Comparison of aPTT (Platelin LS®) and Dilute Russell’s Viper Venom (Viperquik LA Test®) for the Screening of Lupus Anticoagulant in Patients with Venous Thromboembolism.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 4122-4122
Author(s):  
Celso A. Roprigues ◽  
Aline A. Martinez ◽  
Vania M. Morelli ◽  
Raniely C. Silveira ◽  
Maria Aparecida E. Noguti ◽  
...  
Keyword(s):  
Venous Thromboembolism ◽  
Partial Thromboplastin Time ◽  
Lupus Anticoagulant ◽  
Activated Partial Thromboplastin Time ◽  
Screening Tests ◽  
Clotting Time ◽  
Substantial Agreement ◽  
Confirmatory Tests ◽  
Russell’S Viper ◽  
Rule Out

Abstract INTRODUCTION: To rule out the presence of LA antibodies, two or more assays that are sensitive to these antibodies must be negative. The dilute Russell’s Viper Venom Time (dRVVT) and the activated partial thromboplastin time (aPTT) using sensitive reagents have been employed to detect LA. The aim of this study was to assess the concordance level of aPTT using Platelin LS and dRVVT as screening tests to identify LA in patients with venous thromboembolism (VTE). METHODS: 94 patients (58 women, 62%) with VTE were evaluated. The detection of circulating inhibitor with Platelin LS and dRVVT was based on a prolonged clotting time and a prolonged 1:1 mixture of sample plasma and normal pooled plasma. The confirmation of the phospholipid dependency was performed only with dRVVT. RESULTS: Among the 94 patients, an abnormal test was found in 24 patients (26%) with aPTT and in 61 patients (65%) using dRVVT. After mixing tests, aPTT ratio remained long in 25% of patients with abnormal aPTT, and in 9.8% with long dRVVT. Five patients had a prolonged mixing study identified by both tests, which resulted in a substantial agreement between the two tests (Kappa= 0.78). Confirmatory tests for LA were positive in 5 out of the 6 patients with long dRVVT mixture, resulting in a prevalence of LA detected by dRVVT of 5.3%. The 5 patients with LA detected by dRVVT also had prolonged mixture with aPTT. CONCLUSION: Our results indicate that aPTT with Platelin LS is highly associated with the presence of LA detected by dRVVT and may be suitable as a screening test for LA in patients with VTE.

The Activated Seven Lupus Anticoagulant Assay Detects Clinically Significant Antibodies

2008 ◽  
Vol 14 (3) ◽  
pp. 332-337 ◽  
Author(s):  
Gary W. Moore ◽  
Savita Rangarajan ◽  
Geoffrey F. Savidge
Keyword(s):  
Systemic Lupus Erythematosus ◽  
Lupus Erythematosus ◽  
Partial Thromboplastin Time ◽  
Lupus Anticoagulant ◽  
Anticardiolipin Antibodies ◽  
Activated Partial Thromboplastin Time ◽  
Systemic Lupus ◽  
Lupus Anticoagulants ◽  
Russell’S Viper ◽  
Clinically Significant

Lupus anticoagulants are a heterogeneous group of autoantibodies detected by their effects on phospholipid-dependent coagulation assays. Persistent lupus anticoagulants are associated with thrombotic disease, but not all are clinically significant. Antibody heterogeneity and reagent and test variability dictate that at least 2 tests, of different types, should be used to screen lupus anticoagulants. The objective of this study was to investigate whether the activated seven lupus anticoagulant assay detects clinically significant antibodies. Eighty-two patients with antiphospholipid syndrome (APS) and 32 with systemic lupus erythematosus + positive for activated seven lupus anticoagulant and who were without thrombosis, who were positive by activated seven lupus anticoagulant assay, were investigated for lupus anticoagulants by dilute Russell's viper venom time, dilute activated partial thromboplastin time, and Taipan snake venom time, and for anticardiolipin antibodies. Fifty-seven of the APS patients were positive for lupus anticoagulants in multiple assays, 25 in activated seven lupus anticoagulant alone. Fourteen of the latter group were previously positive in other antiphospholipid antibodies assays, and 11 had only been positive for lupus anticoagulants by activated seven lupus anticoagulant. Twenty-eight had elevated anticardiolipin antibodies, 6 of whom were from the group that was positive in activated seven lupus anticoagulant only. Eight of the systemic lupus erythematosus + lupus anticoagulants (without thrombosis) patients were positive for lupus anticoagulant by activated seven lupus anticoagulant alone and had only been positive in activated seven lupus anticoagulant previously, and none had elevated anticardiolipin antibodies. The remaining 24 patients were lupus-anticoagulant positive in multiple assays, and 9 had elevated anticardiolipin antibodies. Dilute Russell's viper venom time and Dilute activated partial thromboplastin time are widely used to detect lupus anticoagulants and are considered to detect clinically significant antibodies. Activated seven lupus anticoagulant detected antibodies in APS patients who were positive by these assays and also lupus anticoagulants undetectable by the dilute Russell's viper venom time/dilute activated partial thromboplastin time reagents used, demonstrating its utility as a first-line or second-line assay.

scholarly journals Correlation between activated partial thromboplastin time and diluted Russell’s viper venom time in the presence of lupus anticoagulant

2021 ◽  
Vol 23 (1) ◽  
Author(s):  
Luz Tarín-Arzaga ◽  
Carlos de la Cruz-de la Cruz ◽  
Martha A. Reyes-López ◽  
Omar Cantu-Martinez ◽  
Karina Vázquez-Hernández ◽  
...  
Keyword(s):  
Partial Thromboplastin Time ◽  
Lupus Anticoagulant ◽  
Activated Partial Thromboplastin Time ◽  
Russell’S Viper

The effect of DOAC-Stop on lupus anticoagulant testing in plasma samples of venous thromboembolism patients receiving direct oral anticoagulants

2019 ◽  
Vol 57 (9) ◽  
pp. 1374-1381 ◽  
Author(s):  
Michał Ząbczyk ◽  
Magdalena Kopytek ◽  
Joanna Natorska ◽  
Anetta Undas
Keyword(s):  
Venous Thromboembolism ◽  
Screening Test ◽  
Lupus Anticoagulant ◽  
Oral Anticoagulants ◽  
Direct Oral Anticoagulants ◽  
Activated Partial Thromboplastin Time ◽  
Clotting Time ◽  
The Impact ◽  
Anticoagulated Patients

Abstract Background Direct oral anticoagulants (DOACs) cause false positive lupus anticoagulant (LA) results. We assessed the impact of DOAC-Stop, reversing in vitro effects of DOACs, on LA testing in anticoagulated patients. Methods We assessed 75 venous thromboembolism patients aged 44.5±14.6 years. Blood samples were collected 2–28 h since intake of DOACs, including 50 patients on rivaroxaban, 20 on dabigatran and five on apixaban. LA testing was performed at baseline and after DOAC-Stop treatment. Positive LA was defined as the normalized (patient/standard plasma clotting time) LA screening and screening (LA1)/confirmation (LA2) ratios exceeding 1.2. Results LA diluted Russell’s viper venom time (dRVVT) normalized screening test revealed abnormal results in 73 (97.3%) and activated partial thromboplastin time (APTT)-LA in 49 (65.3%) patients. In six (8%) patients, antiphospholipid syndrome (APS) was diagnosed. dRVVT LA1/LA2 was abnormal in 35 (50.7%) patients taking DOACs. The APTT ratio was normal in all studied subjects. DOAC-Stop completely removed dabigatran and reduced by 98% rivaroxaban and by 92.3% apixaban concentrations (all p<0.05). After DOAC-Stop screening dRVVT remained prolonged in 34 (49.3%) patients (p<0.001), while dRVVT LA1/LA2 was abnormal in six (8.7%) subjects, with no association with DOAC concentrations at baseline and after DOAC-Stop. The APTT-LA screening test remained prolonged in five (7.2%) patients, while the APTT LA1/LA2 ratio was normal in those subjects. DOAC-Stop did not influence LA testing in APS patients. Conclusions Application of DOAC-Stop effectively reduced plasma DOAC concentrations leading to appropriate dRVVT results in up to 97% of VTE patients.

Clinical safety and cost of heparin titration using bedside activated clotting time

1993 ◽  
Vol 2 (1) ◽  
pp. 81-87 ◽  
Author(s):  
T Thomason ◽  
B Riegel ◽  
D Jessen ◽  
Smith SCJr ◽  
I Gocka ◽  
...  
Keyword(s):  
Partial Thromboplastin Time ◽  
Percutaneous Transluminal Coronary Angioplasty ◽  
Heparin Therapy ◽  
Activated Partial Thromboplastin Time ◽  
Clotting Time ◽  
Clinical Safety ◽  
Activated Clotting Time ◽  
Intravenous Heparin ◽  
Transluminal Coronary Angioplasty ◽  
Percutaneous Transluminal

OBJECTIVE: To evaluate the clinical safety of heparin titration and the procedural cost of anticoagulation measurement using bedside low-range activated clotting time. DESIGN: Quasi-experimental study using data gathered through retrospective record review. SETTING: Coronary care, medical intensive care and telemetry units of a community hospital. SUBJECTS: Sample of 102 patients undergoing elective percutaneous transluminal coronary angioplasty. INTERVENTION: Intravenous heparin therapy was titrated using low-range activated clotting time in 51 percutaneous transluminal coronary angioplasty patients. Data from this group were compared to a matched sample of 51 angioplasty patients whose intravenous heparin therapy was titrated using activated partial thromboplastin time. RESULTS: No differences in procedural, early or late complications were found between the groups. The cost of managing heparin therapy with low-range activated clotting time was less than with activated partial thromboplastin time. CONCLUSION: These results suggest that titrating heparin therapy based on bedside low-range activated clotting time for the angioplasty patients in this sample was as safe as with activated partial thromboplastin time. Use of bedside low-range activated clotting time saved money for the hospital.

How to Optimize Activated Partial Thromboplastin Time (APTT) Testing: Solutions to Establishing and Verifying Normal Reference Intervals and Assessing APTT Reagents for Sensitivity to Heparin, Lupus Anticoagulant, and Clotting Factors

2019 ◽  
Vol 45 (01) ◽  
pp. 022-035 ◽  
Author(s):  
Geoffrey Kershaw ◽  
Soma Mohammed ◽  
Giuseppe Lippi ◽  
Emmanuel Favaloro
Keyword(s):  
Molecular Weight ◽  
Partial Thromboplastin Time ◽  
Lupus Anticoagulant ◽  
High Sensitivity ◽  
Activated Partial Thromboplastin Time ◽  
Factor Xii ◽  
Reference Ranges ◽  
Clotting Factors ◽  
Hospital System ◽  
Normal Reference

AbstractThe activated partial thromboplastin time (APTT) assay is a very common coagulation test, used for several reasons. The test is conventionally used for assessing the contact factor (intrinsic) pathway of blood coagulation, and thus for screening deficiencies in this pathway, most typically factors VIII, IX, and XI. The APTT is also sensitive to contact factor deficiencies, including factor XII, prekallikrein, and high-molecular-weight kininogen. The APTT may also be elevated in a variety of conditions, including liver disease, vitamin K deficiency, and disseminated intravascular coagulation. The APTT can also be used for monitoring unfractionated heparin (UFH) therapy, as well as for screening lupus anticoagulant (LA) or for assessing thrombosis risk. Which of these separate uses is important to a given laboratory or clinician depends on the laboratory and the clinical context. For example, UFH sensitivity is important in hospital-based laboratories, where UFH therapy is used, but not in hospital-based laboratories where low-molecular-weight heparin (LMWH) is largely employed or where UFH may be assessed by anti-factor Xa testing, or in private/community laboratories not associated with a hospital system. High sensitivity to (low levels of) factors VIII, IX, and XI is generally preferred, as their deficiencies are clinically significant. Also preferred, but not usually achieved, is low sensitivity to factor XII and other contact factors, as these deficiencies are usually asymptomatic. Nevertheless, a good knowledge of factor sensitivity is usually needed, if only to help explain the reasons for a prolonged APTT in a given patient, or whether factor testing or other investigation is required. A good working knowledge of reagents sensitivity to LA is also advisable, especially when the reagent is used as part of a LA test panel, or else as a “general-purpose screening reagent.” The current report is aimed at providing some guidance around these questions, and is intended as a kind of “how to” guide, that will enable laboratories to assess APTT reagents in regard to their sensitivity to heparin, LA, and clotting factors. The report also provides some advice on generation of normal reference ranges, as well as solutions for troubleshooting prolonged APTTs, when performing factor testing or searching for inhibitors.

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