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)

Citrated samples from 100 patients on i.v. heparin and 20 normal patients were tested with three batches each of three activated partial thromboplastin time (APTT) reagents: Thrombosil I (Ortho); Automated APTT (Organon Teknika) and Actin FSL (Baxter). The ratio of APTT over the geometric mean normal APTT for each heparinized sample was calculated. One batch of reagent arbitrarily chosen as a reference gave the ratios APTRREF (y). The remaining reagents to be standardized against the reference system gave the ratios APTRTEST (x). The best correlation between systems was given by log vs log x. Standard curves were prepared from the APTT ratios of the 20 normal patients and 65 of the heparinized samples. On plotting log APTRTEST vs log APTRREF the y intercept was close to zero so x was expressed in terms of y using; log x = HSI. log y, where HSI (Heparin Sensitivity Index) = slope. The APTRTEST results of the remaining 35 heparinized samples were transformed using; APTRTRANS = (APTRTEST)HSI.APTRTRANS was then compared to APTRREF to determine whether the transformation brought the results closer to the reference. We conclude that although some improvement was found by using the transform, it was not possible to mathematically relate APTT results due to a high degree of variation between results using different reagents. A standard APTT reagent for the monitoring of heparin therapy is recommended. A separate APTT reagent may be required for the screening of factor deficiencies and lupus anticoagulants.
 ...
PMID:An attempt to standardize APTT reagents used to monitor heparin therapy. 133 84

A simplified dilute Russell's viper venom time (DRVVT) test--in which the venom, trace phospholipid and calcium were combined into a single reagent--was evaluated for the detection of lupus anticoagulants (LA) in 28 plasma samples containing non-specific circulating anticoagulants. In agreement with previous studies, the DRVVT was found to be insensitive to defects in contact and haemophilic factors and was only marginally affected by antibodies directed against factor VIII. Thus, the use of a DRVVT test in investigations of anticoagulants reduces the risk of confusing a haemorrhagic inhibitor of factor VIII with a non-haemorrhagic LA. In comparisons of sensitivity against activated partial thromboplastin time tests (APTT-Actin FSL and Organon-Teknika reagents) the simplified DRVVT was prolonged slightly more than the APTT in most of the test plasmas containing various non-specific circulating anticoagulants. Three anticoagulants affecting APTTs more than the DRVVT were found to be associated with anticardiolipin IgMs. APTT-prolonging anticoagulants, whether prolonging DRVVT tests or not, showed similar 'correction' of their APTTs by the addition of platelets or phospholipid. Thus, phospholipid-dependent or LA show heterogeneity. Those affecting only the APTT and not DRVVT should perhaps be classified differently.
 ...
PMID:Use of a simplified dilute Russell's viper venom time (DRVVT) confirms heterogeneity among 'lupus anticoagulants'. 212 12

The dilute prothrombin time (dPT) is a widely accepted sensitive screening test for the lupus anticoagulant (LA). In general, Simplastin (Organon Teknika), a rabbit brain thromboplastin, diluted 1/500, is used in this test. Recently, human tissue thromboplastin obtained by recombinant DNA technology has become available and we have evaluated the usefulness of one such preparation, Innovin (Dade), for the detection of the LA. dPTs, using several dilutions of Innovin were determined on plasmas from 18 normal individuals and 15 patients with a well-documented LA. The dPT ratios, calculated as the individual result divided by the mean normal, were statistically compared. Innovin in dilutions from 1/100 onwards was found to be significantly more responsive to the LA than Simplastin (P < 0.05). Intra-assay coefficients of variation (CVs) ranged from 1.05% to 14.8% with Innovin, versus 2.7%-24.3% with Simplastin (P < 0.05); inter-assay CVs ranged from 5.6%-11.8% with Innovin, versus 4.2%-33.8% with Simplastin (P < 0.001). Analysis of 316 consecutive plasma samples from non-anticoagulated patients, on which a LA determination was requested, showed a 100% sensitivity and a 96% specificity of the dPT performed with Innovin, as compared to 81% and 93% respectively for the dPT using Simplastin.
 ...
PMID:Optimization of the dilute prothrombin time for the detection of the lupus anticoagulant by use of a recombinant tissue thromboplastin. 794 61

ARACHnase (Hemostasis Diagnostics International Co., Denver, CO) is a normal plasma that contains a venom extract from the brown recluse spider, Loxosceles reclusa, which mimics the presence of a lupus anticoagulant (LA). Seven activated partial thromboplastin time (APTT) reagents were used for platelet neutralization procedure (PNP) testing with ARACHnase: Automated APTT (Organon-Teknika, Durham, NC); Thrombofax and Thrombosil (Ortho, Raritan, NJ); Actin and Actin FSL (Dade, Aguado, PR); and Thromboscreen-Kontact and Thromboscreen-APTT LS (Pacific-Hemostasis, Ventura, CA). ARACHnase consistently displayed a positive PNP result of greater than 5 seconds correction of the initial baseline APTT. Thus, ARACHnase may provide a positive control for LA testing, regardless of the choice of APTT reagent and activator/phospholipid combination.
 ...
PMID:ARACHnase. An evaluation of a positive control for platelet neutralization procedure testing with seven commercial activated partial thromboplastin time reagents. 824 97