Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: UMLS:C0021831 (enteropathy)
4,403 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Gastrointestinal complications in human immunodeficiency virus (HIV) infection are indicative of impaired intestinal mucosal immune system. We used simian immunodeficiency virus (SIV)-infected rhesus macaques as an animal model for HIV to determine pathogenic effects of SIV on intestinal T lymphocytes. Intestinal CD4(+) T-cell depletion and the potential for cytokine responses were examined during SIV infection and compared with results for lymphocytes from lymph nodes and blood. Flow cytometric analysis demonstrated severe depletion of CD4(+)CD8(-) single-positive T cells and CD4(+)CD8(+) double-positive T cells in intestinal lamina propria lymphocytes (LPL) and intraepithelial lymphocytes (IEL) during primary SIV infection which persisted through the entire course of SIV infection. In contrast, CD4(+) T-cell depletion was gradual in peripheral lymph nodes and blood. Flow cytometric analysis of intracellular gamma interferon (IFN-gamma) and interleukin-4 (IL-4) production following short-term mitogenic activation revealed that LPL retained same or higher capacity for IFN-gamma production in all stages of SIV infection compared to uninfected controls, whereas peripheral blood mononuclear cells displayed a gradual decline. The CD8(+) T cells were the major producers of IFN-gamma. There was no detectable change in the frequency of IL-4-producing cells in both LPL and peripheral blood mononuclear cells. Thus, severe depletion of CD4(+) LPL and IEL in primary SIV infection accompanied by altered cytokine responses may reflect altered T-cell homeostasis in intestinal mucosa. This could be a mechanism of SIV-associated enteropathy and viral pathogenesis. Dynamic changes in intestinal T lymphocytes were not adequately represented in peripheral lymph nodes or blood.
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PMID:Gastrointestinal T lymphocytes retain high potential for cytokine responses but have severe CD4(+) T-cell depletion at all stages of simian immunodeficiency virus infection compared to peripheral lymphocytes. 965 11

The simian immunodeficiency virus (SIV) isolate, SIVsmmPBj14, contains an immunoreceptor tyrosine-based activation motif (ITAM) within its nef gene product and triggers efficient lymphoproliferation in vitro. In experimentally inoculated macaque monkeys, this virus causes acutely lethal enteropathy, which is accompanied by high levels of pro-inflammatory cytokines, including tumor necrosis factor (TNF)-alpha. Since TNF-alpha has been shown to possess weak comitogenic activity for antigen- or mitogen-induced human T-cell proliferation, experiments were conducted to examine whether TNF-alpha might also contribute to SIVsmmPBj14-induced lymphoproliferation. Addition of a dimeric soluble human TNF receptor (sTNFR):Fc fusion protein to SIVsmmPBj14-infected simian peripheral blood mononuclear cells (PBMC) resulted in a partial (> 50%) inhibition of virally-induced lymphoproliferation, but had no effect on the strong T-cell activation signal provided by phytohemagglutinin and interleukin-2. Finally, the addition of exogenous human TNF-alpha to simian PBMC infected with a non-mitogenic variant of SIVsmmPBj14 failed to result in detectable lymphoproliferation, suggesting that TNF-alpha alone is not sufficient to cause the proliferation of SIV infected T-cells. Taken together, the data suggest that endogenous TNF-alpha enhances SIVsmmPBj14-induced lymphoproliferation in simian PBMC cultures.
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PMID:Endogenous tumor necrosis factor-alpha contributes to lymphoproliferation induced by simian immunodeficiency virus variant, SIVsmmPBj14. 971 38

Diagnostic anatomic pathologists play a crucial role in the battle against acquired immunodeficiency syndrome (AIDS). Not only are they intimately involved in the treatment of individual patients with human immunodeficiency virus (HIV) infection, but also they make important observations that result in the expansion of the scientific understanding of its pathogenesis. Pathologists studying tissue from patients with HIV infection should be familiar with the conditions to which these patients are susceptible. Although opportunistic infections are important causes of morbidity and mortality, noninfectious conditions frequently make substantial contributions to the disease course. Patients with HIV infection may be at increased risk for neoplastic disease. They do not, however, have an increased incidence of the most common tumors affecting the general population, such as breast, colon, and prostate carcinoma. Immunodeficiency results in increased susceptibility to malignant neoplasms, both by decreased immunologic response to abnormal cells and increased susceptibility to infection by viruses. All of the malignant neoplastic diseases that are Centers for Disease Control and Prevention (CDC) AIDS indicator conditions have been shown to have an association with a virus: Kaposi sarcoma (KS) with herpes hominis virus 8 (HHV-8), malignant lymphoma with Epstein-Barr virus (EBV), and cervical carcinoma with human papilloma virus (HPV). Patients with HIV infection also can develop reactive processes that are attributable to direct effects of HIV or immune system alterations. Such conditions include salivary gland cystic lymphoepithelial lesion, lymphadenopathy, lymphocytic interstitial pneumonitis, encephalopathy, enteropathy, nephropathy, hepatic conditions, dermatologic conditions and anemia.
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PMID:Pathology of human immunodeficiency virus infection: noninfectious conditions. 986 26

Simian immunodeficiency virus strain PBj14, SIVsmmPBj14, is unique among primate lentiviruses in its ability to trigger the proliferation of resting simian lymphocytes and to cause the rapid death of experimentally inoculated pigtailed macaques. Severe enteropathy, immune activation, and extensive apoptosis, particularly within gut-associated lymphoid tissue, characterize the acute disease syndrome associated with SIVsmmPBj14 infection. In the present study, we examined whether the ability of this virus to cause widespread apoptosis might be linked to the up-regulation of Fas ligand (CD95L) expression in virally infected cells. In vitro studies revealed that expression of the viral Nef protein, in the absence of any other viral gene product, was sufficient to up-regulate the transcriptional activity of the CD95L promoter and to cause cell surface expression of Fas ligand. This up-regulation was NFAT dependent (inhibited by cyclosporin A) and did not occur in cells that expressed a mutated derivative of the viral Nef protein, lacking a previously defined immunoreceptor tyrosine-based activation motif. These findings were corroborated by analysis of tissue sections from virally infected macaques. Immunohistochemical staining revealed that Fas ligand expression was efficiently up-regulated in the GALT of animals that had been experimentally infected with wild-type SIVsmmPBj14 but not in animals that were infected with a nonacutely pathogenic viral mutant lacking the Nef ITAM. Taken together, these results suggest that the ability of SIVsmmPBj14 to cause acutely lethal disease and to up-regulate FasL expression may be linked. Additional studies will be required to determine whether the induction of FasL expression is in itself important for acute disease pathogenesis.
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PMID:Induction of fas ligand expression by an acutely lethal simian immunodeficiency virus, SIVsmmPBj14. 987 14

Evidence is increasing that HIV/SIV-induced changes in the highly differentiated gut-associated immune system play a central role in the pathogenesis of gastrointestinal manifestations in HIV/SIV infection. It has been shown in both humans infected with HIV and in nonhuman primates infected with SIV that a rapid, very early, and more pronounced loss of CD4+ T-cells occurs in the mucosa in comparison to the peripheral blood. The loss of this important regulatory T-cell subset might explain mucosal immunodeficiency with the consequence of opportunistic mucosal infections. In addition, there is evidence that small intestinal damage occurs independently of secondary infections (HIV/SIV enteropathy). In late-stage human disease, HIV enteropathy is characterized by villous atrophy with hyporegeneration and dysmaturation of intestinal epithelial cells. In SIV infection of macaques, villous atrophy is a very early event; however, it is accompanied by crypt cell hyperproliferation. Early- and late-stage enteropathy in immunodeficiency virus infection may represent two types of immunologically mediated mucosal transformation in which the number and state of activation of regulatory T cells determine whether hypo- or hyperproliferative villous atrophy occurs.
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PMID:HIV/SIV enteropathy. 992 77

Gastrointestinal lymphomas comprise a group of distinctive clinicopathological entities of B- or T-cell type, with primary gastrointestinal Hodgkin's disease being extremely uncommon. Most low-grade B-cell gastrointestinal lymphomas are of mucosa-associated lymphoid tissue (MALT) type, so called because they recapitulate the features of MALT rather than those of lymph nodes. Paradoxically, however, most MALT lymphomas arise in the stomach, which normally contains no organized lymphoid tissue. Gastric MALT lymphomas appear to arise in MALT acquired as a reaction to infection of the stomach by Helicobacter pylori and their growth can be inhibited by eradication of this organism from the stomach. Low-grade MALT lymphomas, which usually have a very favorable clinical course, may undergo high-grade transformation but high-grade diffuse large B-cell lymphomas may also arise de novo. Immunoproliferative small intestinal disease (IPSID) is a special form of MALT lymphoma characterized by synthesis of alpha heavy-chain immunoglobulin and a restricted geographic distribution. Other B-cell lymphomas that tend to arise in the gastrointestinal tract include mantle cell lymphoma, which presents as lymphomatous polyposis, Burkitt's lymphoma, and B-cell lymphomas associated with immunodeficiency states. Enteropathy (celiac disease)-associated T-cell lymphoma (EATL) is the most common primary gastrointestinal T-cell lymphoma This is a clinically aggressive tumor that arises from the intraepithelial T-cell population.
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PMID:Gastrointestinal lymphomas of T- and B-cell types. 1007 40

The clinical findings of a kindred with an X-linked disorder are characterized by autoimmune polyendocrinopathy, enteropathy with villous atrophy, chronic dermatitis, and variable immunodeficiency. Linkage analysis was performed on 20 members of the affected kindred to determine the location of the responsible locus. Informative recombinations limited the region to an approximate 20 cM interval bordered by DXS1055 and DXS1196/DXS1050. Multipoint analysis generated a lod score >3 for the region contained between DXS8024 and DXS8031. The candidate region includes the Wiskott-Aldrich syndrome (WAS) locus. Evaluation of the Wiskott-Aldrich syndrome protein gene by single strand conformational analysis, heteroduplex analysis, and direct sequencing of the 12 exons in an affected male and two carrier females revealed no abnormalities. We conclude that this kindred has an X-linked disorder, distinct from WAS, that results in autoimmunity and variable immunodeficiency. The responsible locus maps to the pericentromeric region Xp11.23 to Xq21.1.
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PMID:Manifestations and linkage analysis in X-linked autoimmunity-immunodeficiency syndrome. 1070 61

Aetiological diagnosis of protracted diarrhoea remains obscure in as many as 30% of cases despite extensive investigations. A number of newer syndromes have been recognized amongst this "idiopathic group" which includes microvillous inclusion disease, "tufting" enteropathy and epithelial dysplasia, autoimmune enteropathy and "syndromic" immunodeficiency with characteristic facial abnormalities, woolly hair and intractable diarrhea. The molecular basis of some of these syndromes has been reviewed but in only a small series of patients has the functional defect been characterized. If a case is suspected the antenatal history, family history and history of consanguinity should be sought. Extra-intestinal manifestations, presence of gut or other auto-antibodies, together with phenotypic abnormalities should be looked for. Careful light and electron microscopy is done of small bowel biopsies, although microvillous inclusion disease can be usually suspected on PAS staining. Large bowel biopsy may be needed to exclude an unsuspected microscopic colitis. The prognosis of this group of conditions is poor with an overall 50-85% mortality. Although successful gut transplantation has been reported, genetic counselling may be one of the more important aspects of the clinicians' role.
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PMID:Newer diarrheal syndromes. 1113 69

Human immunodeficiency virus (HIV) infection can weaken the immune system causing its inability to combat opportunistic infections. Managing the complexity of these opportunistic infections has created a challenge for healthcare professionals. Our knowledge on the aetiological agents causing opportunistic infections in immunocompromised hosts has increased over the last decade. Diarrhoeal diseases are frequent complications associated with HIV-infected patients. For most of the causes of diarrhoea, the clinical signs are non-specific, and the laboratory diagnostic workup is neither easy nor fast. This review provides data on aetiological approaches of common diarrhoeal diseases including viral, microbacterial, parasitic, bacterial and fungal infections, and HIV enteropathy; diagnostic evaluation; and treatment of diarrhoea in HIV-infected patients. This article will be helpful for those who are in the practice of managing diarrhoea in such patients.
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PMID:Management of diarrhoea in HIV-infected patients. 1156 29

Human immunodeficiency virus (HIV)-infected patients often develop malabsorption and increased intestinal permeability with diarrhea, called HIV enteropathy, even without enteric opportunistic infections. HIV gp120-induced calcium signaling, microtubule loss, and physiological changes resembling HIV enteropathy were previously found in the HT-29 intestinal cell line. How gp120 caused these changes was unclear. We show that the HIV co-receptor Bob/GPR15, unlike CCR5 and CXCR4, is abundant at the basal surface of small intestinal epithelium. The gp120-induced effects on HT-29 cells were inhibited by anti-Bob neutralizing antibodies, the selective G protein inhibitor pertussis toxin, and the phospholipase inhibitor U73122, but not neutralizing antibodies to CXCR4. Gp120 strains that induced signaling in HT-29 cells also induced calcium fluxes in Bob-transfected Ghost (3) cells, whereas gp120 strains not activating HT-29 cells also did not activate Bob-transfected cells. Bob is the first HIV co-receptor shown to be abundantly expressed on the basolateral surface of intestinal epithelium. Although Bob is an inefficient infection-inducing co-receptor, it mediates viral strain-specific gp120-induced calcium signaling at low, physiologically reasonable gp120 concentrations, up to 10,000-fold lower gp120 concentrations than the principal co-receptors. Gp120-induced Bob activation is a plausible cause of HIV enteropathy.
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PMID:Gp120-induced Bob/GPR15 activation: a possible cause of human immunodeficiency virus enteropathy. 1169 54


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