Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0038002 (splenomegaly)
 9,873 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In October 1998, a 37-year-old man was admitted because of petechiae and thrombocytopenia following flu-like symptoms. On admission, there were numerous petechiae on the back and extremities. The WBC count was 3,700/microliter with 3% atypical lymphocytes, the lymphocyte CD4/CD8 ratio 0.37, and the platelet count 1,000/microliter. Mild splenomegaly was detected by CT. Results of blood chemistry and coagulation tests were normal. A bone marrow aspirate was normocellular with no signs of dysplasia, and the megakaryocyte count was normal. The patient was initially diagnosed as having virus infection-associated thrombocytopenia. Steroid therapy was started immediately, and the platelet count rose to 15 x 10(4)/microliter on day 21. The PA-IgG level was 652 ng/10(7) platelets. Mild liver dysfunction developed, and atypical lymphocytes increased in number thereafter. Because IgM anti-cytomegalovirus (CMV) antibody (Ab) was positive and IgG CMV Ab was negative, a diagnosis of CMV mononucleosis was made. Gancyclovir was therefore started. Four months later, steroid therapy was discontinued, and partial remission has since been maintained. In healthy individuals, CMV infection is usually latent, and the development of mononucleosis is rare. So far, 11 cases of CMV-induced mononucleosis associated with severe thrombocytopenia have been reported in immunocompetent adults.
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PMID:[Cytomegalovirus mononucleosis with severe thrombocytopenia]. 1119 35

Murine gamma-herpesvirus 68 (MHV-68) is a natural pathogen of small rodents and insectivores (mice, voles and shrews). The primary infection is characterized by virus replication in lung epithelial cells and the establishment of a latent infection in B lymphocytes. The virus is also observed to persist in lung epithelial cells, dendritic cells and macrophages. Splenomegaly is observed two weeks after infection, in which there is a CD4+ T-cell-mediated expansion of B and T cells in the spleen. At three weeks post-infection an infectious mononucleosis-like syndrome is observed involving a major expansion of Vbeta4+CD8+ T cells. Later in the course of persistent infection, ca. 10% of mice develop lymphoproliferative disease characterized as lymphomas of B-cell origin. The genome from MHV-68 strain g2.4 has been sequenced and contains ca. 73 genes, the majority of which are collinear and homologous to other gamma-herpesviruses. The genome includes cellular homologues for a complement-regulatory protein, Bcl-2, cyclin D and interleukin-8 receptor and a set of novel genes M1 to M4. The function of these genes in the context of latent infections, evasion of immune responses and virus-mediated pathologies is discussed. Both innate and adaptive immune responses play an active role in limiting virus infection. The absence of type I interferon (IFN) results in a lethal MHV-68 infection, emphasizing the central role of these cytokines at the initial stages of infection. In contrast, type II IFN is not essential for the recovery from infection in the lung, but a failure of type II IFN receptor signalling results in the atrophy of lymphoid tissue associated with virus persistence. Splenic atrophy appears to be the result of immunopathology, since in the absence of CD8+ T cells no pathology occurs. CD8+ T cells play a major role in recovery from the primary infection, and also in regulating latently infected cells expressing the M2 gene product. CD4+ T cells have a key role in surveillance against virus recurrences in the lung, in part mediated through 'help' in the genesis of neutralizing antibodies. In the absence of CD4+ T cells, virus-specific CD8+ T cells are able to control the primary infection in the respiratory tract, yet surprisingly the memory CD8+ T cells generated are unable to inhibit virus recurrences in the lung. This could be explained in part by the observations that this virus can downregulate major histocompatibility complex class I expression and also restrict inflammatory cell responses by producing a chemokine-binding protein (M3 gene product). MHV-68 provides an excellent model to explore methods for controlling gamma-herpesvirus infection through vaccination and chemotherapy. Vaccination with gp150 (a homologue of gp350 of Epstein-Barr virus) results in a reduction in splenomegaly and virus latency but does not block replication in the lung, nor the establishment of a latent infection. Even when lung virus infection is greatly reduced following the action of CD8+ T cells, induced via a prime-boost vaccination strategy, a latent infection is established. Potent antiviral compounds such as the nucleoside analogue 2'deoxy-5-ethyl-beta-4'-thiouridine, which disrupts virus replication in vivo, cannot inhibit the establishment of a latent infection. Clearly, devising strategies to interrupt the establishment of latent virus infections may well prove impossible with existing methods.
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PMID:Natural history of murine gamma-herpesvirus infection. 1131 14

We present the clinical case of a 20-year-old male soldier who appeared in general good physical condition. He suffered from infectious mononucleosis caused by Epstein-Barr virus that had recurred 2 years after the first serologically documented episode. The detected splenomegaly persisted in the healthy young man, who otherwise showed no apparent immune deficiency. To our knowledge, this is an extremely rare condition.
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PMID:Recurrent infectious mononucleosis caused by Epstein-Barr virus with persistent splenomegaly. 1151 29

The gamma-herpesviruses establish life-long latency in the host and are important human pathogens. T cells play a major role in controlling the initial acute infection and subsequently maintaining the virus in a quiescent state. However, the nature of the T-cell response to gamma-herpesvirus infection and the requirements for effective vaccination are poorly understood. The recent development of a murine gamma-herpesvirus (murine herpesvirus-68 [MHV-68]) has made it possible to analyze T-cell responses and test vaccination strategies in a small animal model. Intranasal infection with MHV-68 induces an acute infection in the lung and the subsequent establishment of long-term latency, which is associated with splenomegaly and an infectious mononucleosis-like syndrome. Here we review the T-cell response to different phases of the infection and the impact of vaccination against either lytic-cycle, or latency-associated T-cell epitopes.
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PMID:Vaccination against murine gamma-herpesvirus infection. 1157 33

Epstein-Barr virus (EBV) is a ubiquitous human gamma-herpesvirus that establishes life-long latency and is associated with lymphoproliferative disorders and the development of several malignancies. EBV infection is frequently, but not always, associated with the development of a syndrome termed infectious mononucleosis. The recent isolation and characterization of a murine gamma-herpesvirus, MHV-68 (gammaHV-68) has provided the first small animal model for studying immunity and pathogenesis of a gamma-herpesvirus in its natural host. MHV-68 has important biological and genetic similarities with the human gamma-herpesviruses. Following intranasal infection of mice with MHV-68, an acute respiratory infection in the lung develops and is cleared, followed by the establishment of latency. Similar to EBV, MHV-68 latency is largely established in B cells, although other cell types can be latently infected. The establishment of latency correlates with a prominent splenomegaly, polyclonal B cell activation with associated autoantibody production, and CD8+ T cell-dominated peripheral blood lymphocytosis, in many aspects mirroring EBV-induced infectious mononucleosis. There are key differences in the MHV-68- and EBV-induced CD8+ T cell responses however. Whereas the expanded CD8+ T cells associated with EBV-induced mononucleosis are largely the outgrowth of T cells responding to lytic viral epitopes elicited during the acute phase of the response, the CD8+ T cell lymphocytosis associated with MHV-68-induced infectious mononucleosis is dominated by an oligoclonal population of T cells expressing Vbeta4+ T cell receptors that are not reactive to acute viral epitopes. The focus of this article will be to highlight the similarities and differences in the infectious mononucleosis syndrome associated with human and murine gamma-herpesviruses.
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PMID:A mouse model for infectious mononucleosis. 1201 60

A 22-year-old man was hospitalized for assessment of thrombocytopenia and fever. Examination showed that he had infectious mononucleosis and moderately severe thrombocytopenia that was asymptomatic. Examination of blood smears revealed that the thrombocytopenia was caused by the clumping of platelets. We made a diagnosis of ethylenediaminetetraacetic acid-dependent pseudothrombocytopenia after excluding other infectious mononucleosis-related mechanisms of thrombocytopenia. When the patient recovered from infectious mononucleosis 2 months later, his thrombocytopenia improved, and no platelet clumping in peripheral blood smears was noted. Ethylenediaminetetraacetic acid-dependent pseudothrombocytopenia should always be considered as a possible cause of reported low platelet counts, even in patients with infectious mononucleosis and splenomegaly.
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PMID:Pseudothrombocytopenia associated with infectious mononucleosis. 1256 87

Epstein-Barr virus-associated hemophagocytic syndrome (EBV-AHS) is often associated with fatal infectious mononucleosis or T-cell lymphoproliferative diseases (LPD). To elucidate the true nature of fatal LPD observed in Herpesvirus papio (HVP)-induced rabbit hemophagocytosis, reactive or neoplastic, we analyzed sequential development of HVP-induced rabbit LPD and their cell lines. All of the seven Japanese White rabbits inoculated intravenously with HVP died of fatal LPD 18 to 27 days after inoculation. LPD was also accompanied by hemophagocytic syndrome (HPS) in five of these seven rabbits. Sequential autopsy revealed splenomegaly and swollen lymph nodes, often accompanied by bleeding, which developed in the last week. Atypical lymphoid cells infiltrated many organs with a "starry sky" pattern, frequently involving the spleen, lymph nodes, and liver. HVP-small RNA-1 expression in these lymphoid cells was clearly demonstrated by a newly developed in situ hybridization (ISH) system. HVP-ISH of immunomagnetically purified lymphoid cells from spleen or lymph nodes revealed HVP-EBER1+ cells in each CD4+, CD8+, or CD79a+ fraction. Hemophagocytic histiocytosis was observed in the lymph nodes, spleen, bone marrow, and thymus. HVP-DNA was detected in the tissues and peripheral blood from the infected rabbits by PCR or Southern blot analysis. Clonality analysis of HVP-induced LPD by Southern blotting with TCR gene probe revealed polyclonal bands, suggesting polyclonal proliferation. Six IL-2-dependent rabbit T-cell lines were established from transplanted scid mouse tumors from LPD. These showed latency type I/II HVP infection and had normal karyotypes except for one line, and three of them showed tumorigenicity in nude mice. These data suggest that HVP-induced fatal LPD in rabbits is reactive polyclonally in nature.
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PMID:Rabbit model for human EBV-associated hemophagocytic syndrome (HPS): sequential autopsy analysis and characterization of IL-2-dependent cell lines established from herpesvirus papio-induced fatal rabbit lymphoproliferative diseases with HPS. 1270 56

Infectious mononucleosis is an extremely common problem in the athletic population. "Mono" occurs in 3% of college students. Diagnosing infectious mononucleosis requires an understanding of the clinical features such as fever, lymphadenopathy, pharyngitis, and splenomegaly, as well as laboratory findings. The time at which these clinical features and laboratory abnormalities develop is also important to understand. Splenomegaly is common, but splenic rupture is very rare. Whether an athlete may return to activity usually relates to the presence of splenomegaly and the duration of the illness. Splenic rupture has not been reported after an individual has been ill for more than 3 weeks. This article provides an overview of infectious mononucleosis. The most common complications are reviewed and the management of these problems discussed. A practical approach to determining when an athlete may return to activity is presented.
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PMID:Infectious mononucleosis and the spleen. 1283 20

Kikuchi-Fujimoto disease (KFD), also know as histiocytic necrotizing lymphadenitis, is a benign disorder characterized histologically by necrotic foci surrounded by histiocytic aggregates, and with the absence of neutrophils. KFD was recognized in Japan, where it was first described in 1972. The disease is most commonly affecting young women. The cause of the disease is unknown, and its exact pathogenesis has not yet been clarified. Many investigators have postulated viral etiology of KFD, connecting it with Epstein Barr virus, human herpes simplex virus 6 parvo B 19, but also with toxoplasmic infection. Kikuchi-Fujimoto disease is usually manifested with lymphadenopathy and high fever, and is associated with lymphopenia, splenomegaly, and hepatomegaly with abnormal liver function tests, arthralgia, and weight loss. The disease has the tendency of spontaneous remission, with mean duration of three months. Single recurrent episodes of KFD have been reported with many years' pauses between the episodes. Kikuchi-Fujimoto disease may reflect systemic lupus erythematosus (SLE), and self-limited SLE-like conditions. Final diagnosis could only be established on the basis of typical morphological changes in the lymph node, and lymph node biopsy is needed for establishing the diagnosis. Lymphadenopathy in a patient with fever of the unknown origin could provide a clue to the diagnosis of lymphoma, tuberculosis, metastatic carcinoma, toxoplasmosis and infectious mononucleosis. As KFD does not have any classical clinical features and laboratory characteristics, it may lead to diagnostic confusion and erroneous treatment. We described a case of KFD, and suggested that this disease should be considered as a possible cause of fever of the unknown origin with lymphadenopathy.
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PMID:[Kikuchi-Fujimoto disease]. 1460 43

Mild splenomegaly is common in patients with Epstein-Barr virus-associated infectious mononucleosis. Massive splenomegaly, however, is rare and requires further evaluation to exclude other causes. We report an adolescent girl with previously undiagnosed type 1 Gaucher disease who presented with massive splenomegaly. The diagnosis of her underlying condition was hampered by the presence of a positive heterophile antibody test for infectious mononucleosis.
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PMID:Positive heterophile antibody test and massive splenomegaly in an adolescent with previously unsuspected Gaucher disease. 1509 78


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