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)

Programmed cell death (apoptosis) of activated lymphocytes is critical to immune homeostasis. The cell surface protein Fas (CD95) and its ligand play a pivotal role in regulating lymphocyte apoptosis, and defective expression of either Fas or Fas ligand results in marked over accumulation of mature lymphocytes and autoimmune disease in mice. The results of recent studies suggest that defective lymphocyte apoptosis caused by mutations of the Fas gene can result in a severe autoimmune lymphoproliferative syndrome (ALPS) in humans. To define the clinical, genetic, and immunologic spectrum of ALPS, 9 patients and their families were extensively evaluated with routine clinical studies, lymphocyte phenotyping, genotyping, and in vitro assays for lymphocyte apoptosis. Individual patients were followed up for 3 months to 6 years. ALPS was identified in 9 unrelated children as manifested by moderate to massive splenomegaly and lymphadenopathy, hypergammaglobulinemia, autoimmunity, B-cell lymphocytosis, and the expansion of an unusual population of CD4- CD8- T cells that express the alpha/beta T-cell receptor (TCR). All patients showed defective lymphocyte apoptosis in vitro. Heterozygous mutations of the Fas gene were detected in 8 patients. One ALPS patient lacked a Fas gene mutation. Healthy relatives with Fas mutations were identified in 7 of 8 ALPS kindreds. These relatives also showed in vitro abnormalities of Fas-mediated lymphocyte apoptosis, but clinical features of ALPS were not present in the vast majority of these individuals. ALPS is a unique clinical syndrome in which in vitro abnormalities of lymphocyte apoptosis are associated with abnormal lymphoproliferation and autoimmunity. These findings provide evidence that apoptosis of activated lymphocytes is an important mechanism for maintaining immunologic homeostasis and self-tolerance in humans. Fas gene mutations account for impaired lymphocyte apoptosis in only a subset of patients with ALPS.
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PMID:Clincal, immunologic, and genetic features of an autoimmune lymphoproliferative syndrome associated with abnormal lymphocyte apoptosis. 902 57

Fas (CD95) is a transmembrane molecule that induces programmed cell death (PCD) of lymphocytes. We examined its function in children with chronic thrombocytopenia, serum autoantibodies, and lymphadenopathy and/or splenomegaly. We found that T-cell lines from six of seven patients with this autoimmune/lymphoproliferative disease (ALD) were relatively resistant to PCD induced by monoclonal antibodies to Fas. By contrast, Fas function was normal in control patients with typical chronic idiopathic thrombocytopenic purpura (ITP) without lymphadenopathy. The defect was not due to decreased Fas expression, nor to over-production of soluble forms of Fas. Moreover, it specifically involved the Fas system because PCD was induced in the normal way by methylprednisolone. Complementary DNA sequencing of the Fas gene did not identify any causal mutation in patients with ALD. This distinguished them from patients with the human autoimmune lymphoproliferative syndrome (ALPS), who carry mutations of the Fas gene. Moreover, patients with ALD did not show the peripheral expansion of CD4/CD8 double-negative T cells that characterizes the ALPS phenotype. Fas signaling involves activation of a sphingomyelinase-catalyzing production of ceramide. We found that ceramide-induced PCD was defective in patients with ALD and not in patients with typical chronic ITP. These data suggest that the ALD patient defect involves the Fas signaling pathway downstream from the sphingomyelinase and that Fas gene mutations and double-negative T-cell expansion are not the only signs of a defective Fas system.
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PMID:Deficiency of the Fas apoptosis pathway without Fas gene mutations in pediatric patients with autoimmunity/lymphoproliferation. 910 7

We report the clinical, ultrastructural, immunophenotypic and virological features of nine cases of a rare type of mature T cell disorder formerly designated Sezary cell leukaemia. All patients presented with lymphocytosis ranging from 12.7 to 133 x 10(9)/l, bone marrow infiltration, splenomegaly and lymphadenopathy. Skin involvement was absent at presentation but developed as a terminal event in two patients, one of whom showed a pattern of dermal infiltration different from that characteristic of Sezary syndrome. Cells from eight cases bore a mature T cell phenotype and electronmicroscopy revealed lymphocytes with cerebriform nuclei resembling Sezary cells. All cases except one were HTLV-I negative. Patients were treated with various chemotherapy regimens but with poor outcome, the median survival being 13 months. Laboratory and clinical data suggest great similarity between Sezary cell leukaemia and T prolymphocytic leukaemia (T-PLL), namely coexpression of CD4 and CD8 (3/9 cases), identical chromosomal abnormalities in the three cases studied (isochromosome 8q plus inversion 14 or t(X;14)(q28;q11)) and a remarkable sensitivity to CAMPATH-1H (complete remission of 21 months' duration in one patient), suggesting that this entity could be considered a variant form of T-PLL. The alternative diagnosis of adult T cell leukaemia/lymphoma could not be excluded in one patient in whom positive HTLV-I serology was documented.
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PMID:Sezary cell leukaemia: a distinct T cell disorder or a variant form of T prolymphocytic leukaemia? 920 83

We describe the clinical and laboratory features of an unusual case with Sezary cell-like leukemia. Clinical manifestations were: anemia (Hb 9.4 g/dl), severe thrombocytopenia (5 x 10(9)/l), lymphocytosis (43 x 10(9)/l) and splenomegaly. There was no lymphadenopathy, hepatomegaly or skin lesions. Bone marrow trephine showed diffuse infiltration by atypical lymphoid cells. By ultrastructural analysis the cells were small to medium-size lymphocytes with nuclear features identical to Sezary cells. Immunophenotyping showed that most peripheral blood mononuclear cells were negative with B lymphoid, myeloid, and stem cell-associated markers and were also negative with most T lymphoid markers (CD2, CD4, membrane/cytoplasmic CD3, CD5 and CD8). However, they were positive with CD38 (70%), CD7 (25%) and TIA-2 (25%). Molecular analysis showed a clonal rearrangement of the TCR beta and gamma chain genes. The patient was initially treated with vincristine, doxorubicin and asparaginase and then with six cycles of CHOP, achieving a complete remission and remaining free of disease 22 months from diagnosis. Aberrant immunophenotypes are not frequent in primary T cell leukemias. This is the first case of a rare type of T cell neoplasm, Sezary cell-like leukemia, in which cells lacked most of the T cell-associated antigens.
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PMID:Sezary cell-like leukemia with atypical immunophenotype. 926 98

Murine acquired immunodeficiency syndrome (MAIDS) is a fatal disease induced by a mixture of retroviruses known as BM5. It is characterized by splenomegaly, lymphadenopathy, hypergammaglobulinemia, loss of T and B cell function, and development of B cell lymphomas. As the disease progresses, by wk 8 of infection, CD4 T cell response to Ags and mitogens is severely curtailed and the CD4 T cell population becomes anergic. We examined responses of anergic CD4 T cells upon addition of a costimulatory signal (anti-CD28) and a cytokine (IL-12), which might help to restore the function of cells. We report that proliferation and cytokine production were restored in the early stages of infection by the strategies we tested, but not at later stages when anergy was well established. We also examined the effect of the same treatments on anergy of CD4 T cells from thymectomized, BM5-infected mice to determine whether the rescue seen was due to cells freshly derived from the thymus. We report that proliferation and cytokine production decreased in thymectomized mice even at wk 4 of infection, indicating that cells that are freshly derived from thymus are the ones responding to treatment. This study indicates that once anergy has been established in MAIDS, it cannot be reversed by providing costimulation via CD28 and IL-12. Anergy of CD4 T cells in MAIDS appears to be different from that seen in other systems, both in underlying cause and in the ability of the cells to revert to a normal state.
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PMID:CD4 T cell anergy in murine AIDS: costimulation via CD28 and the addition of IL-12 are not sufficient to rescue anergic CD4 T cells. 927 99

A 54-year-old woman presented with a severe autoimmune anemia, thrombocytopenia, neutropenia (Evans' syndrome), and CD8+ lymphocytosis, without signs of lymphadenopathy or splenomegaly. A diagnosis of T cell large granular lymphocyte (T-LGL) leukemia was made, based on cytomorphology, the typical CD3+/CD4-/CD8+/CD16+/CD56-/CD57-/HLA-DR(+/-) immunophenotype of the lymphocytosis (9 x 10(9)/l), and biallelic clonally rearranged T cell receptor beta (TCR beta) genes. Clonality of the TCR alphabeta+ T-LGL was also demonstrated with a panel of antibodies against variable domains of TCR beta chains, which showed single Vbeta7.1 expression on the CD3+ T-lymphocytes. After treatment failure with corticosteroids, splenectomy, and cyclophosphamide, respectively, a complete clinical remission was induced and sustained with cyclosporin A. Vbeta7.1/CD8/CD3 triple immunofluorescence stainings appeared to be valuable for titrating the cyclosporin A dosage by monitoring the T-LGL cells during treatment.
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PMID:Induction of clinical remission in T-large granular lymphocyte leukemia with cyclosporin A, monitored by use of immunophenotyping with Vbeta antibodies. 951 76

It is known that lpr mice develop systemic lymphadenopathy and lupus erythematosus-like autoimmune disease that are associated with the accumulation of CD4- CD8- (double-negative; DN) CD3+ B220+ abnormal T cells as well as normal mature CD4+ or CD8+ single-positive (SP) CD3+ T cells. In order to clarify the role of B cells in the lymphoproliferation and autoimmunity of lpr mice, we created B-cell-deficient C57BL/6 (B6) lpr mice (B6lpr/lpr microMT/microMT) by crossing B6lpr/lpr mice with B6 microMT/microMT mice in which the B-cell development was arrested at pre-B stage owing to a targeted disruption of the immunoglobulin mu heavy-chain gene locus. In the B-cell-deficient B6-lpr mice, both lymphadenopathy and splenomegaly were markedly suppressed. Although the accumulation of both CD3+ B220- SP normal T cells and CD3+ B220+ DN abnormal T cells was inhibited in the B-cell-deficient lpr mice, the decrease in numbers of CD3+ B220- SP normal T cells occurred more strikingly than that of the CD3+ B220+ DN abnormal T cells. Glomerulonephritis did not develop in the B-cell-deficient lpr mice over 40 weeks. The present results indicate that the B cells thus play a crucial role in the extensive proliferation of normal CD3+ B220- mature SP T cells rather than the accumulation of abnormal DN T cells.
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PMID:Proliferation of CD3+ B220- single-positive normal T cells was suppressed in B-cell-deficient lpr mice. 961 74

The effect of systemic administration of anti-inflammatory cytokines (IL-4 and IL-10) on the development and maintenance of an anti-tumor rejection response in vivo was studied by following the growth patterns of P815.B7 tumors on B6D2F1 [(C57BI/6 x DBA/2)F1] mice. The anti-P815.B7 rejection response was found to be T cell dependent, involving both CD4 and CD8 cells. IL-4 treatment resulted in a compromised rejection response; IL-10 treatment alone had little or no effect. These results demonstrate that treatment with an anti-inflammatory cytokine can compromise an otherwise effective anti-tumor rejection response. For the anti-inflammatory cytokine IL-4, the immunosuppressive effects of the cytokine appear to outweigh any possible anti-tumor activities as have been reported using tumor cells genetically altered to produce IL-4. Relatively high systemic doses of IL-10, in contrast, were not immunosuppressive and, when given in combination with IL-4, countered the IL-4 suppressive effect. Pathologically, IL-4 treatment led to splenomegaly characterized by a marked increase in neutrophils and NK activity. The possible linkages between neutrophils, NK activity and IL-12 are discussed.
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PMID:The role of IL-4 and IL-10 cytokines in controlling an anti-tumor response in vivo. 967 64

PD-1, an Ig superfamily member, contains an immunoreceptor tyrosine-based inhibitory motif in the cytoplasmic tail. It is expressed in a minor fraction of CD4-CD8- normal thymocytes and induced in peripheral lymphocytes following activation. To assess the possible roles of PD-1 in the immune responses, PD-1-deficient (PD-1-/-) mice were generated by a gene-targeting strategy. PD-1-4- mice developed and grew normally. Although the thymus was apparently normal, PD-1-/- mice showed moderate but consistent splenomegaly, which reflected the increased cellularity of both lymphoid and myeloid cells. The proliferative response of B cells by anti-IgM antibodies, but not of T cells by an anti-CD3 (145-2C11) mAb in vitro, was augmented in PD-1-/- mice as compared with control littermates. PD-1-/- mice showed increased serum levels of IgG2b, IgA and most strikingly IgG3, while those of IgM and IgG1 were comparable with control mice. Furthermore, PD-1-/- mice exhibited significantly augmented IgG3 anti-DNP antibody response to a type 2 T-independent antigen, DNP-Ficoll, with comparable IgM and IgG1 antibody responses with littermate controls. In the peritoneal cavity, the B-1 cell population in PD-1-/- mice exhibited significantly reduced expression of CD5, a negative regulator of B-1 cell activation, despite a marginal increase in the number of B-1 cells. Thus, PD-1 was suggested to be involved in the negative regulation for particular aspects of B cell proliferation and differentiation including class switching.
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PMID:Immunological studies on PD-1 deficient mice: implication of PD-1 as a negative regulator for B cell responses. 979 23

MRL-lpr/lpr mice have a Fas receptor mutation that leads to abnormalities of apoptosis, lymphoproliferation, and a lupus-like autoimmune disease associated with the production of autoantibodies. Other than Fas pathway defects, little is known about molecular abnormalities that predispose to autoimmunity. Protein kinase CK2 (also termed casein kinase II), a serine-threonine protein kinase whose targets include many critical regulators of cellular growth, is highly expressed in a lymphoproliferative disease of cattle and in many human cancers. Overexpression of the CK2alpha catalytic subunit in lymphocytes of transgenic mice leads to T cell lymphoma. We hypothesized that CK2 dysregulation and Fas mutation might cooperatively augment lymphocyte proliferation and transformation. We find that in MRL-lpr/lpr mice bearing the CK2alpha transgene, the lymphoproliferative process is dramatically exacerbated, as these mice develop massive splenomegaly and lymphadenopathy by 12 wk of age in association with increased autoantibody production and accelerated renal disease. The lymphoid organs are filled with the unusual B220+CD4-CD8- T cells typically seen in MRL-lpr/lpr mice, not the B220-CD4+CD8+ or B220-CD4-CD8+ T cells typically seen in CK2a transgenic lymphomas. The T cells do not fulfill the criteria for transformation, as they are polyclonal and not transplantable or immortal in cell culture. Thus, although the lpr lymphoproliferative and autoimmune syndrome is potentiated by the presence of the CK2a transgene, this combination of apoptotic and proliferative abnormalities appears to be insufficient to transform lymphoid cells.
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PMID:Acceleration of lpr lymphoproliferative and autoimmune disease by transgenic protein kinase CK2 alpha. 982 Apr 86


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