A rapid screen for lupus anticoagulant with good discrimination from oral anticoagulants, congenital factor deficiency and heparin, is provided by comparing a sensitive and an insensitive APTT reagent

Brancaccio, Vincenzo; Ames, P. R. J.; Glynn, J.; Iannaccone, Luigi; Mackie, IJ

doi:10.1097/00001721-199704000-00001

Cited by 34 publications

(34 citation statements)

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“…The evidence so far accumulated would suggest that 1 of the 2 should be the dRVVT and the other may be based on the intrinsic pathway of coagulation (APTT, KCT, or SCT). If the choice is the APTT, it is important to adopt a sensitive reagent, although some authors contend that a combination of 2 APTTs, 1 sensitive and the other insensitive to LA, may give better detection capability (21,32 ). One positive test only may suffice to diagnose LA provided that its positivity is documented on 2 occasions 12 weeks apart (2 ).…”

Section: Choice Of Testsmentioning

confidence: 99%

Laboratory Testing for Lupus Anticoagulants: A Review of Issues Affecting Results

Tripodi

2007

Clinical Chemistry

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Background: Lupus anticoagulants (LA) are a heterogeneous class of immunoglobulins. Persistent LA positivity is a risk factor for the occurrence and recurrence of venous/arterial thromboembolism and/or pregnancy morbidity and qualifies the patient for anticoagulation therapy. The laboratory diagnosis for LA that is used for crucial decision-making about the optimal duration of the therapy rests entirely on diagnostic criteria. These criteria are based on the prolongation of phospholipiddependent tests not corrected upon mixing patient and normal plasmas, with confirmation provided by the evidence that the anticoagulant is directed against proteins bound to negatively charged phospholipids. Aims: This article reviews issues related to the diagnosis of LA, including the effect of preanalytical variables, choice of tests, results interpretation of screening, mixing and confirmation procedures, patients to be investigated, and transmission of results. Unresolved issues and future direction for research on laboratory diagnosis are also discussed. Methods: Search of PubMed with the key term "lupus anticoagulant" plus articles and unpublished data known to the author. Results and Conclusions: The preanalytical variables (i.e., plasma preparation and storage before analysis) as well as the diagnostic steps to detect LA present potential problems that undermine the process of making a correct diagnosis. A truly specific test for LA detection is badly needed, but its development may require understanding of the mechanisms associated with the occurrence of clinical events. Until then, clinical laboratories should rely on the existing procedures, which must be

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Section: Choice Of Testsmentioning

confidence: 99%

Laboratory Testing for Lupus Anticoagulants: A Review of Issues Affecting Results

Tripodi

2007

Clinical Chemistry

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“…In the flurry of the Friday afternoon when the acquired factor VIII inhibitor was detected, whilst the patient was administrated the first dose of recombinant factor VII and then transferred to Bradford Royal Infirmary, we overlooked that the Actin FS aPTTr was shorter than the Synthesil aPTTr (3.21 vs 5.03): a study comparing sensitive and insensitive reagents to the LA showed that the shortening of the aPTTr with Actin FS (the insensitive reagent) can be suggestive of LA even in patients on oral anticoagulants and/or with acquired haemophilia [3]. Hence we could not rule out that our patient also had a LA that was not detected on subsequent testing because of the immunosuppressive treatment she received.…”

Section: Discussionmentioning

confidence: 99%

“…Since 1988 in Airedale the possibility of a bleeding disorder was tested by comparing the clotting times of two aPTT reagents, currently Synthesil (IL) as the reagent sensitive to factor inhibitors and deficiencies and Actin FS (Dade) as the reagent insensitive to factor inhibitors and deficiencies but sensitive to factor XII deficiency [2]. Unbeknown to the laboratory personnel the same comparison can be used to detect a lupus anticoagulant [3]. Both assays are run on an automated coagulometer (TOP-CTS, Instrumentation Laboratories).…”

Section: Case Presentationmentioning

confidence: 99%

Sequential thrombosis and bleeding in a woman with a prolonged activated partial thromboplastin time

Spencer

Pearce

2011

Thrombosis J

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Simultaneous or sequential haemorrhage and thrombosis in the presence of a prolonged activated partial thromboplastin time (aPTT) is a rare occurrence: we describe the case a 37 year old lady who developed post-delivery deep vein thrombosis treated with low molecular heparin and warfarin followed a week later by extensive bruising over legs and forearms, a significant drop in haemoglobin and a very prolonged aPTT. Further tests revealed an acquired factor VIII inhibitor at 35 Bethesda Units. We discuss the clinical and laboratory implications and provide a literature review of simultaneous thrombophilia and haemophilia in the presence of a prolonged aPTT.

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“…The sensitivity of aPTT to lupus anticoagulant is variable and strongly influenced by the source [7] and concentration [8] of the phospholipid in the reagent. Brancaccio et al [7] studied 23 patients with a known diagnosis of lupus anticoagulant, and found that when a sensitive reagent was used 96% of the patients had an abnormal aPTT ratio, against only 17% when the aPTT was performed with an insensitive vegetable-derived reagent.…”

Section: Discussionmentioning

confidence: 99%

Performance of Platelin LS and dilute Russell's viper venom for the screening of lupus anticoagulant in patients with venous thromboembolism

Morelli

Rodrigues²,

Noguti³

et al. 2007

Blood Coagulation &Amp; Fibrinolysis

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Lupus anticoagulant is associated with thrombosis and pregnancy morbidity, and its detection is of major clinical importance. The nature and concentration of phospholipids strongly influence the sensitivity of activated partial thromboplastin time (aPTT) reagents to lupus anticoagulant. We investigated the ability of Platelin LS, an aPTT reagent, to screen lupus anticoagulant among 94 patients with venous thromboembolism by comparing its performance with the dilute Russell viper venom time (dRVVT). Twenty-four patients had an abnormal aPTT and dRVVT, whereas 37 only had a prolonged dRVVT. In users of oral anticoagulants (n = 56), the dRVVT prolonged more frequently than the aPTT (98.2 vs 39.3%, P < 0.0001). After the mixing study, seven patients maintained abnormal aPTT and dRVVT ratios, five of whom had prolonged mixture with both tests. The agreement in the mixing study between aPTT and dRVVT was substantial (kappa = 0.78, 95% confidence interval = 0.48-1.00). Except for one patient, the aPTT screened all cases that demonstrated phospholipid dependency of their inhibitor during the confirmatory procedure with the dRVVT. In conclusion, the aPTT using Platelin LS was highly associated with the presence of lupus anticoagulant detected by the dRVVT among patients with venous thromboembolism, and could be reliably employed as a screening assay for lupus anticoagulant.

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A rapid screen for lupus anticoagulant with good discrimination from oral anticoagulants, congenital factor deficiency and heparin, is provided by comparing a sensitive and an insensitive APTT reagent

Cited by 34 publications

References 0 publications

Laboratory Testing for Lupus Anticoagulants: A Review of Issues Affecting Results

Laboratory Testing for Lupus Anticoagulants: A Review of Issues Affecting Results

Sequential thrombosis and bleeding in a woman with a prolonged activated partial thromboplastin time

Performance of Platelin LS and dilute Russell's viper venom for the screening of lupus anticoagulant in patients with venous thromboembolism

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