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Test Code APROL Prolonged Clot Time Profile, Plasma


Ordering Guidance


Multiple coagulation profile tests are available. See Coagulation Profile Comparison for testing that is performed with each profile.



Shipping Instructions


Send the 5 aliquots in the same shipping container.



Necessary Information


Note if patient is currently receiving heparin, Coumadin (warfarin) or any medication affecting coagulation.



Specimen Required


Specimen Type: Platelet-poor plasma

Patient Preparation:

1. Patient should not be receiving anticoagulant treatment (eg, warfarin, heparin). Treatment with heparin causes false-positive results of in vitro coagulation testing for lupus anticoagulant. Coumadin (warfarin) treatment may impair ability to detect the more subtle varieties of lupus-like anticoagulants.

2. Patient should also not be receiving fibrinolytic agents (streptokinase, urokinase, tissue plasminogen activator [tPA]).

3.It is best to perform this study pretransfusion if possible. If patient has been recently transfused, wait at least 48 hours after transfusion to collect the specimen.

Collection Container/Tube: Light-blue top (3.2% sodium citrate)

Submission Container/Tube: Plastic vial

Specimen Volume: 5 mL in 5 plastic vials, each containing 1 mL

Collection Instructions:

1. Specimen must be collected prior to factor replacement therapy.

2. For complete instructions, see Coagulation Guidelines for Specimen Handling and Processing.

3. Centrifuge, transfer all plasma into a plastic vial, and centrifuge plasma again.

4. Aliquot plasma (1-2 mL per aliquot) into 5 separate plastic vials leaving 0.25 mL in the bottom of centrifuged vial.

5. Freeze plasma immediately (no longer than 4 hours after collection) at -20° C or, ideally, -40° C or below.

Additional Information:

1. Double-centrifuged specimen is critical for accurate results as platelet contamination may cause spurious results.

2. Each coagulation assay requested should have its own vial.


Forms

1. Coagulation Patient Information (T675)

2. If not ordering electronically, complete, print, and send a Coagulation Test Request (T753) with the specimen.

Useful For

Determining the cause of prolongation of prothrombin time or activated partial thromboplastin time

 

Screening for prolonged clotting times and determining the presence of factor deficiencies or inhibitor (eg, factor-specific, lupus-like, or the presence of heparin)

Profile Information

Test ID Reporting Name Available Separately Always Performed
APRI Prolonged Clot Time Prof Interp No Yes
PTSC Prothrombin Time (PT), P Yes, (order PTTP) Yes
APTSC Activated Partial Thrombopl Time, P Yes, (order APTTP) Yes
DRV1 Dilute Russells Viper Venom Time, P Yes, (order DRVI1) Yes
TTSC Thrombin Time (Bovine), P Yes Yes
CLFIB Fibrinogen, Clauss, P Yes, (order FIBTP) Yes
DIMER D-Dimer, P Yes, (order DDITT) Yes

Reflex Tests

Test ID Reporting Name Available Separately Always Performed
GBETH General Factor Bethesda Units, P No No
5BETH FV Bethesda Units, P No No
8BETH FVIII Bethesda Units, P No No
9BETH FIX Bethesda Units, P No No
F8IS Coag Factor VIII Assay Inhib Scrn,P No No
FACTV Coag Factor V Assay, P Yes No
F_7 Coag Factor VII Assay, P Yes No
F_9 Coag Factor IX Assay, P Yes No
F_10 Coag Factor X Assay, P Yes No
F_11 Coag Factor XI Assay, P Yes No
F_12 Coag Factor XII Assay, P Yes No
F8A Coag Factor VIII Activity Assay, P Yes No
RTSC Reptilase Time, P Yes No
F_2 Coag Factor II Assay, P Yes No
PNP Platelet Neutralization Procedure No No
PTMSC PT Mix 1:1 No No
APMSC APTT Mix 1:1 No No
DRV2 DRVVT Mix No No
DRV3 DRVVT Confirmation No No
F5_IS Factor V Inhib Scrn No No
F9_IS Factor IX Inhib Scrn No No
F2_IS Factor II Inhib Scrn No No
F7_IS Factor VII Inhib Scrn No No
10_IS Factor X Inhib Scrn No No
11_IS Factor XI Inhib Scrn No No
PTFIB PT-Fibrinogen, P No No
SOLFM Soluble Fibrin Monomer No No
CH9 Chromogenic FIX, P Yes No
CHF8 Chromogenic FVIII, P Yes No
HEXLA HEX LA, P No No

Testing Algorithm

Initial testing includes prothrombin time (PT), activated partial thromboplastin time (aPTT), dilute Russell's viper venom time (dRVVT), thrombin time (bovine), fibrinogen, D-dimer, and prolonged clot time interpretation.

 

If PT is greater than 13.9 seconds, then PT mix will be performed at an additional charge.

 

If aPTT is greater or equal to 38 seconds, then aPTT mix will be performed at an additional charge.

 

If aPTT mix is greater or equal to 38 seconds and thrombin time is less than 35.0 seconds (no evidence of heparin), then platelet neutralization procedure will be performed at an additional charge.

 

If dRVVT ratio is greater or equal to 1.20, then dRVVT mix and dRVVT confirmation will be performed at an additional charge.

 

If thrombin time is greater or equal to 25.0 seconds, then reptilase time will be performed at an additional charge.

 

If fibrinogen is less than 150 mg/dL or clinically indicated, then PT-fibrinogen will be performed at an additional charge.

 

If D-dimer is greater than 500 ng/mL fibrinogen equivalent units, then soluble fibrin monomer will be performed at an additional charge.

 

If PT, aPTT, or dRVVT is prolonged, then coagulation factor assays may be performed at an additional charge.

 

If factor assay result is below the normal range, the appropriate factor inhibitor screen may be performed along with the Bethesda titering assay, at an additional charge, if inhibitor screen is positive.

 

If appropriate, hexagonal lupus anticoagulant will be performed at an additional charge to clarify significant abnormalities in the screen test results.

Method Name

ARPI: Medical Interpretation

PTSC, APTSC, DRV1, TTSC, GBETH, 5BETH, 8BETH, 9BETH, F8IS, FACTV, F_2, F_7, F_9, F_10, F_11, F_12, F8A, RTSC, PNP, APMSC, PTMSC, PTFIB, DRV2, DRV3: Optical Clot-Based

CLFIB: Clauss

DIMER, SOLFM: Latex Immunoassay (LIA)

CH9, CHF8: Chromogenic

HEXLA: Spectrophotometric

Reporting Name

Prolonged Clot Time Prof

Specimen Type

Plasma Na Cit

Specimen Minimum Volume

4 plastic vials, each containing 1 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Plasma Na Cit Frozen 14 days

Reject Due To

Gross hemolysis Reject
Gross lipemia Reject
Gross icterus Reject

Clinical Information

When coagulation screening tests are performed to verify normal function of the coagulation system (eg, preoperative, routine examination), they sometimes indicate an abnormality that may be unexplained (ie, prolonged clotting times). This consultation provides validation of the prolongation and as comprehensive a workup as needed to define the abnormality.

 

Possibilities for a cause of prolongation include:

-Artifactual due to high hematocrit (dilution of specimen by anticoagulant if patient hematocrit is 55% or greater)

-Factor deficiencies, congenital or acquired

-Factor inhibitors eg, factor VIII inhibitors (bleeding disorder)

-Lupus anticoagulant (risk for thrombosis or recurrent miscarriage)

-Anticoagulant drug effect eg, (including warfarin [Coumadin or Jantoven], oral anti-Xa inhibitors, oral direct thrombin inhibitors), heparin.

Reference Values

An interpretive report will be provided.

Interpretation

An interpretive report will be provided when testing is completed, noting a presence or absence of a prolonged bleeding disease state.

Cautions

If the patient's hematocrit is 55% or greater, the volume of citrate anticoagulant should be adjusted prior to submitting the specimen for analysis to avoid dilution of plasma by anticoagulant.(1)

 

For optimal results, the patient should not be receiving oral vitamin K inhibitor (eg, warfarin, Coumadin), heparin, low-molecular weight heparin, hirudin (Refludan), argatroban, or fibrinolytic agents (eg, streptokinase, tissue plasminogen activator). If necessary, testing may be performed on patients receiving these treatments. Medications affecting coagulation parameters must be noted on requisition for accurate interpretation of results. Treatment with heparin causes false-positive results of in vitro coagulation testing for lupus anticoagulant. Coumadin treatment may impair ability to detect the more subtle varieties of lupus-like anticoagulants.

Day(s) Performed

Monday through Friday

Report Available

3 to 7 days

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Test Classification

See Individual Test IDs

CPT Code Information

85379-DIMER

85384-CLFIB

85390-26-APRI

85610-PTSC

85613-DRV1

85670-TTSC

85730-APTSC

85130-Chromogenic FVIII (if appropriate)

85130-Chromogenic FIX (if appropriate)

85210-Factor II (if appropriate)

85220-Factor V (if appropriate)

85230-Factor VII (if appropriate)

85240-Factor VIII (if appropriate)

85250-Factor IX (if appropriate)

85260-Factor X (if appropriate)

85270-Factor XI (if appropriate)

85280-Factor XII (if appropriate)

85335-Bethesda titer (if appropriate)

85335-Factor V inhibitor screen (if appropriate)

85335-Factor VIII inhibitor screen (if appropriate)

85335-Factor IX inhibitor screen (if appropriate)

85366-Soluble fibrin monomer (if appropriate)

85385-PT-Fibrinogen (if appropriate)

85597-Platelet neutralization for lupus inhibitor (if appropriate)

85598-Hex LA (if appropriate)

85611-PT mix 1:1 (if appropriate)

85613-DRVVT mix (if appropriate)

85613-DRVVT confirm (if appropriate)

85635-Reptilase time (if appropriate)

85732-APTT mix 1:1 (if appropriate)

LOINC Code Information

Test ID Test Order Name Order LOINC Value
APROL Prolonged Clot Time Prof 98125-8

 

Result ID Test Result Name Result LOINC Value
603324 Reviewed by 18771-6
CLFIB Fibrinogen, Clauss, P 48664-7
RVR1 DRVVT Screen Ratio 15359-3
TTSC Thrombin Time (Bovine), P 46717-5
APTSC Activated Partial Thrombopl Time, P 14979-9
PTSEC Prothrombin Time (PT), P 5902-2
603183 Prolonged Clot Time Prof Interp 69049-5
DIMER D-Dimer, P 48067-3
INRSC INR 6301-6