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| A B C D E F G H I J K L M N O P Q R S T U V W X Y Z # |
Prolonged aPTT Asymptomatic Evaluation [19645X]
Test Code18178
CPT Codes
85670, 85730
Includes
Partial Thromboplastin Time, Activated (aPTT)
Thrombin Clotting Time (TCT)
Impression
If aPTT, is minimally prolonged and TCT is normal, then test Minimally Prolonged aPTT/Normal TCT (includes Factors VIII, IX, and XI Activities, and Hexagonal Phase confirm), will be performed at an additional charge (CPT: 85240, 85250, 85270, 85597). If Factor VIII Activity is decreased, then VWF Antigen and Ristocetin Cofactor Activity will be performed at an additional charge (CPT: 85246, 85245).
If TCT is prolonged, then test Prolonged aPTT/Prolonged TCT (includes Fibrinogen and Heparin Anti-Xa), will be performed at an additional charge (CPT: 85384, 85520).
If aPTT is prolonged and TCT is normal, then test aPTT 1:1 Mixing Study Progressive (aPTT 1:1 Mixing Study Progressive), will be performed at an additional charge (CPT: 85732).
If the aPTT immediate and incubated mixing study corrects, then test aPTT 1:1 Mixing Study Profile I (Corrects)(includes Factors VIII, IX, XI and XII Activities) will be performed at an additional charge (CPT: 85240, 85250, 85270, 85280). If the immediate or incubated mixing study does not correct, then Hexagonal Phase confirm will be performed at an additional charge (CPT: 85597).
Additional assays, if needed, will be performed at an additional charge to determine the cause of the abnormality.
Thrombin Clotting Time (TCT)
Impression
If aPTT, is minimally prolonged and TCT is normal, then test Minimally Prolonged aPTT/Normal TCT (includes Factors VIII, IX, and XI Activities, and Hexagonal Phase confirm), will be performed at an additional charge (CPT: 85240, 85250, 85270, 85597). If Factor VIII Activity is decreased, then VWF Antigen and Ristocetin Cofactor Activity will be performed at an additional charge (CPT: 85246, 85245).
If TCT is prolonged, then test Prolonged aPTT/Prolonged TCT (includes Fibrinogen and Heparin Anti-Xa), will be performed at an additional charge (CPT: 85384, 85520).
If aPTT is prolonged and TCT is normal, then test aPTT 1:1 Mixing Study Progressive (aPTT 1:1 Mixing Study Progressive), will be performed at an additional charge (CPT: 85732).
If the aPTT immediate and incubated mixing study corrects, then test aPTT 1:1 Mixing Study Profile I (Corrects)(includes Factors VIII, IX, XI and XII Activities) will be performed at an additional charge (CPT: 85240, 85250, 85270, 85280). If the immediate or incubated mixing study does not correct, then Hexagonal Phase confirm will be performed at an additional charge (CPT: 85597).
Additional assays, if needed, will be performed at an additional charge to determine the cause of the abnormality.
Preferred Specimen
1 mL (x4) platelet-poor plasma collected in 3.2% sodium citrate (light blue-top) tubes
Minimum Volume
1 mL (x4)
Instructions
4 mL citrated platelet poor plasma, frozen.
Submit 4 plasma aliquots, each with 1 mL plasma for possible additional testing.
Refer to Quest Diagnostics Nichols Institute Directory of Services under Specimen Collection section, Coagulation Testing for further information on specimen processing.
Submit 4 plasma aliquots, each with 1 mL plasma for possible additional testing.
Refer to Quest Diagnostics Nichols Institute Directory of Services under Specimen Collection section, Coagulation Testing for further information on specimen processing.
Transport Temperature
Frozen
Specimen Stability
Room temperature: Unacceptable
Refrigerated: Unacceptable
Frozen: 14 days
Refrigerated: Unacceptable
Frozen: 14 days
Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)
Hemolysis • Specimens received room temperature or refrigerated
Methodology
Clot Detection
Setup Schedule
See individual tests
Reference Range
See individual tests
Clinical Significance
This evaluation is for the patient with a prolonged aPTT, who either lacks a history of bleeding/bruising or thrombosis or for someone whose clinical history is unknown. The investigation follows a testing algorithm with an endpoint of arriving at a final diagnosis for either a factor deficiency or the presence of a factor specific or nonspecific inhibitor (i.e., a Lupus Anticoagulant).
