PTT-LA with Reflex to Hexagonal Phase Confirmation

17408

If PTT-LA Screen is prolonged (>40 seconds), then Hexagonal Phase Confirmation will be performed at an additional charge (CPT code(s): 85598).

1.5 mL frozen platelet-poor plasma collected in a 3.2% sodium citrate (light blue-top) tube

0.5 mL

Please submit a separate, frozen vial for each special coagulation assay ordered. Draw blood in a light blue-top tube containing 3.2% sodium citrate, mix gently by inverting 3-4 times. Centrifuge 15 minutes at 1500 g within one hour of collection. Using a plastic pipette, remove plasma, taking care to avoid the WBC/platelet buffy layer and place into a plastic vial. Centrifuge a second time and transfer platelet-poor plasma into a new plastic vial(s). Freeze immediately and transport on dry ice.

Plastic vial

Frozen

Room temperature: Unacceptable
Refrigerated: Unacceptable
Frozen: 30 days

Hemolysis

Set up: Mon-Fri; Report available: 1-4 days

≤40 seconds

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.