation of measles virus in primary rhesus monkey cells from a child with acute interstitial pneumonia who cytologically had giant-cell pneumonia without a rash

The isolation of measles virus in primary Rhesus monkey kidney cells (PRMK) in patients with documented giant-cell pneumonia who have presented without a rash is limited. The diagnosis usually is made by cytologic examination of nasal or bronchial secretions in which characteristic multinucleated giant cells with intranuclear and intracytoplasmic inclusion bodies are observed. The diagnosis of giant-cell pneumonia has been associated with measles virus but not exclusively. Canine distemper, herpes group viruses, and parainfluenza infections have been associated with these cells. In addition, vitamin A deficiency also has been cytologically associated with multinucleated giant cells. The authors describe the isolation of measles virus from bronchial washing and sputum in PRMK cells at 4 days from an 11-year-old child with acute interstitial pneumonia who was in remission for acute lymphocytic leukemia. Classic cytopathologic effect (CPE) consisting of syncytial and hole formation on the PRMK monolayer was apparent. In addition, a foamy appearance of the monolayer was noted in an otherwise clean lot of monkey cells. Confirmatory testing with measles antibody of the infected areas of the monolayer by indirect immunofluorescence (IFA) was positive for measles antigen and negative for mumps, parainfluenza (types I, II, and III) and influenza A and B virus. Serologic studies for measles antibody revealed an IFA IgG titer of greater than 1:10,240, and an IgM titer of 1:128. Cytologic examination of the same bronchial fluid revealed the typical giant cells with characteristic inclusions associated with measles virus. Because this disease usually is severe, and often fatal, prompt recognition of this virus is essential, not only to the patient, who can be treated with immunoglobulin and/or antiviral therapy, but also to prevent the spread of the virus to other patients and medical personnel. These findings also support direct evidence for the etiologic role of measles virus in giant-cell pneumonia that has been detected either histologically or cytologically and in tissue culture at autopsy.

[Measles-related appendicitis. A report of a new case]

We present a case of "Measles Appendicitis" treated recently in our unit. We point out the lack of bibliographic references on this pathology, despite its relatively high rate of incidence. The possible coexistence of appendicitis and measles; along with the possibility of a bacterial superinfection of the obliterated appendix due to submucous lymphoid hyperplasia, in our opinion, justifies an initial surgical approach in patients with measles who suffer from bouts of diagnostically uncertain pain in the lower right abdomen.

Simultaneous infection with human herpesvirus-6 and measles virus in infants

Two infants (4 and 5 months of age) with a febrile episode for 3 and 5 days, respectively, developed skin rashes after the fever subsided and were diagnosed as exanthem subitum. The rash continued for 5 days followed by mild-to-moderate pigmentation. Human herpesvirus-6 and measles virus, which were confirmed by a specific immunofluorescence assay and by electron microscopy, were isolated simultaneously from blood in the acute stage of the disease but not from the convalescent stage. The titer of the herpesvirus-6 in blood was greater than that of measles. Specific serologic assays showed marked seroconversion against human herpesvirus-6 but not to measles virus. The results suggest that dual infection with human herpesvirus-6 and measles virus results in atypical exanthem subitum or modified measles with unique immunologic responses.

[Histological changes in the appendix in the prodromal stage of measles]

Morphological changes of adenoid tissue associated with morbilli are known. However, it is less known that the disease may start with symptoms of acute appendicitis and on the basis of histological picture morbilli can be raised or rendered probable, respectively, before appearance of typical clinical symptoms. Among morbilli cases of recently increased number the later developed morbilli was diagnosed from appendix in an appendectomy performed on a patient being in prodormal stage.

Cytopathic effects of measles virus on the human intestinal mucosa

We reported a case of measles with diarrhea in an infant. Capsule biopsy samples of intestinal mucosa taken 14 days after onset of fever was damaged and had low disaccharidase activities. Virus particles were found in the damaged villous cell. Second intestinal mucosa biopsy samples taken 28 days after onset of fever was found to be normal in structure, but lactase and sucrase activities were still low. Mucosal damage by virus particles was the cause of diarrhea in our infant.

Stability of the nucleotide sequence of the phosphoprotein gene of measles virus during lytic infections

Three clones with cDNA inserts encoding large portions of the measles virus phosphoprotein mRNA were characterized and compared with a previously published sequence of the Edmonston strain of measles virus. The two cloned viruses were separated by more than 100 passages. Only one out of 1477 nucleotides differed in the two sequences reflecting a very low mutation rate of the phosphoprotein gene during dilute lytic passages. The discovery that a third reading frame in the phosphoprotein gene may code for a novel peptide chain in addition to the P and C peptides may explain some of the high stability of the gene. The new reading frame was accessed by a translational shift caused by insertion of one extra G at a particular site in one of three otherwise identical cDNA sequences. A discrepancy was also found between the presumably high error rate of viral RNA polymerases and the stability of nucleotides in which mutations would not lead to amino acid substitutions. A few errors in the previously published sequence were discovered and the corrections are presented.

Neuropathology of two fatal cases of measles in the 1988-1989 Houston epidemic

The clinical course and autopsy findings of 2 patients with measles encephalitis that occurred during the 1988-1989 Houston epidemic are reported. A previously healthy 25-month-old boy had serologically-proved measles, hemophagocytic syndrome, and acute disseminated demyelinating encephalitis. A 19-year-old male with acute lymphocytic leukemia had proved measles pneumonia and acute hemorrhagic leukoencephalitis. These patients represent a broad spectrum of measles-induced immunopathic complications of the central nervous system.

[The mechanisms of persistent measles virus infection in HEp-2 cells]

Persistent infection with Edmonston strain of measles virus was established in a highly susceptible clone of HEp-2 cells. The morphological and cytogenic aspects of persistent infection are presented. Carriage of measles virus in cells persistently infected is marked by important differences between standard Edmonston strain and virus stocks isolated from time to time from the carrier state. It is especially significant that cell fusion capacity decreased in amount concordant with the drop in the yield of infectious virus. Addition of UV inactivated Sendai virus, trypsin treatment or incubation at suboptimal temperatures precipitate the cytocidal effect of measles virus. Some clinical implications of reactivation of the lytic cycle in the carrier state are suggested.