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)

The molecular mechanisms that contribute to autoimmunity remain poorly defined. While inflammation is considered to be one of the major checkpoints in autoimmune disease progression, very little is known about the initiating events that trigger inflammation. We have studied transgenic mice expressing the prosurvival molecule protein kinase B/Akt under control of a T cell-specific CD2 promoter. In this study, we demonstrate that aged mice develop lymphadenopathy and splenomegaly that result from an accumulation of CD4, CD8, and unexpectedly B cells. An increased proportion of T cells express activation markers, while T cell proliferative responses remain normal. B cells are hyperproliferative in response to anti-IgM F(ab')(2) and anti-CD40, and increased IgA and IgG2a were found in the sera. In addition, a profound multiorgan lymphocytic infiltration is observed, and T cells from these mice display a defect in Fas-mediated apoptosis, which may be the mechanism underlying this phenotype. Therefore, T cell expression of active protein kinase B can alter T cell homeostasis, indirectly influence B cell homeostasis, and promote inflammation in vivo.
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PMID:Expression of active protein kinase B in T cells perturbs both T and B cell homeostasis and promotes inflammation. 1141 30

Autoimmune lymphoproliferative syndrome (ALPS), caused by inherited defects in apoptosis secondary to mutations in genes encoding Fas/CD95/APO-1 and Fas ligand (Fasl)/CD95L, is characterized by nonmalignant lymphadenopathy and splenomegaly, increased T cell receptor alpha/beta(+) CD4(-)CD8(-) T cells (alpha/beta(+) double-negative T cells [alpha/beta(+)-DNT cells]), autoimmunity, hypergammaglobulinemia, and cytokine abnormalities. The alpha/beta(+)-DNT cells are immunophenotypically and functionally similar to alpha/beta(+)-DNT cells that accumulate in lpr and gld mice, which bear genetic mutations in Fas and FasL. In these mice, alpha/beta(+)-DNT cells express the B-cell-specific CD45R isoform B220. We show that alpha/beta(+)-DNT cells of ALPS patients, with either Fas or FasL mutations, also express B220. In addition, also similar to LPR/gLD mice, they have an unusual population of B220-positive CD4(+) T cells. B220 expression, together with our finding of characteristic lectin binding profiles, demonstrates that cell surface O-linked glycoproteins have undergone specific modifications, which may have consequences for lymphocyte trafficking, cell-cell interactions, and access to alternative apoptosis pathways.
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PMID:TcR-alpha/beta(+) CD4(-)CD8(-) T cells in humans with the autoimmune lymphoproliferative syndrome express a novel CD45 isoform that is analogous to murine B220 and represents a marker of altered O-glycan biosynthesis. 1151 45

The Fas ligand (FasL)/Fas pathway is crucial for the maintenance of homeostasis of the peripheral immune system. Its importance is illustrated by the spontaneous mouse mutants gld andlpr which lack functional FasL and Fas receptor, respectively. These animals develop lymphadenopathy, splenomegaly, increased serum Ig and autoantibodies, leading to an autoimmune syndromeand premature death. The Rel/NF-kappaB family of transcription factors plays an important role in peripheral lymphocyte proliferation and survival. In this report, we studied the consequences of T cell-specific inhibition of NF-kappaB on the development of the gld phenotype. Transgenic gld/gld mice expressing a non-degradable form of IkappaBalpha under the control of T cell-specific regulatory elements show dramatically reduced lymphadenopathy, splenomegaly, and an almost complete elimination of Thy-1(+)B220(+)CD4(-)CD8(-) abnormal T cells, correlating with reduced proliferative responses and increased apoptosis of peripheral T cells upon TCR triggering. Interestingly, the B cell abnormalities that are characteristic of gld/gld mice, such as the production of autoantibodies, high levels of serum Ig, and the development of glomerulonephritis, are partially corrected. These results suggest that the T cell-specific inhibition of NF-kappaB opens apoptotic pathways distinct from FasL/Fas which, along with a diminished proliferative response, blocks splenomegaly and lymphadenopathy and partially rescues autoimmune disease in gld/gld mice.
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PMID:Inhibition of NF-kappaB in T cells blocks lymphoproliferation and partially rescues autoimmune disease in gld/gld mice. 1153 59

We report an unusual case of aggressive natural killer (NK)-like cytotoxic T-cell lymphoma in a previously healthy immunocompetent West African male. He presented with a fever of unknown origin, subsequently developed erythematous skin nodules, generalized lymphadenopathy, and hepatosplenomegaly, and then died of multiple organ failure. A skin nodule and lymph node biopsy showed an infiltrate of pleomorphic atypical medium and large lymphoid cells with extensive necrosis and prominent apoptosis. Peripheral blood and ascites also harbored these cells, with cytology revealing irregular nuclear folding and basophilic cytoplasm, and some with azurophilic cytoplasmic granules. Flow cytometry and immunohistochemistry demonstrated the expression of CD2, CD7, CD8, CD30, CD56, and cytoplasmic but not surface CD3. In situ hybridization demonstrated Epstein-Barr virus transcripts. A monoclonal T-cell receptor gamma chain gene rearrangement was detected by polymerase chain reaction. This is the first reported case of an NK-like T-cell lymphoma with these unusual features, making precise classification difficult. Some features suggest an NK1.1 or NKT lymphocyte origin. Because the earliest clinical manifestation was splenomegaly and abnormal liver function, the normal cellular counterpart may be a distinct subset of NK1.1 cells normally present in hepatosplenic sinusoids. This tumor disseminated early and pursued a fulminant clinical course, thus emphasizing the importance of early recognition and diagnosis.
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PMID:Aggressive Epstein-Barr virus-associated, CD8+, CD30+, CD56+, surface CD3-, natural killer (NK)-like cytotoxic T-cell lymphoma. 1175 78

We report a case of acute lymphoblastic leukemia (ALL) presenting as severe jaundice. The patient, a 59-year-old man, was found to have abnormal liver function, including an elevated total bilirubin level (13.5 mg/dl) with hepatosplenomegaly, but no detectable lymphadenopathy. A liver biopsy and bone marrow examination revealed a lymphoid neoplasm. Pathologic features included invasion of an abnormal clone into the sinusoidal region of the liver, diffuse bone marrow involvement (41.6% of all nucleated cells) and splenomegaly. Small numbers of malignant cells were also detected in the peripheral blood. B-cell markers, such as terminal deoxynucleotidyl transferase (TdT), CD10, CD19, CD20 and HLA-DR were positive, and CD2, CD3, CD4, CD5, CD7, CD8, kappa, lambda, cytoplasmic mu and myeloperoxidase were negative. Cytogenetic analysis detected hyperdiploidy. In this case, a dose-attenuated CHOP regimen attained complete remission. To date, preferential infiltration to liver sinusoids has been noted in hepatosplenic gamma/delta T-cell lymphoma, other NK/T-cell malignancies, and some cases of hairy cell leukemia. Severe jaundice due to preferential infiltration of leukemic cells into liver sinusoids is rather uncommon as a presenting feature of ALL.
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PMID:[Preferential infiltration of liver sinusoids in acute lymphoblastic leukemia]. 1182 21

A boy of Caucasian origin with a new subtype of autoimmune lymphoproliferative syndrome (ALPS) is described. The clinical picture was dominated by chronic noninfectious lymphadenopathy, splenomegaly, and recurrent bacterial infections. At the age of 6 the patient died of pneumococcal meningitis. Laboratory investigation disclosed impaired apoptosis in both B- and T-lymphocyte subsets and expanded populations of CD3+CD4-CD8- T lymphocytes. Furthermore, marked dysregulation of humoral immune responses with transient expansion of monoclonal B cells, corresponding monoclonal gammopathy, and the presence of autoantibodies was found. Functional and molecular analysis revealed that Fas protein expression was normal, a mutation in the Fas gene was not found. Moreover, transcription of the downstream effector caspase-10 was unremarkable. This patient is unique compared to previously described patients as severe humoral immunodeficiency and monoclonal gammopathy are usually not described in patients with ALPS. This case points out the important role of apoptosis in regulating the degree of humoral immune responses at a clonal level in humans and gives further evidence for the phenotypic diversity of ALPS.
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PMID:Autoimmune lymphoproliferative syndrome associated with severe humoral immunodeficiency and monoclonal gammopathy. 1210 64

The discovery of an unusual T-cell subset characterized by the expression of the alpha/beta T-cell receptor without expression of either CD4 or CD8 [alpha/beta-double-negative T cells (alpha/beta-DNTCs)] provided critical insights in the evaluation of a "new" lymphoproliferative disorder known as autoimmune lymphoproliferative syndrome (ALPS). ALPS is a disorder of defective Fas-mediated lymphocyte apoptosis, manifested by accumulation of alpha/beta-DNTCs and other lymphocyte subsets, leading to lymphadenopathy and splenomegaly, autoimmunity, and an increased risk of lymphoma. The expanded population of alpha/beta-DNTCs from ALPS patients has a remarkable uniform phenotype that is for the most part similar to alpha/beta-DNTCs from mice with defective Fas (lpr) or Fas ligand (gld). This is in contrast to the minor alpha/beta-DNTC compartment in healthy individuals that contains multiple, immunophenotypically distinct subpopulations. Current data indicate that alpha/beta-DNTCs from ALPS patients are derived from cytotoxic CD8(+) T cells, chronically activated in vivo but anergic in vitro. Their anergic state may be related to persistent modifications of O-linked carbohydrates on cell surface molecules, such as CD43 and CD45, as well as to the increased presence of interleukin-10. Although largely consistent with a model of (linear) CD8(+) cytotoxic T-cell differentiation, the expression patterns of certain surface molecules, such as CD27 and CD28, are not consistent with this model. This may be the result of the perturbed homeostasis of lymphocytes in ALPS, thereby revealing pathways of differentiation and immunophenotypes, including phenotypes pertaining to cell surface glycosylation that are hidden from view in healthy individuals.
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PMID:A composite picture of TcR alpha/beta(+) CD4(-)CD8(-) T Cells (alpha/beta-DNTCs) in humans with autoimmune lymphoproliferative syndrome. 1213 44

The major goal of this study was to examine the effects of total-body irradiation (TBI) on lung carcinoma progression and determine if changes in tumor growth could be correlated with radiation-induced alterations of immune system parameters. Lewis lung tumor cells were injected subcutaneously into syngeneic C57BL/6 mice that had been irradiated with a single 3.0 Gy dose of gamma-rays (60Co) at four time points either before or after tumor cell implantation. Subsequently, a second group of mice was irradiated 2 h prior to tumor injection with sequential doses of gamma-rays (0.46-2.66 Gy range). Assays were performed on blood and spleen from mice euthanized 16 days postimplantation. Tumor growth was consistently slower regardless of the timing of radiation exposure. However, dose of radiation influenced tumor growth delay. The preirradiated tumor-bearing mice had high CD4/CD8 T lymphocyte ratios along with increasing percentages of NKT cells in the blood supply with dose. Tumor-induced immunomodulation was also present, as evidenced by splenomegaly, low proliferative response to mitogens, and decreased spontaneous blastogenesis of leukocytes within the blood compared with normal values (P < or = 0.01). Anemia and thrombocytopenia were not observed with either tumor presence or irradiation. The present study demonstrates that a modest dose of TBI prior to tumor cell implantation resulted in a beneficial antitumor effect. A selective radiation-induced depletion of CD8+ T lymphocytes and changes in NKT cell percentages, correlated with findings from cytotoxicity assays, were indicative of a protumoricidal immune environment.
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PMID:Dose and timing of total-body irradiation mediate tumor progression and immunomodulation. 1220 76

Chronic active Epstein-Barr virus (CAEBV) infection syndrome is a heterogeneous EBV-related disorder characterized by chronic fatigue, fever, lymphadenopathy, and/or hepatosplenomegaly, associated with abnormal patterns of antibody to EBV. CAEBV can range from disabling mild/moderate forms to rapidly lethal disorders. Even patients with mild/moderate disease frequently suffer adverse effects from long-term anti-inflammatory agents and have a quality of life that progressively deteriorates. It is still unknown why these individuals are unable to produce an effective immune response to control EBV, and no effective treatment is currently available. Since ex vivo-expanded EBV-specific cytotoxic T lymphocytes (EBV-CTLs) can safely restore EBV-specific cellular immune responses in immunodeficient patients, we assessed the possibility that adoptive immunotherapy might also effectively treat CAEBV infection. Following stimulation with irradiated EBV-transformed lymphoblastoid cell lines (LCLs), EBV-CTLs were successfully generated from 8 of 8 patients with the mild/moderate form of CAEBV infection. These CTLs were predominantly CD3(+) CD8(+) cells and produced specific killing of the autologous LCLs. There were 5 patients with 1- to 12-year histories of disease who were treated with 1 to 4 injections of EBV-CTLs. Following infusion, there was resolution of fatigue and malaise, disappearance of fever, and regression of lymphadenopathy and splenomegaly. The pattern and titers of anti-EBV antibodies also normalized. No toxicity was observed. There were 4 patients who did not show any relapse of disease within 6 to 36 months follow-up; one patient had recurrence of fatigue and myalgia one year after CTL infusion. We suggest that adoptive immunotherapy with autologous EBV-CTLs may represent a safe and feasible alternative treatment for patients affected with mild/moderate CAEBV infection and that this approach should be evaluated in the more severe forms of the disease.
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PMID:Autologous Epstein-Barr virus (EBV)-specific cytotoxic T cells for the treatment of persistent active EBV infection. 1239 55

Many studies have shed light on the mechanisms underlying both immunoprotection and immune dysregulation arising after Trypanosoma cruzi infection. However, little is known about the impact of benznidazole (N-benzyl-2-nitroimidazole acetamide), the drug available for clinical treatment of the infection, on the immune system in the infected host. In the present study we investigated the effect of benznidazole therapy on the lymphoid compartment during the course of experimental T. cruzi infection. Although amelioration of a variety of clinical and parasitological signs was observed in treated mice, amelioration of splenocyte expansion was not detected. Interestingly, this sustained splenomegaly observed in benznidazole-treated mice showed a preferential expansion of CD8(+) T lymphocytes. Moreover, although benznidazole treatment blocked the expansion of recently activated CD4(+) and CD8(+) T cells seen in infected hosts, benznidazole treatment led to a selective expansion of effector and memory CD8(+) T lymphocytes in association with a lower rate of apoptosis. In addition, the surviving treated animals were protected from reinfection. Together, these data suggest that, in addition to its well-known direct role in blocking parasite replication in vivo, benznidazole appears to directly affect immune regulation in T. cruzi-infected hosts.
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PMID:Benznidazole treatment following acute Trypanosoma cruzi infection triggers CD8+ T-cell expansion and promotes resistance to reinfection. 1243 78


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