Sign in →

Test Code LAB478 Lupus Anticoagulant

Clinical Information

Detection of lupus anticoagulant.

Synonym

  • PTI,TT
  • PTT-LA,DRVVT
  • LA Screen
  • APS Screen
  • Antiphospholipid Antibody Screen
  • Staclot LA
  • DRVVT
  • Lupus Workup/ LAWUP 

Profile Information

Reporting Name Available Separately Always Reported
PT INR Yes Yes
Thrombin Time Yes Yes
dRVVT Ratio No Yes
PTT-LA No Yes
StaClot LA No Yes
Pathologist Interpretation No Yes

Specimen Required

Preferred Container/Tube: 3 full 3.2% Citrate Blue Top - 2.7 mL
Specimen Volume: 2.7 mL
Acceptable Container/Tube: 3 full 3.2% Citrate Blue Top - 1.8 mL
Specimen Volume: 1.8 mL
Platelet poor plasma (PPP):
Specimen Volume: 4 - 1 mL aliquots platelet poor plasma (PPP)
Specimen Minimum Volume: 3 - 1 mL aliquot platelet poor plasma (PPP)

Specimen Collection Information

For Outreach, other than OSU Patient Service Centers: Samples must be processed and received frozen/must remain frozen in transit. 

For sending frozen plasma specimens, process immediately upon receipt. Centrifuge capped specimen tube in accordance with CLSI H21, at a speed and time required to consistently produce platelet-poor plasma (PPP = platelet count <10 K/uL). Transfer PPP into plastic aliquot tubes, cap and freeze. DO NOT transport until specimens are completely frozen.

Specimen Stability Information

Ambient: 
     Whole blood: 4 hours
      Platelet poor plasma: 4 hours
Frozen: 
      Platelet poor plasma: PPP removed from the cells and frozen at -20°C or ideally -70°C.

Rejected Due To

  • Ambient specimens >4 hours old
  • Clotted specimens
  • Underfilled or overfilled tube
  • Hemolysis

Testing Algorithm

Mixing studies are reflexive and only performed when the PTT-LA and/or TT are prolonged.

Reflex Tests

Reporting Name Available Separately Always Reported
Thrombin Time Mixing Studies Yes No
PTT-LA Mixing Studies No No

Reference Values

PT: 11.9-14.2 sec

INR: 0.9-1.1

Thrombin Time: 13.0-20.0 sec

PTT-LA: ≤43.6 sec

dRVVT Screen Ratio: ≤1.28

dRVVT Normalized Ratio: ≤1.25

Hexagonal PL Neutralization: ≤10.3 sec

Cautions

This test is non-diagnostic in the setting of Low-molecular-weight heparin/ unfractionated heparin/direct oral anticoagulant use. Test is not indicated for patients receiving anticoagulant therapy. This test is not indicated for inpatient evaluation of acute thrombosis.

Method Description

Hexagonal PL Neutralization: STACLOT-LA: Mechanical clot detection in the presence/absence of hexagonal ring phospholipid

DRVVT: Mechanical clot detection in the presence of Diluted Russell's Viper Venom

PTT-LA: Mechanical clot detection in the presence of cephalin and activator

PT, TT, Mixing Studies: Mechanical clot detection

Performing Lab

Clinical Lab UH

Day(s) Performed

Monday through Friday (excludes OSU holidays)

Report Available

Same day/1 day

 

May be up to 4 days for path interpretation.

Reporting Name

Lupus Anticoagulant Workup - Routine Coag
Lupus Anticoagulant Workup - Special Coag

CPT Code Information

85610
85670
85732 (if appropriate)
85613 (if appropriate)

LOINC Code Information

5902-2
34714-6
46717-5
33673-5
34571-0
14979-9
50410-0
3282-1