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

Fifty-four patients with systemic lupus erythematosus (SLE) were examined for (1) CR1 (C3b/C4b receptor) levels on erythrocytes by an enzyme-linked immunosorbent assay, (2) levels of circulating immune complexes (IC) by a polyethylene glycol precipitation complement consumption method, and (3) concentrations of C3d split products in plasma by intermediate gel rocket immunoelectrophoresis. A preponderance of low CR1 levels was found among patients with SLE (mean 40%, range 13-106) as compared with normal controls (mean 70%, range 24-130) (p less than 0.001). The concentrations of circulating IC were elevated in 38% of 58 samples. The concentrations of C3d were elevated in 72%, and were positively correlated with the levels of IC (tau = 0.28; p less than 0.005) and with disease activity as assessed by a modification of the UCH/Middlesex criteria. Negative correlations were seen between the CR1 numbers and disease activity (p = 0.01), concentrations of circulating IC (tau = -0.14; p less than 0.005), and C3d (tau = -0.21; p less than 0.005). The changes found in CR1 levels on repeated study were, however, relatively small (less than or equal to 27%; median 5), even during periods of changing disease activity.
 ...
PMID:Erythrocyte CR1 (C3b/C4b receptor) levels and disease activity in patients with SLE. 296 Oct 56

Using immobilized anti-C3 antibody and an enzyme immunoassay, sera from 26 patients (eight with systemic lupus erythematosus (SLE), four with Hashimoto's thyroiditis, eight haemophiliacs and six with post-hepatitis cirrhosis) containing high levels of circulating immune complexes (IC) were selected. The IC were precipitated with 2.5% polyethylene glycol, washed, treated with acid buffer, neutralized and tested using an enzyme immunoassay in parallel with the original sera for antibody activity against a panel of antigens: human myosin and thyroglobulin, mouse actin and tubulin, calf thymus DNA and trinitrophenyl coupled to bovine serum albumin (TNP/BSA). It was found that all the isolated IC may contain IgG, IgA and IgM antibodies reacting with actin tubulin and TNP/BSA and also, depending upon the disease, antibodies reacting with some of the other antigens of the panel. By comparison to the antibodies present in the original sera, higher titers of antibodies were found in the isolated IC while some antibody specificities not detected in a given serum were occasionally noted in the isolated IC. The antibodies present in the IC seem to possess characteristics similar to those of polyreactive human natural autoantibodies. It is concluded that natural autoantibodies participate actively in the formation of IC found in pathological sera.
 ...
PMID:Enzyme immunoassay analysis of antibody specificities present in the circulating immune complexes of selected pathological sera. 305 7

By utilizing a monoclonal rheumatoid factor (mRF) and bovine conglutinin (K) in radioimmunoassays, ICs detected in sera of patients with lupus nephritis were partially characterized. The mRF-RIA detected high levels of ICs in 86.9% of patients with active SLE and in only 22.7% of patients with inactive disease. Positive association was observed with clinical scores and significant negative correlation was found with serum levels of C1q, C3 and C4. The mRF-reactive ICs were shown to be cryoprecipitable and analysis by gel filtration through Sephacryl S-300 disclosed a material eluting between IgM and IgG, being dissociated in acidic pH. On the other hand, no association could be demonstrated between levels of ICs detected by K-RIA and clinical activity. Positivity in this assay was only 8.7% and 31.8% for active and inactive groups. Differently from the ICs detected by mRF-RIA, the K-reactive material was not precipitated by 3.5% PEG, nor by centrifugation in the cold, and EDTA did not reduce the binding of IgG to K in positive sera. The reactive IgG in Sephacryl S-300 chromatography eluted in the same position as monomeric IgG both in neutral and dissociating conditions. No C3 could be detected in ICs reactive in both assays.
 ...
PMID:Characterization of circulating immune complexes detected by monoclonal rheumatoid factor and conglutinin radioimmunoassays in SLE nephritis. 325 Oct 47

Antibodies to dsDNA differ in their avidity towards the antigen. The electrostatic interaction between DNA and anti-DNA is sensitive to increases in pH and/or ionic strength and therefore, elution studies employing either of these permit discrimination between anti-dsDNA populations that differ in avidity. Another way to determine anti-dsDNA avidity is the calculation of Farr/PEG ratios. These are obtained by division of the amount of anti-DNA measured with the Farr assay (which does not detect low avidity anti-dsDNA) by the amount measured with the PEG assay (which does detect low avidity anti-dsDNA). With these separate approaches, we compared the sera of 17 SLE patients with nephritis with the sera of 17 patients with central nervous system (CNS) involvement. Farr/PEG ratios and sensitivity to high pH elution of anti-dsDNA in the sera of these patients both permitted discrimination between the two groups of patients. The anti-dsDNA of patients with nephritis was found to have a significantly higher avidity towards DNA than anti-dsDNA of patients with cerebral disease. We also observed a significant correlation between Farr/PEG ratios and the salt lability of anti-dsDNA.
 ...
PMID:Dissociation studies of DNA/anti-DNA complexes in relation to anti-DNA avidity. 328 12

Circulating immune complexes present in the serum of a patient with systemic lupus erythematosus, end-stage renal failure, and thoracic vertebral Candida albicans osteomyelitis were sequentially analysed by isoelectric focusing, immunoblotting, and immunoprinting. Candida antigens (including mannoproteins), Clq and C3 complement components, and specific anti-Candida antibody were detected within polyethylene glycol precipitated complexes. An antigen of 47K molecular weight was amongst those demonstrated by polyacrylamide gel electrophoresis to be present within the complexes. It has been proposed elsewhere that a serologic response to a 47K protein is predictive of recovery from Candida albicans infection. Free antibody had specificity for Candida antigens ranging in molecular weight from 18K to more than 100K including a 47K component. The analytical techniques employed allowed rapid and precise identification of the components of one particular immune complex system and will be widely applicable to the dissection of other diverse systems.
 ...
PMID:The immunochemical characterisation of circulating immune complex constituents in Candida albicans osteomyelitis by isoelectric focusing, immunoblot, and immunoprint. 330 46

HIV-seropositive homosexuals, narcotic addicts and hemophiliacs develop a new syndrome of immunologic thrombocytopenic purpura (ITP) which is clinically indistinguishable from classic autoimmune thrombocytopenic purpura (ATP) with respect to increased megakaryocytes in the bone marrow, peripheral destruction of antibody-coated platelets, negative serology for SLE, response to treatment with prednisone and/or splenectomy. Eleven of 79 homosexual patients have developed AIDS 2 to 43 months after the diagnosis of ITP (mean, 22 months). The mechanism of the ITP appears to be different in homosexuals and narcotic addicts when compared to classic ATP. Homosexuals and narcotic addicts have markedly elevated platelet-bound IgG and C3C4 (2.5-4-fold ATP levels), PEG-precipitable circulating immune complexes and anti-F(ab')2 antibodies (absent in ATP). There is no inverse relationship between platelet-bound IgG and platelet count and platelet antibody is usually not elutable from washed platelets as is the case with classic ATP. Homosexual patients do not have 7S platelet antibody in their sera as do classic ATP patients, but appear to have immune complex deposition on their platelets, possibly due to the presence of anti-F(ab')2 antibodies. Narcotic addict patients do have detectable 7S platelet antibody but also appear to have immune complex deposition on their platelets, possibly due to anti-F(ab')2 antibodies. The anti-F(ab')2 antibodies are of the IgG class. They react with autologous, homologous patient and healthy control F(ab')2 fragments. Some anti-F(ab')2 antibodies have broad reactivity, others are more limited. It is postulated that some of the anti-F(ab')2 antibodies may be responsible for the thrombocytopenia.
 ...
PMID:Immunologic thrombocytopenic purpura in patients at risk for AIDS. 333 92

To evaluate terminal complement pathway activation in plasma from patients with systemic lupus erythematosus (SLE) and primary glomerular diseases, we developed an enzyme-linked immunosorbent assay (ELISA) for measuring the terminal complement complexes (TCC). The method is based on a sandwich technique using rabbit antibodies against native human C5, C7 and C9. To avoid interference by native components, we equilibrated plasma specimens with 5% polyethylene glycol buffer. The precipitates were measured by ELISA. TCC was detectable in all 14 normal controls (0.48 +/- 0.06 AU/ml; mean +/- s.e.m.). TCC levels were elevated in 18 of 54 patients with SLE (0.89 +/- 0.07 AU/ml; P less than 0.01) and in eight of 11 patients with membranoproliferative glomerulonephritis (MPGN) (3.15 +/- 0.62 AU/ml; P less than 0.01). However, only one of six patients with membranous nephropathy and none of 13 with mesangial proliferative glomerulonephritis showed high values. In SLE, TCC was correlated with circulating immune complexes and inversely with CH50, C3, C4, C5 and alternative complement pathway activity (AH50), and showed significantly high values even in normal CH50 cases (n = 34; P less than 0.01). In MPGN, TCC was inversely correlated with CH50, AH50, C3, C5 and C9. These results suggest that the classical pathway plays an important role for TCC generation in SLE and that the alternative pathway does in MPGN.
 ...
PMID:Terminal complement complex in plasma from patients with systemic lupus erythematosus and other glomerular diseases. 342 27

Three different tests which are based on different principles were used for the detection of soluble immune complexes (IC): (i) a PEG precipitation test, which is based on the solubility characteristics of IC; (ii) a solid-phase C1q binding assay, which is based on the complement binding property of IC, and uses peroxidase-linked anti-human IgG to detect the bound IC (C1q-ELISA); and (iii) the indirect granulocyte phagocytosis test (IGPT) which is based on the Fc R- and possibly the C3 R-binding of IC. Using heat-aggregated IgG (A-IgG) as a model for soluble IC all three tests showed a linear relation with the amount of A-IgG. The C1q-ELISA and the IGPT had a detection limit of less than 1 microgram/ml while the PEG test only detected quantities of more than 10 micrograms/ml. However, when using artificially produced soluble IC, which were prepared from human antibodies (ab) of different specificities and their respective antigens (ag) i.e., (i) tetanus toxoid, (ii) Helix pomatia hemocyanin (HPH), and (iii) dsDNA, and which consisted of the two components in a wide range of ag/ab ratios, distinct results were obtained with the three tests. Thus demonstrating that results obtained with A-IgG as a model for soluble IC can not simply be extrapolated to the behavior of real complexes in IC detection assays. No matter which ag was used, the composition of the IC, i.e., the ratio in which ag and ab were present, appeared to be the crucial factor for detectability in the different tests. The C1q-ELISA can detect IC over a wide range of ag/ab ratios, while it is particularly sensitive for IC formed in slight ag excess. The IGPT in contrast primarily detects, and is highly sensitive for, IC formed in ab excess. The PEG test appears to detect IC with freshly bound complement only. Another interesting finding has to be mentioned here: when increasing amounts of dsDNA were added to a SLE serum containing anti-DNA ab, the IC that had been detectable in the native serum with the IGPT completely disappeared, thus demonstrating that these complexes did consist of DNA and anti-DNA.
 ...
PMID:Characterization of the soluble immune complexes that are detected by three different techniques. 348 41

Fibronectin is involved in the opsonic clearance of particulate material. It is present in plasma and synovial fluid and thus might be expected to have a role in the clearance of immune complexes. We have investigated this in a study of polyethylene glycol (PEG) precipitable material from the serum of patients with rheumatoid arthritis, systemic lupus erythematosus, and other connective tissue disorders. Fibronectin is a significant component of PEG precipitates but the amount present is influenced by the method of preparation: more precipitates at 4 degrees C than at 20 degrees C. Fibronectin precipitation by PEG was considered to be related to immune complexes because: there was no direct relationship between serum fibronectin levels and the amount present in PEG precipitates; radiolabelled purified isolated fibronectin did not precipitate in 4% PEG; there was a direct relationship between the amount of fibronectin in PEG precipitates and the amounts of immunoglobulin G, A, and M. These results indicate that fibronectin is involved in immune complexes in rheumatic diseases, though they do not show it has an important biological role in these circumstances.
 ...
PMID:Fibronectin in polyethylene glycol precipitates: evidence for a role in immune complexes. 376 6

A method for detection and quantitation of circulating immune complexes using precipitation of the complexes by polyethylene glycol (PEG) has been reexamined to determine the influence of pH on the recovery and the reproducibility of the results. Results showed that the pH optimum for these determinations was 7.8. The recovery percentages range from 57.8-146.5% at lower immune complex concentrations, and from 73.9-101.3% at higher concentrations. The reproducibility of the method seems reasonably acceptable with a percent coefficient of variation ranging from 0.5-9.5. This method for quantitation of circulating immune complexes by polyethylene glycol precipitation is consistent and relatively reliable. Using this method, the levels of circulating immune complexes in sera in patients with hepatitis, liver cirrhosis, hepatoma, acute post-streptococcal glomerulonephritis (before and after treatment) and systemic lupus erythematosus have been examined. The results showed that except the patients with treated acute post-streptococcal glomerulonephritis who had a similar amount of immune complexes with normal controls, the level of immune complexes in patients with other types of diseases were all higher than the control. In addition, the composition of IgG, IgA, IgM, C3 and C4 of the precipitable complexes in sera of patients with three types of liver disease has been analyzed and demonstrated that the percentages of IgM were higher than the normal control. However, C3 and C4 in hepatitis and liver cirrhosis patients were lower than those of the control.
 ...
PMID:Detection of circulating immune complexes in liver diseases, systemic lupus erythematosus and glomerulonephritis by polyethylene glycol precipitation. 377 14


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>