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Query: UMLS:C0021345 (infectious mononucleosis)
 3,358 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In mice the cytotoxic T-cell response to several types of virus is influenced by genes within the major histocompatibility complex; in particular, genetic control is exercised at the effector cell level through a requirement that virus-specific cytotoxic T cells recognise viral antigens in association with H-2K and H=2D region gene products on the surface of infected cells. In man the restriction which the analogous HLA-A, -B and -C-region gene products might place on virus-specific T-cell function is still in dispute. The earliest and most controversial evidence concerns the Epstein-Barr virus (EBV), a B lymphotropic agent which causes infectious mononucleosis (IM) and which induces an unusually vigorous T-cell response; cytotoxic T cells from IM patients' blood were shown to be EBV-specific yet, in contrast to mouse systems, apparently free of any obvious HLA restriction. Since then T-cell recognition of EBV-infected B cells has assumed particular significance as a model system for the study of cytotoxic T-cell function in man. This report describes the results of a new approach clearly indicating that HLA-A and -B region products do indeed have a role in this system.
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PMID:HLA-restricted T-cell recognition of Epstein-Barr virus-infected B cells. 624 95

The reactive cell population in Hodgkin's disease consists of predominantly CD4+ helper T cells and lacks CD8+ cytotoxic T cells and natural killer cells. This lack of a CD8+ response is surprising in view of the expression of the latent Epstein-Barr viral protein LMP by Reed-Sternberg cells in many cases of Hodgkin's disease, Deficient HLA class I expression would be one possible mechanism to avoid a CD8+ cytotoxic immune response. To test this possibility we studied the expression of HLA class I and II determinants on Reed-Sternberg cells in tissue sections and cell suspensions of Hodgkin's disease. Frozen tissue sections of 40 cases and cytocentrifuge preparations from cell suspensions of 10 lymph nodes involved by Hodgkin's disease were studied with monoclonal antibodies reactive with HLA determinants. As a control frozen tissue sections of two cases of infectious mononucleosis were studied. Careful examination of the tissue sections and subsequently of cytospins of cell suspensions showed that the Reed-Sternberg cells frequently lacked HLA class I but showed strong staining for HLA class II. Absence of HLA class I expression on Reed-Sternberg cells and their variants provides an explanation for the lack of a CD8+ cytotoxic immune response against antigens expressed on Reed-Sternberg cells.
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PMID:Absence of HLA class I expression by Reed-Sternberg cells. 751 95

Mononucleosis is defined as atypical lymphocyte proliferation which causes clinical symptoms such as tonsillitis, lymphadenopathy, or hepatosplenomegaly. Mononucleosis syndrome is caused by cytomegalovirus (CMV), Toxoplasma, hepatitis virus, adenovirus, or other agents as well as by Epstein-Barr virus. The syndrome is immunologically characterized by the proliferation of activated T cells (HLA-DR+ T cells). We encountered three infants with hepatosplenomegaly who were diagnosed as primary CMV infection by the detection of anti-CMV IgM antibody. Although the patients were otherwise asymptomatic, analysis of lymphocyte subpopulations showed a decreased ratio of CD4+ to CD8+ T cells and augmented expression of HLA-DR antigen on T cells characteristic of infectious mononucleosis. We conclude that inapparent CMV disease may affect the immunologic status of infected children even if it is asymptomatic.
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PMID:Peripheral blood lymphocyte subpopulations in three infants with hepatosplenomegaly caused by cytomegalovirus infection. 764 91

PTLD may be considered as an "opportunistic cancer" in which the immunodeficiency state of the host plays a key role in fostering the environment necessary for abnormal lymphoproliferation. The following discussion reflects our own current thoughts regarding events which may result in PTLD and its sequelae. Many of the individual steps have not been rigorously proved or disproved at this point in time. Following transplantation and iatrogenic immunosuppression, the host:EBV equilibrium is shifted in favor of the virus. Most seronegative patients will become infected either via the graft or through natural means; seropositive patients will begin to shed higher levels of virus and may become secondarily superinfected via the graft. There is a "grace" period of approximately one month posttransplant before increased viral shedding begins. PTLD is almost never seen during this interval. In many cases infection continues to be silent whereas in rare individuals there is an overwhelming polyclonal proliferation of infected B lymphocytes. This is the parallel of infectious mononucleosis occurring in patients with a congenital defect in virus handling (X-linked lymphoproliferative disorder). It is possible that transplant patients with this presentation also suffer a defect in virus handling. In other cases excessive iatrogenic immunosuppression may paralyze their ability to respond to the infection. With CsA and FK506 regimens, individual tumors may occur within a matter of months following transplant. The short time of incubation suggests that these are less than fully developed malignancies. It may be that local events conspire to allow outgrowth of limited numbers of B-lymphocyte clones. A cytokine environment favoring B-lymphocyte growth may be one factor and differential inhibition by the immuno-suppressive drugs of calcium-dependent and -independent B-cell stimulation may be another. In addition, there is some evidence that CsA itself may inhibit apoptosis within B cells. Since most patients do not develop PTLDs, an additional signal(s) for B-cell stimulation may be required. Indeed, it is possible that the virus may simply serve to lower the threshold for B-cell activation and/or provide a survival advantage to these cells. The ability of individual cell clones to evade a weakened immune system may set into play a Darwinian type of competition in which the most rapidly proliferating cells with the least number of antigenic targets predominate. In this regard, differences in host HLA types may determine the repertoire of viral antigens which are subject to attack.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Epstein-Barr virus, infectious mononucleosis, and posttransplant lymphoproliferative disorders. 780

Plasma levels of soluble CD8 (sCD8) and soluble CD4 (sCD4) in 44 patients with infectious mononucleosis (IM) were studied. A marked increase in sCD8 (22366 +/- 2702 U/ml; control: 219 +/- 10 U/ml; P < 0.0001) and significant increase in sCD4 (19.3 +/- 0.9; control: 8.1 +/- 0.2, P < 0.0001) strongly suggest activation of both CD8+ and CD4+ lymphocytes, which is important in restraining Epstein-Barr virus-infected B lymphocytes. Levels of sCD8 strongly correlated with the percentage and the absolute number of both CD8+ and CD8(+)-HLA-DR+ lymphocytes. In addition, we showed increased release of sCD8 from lymphocytes in vitro and increased ratio between plasma sCD8 and the number of CD8+ lymphocytes in blood, indicating that elevation of plasma sCD8 is due to expansion of CD8+ subset as well as increased sCD8 release from each CD8+ cell. Increased sCD4 release from CD4+ lymphocytes, the number of which is not increased in the blood during IM, was also seen. Patients with more severe fever had higher levels of sCD8 and sCD4. During convalescence sCD8 and sCD4 levels showed progressive decrease; however, even at 60-119 d after onset the levels of sCD8 and sCD4 remained higher than normal, suggesting prolonged lymphocyte activation. These results suggest that sCD8 and sCD4 are useful in monitoring immune activation during IM.
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PMID:Increased levels of soluble CD8 and CD4 in patients with infectious mononucleosis. 783 76

Acute infectious mononucleosis (IM) is a lymphoproliferative disease caused by the Epstein-Barr virus (EBV) infection. It has been reported that soluble T cell antigens are released from cells in response to T cell activation. In the present study, we investigated whether soluble antigen levels of CD2, CD4 and CD8 in serum increase during acute IM. Soluble CD2, CD4 and CD8 levels in serum were measured by a sandwich enzyme immunoassay. In addition, peripheral blood T cell subsets were analyzed by single and two color flow-cytometric analyses in IM. Patients with IM had increased levels of soluble CD2, CD4 and CD8 in serum samples obtained during acute stages. We found a positive correlation between serum levels of soluble CD8 and absolute counts of HLA-DR+CD8+T cells during acute IM. In addition, the correlation between soluble CD8 levels and serum GOT or GPT levels was shown to be positive during acute IM. Our findings suggest that the soluble antigen levels of CD2, CD4 and CD8, in particular CD8, in serum are an important immunologic parameter for determining the activation of T cells during acute IM.
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PMID:[Serum soluble CD2, CD4 and CD8 levels in infectious mononucleosis]. 790 99

Over a period of three years (1989-1992) five children suffering from localized scleroderma were seen at the Department of Pediatrics of the University of Trieste. Evidence of a previous infectious mononucleosis (IM) was present in four out of five patients. The clinical history of these four children is reported. The association between the appearance of scleroderma and a previous viral infection is not surprising. However, in the pediatric literature there is only one case of progressive systemic sclerosis (PSS) developing in a 15-month-old girl less than one month after she contracted IM. The presence of shared epitopes between an Epstein-Barr virus protein, BOLF1, and the hypervariable region of HLA associated with the pauciarticular form of JCA, recently reported, could provide a key to the pathogenesis of other collagen diseases such as scleroderma.
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PMID:Localized scleroderma after infection with Epstein-Barr virus. 829 65

Cytomegalovirus infection can be transmitted by transfusion of leucocyte-containing blood products (i.e. red cells and platelets). In otherwise healthy persons this virus infection causes a mild mononucleosis-like syndrome. In immunocompromised patients (neonatal patients if birth weight is less than 1200 grams; immunodeficiencies; haematological malignancies; bone marrow transplanted patients) a cytomegalovirus infection can be fatal. The transmission of cytomegalovirus by blood can be avoided by using seronegative blood donors. Recent experiences indicate that efficient removal of viable leukocytes by filtration (which removes more than log-3 of leukocytes) will prevent transmission of cytomegalovirus infection even when using blood from seropositive blood donors. All cellular blood products for the risk groups must be filtrated in any case, to avoid HLA-immunization and graft-versus-host reaction. Since this filtration seems to prevent the transmission of cytomegalovirus, the cost of screening of blood donors for anti-cytomegalovirus-antibodies is an unnecessary expense.
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PMID:[Cytomegalovirus and blood transfusion]. 838 Sep 44

Epstein-Barr virus (EBV) as a member of the herpesvirus family persists lifelong in the human body and causes diseases associated with virus replication (infectious mononucleosis, oral hairy leukoplakia) as well as neoplastic conditions such as nasopharyngeal carcinoma, B-cell lymphoma, Hodgkin's disease associated with viral latency. This complex biology relates to a highly regulated control of the persisting virus. Still, EBV is lytically produced in certain compartments of the human body. Epithelial cells were found to be of key importance for this. Various routes (cell fusion, IgA receptor-mediated uptake) were described for EBV to enter epithelial cells in the absence of CR2 receptor. Viral entry into cells, however, via CR2 receptor fusion or IgA mediated was not found to be sufficient for viral production. The molecular mechanisms for the lack of viral production in most target cells are primarily the presence of silencer activities and the early elimination of cells entering the lytic cycle. Only terminally differentiated epithelial cells are capable of supporting an efficient lytic cycle of EBV replication. EBV-mediated suppression of apoptosis as well as down-regulation of cellular and viral gene products, such as HLA molecules, which mediate recognition by the immune system, are important contributing factors to the development of these neoplasias where viral genes, possibly via interaction with anti-oncogenes, such as p53, in context with genetic and environmental factors play a key role. Novel diagnostic tools and a vaccine have been developed which could help to control EBV-related diseases.
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PMID:Epstein-Barr virus and its interaction with the host. 840 48

Epstein-Barr virus (EBV) is the aetiological agent of infectious mononucleosis (IM) which is a common sequel to primary EBV infection. Thereafter, the virus is maintained as a lifetime latent infection. Although the proteins expressed during the latent EBV infection provide a rich source of immunogenic epitopes, very little is known about cytotoxic T lymphocyte (CTL) control of primary EBV infection. The present report is based on an analysis of CTL clones derived from a patient suffering from acute IM. An intriguing feature of six CTL clones that displayed an HLA-restricted pattern of cell lysis was their initial coexpression of the T cell markers CD3, CD4, and CD8. Detailed analysis of one of these clones, which was restricted through the class II MHC antigen DR2, revealed reactivity with an epitope within the EBV lytic cycle early antigen, BHRF-1, which corresponds to the C-terminal region of the protein (AGLTLSLLVICSYLFISRG) (residues 171-189). There have been no previously published reports describing a CTL response during acute IM directed against an EBV lytic antigen. Interestingly, the coexpression of CD4 and CD8 by these CTLs during acute IM suggests that CD3+CD4+CD8+ cortical thymocytic precursor cells are recruited in order to overcome the EBV infection.
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PMID:Recruitment during infectious mononucleosis of CD3+CD4+CD8+ virus-specific cytotoxic T cells which recognise Epstein-Barr virus lytic antigen BHRF1. 863 17


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