QUANTITATIVE D-DIMER ASSAY

Effective Date: 
Fri, 03/24/2017
Reviewed: 
Tue, 08/15/2017
Revised: 
Mon, 08/14/2017
Policy: 

ALERE TRIAGE® D-DIMER TEST

The Alere Triage® D-Dimer Test is a fluorescence immunoassay to be used with the Alere Triage® Meters for the quantitative determination of cross-linked fibrin degradation products containing D-dimer in EDTA anticoagulated whole blood and plasma specimens. The test is used as an aid in the assessment and evaluation of patients suspected of having disseminated intravascular coagulation or thromboembolic events including pulmonary embolism

Procedure: 

 

TEST PRINCIPLE

The test procedure involves the addition of several drops of an EDTA anticoagulated whole blood or plasma specimen to the sample port on the Test Device. After addition of the specimen, the whole blood cells are separated from the plasma using a filter contained in the Test Device. The specimen reacts with fluorescent antibody conjugates and flows through the Test Device by capillary action. Complexes of fluorescent antibody conjugate are captured on a discrete zone specific to that analyte.

REAGENT

The Alere Triage® D-Dimer Test Device contains all the reagents necessary for the quantification of cross-linked fibrin degradation products containing D-dimer in EDTA anticoagulated whole blood or plasma specimens

INSTRUMENT OPERATION

The Test Device is inserted into the Alere Triage® Meter (hereafter referred to as Meter). The Meter is programmed to perform the analysis after the specimen has reacted with the reagents within the Test Device. The analysis is based on the amount of fluorescence the Meter detects within a measurement zone on the Test Device. The concentration of the analyte in the specimen is directly proportional to the fluorescence detected. The results are displayed on the Meter screen in approximately 20 minutes from the addition of specimen. All results are stored in the Meter memory to display or print when needed. If connected, the Meter can transmit results to the lab or hospital information system.

SAMPLE COLLECTION AND HANDLING

SAMPLE TYPE

A venous whole blood or plasma specimen using K2 EDTA as the anticoagulant is acceptable for testing with this product. Other blood specimen types have not been evaluated.

COLLECTION

For specimen collection, follow the sample tube manufacturer’s recommended procedure.

STORAGE AND STABILITY

If using whole blood, test patient specimen within 24 hours of sample collection. If testing cannot be completed within 24 hours, the plasma should be separated and stored at -20°C until it can be tested. No more than a single freeze/thaw cycle is recommended.

After testing is complete, hold whole blood same for 24 hours for possible retest.  If plasma is used and has not been frozen prior to testing, freeze plasma sample and hold for 30 days.

HANDLING PRECAUTIONS

Transport specimens at room temperature or chilled and avoid extreme temperatures.

Avoid using severely hemolyzed specimens whenever possible. If a specimen appears to be severely hemolyzed, another specimen should be obtained and tested.

REAGENTS AND EQUIPMENT

REAGENTS AND MATERIALS PROVIDED

Alere Triage® D-Dimer Test Device kit

Quantity: 25 Test Devices

Description of reagent: Single Use test device

Murine monoclonal antibodies against D-Dimer

Fluorescent dye

Stabilizers

Storage requirements:

Store the Test Devices in a refrigerator at 2-8°C (35-46°F).

Once removed from refrigeration, the pouched Test Device is stable for up to 14 days at room temperature, but not beyond the expiration date printed on the pouch. With a soft, felt tip marker, gently write the date and time of removal from the refrigerator on the pouch and cross out the manufacturer expiration date printed on the pouch. Care must be taken to document the time the product is at room temperature. Once equilibrated to room temperature, do not return the Test Device to refrigeration.

Before using refrigerated Test Devices, allow individual foil pouches to reach operating temperature (20-24°C or 68-75°F). This will take a minimum of 15 minutes. If a kit containing multiple Test Devices is removed from refrigeration, allow the kit to reach room temperature before use. This will take a minimum of 60 minutes.

Do not remove the Test Device from the pouch until prepared for immediate use.

Discard after single use.

Special handling requirements:

For In Vitro Diagnostic Use.

For use by healthcare professionals.

Do not use the kit beyond the expiration date printed on the outside of the box.

Carefully follow the instructions and procedures described in this document and the package insert.

Optimal results will be achieved by performing testing at temperatures between

20-24ºC (68-75 ºF).

If results from multiple samples within the same patient will be compared, it is recommended to maintain a consistent sample type (whole blood or plasma).

Sample dilution is not recommended.

Transfer pipettes

Quantity: 25

Storage requirements: room temperature

Special handling requirements:

The transfer pipette should be used for one patient specimen only. Discard after single use.

Reagent CODE CHIP™ Module

Quantity: 1

Paper Roll

Quantity: 1

QUALITY CONTROL

ALERE TRIAGE® QC DEVICE

Use the QC Device to ensure proper function of the Meter. Perform QC Device testing for the following conditions:

Upon initial setup of the Meter.

Each day of patient testing.

When the Meter has been transported or moved.

Whenever there is uncertainty about the performance of the Meter.

Whenever required by your laboratory’s quality control requirements.

Do not discard the Alere Triage® QC Device and associated CODE CHIP™ module. Store them in the QC Device Box.

Refer to the Alere Triage® Meter User Manual for complete instructions for use of the QC Device.

The first time a new QC Device is run in the Meter, install the QC Device CODE CHIP™ module. The QC Device CODE CHIP™ module data is stored in the Meter memory. The QC Device CODE CHIP™ module does not need to be reinstalled after the first time.

Installing QC Device CODE CHIP™

From the main screen, select Install New Code Chip and press Enter.

Place the QC Device CODE CHIP™ module into the lower left front corner of the Meter. Follow the prompts on the screen.

Remove the QC Device CODE CHIP™ module from the Meter when data transfer is complete.

Place the QC Device CODE CHIP™ module back into the QC Device Box for storage.

From the main screen, select Run Test and press Enter.

If User ID is enabled enter your User ID number and press Enter.

Select QC Device and press Enter.

Insert QC Device into the Meter and press Enter.

A Pass or Fail result will be displayed when complete. Each parameter should pass before patient testing is performed.

Remove the QC Device from the Meter and place in the QC Device Box. DO NOT DISCARD THE QC DEVICE.

Note: If the QC Device or external controls do not perform as expected, review the above instructions to see if the test was performed correctly, repeat the test, then contact Alere or your local Alere representative (refer to Contact Alere section). Refer to the Alere Triage® Meter User Manual for a complete description of the quality control system.

INTERNAL PROCEDURAL CONTROLS

Every Alere Triage® D-Dimer Test is a quantitative test that includes two control materials of different concentrations that are run automatically with every patient specimen, external liquid control solution, or proficiency testing sample. If the automatic check of these built-in controls shows that the control value results are within the limits set during manufacturing, the Meter will report a result for the specimen or sample being tested. If the automatic check of these built-in controls shows that the control value results are not within the limits set during manufacturing, a test result will not be reported. Instead, the Meter will display a warning or error message that is described in the Alere Triage® Meter User Manual.

Users should follow government guidelines (for example, federal, state or local) and/or accreditation requirements for quality control.

EXTERNAL LIQUID CONTROLS

Good Laboratory Practice suggests that external controls should be tested with each new lot of test materials, or every 30 days, and as otherwise required by your laboratory’s standard quality control procedures. Controls should be tested in the same manner as if testing patient samples. When running patient specimens or external controls, if an analyte fails for any reason (built-in control failure or an external control out of range) no patient results will be reported.

The use of non-Alere Controls and Calibration Verification materials is not recommended.

CALIBRATION

Lot Calibration Using the Reagent CODE CHIP™ Module

When a new lot of Test Devices is opened, the calibration and expiration data for that lot of Test Devices must be transferred to the Meter before patient testing. Use the Reagent CODE CHIP™ module supplied with the new lot of Test Devices to transfer the data to the Meter.

Installing the Reagent CODE CHIP™

Perform one time for each new lot of Test Devices

From the main screen, select Install New Code Chip. Press Enter.

Place the Reagent CODE CHIP™ module into the lower left front corner of the Meter and follow the prompts on the screen.

Remove the Reagent CODE CHIP™ module from the Meter when data transfer is complete.

Place the Reagent CODE CHIP™ module back into its original container for storage.

PRECAUTIONS

For professional in vitro diagnostic use only.

Patient specimens, used Test Devices and used transfer pipettes are potentially infectious. Proper handling and disposal methods should be followed in accordance with local, state and federal regulations.

Proper laboratory safety techniques should be followed at all times when working with patient specimens because they are potentially infectious.

The Alere Triage® D-Dimer Test should not be used as absolute evidence for PE or DVT. As with all in vitro diagnostic tests, the test results should be interpreted by the physician in conjunction with clinical findings and other test results.

PERFORMING A TEST

TESTING INSTRUCTIONS

Procedural Notes

For each day of patient testing, perform QC Device testing. Refer to the Quality Control section.

Frozen plasma and refrigerated whole blood or plasma specimens must be allowed to reach room temperature and be mixed thoroughly before testing.

Mix whole blood specimens by gently inverting the tube several times before testing.

It is recommended to mix plasma specimens by vortexing the tube before testing.

Add Patient Specimen

Open the pouch and label the Test Device with the patient identification number.

Place the Test Device on a level, horizontal surface.

Using the transfer pipette, squeeze the larger (top) bulb completely and insert the tip into the specimen.

Release the bulb slowly. The transfer pipette barrel should fill completely with some fluid flowing into the smaller (lower) bulb.

Place the tip of the transfer pipette into the sample port of the Test Device and squeeze the larger bulb completely. The entire volume of fluid in the transfer pipette barrel must flow into the sample port. The specimen in the smaller (lower) bulb will not be expelled.

Remove the transfer pipette tip from the sample port and then release the larger (top) bulb.

Discard the transfer pipette.

Allow specimen to absorb completely before moving the Test Device.

Run Test

From the main screen, select Run Test and press Enter.

If User ID is enabled enter your User ID number and press Enter.

Select Patient Sample and press Enter.

Enter the patient identification number and press Enter.

Confirm that the number was entered correctly by selecting Confirm Patient ID and pressing Enter. If the number was not entered correctly, select Correct Patient ID, press Enter and repeat the previous step.

Holding the Test Device by the edges, insert the Test Device into the Meter and press Enter. The results will be displayed when the analysis is complete.

Note: The Test Device must be inserted into the Meter within 30 minutes from the time the patient specimen was added. A delay longer than 30 minutes may cause the results to be invalid and blocked out on the printout.

Read The Results

Repeat Critical Results

Results may be printed by pressing the Print button.

Discard the Test Device after release from the Meter.

A blocked out result indicates the result was invalid and the test should be repeated.

RESULTS

EXPECTED VALUES

Normal: </=500ng.mL DDU

A normal D-Dimer result has a negative predictive value of approximately 95% for the exclusion of acute pulmonary embolism (PE) or deep vein thrombosis when there is low or moderate pretest PE probability.

The Alere Triage® D-Dimer Test has been standardized using a purified protein preparation of D-dimer based on the mass (concentration) of the analyte present in EDTA anticoagulated plasma.

The D-dimer values are presented in units of mass (ng/mL) of D-dimer, also known as D-dimer Units (D-DU). There are no international standards for D-dimer and different assays use antibodies with differing specificities for D-dimer and other fibrin degradation products. This can lead to poor correlation between methods reporting results in D-DU.

METHOD PERFORMANCE SPECIFICATIONS

MEASURABLE RANGE

The D-Dimer range reported by the test system is 100 ng/mL to 5000 ng/mL. Due to calibration constraints, our lab will, as of 8/14/2017, report values of <171 ng/mL as <171 ng/mL.  This change and have no significant effects on any patient outcomes with values </=500 ng/mL  reported before this time.)

LIMITATIONS

The results should be evaluated in the context of all the clinical and laboratory data available. In those instances where test results do not agree with the clinical evaluation, additional tests should be performed.

Severely hemolyzed specimens should be avoided. When a sample appears to be severely hemolyzed, another specimen should be obtained and tested.

This test has been evaluated with venous whole blood and plasma using K2 EDTA as the anticoagulant. Other specimen types, draw methods, or anticoagulants have not been evaluated. Use standard veni-puncture techniques. Follow the sample collection recommendations of the sample tube manufacturer.

There is the possibility that factors such as technical or procedural errors, as well as substances in blood specimens that may interfere with the test and cause erroneous results. Please refer to the package insert for a list of interfering substances.

As with any assay employing mouse antibodies, the possibility exists for interference by human anti-mouse antibodies (HAMA) in the sample. Similarly, specimens from patients who have been routinely exposed to animals or to animal serum products may contain heterophile antibodies which may cause erroneous results.

This assay is a fluorescence immunoassay, and may be affected by environmental conditions.

REFERENCES

Fedullo, P.F. and V.F. Tapson. The evaluation of suspected pulmonary embolism.New England Journal of Medicine 349: 1247-1256, 2003.

S.Z. Goldhaber. Pulmonary embolism. New England Journal of Medicine 339: 93-104, 1998.

Kline, J.A., Mitchell, A.M., Kabrhel, C., Richman, P.B., and D.M. Courtney. Clinical criteria to prevent unnecessary diagnostic testing in emergency department patients with suspected pulmonary embolism. Journal of Thrombosis and Haemostasis 2(8):1247-1255, 2004.

Ramzi, D.W. and K.V. Leeper. DVT and pulmonary embolism: Part I. Diagnosis. American Family Physician 69(12): 2829-2836, 2004.

Wells, P.S., Anderson, D.R., Rodger, M., et al. Evaluation of D-dimer in the diagnosis of suspected deep-vein thrombosis. New England Journal of Medicine 349: 1227-1235, 2003.

Wells, P.S., Anderson, D.R., Rodger, M., et al. Excluding pulmonary embolism at the bedside without diagnostic imaging: management of patients with suspected pulmonary embolism presenting to ED by using a simple clinical model and D-dimer. Annals of Internal Medicine 135: 98-107, 2001.

Humphreys, C.W., Moores, L.K., Shorr, A.F., Cost-minimization analysis of two algorithms for diagnosing acute pulmonary embolism. Thrombosis Research 113(5): 275-82, 2004.

ACEP Clinical Policy; Critical Issues in the Evaluation and Management of Adult Patients Presenting with Suspected Lower-extremity Deep Vein Thrombosis. Annals of Emergency Medicine 41: 124-135, 2003.

ACEP Clinical Policy; Critical Issues in the Evaluation and Management of Adult Patients Presenting with Suspected Pulmonary Embolism. Annals of Emergency Medicine 41(2): 257-270, 2003.