Lupus Anticoagulant Antibody Screen

Coagulation

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Description

Antiphospholipid antibodies are a group of antibodies which include lupus anticoagulant, anticardiolipin antibodies (IgG or IgM) and antiβ2-glycoprotein-1 antibodies (IgG) which are associated with thrombosis and pregnancy loss/morbidity. Antiphospholipid syndrome is characterised by persistent positivity of these antibodies together with the clinical symptoms.

Lupus anticoagulant (LA) is detected by performing the DRVVT with two reagents (Screen and Confirm). Russell’s viper venom present in the screeening reagent initiates plasma clotting by directly activating factor X.. The confirmation reagent contains a high phospholipid concentration which counteracts the LA antibodies and normalises the clotting time.Anti-cardiolipin antibodies and anti-β2GP1 antibodies are measured by automated immunoassays using chemiluminescent technology.

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Indications

Antiphospholipid antibodies can be found in patients with Antiphospholipid Syndrome either in isolation or in association with other autoimmune disorders such as systemic lupus erythematous.

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Sample Type

Plasma (Citrate Blue) x 3 and Plain Serum x 1.

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Reference Range

Indicated on report

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Turnaround Time

Within 2 weeks

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Testing Frequency

Twice weekly.

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External Notes

The accuracy of all coagulation tests is greatly influenced by pre analytical variables. It is essential that sample quality is given the highest of priorities. Samples which fail to meet quality criteria including age of sample, specimen fill ( >90% ), haemolysed, clotted or activated samples will be rejected and a repeat sample requested.

Citrate samples sent frozen must be double spun before freezing.

Note: the DRVVT cannot be performed on plasma from patients receiving unfractionated heparin or new anticoagulants such as Rivaroxaban or Dabigatran.

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Patient Preparation

No special requirements.

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References

Keeling D. Guidelines on the investigation and management of antiphospholipid syndrome. Br J Haem, 2012, 157, 47-58

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See Also

Dilute Russell's Viper Venom Time (DRVVT)
Anticardiolipin Antibodies
Anti-Beta 2 Glycoprotein 1 Antibodies

Please note: the above information is subject to change and we endeavour to keep this website up to date wherever necessary.