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)

Four murine monoclonal antibodies having high levels of activity against phosphatidyl-inositol phosphate (PIP) were tested for lupus anticoagulant activity. The antibodies showed different degrees of potency in a modified partial thromboplastin time test (APTT) that used dilutions of either bovine brain extract (Thrombofax) or liposomes consisting of phosphatidylcholine/phosphatidylserine (PC/PS) as the phospholipid source. The same relative order of anticoagulant potency that was observed in the APTT that used the PC/PS liposomes was maintained when the anti-PIP antibodies were tested for cross-reactivity either by induction of complement-dependent immune damage to liposomes containing PS, or in enzyme-linked immunosorbent assays that used PS, cardiolipin (CL), or phosphatidylinositol (PI) as antigens. The data indicate that monoclonal antibodies to PIP can express anticoagulant activity in a modified APTT that correlates with their different degrees of cross-reactivity against the negatively-charged phospholipids PS, CL, and PI.
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PMID:Lupus anticoagulant activities of murine monoclonal antibodies to liposomal phosphatidylinositol phosphate. 282 Jun 40

Biventricular hypertrophy and failure developed in two patients during treatment of systemic lupus erythematosus with chloroquine phosphate. In both patients, morphologic analysis of the myocardium, obtained by a right ventricular endomyocardial biopsy in one patient and at autopsy in the other, revealed accumulations of electron-dense concentric and parallel lamellae and curvilinear bodies within cardiac myocytes. These deposits were similar to those reported in chloroquine-induced skeletal myopathy and were considered to represent evidence of chloroquine-induced cardiotoxicity rather than a cardiovascular manifestation of the underlying disease. Clinical awareness and an endomyocardial biopsy specimen are necessary for the appropriate diagnosis of chloroquine-induced cardiomyopathy.
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PMID:Chloroquine-induced cardiomyopathy. 295 73

Although observations have implied that lupus anticoagulants have immunologic specificity toward anionic phospholipids, this assumption has been directly demonstrated in only one patient with a monoclonal IgM paraprotein. We tested the generality of this hypothesis directly by isolating five IgG lupus anticoagulants from patients with lupuslike syndromes and/or thrombosis. IgG lupus anticoagulant fractions were isolated free of other plasma proteins and free of contaminating phospholipid by adsorption to and elution from cardiolipin-cholesterol-dicetyl phosphate liposomes, followed by chromatography on protein A-Sepharose. Cardiolipin liposomes, but not phosphatidylcholine liposomes, were capable of removing all, or nearly all, lupus anticoagulant activity from patient plasma. The affinity-purified IgG preparations reacted with cardiolipin, phosphatidylserine, phosphatidylinositol, and phosphatidic acid, but not with phosphatidylcholine or phosphatidylethanolamine, and inhibited calcium-dependent binding of prothrombin and of factor X to phosphatidylserine-coated and to cardiolipin-coated surfaces. F(ab')2 fragments retained lupus anticoagulant activity and bound to cardiolipin in an enzyme-linked immunosorbent assay (ELISA). Anticardiolipin and lupus anticoagulant activity were both present in acidic fractions on isoelectric focusing. These data strongly suggest that most, if not all, lupus anticoagulants are antibodies that have immunologic specificity towards anionic phospholipids, thereby blocking the calcium-mediated binding of vitamin K-dependent coagulation factors to coagulation-active phospholipid surfaces.
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PMID:Immunological specificity and mechanism of action of IgG lupus anticoagulants. 310 26

The lupus anticoagulant is usually found in the plasma of patients with systemic lupus erythematosus. Lupus anticoagulants are antibodies to phospholipids and probably to phosphodiester-linked phosphate groups. A high frequency of thrombotic events in patients with lupus anticoagulant has been reported. Nevertheless the pathogenesis of thrombosis in these patients remains unknown. Endothelium which plays a key role in the antithrombogenic-thrombogenic balance could be a target for the lupus anticoagulant and alterations of some endothelial-cell functions could be responsible for the thrombotic events. The effects of the lupus anticoagulant on the phospholipids of the protein C-thrombomodulin complex may be important although evidence of such a reaction in vivo is awaited.
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PMID:The lupus anticoagulant and its role in thrombosis. 313 12

Ratios of activities of oxidative and nonoxidative enzymes involved in the pentose phosphate pathway of carbohydrate metabolism were altered in blood plasma and cells of the patients with systemic impairments of connective tissue. In rheumatoid arthritis and systemic lupus erythematosus the enzymatic activity was increased in blood plasma and cells, while the most distinct activation of the enzymes was found in granulocytes. In systemic sclerodermia total activity of the enzymes involved in metabolism of pentose phosphates in granulocytes exceeded 2.6-fold their values under conditions of normal state, whereas activities of the other enzymes studied remained near normal values. Calculation of ratios (mu value) between activities of the pathway oxidative and nonoxidative enzymes showed that the mu value was increased 2.7-fold in rheumatoid arthritis, while this value was decreased in lupus erythematosus and systemic sclerodermia 4.2- and 2-fold, respectively. The mu values, calculated on the basis of estimation of total activity of dehydrogenases from pentose phosphate pathway and total pentose phosphate metabolizing activity, might serve as a convenient diagnostic criterion for estimation of the ratio between activities of oxidative and nonoxidative enzymes involved in pentose phosphate pathway in granulocytes used for differential diagnosis of systemic impairments of connective tissue (rheumatoid arthritis, lupus erythematosus and systemic sclerodermia).
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PMID:[Pentose phosphate pathway of carbohydrate metabolism in various systemic diseases of the connective tissue]. 323 42

We describe an ELISA for assessment of complement function based on the capacity of serum to support fixation of complement components to solid phase immune complexes (IC). Microplates were coated with aggregated bovine serum albumin (BSA) followed by rabbit anti-BSA IgG. The solid phase IC were reacted with human serum. The uptake of C3b, C4b and properdin was measured using biotinylated F(ab)2 antibodies to each of the proteins, avidin alkaline phosphatase, and paranitrophenyl phosphate. Serial samples obtained from 15 patients with systemic lupus erythematosus were investigated. Out of 72 sera, 24 showed a reduced capacity to support incorporation of C4b into solid phase IC. Thirty-one of the sera showed low C3b binding and 59 of the sera a reduced uptake of properdin. The incorporation into solid phase IC of C3b and C4b as well as of C3b and properdin were closely correlated at high disease activity. In general, patients with severe disease manifestations showed low values in the uptake assays. Judging from the results obtained by analysis of serial samples, the uptake of C3b, C4b and properdin, complement mediated solubilization of fluid phase IC and the concentrations of C1q binding IC were useful indicators of disease activity in the patients. The concentrations of circulating C4, C3 and properdin varied less consistently according to disease activity. The concentrations of serum properdin were never found to be low, which was in contrast to the finding of reduced properdin uptake by solid phase IC in most of the samples.
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PMID:Complement fixation by solid phase immune complexes. Reduced capacity in SLE sera. 326 27

A panel of 65 systemic lupus erythematosus (SLE) and 61 normal-derived human hybridoma auto-antibodies was studied for cytoskeletal reactivity, using an indirect immunofluorescence method. Reactivity with the cytoskeleton was expressed 3 times more frequently in the SLE-derived antibody group and included intermediate filaments, microfilaments, microtubules, and centrioles. By immunoblot analysis, the antigenic specificity of intermediate filament-reactive SLE hybridoma antibodies was not restricted to vimentin, but included cytokeratins and desmin. The antibodies were also studied for their DNA-binding, lupus anticoagulant, and rheumatoid factor activities. These autoantibody activities were expressed 3-5 times more frequently in the SLE-derived group. The ability to bind DNA was not a prerequisite for reactivity with intermediate filament proteins. Our findings suggest that there are at least 2 subsets of cytoskeletal-reactive hybridoma antibodies: those that recognize epitopes found only on cytoskeletal proteins, and those that recognize epitopes common to both DNA and certain cytoskeletal proteins. In addition, we hypothesize that there may be a third subset of antibodies that recognize a phosphate-containing moiety (phospholipid or phosphoprotein) associated with cytoskeletal filaments.
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PMID:Hybridoma lupus autoantibodies can bind major cytoskeletal filaments in the absence of DNA-binding activity. 329 72

Antimalarial drugs containing the 4-amino quinoline radical are used to help control disease activity in discoid lupus erythematosus and systemic lupus erythematosus (SLE). Many patients with these complaints are young women, some of whom will become pregnant. The use of these substituted 4-amino quinoline compounds in pregnancy is controversial. We studied the full obstetric histories of 8 women with SLE who had taken either chloroquine phosphate or hydroxychloroquine sulphate (Plaquenil) throughout the entire length of at least 1 pregnancy. These 8 women had 14 pregnancies while receiving antimalarial drugs. Fetal wastage was high in these patients, regardless of antimalarial therapy, and was almost 100% in patients who were clinically active. Six normal full term spontaneous deliveries resulted from these pregnancies with clinically healthy normal babies born despite exposure to antimalarial therapy throughout the pregnancies.
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PMID:Antimalarial drugs, systemic lupus erythematosus and pregnancy. 339 70

Self recently described a substrate system for alkaline phosphatase (AP)-dependent ELISAs which markedly increased sensitivity, compared to using p-nitrophenyl phosphate. This increase is achieved by having AP, the primary enzyme, produce an activator for a secondary enzyme-substrate system, within which marked amplification occurs. We adapted this technique to study antibodies to casein, bovine serum albumin, ovalbumin, and cardiolipin in the sera of patients with systemic lupus erythematosus (SLE) and normal individuals. The new substrate system yielded titres 30-50-fold higher than those with p-nitrophenyl phosphate (Sigma 104, p-NPP). In addition, when used in a solid-phase C1q binding assay we were able to use a 1 : 100,000 dilution of AP-conjugated anti-human IgG with the amplified substrate, compared to the 1 : 1000 dilution needed with p-NPP. This system is extremely valuable because of its flexibility. It can either be very sparing of limited samples, or if the added sensitivity is not needed, 100-fold less AP conjugate may be used. Thus rare or expensive conjugates can be significantly conserved.
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PMID:A substrate amplification system for enzyme-linked immunoassays. Demonstration of its general applicability to ELISA systems for detecting antibodies and immune complexes. 349 82

Five drugs associated with systemic lupus erythematosus were studied for their effect on the salt-induced right-handed (B) to left-handed (Z) transition of poly(dG-me5dC) X poly(dG-me5dC). Using circular dichroism spectroscopy, procainamide and hydralazine were found to reduce the midpoint of B to Z transition from 0.8M NaCl to 0.5M NaCl and to increase the rate of this transition at 1M NaCl. Isoniazid and D-penicillamine had less effect on the midpoint of transition and practically no effect on the kinetics. N-acetyl procainamide (a structurally related control for procainamide) and L-canavanine had no effect. Procainamide caused slight reduction in the helix-coil transition (melting) temperature of calf thymus DNA. At a concentration of 1:1 (DNA phosphate:drug ratio), procainamide and hydralazine also caused the aggregation of calf thymus DNA. Since altered DNA conformations, such as Z-DNA, are more immunogenic, these results suggest that the induction or stabilization of Z-DNA by these drugs might be important in the pathogenesis of at least some cases of systemic lupus erythematosus.
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PMID:Effects of lupus-inducing drugs on the B to Z transition of synthetic DNA. 371 55


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