Share to
  • Email
  • Facebook
  • X
  • Bluesky
  • Instagram
  • LinkedIn
Share to
  • Email
  • Facebook
  • X
  • Bluesky
  • Instagram
  • LinkedIn
Back to Test Catalogue
Test ID: NSCI

Lupus Anticoagulant, Plasma

Test Overview

Clinical Utility

Testing is done in accordance with recent International Society on Thrombosis and Haemostasis (ISTH) guidelines on lupus anticoagulant (LA), that recommend:

  1. assessment of the PT, APTT, thrombin clotting time (TCT) and fibrinogen as part of LA test panel to evaluate for potential interference from anticoagulants or a coagulopathy
  2. testing for LA by a LA-sensitive APTT and a dilute Russel Viper Venom Time (dRVVT)
  3. mixing and confirmatory tests (for phospholipipd dependence) if the LA screening tests are abnormal.

Method

Lupus Anticoagulant-Sensitive APTT Reagent/RVV Time Test

Method Description

LA testing is done by optical clot detection methods, using the HemosIL Silica Clotting Time and dRVVT Screen and Confirm reagents on the ACL TOP analyzer.

Result Included

INR; Prothorombin Time; Thrombin time; Fibrinogen; APTT; Lupus Anticoagulant Interpretation; SCT; DRVVT

Aliases/Synonyms

LA; Non-Specific Inhibitor; NSI; Non Specific Inhibitor; Circulating Anticoagulant; Phospholipid Antibody; Antiphospholipid; APL; Diluted Russell Viper Venom Time

Specimen

Specimen Type

Plasma

Containers

Collection Containers

Blue top (3.2% buffered citrate)

Volume

Sample Volume

1 mL

Collection & Handling

Collection Instructions

Ensure full draw with 9:1 ratio (9 parts blood to 1 part anticoagulant).

Handling Information

Prepare platelet-poor plasma (double spun) within 4 hours of collection and freeze immediately. Store and send frozen.

Stability

Ambient Refrigerated Frozen
Unacceptable Unacceptable 60 days

Stable up to twelve months at -70°C

Rejection Criteria

Criteria Specification
Specimen Not frozen

Performance & Interpretation

Turnaround Time

9 days

Results

Name
Units
Reference Range
Conversion
  1. INR
    0.8 - 1.1
  2. Prothrombin Time (PT) in PPP by Coagulation Assay
    s
    9.4 - 12.5
  3. Thrombin Time
    s
    12 - 19
  4. Fibrinogen (g/L) in PPP by Coagulation Assay
    g/L
    2.0 - 3.9
  5. APPT
    s
    25 - 37
  6. Lupus Anticoagulant Interpretation
  7. SCT Screen
    ≤ 1.28
  8. SCT Confirm

    Comment

    Only reported when screen is abnormal

  9. SCT SC Ratio
    ≤ 1.18

    Comment

    Only reported when screen is abnormal

  10. SCT MIX
    ≤ 1.14

    Comment

    Only reported when screen is abnormal

  11. DRVVT Screen
    ≤ 1.34
  12. DRVVT Confirm

    Comment

    Only reported when screen is abnormal

  13. DRVVT SC Ratio
    ≤ 1.21

    Comment

    Only reported when screen is abnormal

  14. DRVVT Mix
    ≤ 1.16

    Comment

    Only reported when screen is abnormal

Referral Location

Canada

Interface & Setup

HL7 Interface Codes

Order Code Result Name Result Codes Units
NSCI INR 64493
PROTHROMBIN TIME (PT) IN PPP BY COAGULATION ASSAY 64494 s
THROMBIN TIME 64481 s
FIBRINOGEN (G/L) IN PPP BY COAGULATION ASSAY 7395 g/L
APTT 64504 s
LUPUS ANTICOAGULANT INTERPRETATION 64503
SCT SCREEN 64495
SCT CONFIRM 64496
SCT SC RATIO 64497
SCT MIX 64498
DRVVT SCREEN 64499
DRVVT CONFIRM 64500
DRVVT SC RATIO 64501
DRVVT MIX 64502

Test Version

Last Updated

2025-06-24