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Query: UMLS:C0024141 (systemic lupus erythematosus)
 44,322 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Plasma proteins which interfere with blood coagulation have often been described in patients with systemic lupus erythematosus (SLE). The most frequent type interferes with the conversion of prothrombin to thrombin and thus prolongs the prothrombin time. Infrequently, SLE patients exhibit anticoagulants which appear to block the earlier stages of coagulation such as those involving factor VIII or the formation of activated factor XI (factor XIa). The anticoagulant reported here was studied by means of a sequential clotting system utilizing crude coagulation factors and was noted to interfere with the action of activated plasma thromboplastin antecedent (PTA) during the activation of factor IX. This anticoagulant was found in gamma-globulin-rich ethanol fractions of plasma. After gel filtration, it was found principally in fractions containing IgM globulins but also, to a lesser extent, in IgG-rich fractions. In this respect, it is similar to anticoagulants reported in certain other cases of SLE. Attempts to confirm the immunoglobulin nature of the anticoagulant by immunoabsorption were, however, inconclusive
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PMID:Studies on a circulating anticoagulant in systemic lupus erythematosus: evidence for inhibition of the function of activated plasma thromboplastin antecedent (factor XIa). 23 89

Of 36 patients with systemic lupus erythematosus, 3 were demonstrated to have an abnormality in their haemostatic mechanism. In 2 this was believed to be on the basis of an auto-antibody to the phospholipid of platelets in the prothrombin activator complex. In the third an inhibitor was directed against factor VIII.
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PMID:Systemic lupus erythematosus and spontaneously arising anticoagulants. 118 58

We have developed a Silica Clotting Time (SCT) test suitable to screen patients with lupus anticoagulants (LA) and compatible with photo-optical instruments. The SCT results were considered to be positive for LA whenever the clotting times were longer than the upper normal limit at low phospholipid concentration and to be confirmed when the prolonged clotting times were corrected to normal by high phospholipid concentration. We studied plasmas from healthy subjects, patients with known diagnoses of LA, patients with acquired deficiencies of blood coagulation and hemophiliacs with anti-factor VIII antibodies. The test was positive for all LA patients, and negative for all non-LA patients except 7 hemophiliacs with anti-factor VIII antibodies. Our data indicate that the SCT is a sensitive test, suitable for screening patients suspected of having LA. Its compatibility with photo-optical instruments makes it a suitable candidate to replace the kaolin clotting time. The contemporaneous performance of SCT at low and high phospholipid concentrations provides screening and confirmation in a single procedure.
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PMID:Silica clotting time (SCT) as a screening and confirmatory test for detection of the lupus anticoagulants. 132 61

Ocular vascular occlusive disease resulting in severe retinopathy and/or post-thrombotic glaucoma has been extensively discussed in patients with lupus anticoagulant and/or anticardiolipin antibodies (LA/aCL). Inadequate circulation plays an important role in the pathogenesis of another ophthalmic entity--the normal tension glaucoma. We studied 22 patients with normal tension glaucoma (group I) and 23 with chronic open-angle glaucoma (group II) and compared them with a control group (n = 25, group III). LA, aCL, the aCL cofactor beta 2-Glycoprotein I, and other haemostatic parameters including factor VIII:C, von Willebrand factor, factors II, V, VII and plasminogen activator inhibitor were measured. Five out of 22 (22.7%) in group I, five out of 23 (21.7%) in group II and three out of 25 (12.0%) in group III had positive LA and/or aCL. These prevalences were not statistically significantly different. beta 2-Glycoprotein I was normal in all groups. No other parameters were significantly different between groups. These findings do not support the contribution of ocular microvascular occlusive disease, due to elevated aCL, in the pathogenesis of glaucomatous damage.
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PMID:Lupus anticoagulants/anticardiolipin antibodies in patients with normal tension glaucoma. 145 Mar 20

We here present an easily standardizable and reproducible procedure which clearly separates lupus anticoagulants (LA) from coagulation factor inhibitors. This new LA neutralization test makes use of platelet-derived microvesicles which were prepared as follows: gel-filtered platelets (4 x 10(5)/microliters) were incubated with 60 microM of the calcium ionophore A23187 for 20 min at 37 degrees C. The vesicles were separated from the platelet aggregates by centrifugation at 1000 g for 10 min. The vesicle containing supernatant was then spun down at 15,000 g for 15 min, lyophilized and stored at -20 degrees C until used. The vesicles were resuspended in plasma from normal individuals, from patients with LA activity, from patients with factor VIII inhibitors, from patients with congenital factor deficiencies and from patients receiving oral anticoagulants or intravenous heparin. A kaolin clotting time was performed in the absence (KCT) or presence of these vesicles (KCTves) and the ratios of these times to their respective mean normal times were calculated. Segregation of LA patients from all remaining patients except heparinized ones could be made with a high degree of accuracy. A thrombin time was needed to separate LA from heparinized patients. The method was highly reproducible and only minor (negligible) differences in potencies were observed between different vesicle preparations. Both the intra-batch and the inter-batch coefficients of variations on the KCTves were lower than 6%.
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PMID:A new lupus anticoagulant neutralization test based on platelet-derived vesicles. 158 Dec 14

Lupus anticoagulant was detected in 205 newly diagnosed, untreated patients with systemic lupus erythematosus by the following tests: kaolin clotting time, activated partial thromboplastin time, plasma prothrombin time, and, in the last 99 patients, by dilute Russell's viper venom time. In 10 patients, lupus anticoagulant was detected by kaolin clotting time prolongation, corrected by inosithin but not by normal plasma; 12 and 6 of them had prolonged activated partial thromboplastin time and partial plasma prothrombin time, respectively. Only 10 patients had a history of recurrent abortions and/or thrombosis, nine of whom had lupus anticoagulant as shown by the kaolin clotting time test. Of the 99 patients studied by all four tests, 9 showed lupus anticoagulant by both kaolin clotting time and dilute Russell's viper venom time; 7 had a history of abortion and/or thrombosis. The dilute Russell's viper venom time test is easy to perform and not affected by inhibitors to factor VIII or IX. It is recommended as a primary screening test for lupus anticoagulant detection in a hospital clinical laboratory.
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PMID:Evaluation of four coagulation tests to detect plasma lupus anticoagulants. 174 92

Lupus anticoagulants are antibodies that interfere with in vitro phospholipid-dependent coagulation reactions. In vivo, they have been associated with a variety of thromboembolic problems. Samples from patients with lupus anticoagulants were included in the 1986 and 1987 College of American Pathologists proficiency survey program. Participant performance on these samples demonstrated significant variation in the responsiveness of different activated partial thromboplastin reagents to lupus anticoagulants. The level of factor VIII in these samples reported by the participants also varied with the reagent used. Follow-up studies demonstrated striking reagent-dependent differences in the dilutional effect on apparent factor VIII, IX, XI, and XII activity. These results point out the importance of selecting sensitive and responsive reagents for appropriate identification of lupus inhibitors. In addition, the results indicate that the choice of reagent used for factor assays can affect the apparent factor activity as well as whether a dilutional effect is noted when a lupus anticoagulant is present in the test sample, an important consideration when trying to distinguish a lupus anticoagulant from a specific factor inhibitor.
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PMID:Effect of lupus anticoagulants on the activated partial thromboplastin time. Results of the College of American Pathologists survey program. 189 55

To determine splenic pathology in thrombotic thrombocytopenic purpura (TTP), 10 spleens and two accessory spleens were studied. The eight women and two men ranged from 20 to 66 years of age (mean age, 39 years). Three spleens were enlarged. Thrombi were noted in arteries and arterioles in nine specimens: no associated inflammation was seen. Periodic acid-Schiff-positive diastase-resistant hyaline subendothelial deposits (SEDs) were present in all cases. Some arterioles showed a transition between thrombi and SEDs. The presence of platelets or platelet-related material in SEDs and thrombi was documented by factor VIII staining. Hyperplasia of B cells and germinal centers was present in 67%, and periarteriolar concentric fibrosis ("onion-skinning") in 58%. Histiocytes showed prominent iron deposits in 92% and hemophagocytosis in 83% of cases. Extramedullary hematopoiesis was present in 42%. Blood lakes, infarcts, and endothelial hyperplasia were rarely noted; microaneurysms were not seen. Ten spleens from patients with idiopathic thrombocytopenic purpura and 10 age-matched control spleens rarely showed SEDs or hemosiderosis and did not show hemophagocytosis or thrombi. We conclude that subendothelial deposits may be related to platelet thrombi incorporated into vessel walls. Germinal centers and periarteriolar concentric fibrosis may indicate an immunologic role in TTP, as in systemic lupus erythematosus.
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PMID:Splenic pathology in thrombotic thrombocytopenic purpura. 210 72

Lupus anticoagulants (LA) are IgG or IgM antibodies which prolong phospholipid-dependent coagulation tests. For the detection and quantitation of such antibodies, we have developed an ELISA with cephalin as the coating antigen. The sensitivity of this assay was compared to the activated partial thromboplastin time (APTT). LA was defined as greater than or equal to 5 sec prolongation of the APTT with standard cephalin dilution, or greater than or equal to 10 sec prolongation with a high cephalin dilution, on a 1:1 mixture of patient and control plasma. Plasma samples from 158 healthy individuals were tested for anticephalin antibodies. The 97.5 percentile was chosen as the upper reference limit and allocated a value of 1 ELISA unit. A "four-parameter logistic" model was used for transformation of the absorbances to ELISA units. Of 314 plasma samples referred for LA screening, positive results were found in 62 by both APTT and ELISA. Twenty-three samples were ELISA positive and APTT negative; this finding may be explained by greater sensitivity of the ELISA, which gave positive results in a four-fold greater dilution than the APTT. Prolongation of the APTT without antibody activity was found in 8 samples of which 2 had an inhibitor of factor VIII:C, the remaining 6 probably had true LA. In conclusion, our computer-assisted ELISA is a sensitive and reliable test method for quantitation of anticephalin antibodies. This assay has a high concordance with LA as detected with the APTT.
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PMID:Quantitation of anticephalin antibodies in a computer-assisted enzyme-linked immunosorbent assay (ELISA): relation to lupus anticoagulant. 210 90

A micro-ELISA method for the immunological characterization of factor VIII (F. VIII) inhibitors is described. Microplates sensitized with purified monospecific anti-von Willebrand factor (vWF) IgG were firstly incubated with a commercial F. VIII concentrate and then with the samples containing the F. VIII inhibitors to be characterized. Peroxidase conjugated monospecific antisera were used to determine the Ig class and the light chain type. Alkaline phosphatase conjugated monoclonal antibodies were employed to investigate the IgG subclasses. The F. VIII inhibitors from 8 hemophiliacs and 1 patient with systemic lupus erythematosus (SLE) were characterized. All of them belonged to the IgG class but one case simultaneously exhibited another inhibitor of the IgA class. Eight inhibitors analyzed for light chains resulted to be polyclonal. In 7 cases the inhibitors belonged solely to the IgG4 subclass while in the other 2 cases contained all the 4 IgG subclasses. The method appears to be simple, accurate and highly sensitive (detecting as low as 0.156 Bethesda Units/ml) for the immunological characterization of F. VIII inhibitors.
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PMID:Immunological characterization of factor VIII inhibitors by a sensitive micro-ELISA method. 211 82


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