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

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.

1999 ◽  
Vol 81 (02) ◽  
pp. 256-258 ◽  
Author(s):  
A. Biasiolo ◽  
P. Rampazzo ◽  
T. Brocco ◽  
V. Pengo

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.


1987 ◽  
Author(s):  
A Criel ◽  
B Gilbert ◽  
A Van Hoof ◽  
M Hidajat ◽  
A Louwagie

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.


Blood ◽  
2003 ◽  
Vol 101 (5) ◽  
pp. 1827-1832 ◽  
Author(s):  
Monica Galli ◽  
Davide Luciani ◽  
Guido Bertolini ◽  
Tiziano Barbui

To formally establish the risk of lupus anticoagulants and anticardiolipin antibodies for arterial and venous thrombosis, we ran a MEDLINE search of the literature from 1988 to 2000. Studies were selected for their case-control (11), prospective (9), cross-sectional (3), and ambispective (2) design. They provided or enabled us to calculate the odds ratio with 95% confidence interval (CI) of lupus anticoagulants and/or anticardiolipin antibodies for thrombosis in 4184 patients and 3151 controls. Studies were grouped according to the antibody investigated. Five studies compared lupus anticoagulants with anticardiolipin antibodies: the odds ratio with 95% CI of lupus anticoagulants for thrombosis was always significant. None of them found anticardiolipin antibodies were associated with thrombosis. Four studies analyzed only lupus anticoagulants: the odds ratio with 95% CI was always significant. The risk of lupus anticoagulants was independent of the site and type of thrombosis, the presence of systemic lupus erythematosus, and the coagulation tests employed to detect them. Sixteen studies served to assess 28 associations between anticardiolipin antibodies and thrombosis: the odds ratio with 95% CI was significant in 15 cases. Anticardiolipin titer correlated with the odds ratio of thrombosis. In conclusion, the detection of lupus anticoagulants and, possibly, of immunoglobulin G (IgG) anticardiolipin antibodies at medium or high titers helps to identify patients at risk for thrombosis. However, to take full advantage of the conclusions provided by the available evidence, there is an urgent need to harmonize investigational methods.


1987 ◽  
Vol 57 (02) ◽  
pp. 144-147 ◽  
Author(s):  
Esther Rosner ◽  
Rachel Pauzner ◽  
Ayala Lusky ◽  
Michaela Modan ◽  
Amira Many

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.


Blood ◽  
1986 ◽  
Vol 68 (2) ◽  
pp. 472-478 ◽  
Author(s):  
MH Rosove ◽  
M Ismail ◽  
BJ Koziol ◽  
A Runge ◽  
CK Kasper

Abstract We utilized a kaolin-activated partial thromboplastin time (APTT) using rabbit brain phospholipid, in which the capacity of a fourfold increased “high” phospholipid concentration (PC) to normalize the abnormal “standard” PC-APTT in patients with lupus anticoagulants is assessed. This system was also used to measure factors VIIIC, IX, and XI. The tissue thromboplastin inhibition test (TTI), a prothrombin time system in which the activity of a lupus anticoagulant is unmasked by the use of dilute thromboplastin, was simultaneously evaluated. Test sensitivity was defined by results on 31 consecutive patients with standard PC-APTT inhibitors and no bleeding tendency. Specificity was based on 94 patients with various other coagulopathies, including coagulation factor inhibitors, severe congenital factor deficiencies, hepatic insufficiency, and warfarin and heparin treatment. Twenty-one patients with lupus erythematosus and standard PC-APTT results within normal limits were also tested. Sensitivity of the APTT system was superior to that of the TTI (97% v 58%); high PC normalized clotting time ratios and factor levels. Positive results were common with both assays in the group of 20 heparinized patients. The APTT system had superior specificity in remaining cases; there were no positive tests among 74 patients. The lupus erythematosus group had a significant decrease in the clotting time ratio with high PC, indicating that low- level lupus anticoagulants are quite prevalent in this group. The kaolin clotting time using rabbit brain phospholipid in standard and high concentrations is a simple, sensitive, and specific technique for diagnosis of lupus anticoagulants.


1990 ◽  
Vol 64 (01) ◽  
pp. 026-031 ◽  
Author(s):  
J Arnout ◽  
E Huybrechts ◽  
M Vanrusselt ◽  
C Falcon ◽  
J Vermylen

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.


1994 ◽  
Vol 72 (05) ◽  
pp. 728-733 ◽  
Author(s):  
Ricardo R Forastiero ◽  
Graciela S Cerrato ◽  
Luis O Carreras

SummaryIt is known that lupus anticoagulants (LA) are antibodies which interfere with phospholipid-dependent coagulation tests, but due to the heterogeneity of LA and the differences in sensitivity of reagents and tests, the diagnosis of LA remains difficult.Recently, Triplett et al. (26) have proposed a new test based on two venoms, Textarin (T) and Ecarin (E), that activate prothrombin but differ in their phospholipid requirements. By testing this new assay we have evaluated 36 patient plasmas containing LA according to standard tests (activated partial thromboplastin time, dilute Russell viper venom time and platelet neutralization procedure) and our results confirm a high sensitivity for LA of the T/E test.In addition, we observed a greater sensitivity of the tissue thromboplastin inhibition test using a recombinant thromboplastin instead of a human placenta thromboplastin.Our study also showed that the T/E test seems to be a useful assay in confirming the diagnosis of LA in patients with an unexplained prolonged APTT.


Blood ◽  
1986 ◽  
Vol 68 (2) ◽  
pp. 472-478
Author(s):  
MH Rosove ◽  
M Ismail ◽  
BJ Koziol ◽  
A Runge ◽  
CK Kasper

We utilized a kaolin-activated partial thromboplastin time (APTT) using rabbit brain phospholipid, in which the capacity of a fourfold increased “high” phospholipid concentration (PC) to normalize the abnormal “standard” PC-APTT in patients with lupus anticoagulants is assessed. This system was also used to measure factors VIIIC, IX, and XI. The tissue thromboplastin inhibition test (TTI), a prothrombin time system in which the activity of a lupus anticoagulant is unmasked by the use of dilute thromboplastin, was simultaneously evaluated. Test sensitivity was defined by results on 31 consecutive patients with standard PC-APTT inhibitors and no bleeding tendency. Specificity was based on 94 patients with various other coagulopathies, including coagulation factor inhibitors, severe congenital factor deficiencies, hepatic insufficiency, and warfarin and heparin treatment. Twenty-one patients with lupus erythematosus and standard PC-APTT results within normal limits were also tested. Sensitivity of the APTT system was superior to that of the TTI (97% v 58%); high PC normalized clotting time ratios and factor levels. Positive results were common with both assays in the group of 20 heparinized patients. The APTT system had superior specificity in remaining cases; there were no positive tests among 74 patients. The lupus erythematosus group had a significant decrease in the clotting time ratio with high PC, indicating that low- level lupus anticoagulants are quite prevalent in this group. The kaolin clotting time using rabbit brain phospholipid in standard and high concentrations is a simple, sensitive, and specific technique for diagnosis of lupus anticoagulants.


2000 ◽  
Vol 84 (12) ◽  
pp. 1012-1016 ◽  
Author(s):  
Jeffrey Dlott ◽  
Francesca Norbis ◽  
Luisa Ruggeri ◽  
Linda Cler ◽  
Douglas Triplett ◽  
...  

SummaryThe dilute Russell’s viper venom time (dRVVT) and the kaolin clotting time (KCT) are two among the most commonly used coagulation tests for the detection of lupus anticoagulants. The dRVVT seems superior to the KCT in identifying LA-positive patients at risk of thrombosis. However, this relationship is greatly influenced by both the source of reagents and the instrumentation employed to carry out the assays. Therefore, 4 dRVVTs (“home-made” dRVVT, DVV test, Bioclot LA, LA Screen), and one KCT (Kaoclot) were performed in two centers and compared for their retrospective correlation with the thrombotic complications of 72 patients with a previously established diagnosis of lupus anticoagulants. Two other assays (“home-made” KCT, and Colloidal Silica Clotting Time, CSCT) were performed in one of the two centers, and compared with Kaoclot for their clinical correlations in the same population of patients, 44 of whom (61%) had suffered from arterial and/or venous thrombosis. A rather good degree of inter-laboratory and inter-assay correlations of the different tests was found. However, a statistically significant association with thrombosis was found only with the coagulation profile generated using the “homemade” dRVVT. When the commercially available dRVVTs were used, none of the coagulation profiles remained associated with thrombosis. When the assays were analyzed separately, the association with thrombosis was statistically significant for LA screen (p = 0.0019), DVV test (p = 0.0043), and Bioclot (p = 0.0255), and of borderline significance for the “home-made” dRVVT (p = 0.0503) in one center. This last assay was also significantly associated with thrombosis in the other center (p = 0.0139). When venous and arterial thrombosis were considered separately, DVV test was statistically associated with venous thrombosis in both centers (p = 0.0076 and p = 0.0187, respectively), and LA screen in one center (p = 0.0303). No dRVVT was found to correlate with arterial thrombosis. Kaoclot, Colloidal Silica Clotting Time, and the “home-made” KCT did not correlate with thrombosis. The prevalence of IgG and/or IgM antibodies to cardiolipin, β2-glycoprotein I and prothrombin were 74%, 86% and 85%, respectively. Increased titers of IgG anticardiolipin antibodies were associated with arterial thrombosis (p = 0.0375), whereas IgM anti-β2-glycoprotein I antibodies were associated with venous thrombosis (p = 0.0433). In conclusion, these retrospective data support the notion that the dRVVT, rather than other coagulation or ELISA tests, are able to identify lupus anticoagulant-positive patients at risk of thrombosis. This property appears common to several commercially available dRVVT kits, making this type of assay the ideal target of future efforts of laboratory standardization.


1990 ◽  
Vol 64 (03) ◽  
pp. 478-484 ◽  
Author(s):  
Thomas Exner ◽  
Douglas A Triplett ◽  
David A Taberner ◽  
Margaret A Howard ◽  
E Nigel Harris

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.


Sign in / Sign up

Export Citation Format

Share Document