Detection and Quantitative Evaluation of Lupus Circulating Anticoagulant Activity

1987 ◽  
Vol 57 (02) ◽  
pp. 144-147 ◽  
Author(s):  
Esther Rosner ◽  
Rachel Pauzner ◽  
Ayala Lusky ◽  
Michaela Modan ◽  
Amira Many
Keyword(s):  
Quantitative Evaluation ◽  
Anticoagulant Activity ◽  
Clotting Time ◽  
False Negatives ◽  
Coagulation Tests ◽  
Recurrent Abortions ◽  
Tissue Thromboplastin ◽  
Kaolin Clotting Time ◽  
Recalcification Time ◽  
Numerical Index

SummarySixty-six SLE patients were studied for the presence of lupus type circulating anticoagulant. Forty-nine percent of them showed activity of this anticoagulant. The sensitivity of various coagulation tests was compared. Recalcification time was found to be the most sensitive screening test and the kaolin clotting time mixture test, the best for determining the presence of the anticoagulant.Tissue thromboplastin inhibition test detected only half of the patients in whom the anticoagulant was found by recalcification time and kaolin clotting time mixture test.APTT, using 2 different reagents, resulted in 73% and 52% false negatives. A numerical index for determining the presence of the anticoagulant and its quantitative evaluation is suggested.The association between thromboembolic events, recurrent abortions and the different coagulation tests is shown.

dRVVT Is more Sensitive than KCT or TTI for Detecting Lupus Anticoagulant Activity of Anti-β2-glycoprotein I Autoantibodies

1999 ◽  
Vol 81 (02) ◽  
pp. 256-258 ◽  
Author(s):  
A. Biasiolo ◽  
P. Rampazzo ◽  
T. Brocco ◽  
V. Pengo
Keyword(s):  
Lupus Anticoagulant ◽  
Anticoagulant Activity ◽  
Test System ◽  
Clotting Time ◽  
Lupus Anticoagulants ◽  
Glycoprotein I ◽  
Tissue Thromboplastin ◽  
The Mean ◽  
Kaolin Clotting Time ◽  
Antibody Preparations

SummaryAnti-β2-glycoprotein I (β2-GPI) antibodies behave as classical Lupus Anticoagulants (LA), as they inhibit phospholipid-dependent coagulation reactions and their activity disappears in the presence of excess exogenous phospholipids (PLs). We have recently shown that a certain amount of PLs in the dilute Russell Viper Venom Time (dRVVT) test system is required to express LA activity of anti β2-GPI antibodies. We have now extended this observation to two other tests, i.e., Kaolin Clotting Time (KCT) in which PLs are not added, and Tissue Thromboplastin Inhibition test (TTI) in which PLs are extremely diluted. In fact, affinity-purified antibody preparations from 5 patients with antiphospholipid syndrome did not express or only weakly expressed anticoagulant activity in both tests; the mean ratios of coagulation times obtained with purified antibodies and that of control buffer were 1.11 and 1.0 for KCT and TTI, respectively. On the contrary, the mean ratios in dRVVT were 1.31 and 1.49 at a PLs dilution of 1:8 and 1:64, respectively. Therefore, the presence of LA activity due to autoantibodies to β2-GPI is characterized by a positive dRVVT and negative or only weakly positive KCT and TTI.

Detection of Lupus-Like Anticoagulants by an Enzyme-Linked Immunosorbent Assay Using a Partial Thromboplastin as Antigen; A Comparative Study

1990 ◽  
Vol 64 (01) ◽  
pp. 026-031 ◽  
Author(s):  
J Arnout ◽  
E Huybrechts ◽  
M Vanrusselt ◽  
C Falcon ◽  
J Vermylen
Keyword(s):  
Antiphospholipid Antibodies ◽  
Lupus Anticoagulant ◽  
Activated Partial Thromboplastin Time ◽  
The Other ◽  
Quantitative Detection ◽  
Enzyme Linked Immunosorbent Assay ◽  
Clotting Time ◽  
Coagulation Tests ◽  
Tissue Thromboplastin ◽  
Kaolin Clotting Time

SummaryClotting assays allow qualitative rather than quantitative detection of the lupus anticoagulant. We have therefore studied the usefulness of an ELISA using a commercial partial thromboplastin, Thrombofax, oS antigen; the results obtained on 146 selected patient plasmas were compared to the results of coagulation tests (kaolin clotting time, tissue thromboplastin inhibition test, activated partial thromboplastin time) and of ELISAs using cardiolipin or phosphatidylserine as antigen. While satisfactory agreement was found within the group of coagulation tests or that of ELISAs, only a moderate agreement was obtained between clotting tests and ELISAs, the best being with the partial thromboplastin ELISA using low plasma dilutions. The study further indicates that ELISA techniques cannot entirely replace coagulation tests for the detection of a lupus anticoagulant, even when a partial thromboplastin is used as antigen. On the other hand, coagulation tests are less sensitive than ELISAs for the detection of antiphospholipid antibodies.

Relative Sensitivity of Different Tests in the Detection of Low Titer Lupus Anticoagulants

1988 ◽  
Vol 60 (02) ◽  
pp. 217-219 ◽  
Author(s):  
B Lesperance ◽  
M David ◽  
J Rauch ◽  
C Infante-Rivard ◽  
G E Rivard
Keyword(s):  
Relative Sensitivity ◽  
Fetal Outcome ◽  
Anticardiolipin Antibodies ◽  
Lupus Anticoagulants ◽  
Normal Plasma ◽  
Coagulation Tests ◽  
High Dilutions ◽  
Tissue Thromboplastin ◽  
High Concentrations ◽  
Kaolin Clotting Time

SummaryLupus anticoagulants (LA) and anticardiolipin antibodies have been strongly associated with recurrent abortion and fetal death. Because steroids have been reported to improve the fetal outcome of LA associated pregnancies, presumably by decreasing the levels of LA, it becomes desirable to have a simple and reliable test to monitor the levels of the putative antibody. To this effect, we assessed the capacity of the following coagulation tests to detect the presence of LA in serial dilutions of patient plasma with pooled normal plasma: kaolin clotting time (KCT), tissue thromboplastin inhibition test (TTIT), dilute Russell Viper venom time (DRVVT) and activated partial thromboplastin time with standard and high concentrations of phospholipids (SC and HCAPTT). All samples were also evaluated for the presence of anticardiolipin antibodies with an ELISA. The KCT was able to detect LA at a much greater dilution in normal plasma than any of the other clotting assays. The ELISA was comparable to KCT in its ability to detect high dilutions of LA.

Scientific and Standardization Committee Communications Comparison of Test Methods for the Lupus Anticoagulant: International Survey on Lupus Anticoagulants-I (ISLA-1)

1990 ◽  
Vol 64 (03) ◽  
pp. 478-484 ◽  
Author(s):  
Thomas Exner ◽  
Douglas A Triplett ◽  
David A Taberner ◽  
Margaret A Howard ◽  
E Nigel Harris
Keyword(s):  
Lupus Anticoagulant ◽  
Test Methods ◽  
Positive Sample ◽  
Direct Proportion ◽  
Clotting Time ◽  
Preliminary Screening ◽  
Activated Platelets ◽  
Tissue Thromboplastin ◽  
Kaolin Clotting Time ◽  
Induced Defects

SummarySix lyophilized plasma samples were sent to 20 “expert” laboratories for assessment of lupus anticoagulant (LA). Four samples contained pooled LA of graded potency mixed with aged normal plasma. One contained LA plus cephalin phospholipid and one contained a nonspecific venom anticoagulant. Sixteen methods were used overall with some participants using up to 8 methods. Results were scored in regard to the known potencies of LA in the samples and other known induced defects.Activated partial thromboplastin time (APTT) tests used by most participants for preliminary screening were relatively sensitive, but non-specific. Platelet or phospholipid neutralization procedures (PNP) appeared to be sensitive and specific but showed a non-linear response to increased LA content. Kaolin clotting time (KCT) tests showed the most sensitive response to increased LA content but the weaker LA were not scored as abnormal by most laboratories as the samples may have contained platelet fragments. Other commonly used tests such as the tissue thromboplastin inhibition (TTI) test and the dilute Russell’s viper venom test (DRVVT) were carried out somewhat inconsistently. The variability in performance of tests in different laboratories indicates that standardization of methodology is urgently required.Generally it seemed that most clotting tests were “bypassed” by the addition of phospholipid to a known LA-positive sample in apparently direct proportion to their sensitivity. Sample preparation, especially prevention of contamination with activated platelets is a vital preliminary part in the assay of LA.

COMPARISION OF THE DETECTION OF LUPUS ANTICOAGULANTS USING THREE DIFFERENT METHODS AND THE PRESENCE OF ANTI-CARDIOLIPIN ANTIBODIES

1987 ◽  
Author(s):  
A Criel ◽  
B Gilbert ◽  
A Van Hoof ◽  
M Hidajat ◽  
A Louwagie
Keyword(s):  
Elisa Test ◽  
Activated Partial Thromboplastin Time ◽  
Detection Methods ◽  
Recurrent Abortion ◽  
Clotting Time ◽  
Lupus Anticoagulants ◽  
Cardiolipin Antibodies ◽  
Tissue Thromboplastin ◽  
Kaolin Clotting Time

Lupus anticoagulant (LAC) is an antibody directed against phospholipids which prolongs in vitro clotting assays. Several detection methods have been described; however all give some different results. Recently ELISA and RIA assays have been developed which detect IgG and IgM anti-cardiolipin antibodies. The aim of our study was to compare three different LAC tests with an ELISA anti-cardiolipin test. The tests used were : kaolin clotting time (KCT or Exnertest), tissue thromboplastin inhibition test (TTI or Schleider test), activated partial thromboplastin time using a 50, 100, 200 fold dilution of the phospholipid preparation (APTT dilution test), and an IgG and IgM anti-cardiolipin ELISA test. 114 samples of patients suffering from diseases known to be accompanied with LAC antibodies (auto-immune diseases, recurrent abortion, thromboembolism, etc.) were studied. Positivity with one of the tests was found in 45 patients (39%). Patients with the diagnosis of SLE or otherimmune diseases showed the highest positivity (56%) whereas those with thromboembolism, recurrent abortion etc. were only positive in 27%.Among these 45 positive patients the TTI was positive in 41 cases (91 %);however in 10 cases (24 %) this was the only positivity found. The KCT test and the APTT dilution test were both positive in 18 cases (40 %). Anti-cardiolipin antibodies were found in 21 patients (47 %): IgG only in 12 (27 %), IgM only in 5 (11 %), both IgG and IgM in 2 (4 %); in 19 of these 21 patientsthe TTI was also positive.In our study the TTI test seems to be the most sensitive test but possibly also the test with the highest aspecific positivities. IgG and IgM anti-cardiolipin antibodies were less frequently found than expected.

Prothrombin as cofactor for antiphospholipids

Lupus ◽  
1998 ◽  
Vol 7 (2_suppl) ◽  
pp. 37-40 ◽  
Author(s):  
M Galli ◽  
T Barbui
Keyword(s):  
Clinical Relevance ◽  
Antiphospholipid Antibodies ◽  
Lupus Anticoagulant ◽  
Anticoagulant Activity ◽  
Low Risk ◽  
Immune Recognition ◽  
Clotting Time ◽  
Glycoprotein I ◽  
Russell’S Viper ◽  
Kaolin Clotting Time

Prothrombin is a common antigenic target of antiphospholipid antibodies, since anti-prothrombin antibodies are detected in about 50-90% of the patients. To allow proper immune recognition, prothrombin must be adsorbed on suitable anionic surfaces. The epitope(s) have not yet been identified: the majority of anti-prothrombin antibodies appear to be of poly- or oligoclonal nature. Anti-prothrombin antibodies, either alone or in combination with anti-β2-glycoprotein I antibodies, are responsible for the lupus anticoagulant activity of about 75% of the cases of phospholipid-dependent inhibitors of coagulation. The two antibodies may be discriminated by means of specific coagulation profiles generated by the comparison of the ratio of the Kaolin Clotting Time (KCT) and the dilute Russell's Viper Venom Time (dRVVT): the KCT profile, which mainly reflects the presence of anti-prothrombin antibodies and the dRVVT profile, which is mostly associated with anti-β2-glycoprotein I antibodies. This distinction, although somewhat artificial, may be clinically useful, since the KCT profile identifies patients at low risk to develop thrombosis. Similarly, most of the studies that measured anti-prothrombin antibodies by ELISA failed to find a significant association with thrombosis. In conclusion, the clinical relevance of these antibodies has not yet been established.

Automatic Recording of Prothrombin Times and Other Coagulation Tests in Multiple Samples

1966 ◽  
Vol 16 (01/02) ◽  
pp. 311-317
Author(s):  
J Margolis ◽  
J. S Jackson
Keyword(s):  
Prothrombin Time ◽  
Automatic Recording ◽  
Clotting Time ◽  
Coagulation Tests ◽  
Instrumental Recording ◽  
Kaolin Clotting Time ◽  
Transparent Windows ◽  
Multiple Samples

SummarySimultaneous coagulation tests on multiple samples are performed in parallel compartments of metal trays mounted on a heated rocking platform. Transparent windows and underlaying photo-resistive cells may be incorporated into the apparatus for instrumental recording of the results. The use of the system for the measurement of prothrombin time and kaolin clotting time is described.

Activation of Hageman Factor in Rat Anaphylaxis

1975 ◽  
Author(s):  
L. Fésüs ◽  
L. Muszbek
Keyword(s):  
Blood Clotting ◽  
Plasminogen Activators ◽  
Factor Xii ◽  
Clotting Time ◽  
Hageman Factor ◽  
Kaolin Clotting Time ◽  
Aggregation Of Platelets ◽  
Recalcification Time

At various intervals after antigen injection assays concerning haemostatic parameters were carried out in anaphylactic shock of rats pretreated with Bordetella Pertussis Vaccine. These were as follows: measurement of whole blood clotting time, recalcification time, partial thromboplastin time, kaolin clotting time in siliconised tubes, determination of the level of factor XII, measurement of plasminogen activator level, in vitro aggregation of platelets. The different clotting times shortened and the aggregation of platelets was inhibited within the first three-four minutes. The clotting times lengthened, the level of plasminogen activators increased, the level of factor XII decreased during the further minutes. These results and their comparison with that of produced by ellagic acid injection suggest that during anaphylaxis of rats the activation of Hageman factor takes place, which is followed by its partial consumption.

Partial Characterization Of An Igm Ciroiating Anticqagu- Lant In A Patient With Systemic Scleroderma

1981 ◽  
Author(s):  
J Hauert ◽  
A von Felten
Keyword(s):  
Anticoagulant Activity ◽  
Time Factors ◽  
Human Platelets ◽  
Systemic Scleroderma ◽  
Fibrinogen Concentration ◽  
Spontaneous Bleeding ◽  
Coagulation Tests ◽  
Bleeding Manifestation ◽  
Tissue Thromboplastin ◽  
Partial Neutralization

All coagulation tests, utilizing phospholipids, were found to be prolonged in the plasma of a 71 year old wcman with systemic scleroderma. Hie patient had no spontaneous bleeding manifestations and underwent eye surgery for cataract without complications. Thrcmbin time and fibrinogen concentration were normal. Coagulation tests, performed with partial thromboplastin (APTT, factors VIII-XII), were more prolonged than those done with regular tissue thromboplastin (one-stage prothrombin time, factors II, V, VII, X). The addition of 1 part of the patient’s plasma (PP) to 99 parts of normal plasma (NP) resulted in a prolongation of the APTT from 34" to 49". No decrease of the anticoagulant activity (AA) was observed when freshly prepared intact platelets were incubated with the PP. However, incubation of PP with platelets, which had been 5 × frozen and thawed or incubated for 90 min in the presence of kaolin, partially neutralized AA.When the patient’s serum was fractionated on Bio-Gel A-5m, all the inhibitory activity was found in the IgM peak. The AA of the purified IgM fraction was quenched after incubation with an anti-IgM antiserum, but not with anti-IgA or anti-IgG. Incubation of the IgM fraction with stored washed human platelets also led to partial neutralization of the AA. The patient’s IgM adsorbed to lysophosphatidylserine, which had been coupled to octyl-Sepharose, but did not fix complement when incubated with phospholipid micelles consisting of phosphatidylserine-phosphatidylcholine (1:1) and cholesterol in excess.The absence of any bleeding manifestation in this patient; despite the presence of an extremely potent inhibitor against phospholipids, may be explained by the nonreactivity of the IgM inhibitor with fresh intact platelets.

The Significance of TFPI in Clotting Assays – Gomparison and Combination with other Anticoagulants

1993 ◽  
Vol 70 (03) ◽  
pp. 448-453 ◽  
Author(s):  
Ole Nordfang ◽  
Hanne I Kristensen ◽  
Sanne Valentin ◽  
Per Østergaard ◽  
Johnny Wadt
Keyword(s):  
Tissue Factor ◽  
Tissue Factor Pathway Inhibitor ◽  
Antithrombin Iii ◽  
Anticoagulant Activity ◽  
Assay System ◽  
Thrombin Inhibitor ◽  
Clotting Time ◽  
Normal Plasma ◽  
Tissue Factor Pathway ◽  
Plasma Heparin

SummaryThe anticoagulant activities of Tissue Factor Pathway Inhibitor (TFPI), heparin and hirudin were compared in intrinsic (APTT) and extrinsic (PT) activated clotting assays. In contrast to the thrombin inhibitor hirudin, heparin was 10 fold more potent in the APTT assay than in the PT assay, indicating that inhibition of intrinsic activation is important for the anticoagulant activity of heparin as measured in an APTT assay. TFPI was most potent in the PT assay and the effect of TFPI was most pronounced in the presence of other anticoagulants (heparin and hirudin). The activities of the two natural anticoagulants antithrombin III (ATIII) and TFPI were compared in a PT assay with very dilute tissue factor. In this assay system TFPI in normal plasma affected the clotting time more than ATIII in the plasma. However, when heparin was added ATIII was the major anticoagulant, but profound Prolongation of the clotting time was only seen when TFPI was also added. In an ATIII deficient plasma heparin did not augment the effect of TFPI, showing that the increased effect of TFPI in the presence of heparin is dependent on the anticoagulant activity of ATIII/heparin. The effect of TFPI at prolonged clotting times was also illustrated by the significant effect of blocking TFPI in the plasma from warfarin-treated patients. Thus TFPI is a major anticoagulant in normal plasma and the effect of TFPI is especially seen at prolonged clotting times.

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