Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0024141 (systemic lupus erythematosus)
 44,322 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

To gain insight into the immunopathogenesis of drug-induced autoimmune disorders, lymphocyte and immunoglobulin distributions and cytokine levels were monitored in the peripheral blood and pleural fluid of a patient with procainamide-induced lupus and pleural effusion. Approximately 80% of the B cells in both compartments were CD5+ compared to 10% to 25% in normal adults. CD4/CD8 ratio and percentage CD4 were normal in peripheral blood. Serum levels of IgG (particularly IgG2), IL-6, and soluble IL-2R were slightly elevated, and those of IgA were significantly elevated compared to normal controls. Analysis of the pleural effusion revealed an increased CD4/CD8 ratio because of an increased percentage of CD4+CD29+ helper memory T cells, lack of expression of the resting B-cell marker CD21, immune complex deposition and complement consumption, increased relative levels of ANA, abnormally high levels of IL-6 and soluble IL-2R, and detectable levels of IL-1b, IFN-g and TNF-a. These observations provide evidence for the involvement of CD5+ B cells and differential helper T-cell activity in procainamide-induced lupus and for an association between local lymphocyte activation and organ pathology.
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PMID:Case report: distinctive immune abnormalities in a patient with procainamide-induced lupus and serositis. 137 40

To investigate the possible role of IL-6 in the activation of the autoimmune process in systemic lupus erythematosus (SLE), we serially measured concentrations of IL-6, IgG, and anti-dsDNA antibodies before and during exacerbations in patients with SLE. In addition, we serially related the IL-6 response to the generation of the acute phase reactant C-reactive protein (CRP). Sixteen consecutive patients who developed an exacerbation were analysed in this study. Blood samples were drawn in EDTA monthly. At the time of maximal disease activity during exacerbation, IL-6 plasma concentrations were increased (greater than or equal to 6 pg/ml) in 12 out of the 16 cases. Concentrations of IL-6 correlated with the concentrations of CRP (P less than 0.01) and the score of the disease activity index (P less than 0.05). No correlation was found between IL-6 concentrations and concentrations of anti-dsDNA or IgG. The course of changes in IL-6 concentrations before the exacerbation was variable. Five out of the 16 exacerbations studied were characterized by a prominent rise of IL-6 at the time of maximum disease activity. In this subgroup serositis as well as elevated concentrations of CRP were observed more frequently (P less than 0.02). Seven exacerbations were not accompanied or preceded by changes in IL-6 concentrations and showed generally low IL-6 concentrations. In this latter subgroup cerebral involvement was seen more frequently (P less than 0.02). Our data do not suggest a pathogenic role for IL-6 in the generation of IgG and/or anti-dsDNA antibodies before exacerbations. Rises of IL-6 concentrations before exacerbations in SLE seem only to occur in a subgroup of patients with SLE characterized by the presence of serositis and elevated concentrations of CRP during exacerbation.
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PMID:Plasma concentration of IL-6 in systemic lupus erythematosus; an indicator of disease activity? 139 90

Introducing avidin-biotin complex ELISA for anti-DNA antibody, the mechanism of in vitro production of anti-ssDNA antibody as well as of polyclonal immunoglobulin mediated by an IL-6-IL-6R loop was studied in patients with systemic lupus erythematosus (SLE). Regardless of the presence or absence of T cells, B cells from SLE patients could produce IgG anti-ssDNA antibody as well as total IgG without any stimulation. Low density B cells obtained by Percoll gradient density centrifugation responded to rIL-6 to produce IgG and IgG anti-ssDNA antibody. rIL-2 and rIL-4 had lesser effects on the differentiation of low density B cells. In fact, IL-6R was preferentially expressed on low density B cells from active SLE patients, as detected by anti-IL-6R MoAb, MT18, which did not inhibit IL-6 binding. SLE B cells, especially high density B cells, produced greater amounts of IL-6 in culture supernatants than did T cells, regardless of whether disease was active or inactive. Normal T cells and B cells did not produce significant amounts of IL-6. Thus, endogenous IL-6 produced by high density B cells bound to the IL-6R preferentially expressed on the low density B cells, and drove them into terminal differentiation, especially in active SLE patients. Further, addition of polyclonal anti-IL-6 or anti-IL-6R MoAb (PM1), which inhibited IL-6 binding, both inhibited IgG anti-ssDNA antibody as well as total IgG production by SLE B cells in a dose-dependent manner. These results suggest that interruption of the autocrine IL-6 loop would be of therapeutic value in SLE.
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PMID:Autostimulatory effects of IL-6 on excessive B cell differentiation in patients with systemic lupus erythematosus: analysis of IL-6 production and IL-6R expression. 156 9

The molecular basis for the cellular interaction of DNA and nucleosomes and the physiological consequences of this binding were examined. Both DNA and nucleosomes were demonstrated to bind specifically to the surface of human peripheral blood mononuclear cells and the murine T cell line S49. Western blots of S49 cell membranes, using probes of biotin-labeled DNA and nucleosomes, showed reactivity at 29 and 69 kDa. Functionally, the interaction of DNA and nucleosomes with murine spleen cells stimulated the release of significant amounts of IL-6 activity. There is evidence that nucleosomes, a product of apoptosis, are the major component of circulating DNA found in the plasma of patients with systemic lupus erythematosus (SLE). The interaction of nucleosomes with cell-surface DNA binding molecules may have physiological relevance to some of the immune aberrations observed in patients with SLE.
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PMID:Nucleosomes and DNA bind to specific cell-surface molecules on murine cells and induce cytokine production. 162 45

Cultured mononuclear cells from patients with systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), and normal donors were assayed for their ability to secrete IL-6 both spontaneously and after exposure to UV light. Mononuclear cells from SLE, RA and atopic control patients produced IL-6 spontaneously, while those from normal donors did not. Spontaneous production of IL-6 occurred in the non-adherent cell population. UV light-induced IL-6 production was confined exclusively to the SLE patients and was present only in the macrophage/monocyte fraction. This stimulation was induced by wavelengths in the UVA, UVB but not the UVC portion of the spectrum. These results suggest that cytokine release may be involved in the exacerbations of SLE provoked by photosensitivity.
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PMID:Activation of IL-6 production by UV irradiation of blood mononuclear cells from patients with systemic lupus erythematosus. 163 68

Eicosanoids, lymphokines, and free radicals are known to participate in the pathogenesis of inflammation. Tumour necrosis factor (TNF), interleukin-1 and 6 (IL-1 and IL-6) and colony stimulating factor -1 (CSF-1) are secreted mainly by activated macrophages, whereas T-cells secrete IL-2, IL-3, IL-4 and interferon-gamma (IFN-gamma). In addition, activated macrophages and lymphocytes can also produce eicosanoids and free radicals which have potent pro-inflammatory actions. Eicosanoids, lymphokines, and free radicals can modulate the immune response, cell proliferation, stimulate collagenase and proteases secretion and induce bone resorption; events which are known to be associated with various collagen vascular diseases. On the other hand transforming growth factor-beta (TGF-beta) produced by synovial tissue, platelets and lymphocytes can inhibit collagenase production, suppress T-cell and NK-cell proliferation and activation and block free radical generation and seems to be of benefit in rheumatoid arthritis. Drugs such as cyclosporine, 1,25,dihydroxycholecalciferol and pentoxyfylline can block lymphokine and TNF production and thus, may inhibit the inflammatory process. Essential fatty acids, the precursors of eicosanoids, are suppressors of T-cell proliferation, IL-1, IL-2 and TNF production and have been shown to be of benefit in rheumatoid arthritis, systemic lupus erythematosus and glomerulonephritis. Thus, the interactions between essential fatty acids, eicosanoids, lymphokines, TGF-beta and free radicals suggest that new therapeutic strategies can be devised to modify the course of collagen vascular diseases.
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PMID:Interaction(s) between essential fatty acids, eicosanoids, cytokines, growth factors and free radicals: relevance to new therapeutic strategies in rheumatoid arthritis and other collagen vascular diseases. 172 26

Elevated spontaneous IgG production is characteristic of SLE. To identify the factors that support it, IL-6, a cytokine with an important role in the differentiation of IgG-secreting cells, was studied in SLE patients. Higher than normal levels of IL-6 were found, by a B9 assay, in sera of 63 of 70 patients (p less than 0.05). IL-6 was detected in 36 of 37 active SLE sera in higher titers (p = 0.009) than those for inactive SLE (n = 33), which were higher (p less than 0.05) than healthy controls (n = 15). IL-6 mRNA was detected in freshly isolated PBMC of 11 of 11 patients but not in normal PBMC, whereas IL-1 mRNA was detected only in patients with active disease. IL-6 activity was recovered from PBMC of four SLE patients, but not from four normal donors. By immunoperoxidase, IL-6 was detected in the cytoplasm of SLE monocytes and lymphocytes. When SLE PBMC were grown in short term cultures with no deliberate stimulation, expression of the IL-6 gene declined rapidly. Accordingly, the spontaneous production of IgG by SLE PBMC could be enhanced by exogenous IL-6. Spontaneous IgG production was diminished by 20 to 65% in the presence of neutralizing antibodies to IL-6, TNF-alpha, or IL-1. In contrast, neutralization of endogenous IL-4 increased production by approximately 40%. Anti-TNF-alpha treatment decreased IL-6 content of PBMC cultures, whereas anti-IL-4 augmented it, and exogenous IL-6 reversed anti-TNF-alpha effects on IgG production. Therefore, it is possible that the neutralization of TNF-alpha and IL-4 affected IgG production by modulating the synthesis/activity of IL-6. These results support the concept that SLE B cell hyperactivity is promoted by dysregulation of endogenous cytokines and suggest that IL-6, in particular, has an important pathogenic role.
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PMID:Elevated levels of endogenous IL-6 in systemic lupus erythematosus. A putative role in pathogenesis. 205 Oct 17

A low-frequency suppressor-cell population in normal peripheral blood inhibits the B-cell CESS response to IL-6, following pokeweed mitogen stimulation. The suppression of IL-6 responsiveness is (i) radiation sensitive, (ii) directed against CESS targets and not mediated by inhibition of IL-6 production, and (iii) associated with nonspecific cytotoxic activity against CESS targets. The generation of these cytolytic cells is also radiation sensitive. A correlation was found between PWM-induced cytotoxicity against CESS and the suppression of IL-6-dependent IgG production. But cytotoxicity toward CESS targets is not responsible for this suppression because (i) IL-2 induces equivalent or greater nonspecific cytotoxicity against CESS in the total absence of suppression of CESS-derived IgG production and (ii) suppression is also induced by mitogen-activated PBL separated from CESS targets by a cell-impermeable membrane. This suppression was not mediated by TNF alpha/beta or IFN-gamma. In systemic lupus erythematosus, suppression of IL-6-dependent IgG production is impaired in patients with active disease (29.2 +/- 13.7%) compared to patients with inactive disease (70 +/- 19.5%) or normal controls (82.8 +/- 9.2%). There is also a defect in mitogen-induced nonspecific cytotoxicity in active SLE (specific lysis 15.1 +/- 3.5%, compared to 34 +/- 4% in normals). Pokeweed mitogen-activated PBL can therefore normally induce suppression of B-cell IL-6 responses and this response is deficient in lupus.
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PMID:Normal mitogen-induced suppression of the interleukin-6 (IL-6) response and its deficiency in systemic lupus erythematosus. 210 95

We have studied the ability of isolated T cell subpopulations from the autoimmune mouse MRL/MPJ/lpr/lpr (lpr) to proliferate and to undergo changes in cytokine gene transcription in vitro, in the presence or absence of cytokines. The lpr mouse develops lupus-like symptoms and massive lymphadenopathy due to accumulation of abnormal CD4-/CD8- T lymphocytes, which are unusual in coexpressing Thy1 and B220. FACS-purified B220+/Thy1+ lpr lymph node cells showed little proliferative response to cytokines, even in the presence of PMA, and failed to proliferate in response to stimulation through the CD3/TcR complex. Polymerase chain reaction was used to examine the presence of cytokine gene transcripts in B220-/Thy1+ and B220+/Thy1+ ("abnormal") T cells, before and after in vitro culture. The high level of transcripts of IFN-gamma and TNF-alpha genes observed in freshly isolated B220+/Thy1+ cells decreased after 10 hr of in vitro culture, while levels of TNF-beta, IL-6 and TGF-beta transcripts were maintained. These results suggest that a positive stimulus for IFN-gamma and TNF-alpha gene transcription by lpr B220+/Thy1+ cells may exist in vivo but is removed upon purification of this abnormal T cell subset.
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PMID:Abnormal T cells from lpr mice down-regulate transcription of interferon-gamma and tumor necrosis factor-alpha in vitro. 213 61

Interleukin-6 (IL-6) is a pleiotropic cytokine previously known as B cell stimulatory factor (BSF-2), interferon-beta 2 (IFN-beta 2), 26-kDa protein, and hepatocyte stimulating factor (HSF). The name IL-6 was proposed when the nucleotide sequences of the cDNAs for these proteins had been determined and the molecules were found to be identical. IL-6 production can be induced by a wide variety of agents in a wide range of cells, although IL-6 gene expression seems to be regulated in a tissue and stimulus specific manner. At least 3 different signal pathways regulate IL-6 gene expression, emphasizing its multiply inducible nature. The currently known activities of IL-6 include regulatory functions in hematopoiesis, immune reactions and acute phase responses. IL-6 appears to be a key member of the IL family; however, it is still poorly understood how IL-6 interacts with other lymphokines within the network. The anti-viral activity of IL-6 seems to be negligible. Elevated IL-6 levels have been found in diseases like rheumatoid arthritis, multiple myeloma and systemic lupus erythematosus. The abnormal expression and dysregulation of IL-6 in certain disorders may be a typical feature of this cytokine, making it the first cytokine that may be directly related to pathogenesis.
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PMID:Interleukin-6: historical background, genetics and biological significance. 219 19


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