Geisinger Medical Laboratories/Geisinger Proven Diagnostics Test Catalog

Test Name: Sunquest Test Code Epic Procedure Code Or ID CPT Code:  


Sunquest Test Code:
PTLA50      Geisinger Epic Procedure Code: PTLA50         Geisinger Epic ID: 29483

Specimen type:
Platelet-free plasma
Preferred collection container:
Specimen required:
1 mL aliquot plasma
Special notes:
Do not draw blood from a heparinized line. Avoid contaminating the sample with tissue thromboplastin or heparin. Venipuncture must be performed with no trauma. If blood is drawn from an indwelling catheter, flush with 5 mL of saline and discard the first 5 mL of blood collected.

Specimen processing instructions:
Centrifuge the citrated blue-top tubes as soon as possible (within 60 minutes) at designated time and speed to obtain platelet-poor plasma (<10,000/µL). Using a plastic pipette, remove 1 mL of plasma and transfer to a plastic aliquot tube and label with patient's name and a second patient identifier (e.g., date of birth, medical record number). 
Transport temperature:
Specimen stability:
Frozen: -20°C for 30 days, -70°C for 6 months. Room temperature: 4 hours.
Rejection criteria:
Clotted specimen. Stability limits exceeded.

Reference interval:
Varies by site and lot of reagents. Current GMC = 32-49 sec.
Additional information:
Testing done with LUPACP, LUPACC, THRMP and THRMPC batteries. If initial PTTLAB is prolonged, then this test is done by reflex. If PTLA50 is ordered directly PTTLAB will be ordered and the appropriate testing performed and resulted. If a test is not needed then it will appear as credited by SWNL (Testing not performed- screen within normal limits).
CPT code(s):
85732 x2, 85730
Note: The billing party has sole responsibility for CPT coding.  Any questions regarding coding should be directed to the payer being billed.  The CPT codes provided by GML are based on AMA guidelines and are for informational purposes only.
Test includes:
Lupus sensitive APTT Mix with normal plasma at 0 and 60 min at 37°C.
Mechanical Clot-Based
Clinical significance:
The Lupus sensitive APTT test is used to rule out the possible existence of a lupus anticoagulant. It is one of the various tests that aide in the true diagnosis of a lupus anticoagulant (anti-phospholipid syndrome). It is a high phospholipid test. Lupus anticoagulants (LA) are immunglobulins that generally interfere with phospholipid-dependent in vitro coagulation tests, the most frequently used being the aPTT assay. The common association of LA with recurrent spontaneous abortions and idiopathic thromboembolic diseases underlies the importance of diagnostic tests capable of distinguishing these LA antibodies from anti-factor antibodies, factor deficiencies and heparin, since all four conditions may cause a prolongation of the aPTT test.
Doctoral Director(s:)
Michelle Grant DO    
Review Date: 04/29/2019

Performing Locations

Geisinger Medical Center

Performing laboratory: Coagulation
Technical Lead: Margaret Knowles-Tuchman
Frequency: Daily, 1st shift
Performed stat? No
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