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)

A longitudinal study of circulating immune complexes (CIC) was performed in 121 patients with biopsy verified glomerulonephritis (GN). 1286 blood samples were obtained during a mean observation period of 21 months. Two methods for detection of CIC were used, the Clq-binding activity and a PEG precipitation test. CIC were detected by both tests in 21% of all blood samples and detected in at least one blood sample from 57 patients. The presence of CIC was found to be either transient (34 patients), intermittent (11 patients) or permanent (12 patients). CIC were found transiently at the time of renal biopsy and disappeared within months in patients with idiopathic extracapillary GN (7 of 9 patients), endocapillary GN (2/2) and GN associated with polyarteritis nodosa (5/6), Wegener's granulomatosis (3/3) and Henoch-Schoenlein syndrome (3/6). CIC were detected either transiently, intermittently or permanently for years after renal biopsy in patients with SLE (12/14) and membranoproliferative GN type I (7/12). CIC were only occasionally detected in patients with minor change nephropathy (1/9), membranoproliferative GN type II (0/2), IgA nephropathy (6/17), focal segmental sclerosis (1/8) and membranous GN (2/11). In these patients CIC were often transiently present without apparent relationship to time since renal biopsy. Overall, a relationship was found between the presence of CIC and decreasing serum creatinine, but there was no correlation with changes in proteinuria or with increasing blood pressure. Serial measurements of CIC showed correlations with clinical events only in individual patients, but not in the population as a whole.
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PMID:Circulating immune complexes in glomerulonephritis: a longitudinal study. 613 94

The occurrence and composition of complexed beta2-microglobulin (beta2m) in sera and synovial fluids of rheumatoid arthritis and systemic lupus erythematosus patients and control persons was investigated. Beta2m-containing complexes were detected in immune complex (IC)-enriched fractions isolated by precipitation with 3% polyethylene glycol 6000, in the macromolecular peaks after Sephadex G-200 gel filtration, and in IC desorbed from solid-phase Clq. Beta2m complexes were demonstrated also after precipitation of redissolved PEG-insoluble material by anti-human beta2m serum or isolation of the complexes by use of Sephadex-anti-beta2m. IgG was co-isolated with beta2m on Sephadex-anti-beta2m and free beta2m inhibited the binding of IgG to Sephadex anti-beta2m, indicating that IgG was present in the complexed beta2m. Analysis by SDS-polyacrylamide gradient electrophoresis under reducing conditions indicated that the purified beta2m complexes contained IgG and beta2m.
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PMID:Beta2-microglobulin-containing IgG complexes in sera and synovial fluids of rheumatoid arthritis and systemic lupus erythematosus patients. 616 72

In 2 radioimmunoassays in use to detect antibodies to dsDNA, the Farr assay and the PEG assay, we observed inhibitory effects of normal human serum (NHS) on the DNA binding by SLE sera. This was found to be due by the fact that, during incubation at 37 degrees C, CO2, introduced in the incubation mixture by the serum, evaporates from the mixture. This results in increase in pH to values well above pH 8.0, which in turn leads to a decreased DNA binding by antibody. When SLE sera are tested at low dilution, this phenomenon may lead to false negative results. Proper pH control, by the use of buffers with a greater buffering capacity than PBS, completely prevented the observed inhibitory effects. However, under these conditions NHS bound significant amounts of DNA in both assays. The non-specific DNA binding by NHS was found to be heat-stable, but could be eliminated either by aerosil treatment of the sera or by addition of dextran sulphate to the incubation mixture. Lipoproteins and, to a lesser extent, the complement component C1q appear responsible for this non-specific binding. To avoid false negative results with SLE sera as well as non-specific binding by NHS, we propose the use of stronger buffers in combination with added dextran sulphate to the incubation mixture in both the Farr assay and the PEG assay.
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PMID:Influence of pH on the detection of low- and high-avidity anti-dsDNA. 618 61

Lymphocytotoxic activity is known to better occur at low temperatures and to be relatively enriched in cryoglobulins. As the cold insoluble globulin, Fibronectin, is a main component of cryoglobulins, experiments were carried out to find out whether Fibronectin was involved in the mechanism of cytotoxicity or not. No direct or indirect (complement-mediated) effects were seen. A significant association was observed between lymphocytotoxic activity and circulating immune complexes and between Fibronectin positivity and cytotoxicity in PEG-precipitates of sera from three groups of patients affected with SLE, RA and Ps.A. respectively. As Fibronectin is a cryoprecipitagogue protein, possible implications of these findings are discussed.
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PMID:Cold insoluble globulin: relationship with lymphocytotoxins in autoimmune diseases. 633 64

A method for rapid determination of average masses and concentrations of circulating immune complexes in human sera is suggested. It is based on the dissimilarity in solubilities of immune complexes with different masses in the presence of polyethyleneglycol. Light-scattering intensities are measured by a laser nephelometer after adding to the serum of PEG in two different concentrations. The experimental values of the average masses and concentrations are calculated using calibration curves. The calibration curves are plotted for model immune complexes with different average masses obtained by heat-aggregation of IgG at various concentrations. This technique has been employed for determination of the average masses and concentrations of circulating immune complexes in 17 patients suffering from systemic lupus erythematosus and in 8 control individuals.
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PMID:A method for quantitative determination of average masses and concentrations of circulating immune complexes in human sera. 634 Dec 14

A comparative study of four nonspecific screening techniques (direct nephelometry, PEG-C4, PEG-IgG, and radiolabeled Clq binding) for immune complexes (IC) and of a technique specific for the detection of insulin-anti-insulin IC was undertaken in four groups of patients with diagnosis of infectious endocarditis, systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), and diabetes. The highest frequency of positive results was given by the PEG-IgG test in RA, the Clq-binding test in SLE, the insulin-anti-insulin IC screening test in diabetes, and the PEG-IgG and Clq-binding tests in infectious endocarditis. Of the four nonspecific tests, the PEG-C4 assay appeared to be the least discriminative, since it failed to show significant differences between any group of patients and the group of controls. Direct nephelometry, PEG-IgG, and radiolabeled Clq binding gave consistently higher results in RA than in other diseases, and in this disease the rates of agreement between these tests were highly significant. Significant agreements between the rates of positivity of Clq binding and PEG-IgG tests were seen in all groups of patients studied. Spearman's analysis of rank showed the best correlations among tests based on similar principles (ie, PEG precipitation), and also a strong correlation between Clq binding and the PEG-IgG test in RA. The PEG-IgG test appears to be a reliable IC screening test for general use with the advantage of not involving radioisotopes. In regard to antigen-specific tests, although their specificity and sensitivity may be high, their results may show no correlation with nonspecific screening tests nor with the presence or absence of clinical or laboratory abnormalities suggestive of IC deposition, as exemplified by the insulin-anti-insulin IC screening test in diabetic patients.
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PMID:Statistical analysis of five immune complex screening assays: patterns of detection in patients with rheumatoid arthritis, systemic lupus erythematosus, infectious endocarditis, and diabetes mellitus. 638 65

A method, measuring the activity of circulating immune complexes, based on C3 conversion of fresh human plasma by means of 3 per cent PEG precipitable immune complex-rich sera fractions is reported. Sera of patients suffering from autoimmune diseases of the connective tissue as well as of healthy controls were investigated. In case of standardised protein concentration of immune complexes, significantly low C3 conversion frequency of the isolated fractions has been observed in the control group as compared to the examined patients (rheumatoid arthritis with and without extraarticular manifestations, or juvenile chronic arthritis, or systemic lupus erythematosus). PEG fractions of RA with extraarticular manifestations induced the significantly highest C3 splitting. It is assumed that immune complexes will show a distinct interaction with the complement system also in vivo, and are therefore directly implicated in the systemic course of the disease process.
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PMID:[Functional analysis of immune complex-rich serum fractions in autoimmune diseases by in vitro C3 activation of fresh blood]. 645 23

Reticuloendothelial system (RES) Fc receptor-mediated immune clearance was measured in 18 patients with systemic lupus erythematosus (SLE). Only two patients, with major disease activity, had a prolonged T 1/2 of the blood disappearance curve of injected IgG coated red cells in comparison to 22 healthy controls. Circulating immune complexes (CIC) were studied with three methods: PEG precipitation, C1q-ELISA and the indirect granulocyte phagocytosis test (IGFT). The T 1/2 of the blood disappearance curve related significantly to the IGFT (r = 0.55, P less than 0.05) and not to the PEG and C1q-ELISA test. Although HLA-DR3 phenotype frequency was significantly increased in our SLE population (P less than 0.05), it was not related to Fc receptor function. Similarly, HLA-DR2 phenotype was not related to RES Fc receptor function. These data do not support the concept that a genetic HLA linked defect in reticuloendothelial Fc receptor function is a primary cause of SLE, predisposing the inflicted individual to immune complex deposition. However, Fc receptor-mediated immune clearance seems to be related to disease activity itself and to levels of CIC.
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PMID:Reticuloendothelial Fc receptor function in SLE patients. I. Primary HLA linked defect or acquired dysfunction secondary to disease activity? 658 55

Twenty children with juvenile chronic arthritis (JCA) and two children with SLE were investigated as to the existence of immune complexes in a long-term survey over 24 months. Two different methods were applied, a solid phase C1q RIA and a polyethylene glycol precipitation test. Detection of immune complexes was compared to the course of the disease and other laboratory data. C1q RIA showed a distinctly higher number of positive tests than the PEG precipitation test. The presence of immune complexes appears to be transitory in the course of JCA, as was demonstrated by C1q RIA. A connection with a more advanced stage of the disease is postulated. The positive test can be regarded as a prognostic parameter which, however, cannot be used for the diagnosis of JCA.
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PMID:Immune complexes in juvenile chronic arthritis. 660 15

The nature and the quantity of DNA present in the circulating immune complexes (ICs) from 30 patients with systemic lupus erythematosus (SLE) was characterized. DNA was extracted from IC enriched material prepared by polyethylene glycol precipitation of serum and the extracted DNA was labelled with 32P-phosphate. The size and the nature of DNA was determined by polyacrylamide gel electrophoresis and autoradiography. The quantity of DNA in the PEG precipitates from sera of 10 clinically active SLE was found to be significantly higher (mean 159 X 10(4) ct/min, range 49.9-807 X 10(4) ct/min) than 10 normal controls (mean 24.7 X 10(4) ct/min, range 8.7-47.8 X 10(4) ct/min). Four different sizes of DNA fragments were detected: 370-470, 150-240, 30-40 and 20 base pairs (bp). DNA of 30-40 bp and 20 bp were frequently present in both SLE and normals, but the other two large sized DNA fragments were particularly prominent in SLE patients. In the majority of samples, DNA fragments appeared double stranded.
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PMID:Characterization of DNA in polyethylene glycol precipitated immune complexes from sera of patients with systemic lupus erythematosus. 661 66


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