PTT-LA with Reflex to Hexagonal Phase Confirmation

Last Modified: 5/11/2023 10:05:37 AM


Medical Necessity Documentation:  
Client Notes:  
Patient Preparation:  
Specimen Requirements: 1.5 mL Frozen Plasma from a Blue Top Tube - 3.2% Na Citrate in a Plastic Vial
Collection Instructions:
  1. Please submit a separate, frozen vial for each special coagulation assay ordered.
  2. Draw blood in a light blue-top tube containing 3.2% sodium citrate
  3. mix gently by inverting 3-4 times.
  4. Centrifuge 15 minutes at 1500 g within one hour of collection.
  5. Using a plastic pipette, remove plasma, taking care to avoid the WBC/platelet buffy layer and place into a plastic vial.
  6. Centrifuge a second time and transfer platelet-poor plasma into a new plastic vial(s). 
  7. Freeze immediately and transport on dry ice. 
Minimum Volume: 0.5 mL Frozen Plazma
Transport & Storage: Temperature/Stability: 30 days Frozen
Rejection Criteria: Hemolysis
Reference Range: ≤40 seconds
Critical Ranges:  
Test Comments: If PTT-LA Screen is prolonged (>40 seconds), then Hexagonal Phase Confirmation will be performed at an additional charge
Methodology: Clot Detection
Clinical Significance: PTT-LA with Reflex to Hexagonal Phase Confirmation - The PTT-LA is a sensitive, but non-specific assay for Lupus anticoagulants (LA). The Hexagonal Phase confirm is a specific LA test. As international guidelines recommend a multi-test approach to LA detection due to antibody heterogeneity, a comprehensive panel is available (Lupus anticoagulant Comprehensive Evaluation). Lupus anticoagulant Comprehensive Evaluation includes the PTT-LA with reflex to Hexagonal Phase Confirm, plus the DRVVT pathway of testing.
Note: Target specific anticoagulant therapy (anti-Xa medications, direct thrombin inhibitors) may cause false positive results.
Documentation:  
Custom Panel: No

PRODUCTION SCHEDULE

Turn Around Time: 1 to 4 days
Days Performed: Monday, Tuesday, Wednesday, Thursday, Friday
Sites Performed: Quest - Chantilly
PHL Test Code: MSOT
EPIC Test Code: MISC
Send Out Test Code: 17408
Alternate Test Names: Staclot LA; Lupus Anticoagulant; Staclot-LA
Included Tests:
CPT Coding: 85730 (R 85598)

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