Ordering Recommendation

Use to aid in the evaluation of unexplained prolonged partial thromboplastin time (PTT) or for patients with a significant probability of having antiphospholipid syndrome (APS). For APS, order with Cardiolipin Antibodies, IgG and IgM (0099344) and Beta-2 Glycoprotein 1 Antibodies, IgG and IgM (anti-beta2GP1) (0050321).

New York DOH Approval Status

This test is New York state approved.

Specimen Required

Patient Preparation

Light blue (sodium citrate). Refer to Specimen Handling at aruplab.com for hemostasis/thrombosis specimen handling guidelines.

Specimen Preparation

Transfer 3 mL platelet-poor plasma to an ARUP standard transport tube. (Min: 2 mL)

Storage/Transport Temperature

CRITICAL FROZEN. Separate specimens must be submitted when multiple tests are ordered.

Unacceptable Conditions

Serum. EDTA plasma, clotted or hemolyzed specimens.


Ambient: 4 hours; Refrigerated: Unacceptable; Frozen at -20 C or below: 3 months


Electromagnetic Mechanical Clot Detection/Chromogenic Assay




1-3 days

Reference Interval

Test Number
Reference Interval
  Prothrombin Time (PT) 12.0-15.5 seconds
  PTT-LA Ratio ≤1.20
  dRVVT Screen Ratio ≤1.20
  Anti-Xa Qualitative Interpretation Not Present
  Thrombin Time (TT) ≤19.5 seconds
  Anticoagulant Medication Neutralization Not Performed
  Neutralized PTT-LA Ratio ≤1.20
  Neutralized dRVVT Screen Ratio ≤1.20
  dRVVT 1:1 Mix Ratio ≤1.20
  dRVVT Confirmation Ratio ≤1.20
  Hexagonal Phospholipid Confirmation ≤7.9

Interpretive Data

Compliance Category

Modified FDA


If PTT-LA Ratio and dRVVT Screen Ratio are normal, then no further testing is performed. If either the PTT-LA Ratio or dRVVT Screen Ratio are elevated, then Anti-Xa Qualitative Interpretation is added. If PTT-LA Ratio is elevated, then Thrombin Time is also added. If Anti-Xa Qualitative Interpretation is Present and Thrombin Time is elevated, then Hepzyme treatment is added. If PTT-LA Ratio is Normal and Anti-Xa Qualitative Interpretation is Present, or Thrombin Time is Abnormal and Anti-Xa Qualitative Interpretation is Not Present, or Thrombin Time is Normal and Anti-Xa Qualitative Interpretation is Present, then DOAC-Stop treatment is added. If either Hepzyme or DOAC-Stop treatment is added, then Neutralized PTT-LA Ratio and/or Neutralized dRVVT Screen Ratio are added. If dRVVT Screen Ratio is elevated in the absence of Hepzyme or DOAC-Stop, or if Neutralized dRVVT Screen Ratio is elevated, then dRVVT 1:1 Mix Ratio and dRVVT Confirmation Ratio are added. If PTT-LA Ratio is elevated in the absence of Hepzyme or DOAC-Stop treatment, or if Neutralized PTT-LA Ratio is elevated, then Hexagonal Phospholipid Confirmation is added. Additional charges apply.

Hotline History


CPT Codes

85610; 85613; 85730; if reflexed, additional CPT codes may apply: 85520; 85525; 85598; 85613; 85670; 85730.


Component Test Code* Component Chart Name LOINC
3017010 Prothrombin Time (PT) 5902-2
3017011 PTT-LA Ratio 48022-8
3017013 dRVVT Screen Ratio 15359-3
3017016 Anti-Xa Qualitative Interpretation 45274-8
3017017 Thrombin Time (TT) 3243-3
3017018 Anticoagulant Medication Neutralization 3269-8
3017019 Neutralized PTT-LA Ratio 48022-8
3017021 Neutralized dRVVT Screen Ratio 97641-5
3017023 dRVVT 1:1 Mix Ratio 75512-4
3017027 dRVVT Confirmation Ratio 50410-0
3017030 Hexagonal Phospholipid Confirmation 75883-9
3017031 Lupus Anticoagulant, Interpretation 75882-1
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, please click the sidebar link to access the Interface Map.


  • DOAC
  • DOAC-Stop
  • dRVVT 1:1 Mix
  • dRVVT Confirmation
  • dRVVT Screen
  • Hexagonal Phospholipid Neutral Reflex
  • Lupus 1
  • Lupus Anticoagulant
  • Lupus Anticoagulant Comprehensive
  • Lupus Anticoagulant with Reflex to Phospholipid Neutralization
  • Lupus Inhibitor
  • Prothrombin Time
  • PTT
  • PTT-LA Screen
  • Thrombin Time
Lupus Anticoagulant Reflex Panel