Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0019214 (hepatosplenomegaly)
 4,408 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Autoimmune lymphoproliferative syndrome (ALPS) is marked by massive lymphadenopathy, hepatosplenomegaly, autoimmunity and the presence of increased numbers of circulating and tissue TCR-alpha beta, CD4- CD8- T cells. The underlying defect is that of decreased T cell and B cell apoptosis, due in most, but not all, cases to heterozygous mutations of the Fas gene and corresponding defective Fas signaling function. Here we measure in vivo and in vitro cytokine secretion in ALPS to shed light on the relation of apoptosis defects to the development of autoimmunity. In in vivo studies, ALPS patients manifested greatly increased circulating levels of IL-10 (> 100-fold), compared with both healthy individuals and various disease controls; in contrast, their levels of IL-1 beta, IL-4, and IFN-gamma were normal and their levels of IL-2 and TNF-alpha were marginally increased. In parallel in vitro studies, ALPS patients CD4+ DR+ T cells stimulated either with anti-CD3/CD28 or anti-CD2/CD28 produced increased amounts of IL-4 and IL-5 (10 to 20-fold) and decreased amounts of IFN-gamma (4-fold) as compared with those of control CD4+ DR+ T cells. In contrast, ALPS patients' CD4-/CD8- T cells produced very low amounts of cytokines. Finally, ALPS patients' peripheral monocytes/macrophages produced decreased amounts of IL-12 (30-fold) and increased amounts of IL-10 (5-fold). In conclusion, ALPS is marked by the presence of DR+ T cells that exhibit a skewed Th2 cytokine response upon various forms of stimulation. This cytokine response, in the presence of increased circulating IL-10 levels, is likely to define the cytokine milieu that accounts for the humoral autoimmune features of ALPS and, perhaps, of other humoral autoimmune states.
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PMID:Characteristic T helper 2 T cell cytokine abnormalities in autoimmune lymphoproliferative syndrome, a syndrome marked by defective apoptosis and humoral autoimmunity. 902 33

Inherited mutations of the Fas/Apo1/CD95 gene, a cell-surface receptor involved in cell death signaling and in the control of self-reactivity, characterize the recently identified autoimmune lymphoproliferative syndromes. A patient with type 2 autoimmune hepatitis with the immunologic and genetic features of autoimmune lymphoproliferative syndrome is described. The clinical picture was dominated by liver disease with hepatosplenomegaly and positivity for anti-liver-kidney microsome 1 and anti-liver-cytosol 1 antibodies. A marked increase in CD3+CD4-CD8-T lymphocytes and inherited mutations in Fas alleles that led to the expression of a soluble form of the protein were also found. Fas-mediated apoptosis was deficient in the patient as it was in her mother and her sister, who carried the same allele 2 mutation. This observation links type 2 autoimmune hepatitis, an organ-specific disease, with a genetically determined defect in peripheral tolerance control.
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PMID:Fas/Apo1 mutations and autoimmune lymphoproliferative syndrome in a patient with type 2 autoimmune hepatitis. 961 60

Omenn's syndrome (OS) is characterized by erythrodermia, hepatosplenomegaly, lymphadenopathy, hypereosinophilia and elevated IgE levels associated with increased susceptibility to severe infections. Peripheral blood T cells, though usually present in normal number, show an activated phenotype (including an increased expression of CD95/Fas), a Th2 pattern of cytokine secretion and defective proliferative response to mitogens. In this report, we demonstrate that T cells from patients with OS undergo an excessive cell death in vitro resulting from two mechanisms. First, a substantial number of peripheral blood lymphocytes from OS patients die in unstimulated cultures (p = 0.009 vs. healthy controls). This spontaneous apoptosis is associated with reduced expression of bcl-2 gene product (p < 0.05) and can be prevented by addition of interleukin (IL)-2 (which also prevents down-modulation of bcl-2), while is independent from CD95 signaling. Second, lymphocytes from OS patients are highly susceptible to activation-induced cell death (AICD) induced with mitogens. This mechanism is largely independent from IL-2, while it can be significantly inhibited blocking CD95 with an IgG2b monoclonal antibody (mAb). The dependence of AICD from signals transduced via CD95 was confirmed showing that cross-linking CD95 with an IgM mAb induces a higher cell death in purified CD4+ CD45R0+ cells from OS patients than in controls (comparable for CD95 expression). Both mechanisms of cell death observed in this study result from lymphocyte hyperactivation occurring in vivo in these patients and may contribute to functional T cell defects of OS.
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PMID:In vitro cell death of activated lymphocytes in Omenn's syndrome. 939 97

Fas is an apoptosis-signaling receptor important for homeostasis of the immune system. In this study, Fas-mediated apoptosis and Fas mutations were analyzed in three Japanese children from two families with a lymphoproliferative disorder characterized by lymphadenopathy, hepatosplenomegaly, pancytopenia, hypergammaglobulinemia and an increase in TCR alphabeta+ CD4- CD8- T cells. Apoptosis induced by anti-Fas mAb was defective in both activated T cells and B cells, and granulocytes from these patients. Truncated Fas receptor lacking the cytoplasmic death domain caused by a point mutation in the splice region of intron 7 were demonstrated in two siblings. A homozygous point mutation in the splice acceptor of intron 3 was found in the Fas gene of the third patient, which resulted in the skipping of exon 4 and complete loss of Fas expression. Corresponding to these mutations, soluble Fas concentrations were decreased and reciprocally soluble Fas ligands were increased in patients' sera. Interestingly, co-stimulation by immobilized anti-Fas mAb in T cells from the two siblings was comparable to that seen in normal T cells. These results suggest that Fas-mediated apoptosis plays a pivotal role in immunological homeostasis in vivo, especially regarding clonal deletion of immune cells in humans.
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PMID:Novel Fas (CD95/APO-1) mutations in infants with a lymphoproliferative disorder. 953 47

Involvement of malignant lymphoma in the liver inducing fulminant hepatic failure has rarely been reported. Therefore, a close association between some lymphoma types with severe liver damage and the mechanism underlying the liver damage is intriguing. Three malignant lymphoma cases, which were clinically diagnosed as fulminant hepatitis, were collected from the autopsy records of Kawasaki Medical School (Kurashiki, Japan). All three cases were characterized by the presence of hepatosplenomegaly without superficial lymph node swelling, high elevation of transaminase and lactate dehydrogenase (LDH; especially LDH-2), and a quite aggressive clinical course. Immunohistochemically, the tumor cells in all three cases were positive for T cell intracellular antigen (TIA-1), which is a cytolytic protein in cytotoxic T and natural killer (NK) cells. The lymphomas were CD8+ peripheral T cell lymphoma (case 1), CD56+ T/NK cell lymphoma (case 2), and T cell lymphoma in a patient with mosquito hypersensitivity (case 3). Epstein-Barr virus infection was demonstrated on the tumor cells of cases 2 and 3 using an in situ hybridization method and those cases showed high titers of serum interferon-gamma and Fas. Frequent apoptosis of liver cells, where the lymphoma cells had infiltrated, was revealed by a terminal deoxyribosyl transferase-mediated deoxyuridine nick end-labeling (TUNEL) method. The findings in this study suggest that fulminant hepatic injury is closely associated with cytotoxic molecule TIA-1 expression of the lymphoma cells and that some specific mechanism may be involved in liver damage.
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PMID:Expression of cytotoxic molecule TIA-1 in malignant lymphomas mimicking fulminant hepatitis. 977 8

Familial haemophagocytic lymphohistiocytosis (FHL) is a rare and uniformly fatal disorder of early childhood characterized by fever, hepatosplenomegaly, cytopenia and widespread infiltration of vital organs by activated lymphocytes and macrophages. In order to test whether the massive accumulation of immune cells in these patients is associated with a perturbation of apoptosis, lymphocytes were isolated from eight patients and subjected to the chemotherapeutic agent etoposide or agonistic anti-Fas monoclonal antibodies in vitro. These stimuli elicited a normal apoptotic response in FHL patient cells when compared to healthy controls, as determined by phosphatidylserine exposure, DNA fragmentation, in vitro cleavage of the caspase-3-like substrate aspartate-glutamate-valine-aspartate-7-amino-4-methyl-coumarin (DEVD-AMC) and proteolysis of the anti-apoptotic protein Bcl-2. In addition, the degree of constitutive and Fas-triggered apoptosis in freshly isolated neutrophils was monitored in three children, with similar results. These studies indicate that immune cells derived from FHL patients are not inherently resistant to apoptosis induction. Specifically, etoposide-induced and Fas-triggered activation of intracellular caspases appears to remain intact in these individuals. However, the degree of spontaneous activation of caspase-3-like enzymes in activated lymphocytes was attenuated in three of the four patients tested prior to initiation of therapy, suggesting a possible biological deficiency in these individuals.
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PMID:Induction of apoptosis and caspase activation in cells obtained from familial haemophagocytic lymphohistiocytosis patients. 1046 May 99

Most humans with autoimmune lymphoproliferative syndrome (ALPS) carry heterozygous dominant mutations in one allele of the gene encoding Fas/APO-1/CD95. ALPS patients, like Fas-deficient MRL lpr/lpr mice, have lymphoproliferation, autoimmunity, increased CD4(-)/CD8(-) T lymphocytes, and apoptosis defects. Consistent with the phenotypic variability of lpr/lpr mice of different background strains, human genetic studies indicate that a Fas mutation is insufficient to induce ALPS in all mutation carriers. To investigate the dominant function of human Fas mutations and the additional genetic factor(s) involved in the development of ALPS, we generated transgenic mice expressing, in addition to endogenous Fas, mouse Fas molecules bearing mutations in the intracellular death domain corresponding to mutations identified in ALPS patients. Transgenic mice developed mild features of ALPS, including hepatosplenomegaly, elevated proportions of lymphocytes in spleen and lymph nodes, apoptotic defects, and hepatic lymphocytic infiltrates. Therefore defective murine Fas proteins act in a dominant manner to impair apoptosis of activated lymphocytes and disrupt lymphocyte homeostasis. The influence of genetic background on phenotype was studied by comparing transgenic mice on FVB/N and (FVB/N x MRL) backgrounds with syngenetic control mice and with MRL and MRL lpr/lpr mice. While expression of transgenic mutant Fas contributed mainly to hepatosplenomegaly and accumulation of lymphocytes, MRL background genes played a major role in the production of autoantibodies and elevated serum immunoglobulin levels. Moreover, compared to FVB/N (+/+) mice, a substantial Fas-specific apoptotic defect was found in MRL (+/+) mice, suggesting a mechanism for the known tendency of this strain to develop autoimmunity.
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PMID:Expression in transgenic mice of dominant interfering Fas mutations: a model for human autoimmune lymphoproliferative syndrome. 1049 9

The importance of Fas in the homeostatic balance between lymphocyte survival and death is underscored by the three main consequences of defective Fas-mediated apoptosis, as experienced by patients with ALPS: (1) abnormal accumulation of lymphocytes results in lymphadenopathy, hepatosplenomegaly, and hypersplenism; (2) failure of removal of potentially autoreactive lymphocytes, a process normally used to eliminate lymphocytes that have escaped negative selection in the thymus and bone marrow (see article by Fleisher and Blessing, p. 1197), is associated with the appearance of autoimmune manifestations; and (3) inappropriate survival of lymphocytes may lead to the development of malignancies. As with other "experiments of nature," the many aspects of ALPS have provided valuable new insights into the immune system and the importance of a proper balance between life and death of lymphocytes. ALPS is an example of how a mouse disease model was applied directly to the identification of the molecular basis and the understanding of a remarkable disease in humans. It is also an example of clinical observations being linked to basic scientific data to unlock the underlying defect(s) causing a disease. Despite the difficulty in fully understanding the complex nature of the clinical course, the immunologic abnormalities, and the genetic aspects of ALPS, the accumulated experience in diagnosis, treatment, and follow-up of patients and relatives has generated a "road map" that can be used as a guide for their care. As examples, the appreciation that manifestations of lymphoproliferation usually subside over time has allowed a "wait-and-see" approach in many patients who might previously have been treated aggressively. The appreciation that these patients are at increased risk for malignancies has mandated the adoption of careful and lifelong follow-up. Future efforts directed at careful clinical follow-up and scientific investigation are required to learn more about the incidence and natural history of ALPS, therapeutic interventions directed at altering the consequences of TNFRSF6 mutations, and the identification of other genetic and environmental factors that may have a role in the pathogenesis of ALPS.
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PMID:Autoimmune lymphoproliferative syndrome. A human disorder of abnormal lymphocyte survival. 1113 Sep 97

Autoimmune lymphoproliferative syndrome (ALPS) is a rare disease occurring in childhood. Recently, it has been shown that heritable mutations in Fas or Fas ligand genes, which regulate lymphocyte survival by triggering apoptosis of lymphocytes, are the most frequent cause of ALPS. Patients with ALPS frequently have lymphadenopathy, splenomegaly and hepatomegaly, especially at young ages. A positive result of the Direct Coomb's test, autoimmune hemolytic anemia, and idiopathic thrombocytopenic purpura are the most common features of autoimmunity in patients with ALPS. Elevated numbers and percentages (>1%) of double-negative (CD4-CD8-) T cells, and characteristic pathologic findings in lymph nodes or spleen are other important diagnostic features. In this report, we present the clinical, immunologic, and pathologic features of two children who were diagnosed with ALPS. The early recognition of ALPS in children with enlarged lymph nodes, hepatosplenomegaly, and autoimmune hematologic features has important diagnostic and prognostic value in avoiding expensive and time-consuming studies and unnecessary treatments. The ratio of CD4-CD8- T cells, immunoglobulin levels and the histopathologic features of lymph nodes should be rapidly determined in these patients in order to establish an early diagnosis and treatment.
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PMID:Autoimmune lymphoproliferative syndrome: report of two cases and review of the literature. 1245 4

Autoimmune lymphoproliferative syndrome (ALPS) is characterized clinically by chronic non-malignant lymphoproliferation and autoimmunity and is caused by a genetic defect in programmed cell death (apoptosis). Most patients with ALPS have heterozygous mutations in the Fas gene. We describe an 11-year-old Brazilian boy with hepatosplenomegaly, lymphadenopathy, hemolytic anemia, and hypergammaglobulinemia since early infancy. T cell lines from the patient were defective in Fas-mediated apoptosis. He was diagnosed as having ALPS and found to have a novel Fas gene mutation (IVS4+1G>A). In addition, he presented with glomerulonephritis in infancy. An aunt and uncle who had the same Fas mutations also had histories of glomerulonephritis. Although glomerulonephritis is common in Fas-deficient mice, it is infrequent in human ALPS. Corticosteroid therapy ameliorated the glomerulonephritis in our patient, as well as his lymphoproliferation, anemia, and hypergammaglobulinemia. This study suggests that glomerulonephritis is one of the characteristic features of ALPS.
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PMID:Autoimmune lymphoproliferative syndrome presenting with glomerulonephritis. 1273 7


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