Test Catalog

Test Id : STACL

Staclot Lupus Anticoagulant, Plasma

Useful For
Suggests clinical disorders or settings where the test may be helpful

Confirming or excluding the presence of a lupus-like circulating anticoagulant inhibitor (LA), in conjunction with other appropriate coagulation tests

 

Differentiating between deficiencies or inhibitors of specific coagulation factors and LA inhibitors

 

Evaluating a prolonged activated partial thromboplastin time resulting from inhibition

Method Name
A short description of the method used to perform the test

Only orderable as part of a reflex. For more information see:

ALUPP / Lupus Anticoagulant Profile, Plasma

ALBLD / Bleeding Diathesis Profile, Limited, Plasma

AATHR / Thrombophilia Profile, Plasma

APROL / Prolonged Clot Time Profile, Plasma

ADIC / Disseminated Intravascular Coagulation/Intravascular Coagulation and Fibrinolysis (DIC/ICF) Profile, Plasma

NY State Available
Indicates the status of NY State approval and if the test is orderable for NY State clients.

Yes

Reporting Name
Lists a shorter or abbreviated version of the Published Name for a test

Staclot LA, P

Aliases
Lists additional common names for a test, as an aid in searching

APTT

Hexagonal phase phospholipid

Staclot assay

STLA

Specimen Type
Describes the specimen type validated for testing

Plasma Na Cit

Specimen Required
Defines the optimal specimen required to perform the test and the preferred volume to complete testing

Only orderable as part of a reflex. For more information see:

ALUPP / Lupus Anticoagulant Profile, Plasma

ALBLD / Bleeding Diathesis Profile, Limited, Plasma

AATHR / Thrombophilia Profile, Plasma

APROL / Prolonged Clot Time Profile, Plasma

ADIC / Disseminated Intravascular Coagulation/Intravascular Coagulation and Fibrinolysis (DIC/ICF) Profile, Plasma

Reject Due To
Identifies specimen types and conditions that may cause the specimen to be rejected

Gross hemolysis Reject
Gross lipemia Reject
Gross icterus Reject

Specimen Stability Information
Provides a description of the temperatures required to transport a specimen to the performing laboratory, alternate acceptable temperatures are also included

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

Useful For
Suggests clinical disorders or settings where the test may be helpful

Confirming or excluding the presence of a lupus-like circulating anticoagulant inhibitor (LA), in conjunction with other appropriate coagulation tests

 

Differentiating between deficiencies or inhibitors of specific coagulation factors and LA inhibitors

 

Evaluating a prolonged activated partial thromboplastin time resulting from inhibition

Clinical Information
Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test

Lupus anticoagulant (LA) is one of several antibodies referred to as antiphospholipid antibodies (APA). Lupus anticoagulants are immunoglobulins (IgG, IgM, IgA, or a combination of these) that interfere with specific coagulation factor-phospholipid interactions, typically causing prolongation of one or more phospholipid-dependent clotting time tests (eg, activated partial thromboplastin time: APTT; dilute Russell viper venom time: DRVVT due to inhibition). The characteristic in vitro inhibition caused by the presence of LA inhibitors can be overcome by additional phospholipid, which can be used to confirm the presence of LA.

 

The Staclot LA assay system enhances the sensitivity and specificity of APTT-based LA detection by employing:

1. A partial thromboplastin that is more sensitive to LA than many other reagents.

2. Hexagonal (II) phase phosphatidylethanolamine for neutralization of LA inhibition rather than lamellar phase phospholipid.

 

Although LA causes prolonged clotting times in vitro, there is a strong association with thrombosis risk.

Reference Values
Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.

Only orderable as part of a reflex. For more information see:

ALUPP / Lupus Anticoagulant Profile, Plasma

ALBLD / Bleeding Diathesis Profile, Limited, Plasma

AATHR / Thrombophilia Profile, Plasma

APROL / Prolonged Clot Time Profile, Plasma

ADIC / Disseminated Intravascular Coagulation/Intravascular Coagulation and Fibrinolysis (DIC/ICF) Profile, Plasma

 

Staclot delta:

< or =8 seconds

Interpretation
Provides information to assist in interpretation of the test results

The diagnosis of a lupus anticoagulant (LA) requires performance and interpretation of complex coagulation testing, as well as correlation with available clinical information. Because of the heterogeneous nature of LA antibodies, no single coagulation test can identify or exclude all LAs. Consequently, a combination or panel of coagulation tests are performed, including the activated partial thromboplastin time (APTT) and the dilute Russell viper venom time (DRVVT). If the APTT and/or DRVVT are prolonged, additional testing may include mixing tests with normal plasma (to demonstrate inhibition) and the use of excess phospholipid in appropriate assay systems to confirm the presence of LA.

 

Interpretation of Staclot LA testing is complex, and must be done within the context of several additional laboratory tests (eg, APTT with reflexive APTT mixing study and platelet neutralization procedure: PNP; and DRVVT with reflexive mixing study and confirmatory procedure). The Staclot LA test is based on the comparison between the hexagonal phase phospholipid APTT (Staclot APTT + HEX) and the buffer control APTT (Staclot APTT). Both test specimens include a 1:1 mixture of patient and normal plasma. Plasma containing a LA will demonstrate: 1) a prolonged buffer control APTT (Staclot APTT); 2) a shortened APTT with addition of hexagonal phase phospholipid (Staclot APTT + HEX) relative to the buffer control APTT (Staclot delta). A positive Staclot LA test result is one in which the added hexagonal phase phospholipid (excess phospholipid) shortens the prolonged APTT by at least 8 seconds.

 

The Staclot LA test is highly specific for a LA even in the presence of therapeutic anticoagulation. In evaluation of patient specimens and based on established laboratory procedures and clinical diagnosis, we found that the sensitivity is 96% and the specificity is 88%. However, the overall sensitivity of the Staclot LA test is likely somewhat lower (70%-80%).

Cautions
Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances

No significant cautionary statements

Clinical Reference
Recommendations for in-depth reading of a clinical nature

1. Brandt JT, Triplett DA, Alving B, Sharrer I: Criteria for the diagnosis of lupus anticoagulants: an update. Thromb Haemost 1995;74(4):1185-1190

2. Blanco AN, Cardozo MA, Candela Me, et al: Anti-factor VIII inhibitors and lupus anticoagulants in haemophilia A patients. Thromb Haemost 1997;77(4):656-659

3. Rauch J, Tannenbaum M, Janoff AS: Distinguishing plasma lupus anticoagulants from anti-factor antibodies using hexagonal (II) phase phospholipids. Thromb Haemost 1989;68(3):892-896

Method Description
Describes how the test is performed and provides a method-specific reference

The Staclot LA test is performed on the Instrumentation Laboratory ACL TOP instrument. The procedure is based on the following principle: the test plasma that is suspected to contain a lupus anticoagulant (LA) is mixed with either hexagonal phase phospholipid (tube 2) or with buffer (tube 1). Normal plasma (1 part normal plasma + 1 part test plasma) is added to each tube to correct for any prolongation of the clotting time due to factor deficiencies that may be present. Next, an activated partial thromboplastin time (APTT) is performed on both tubes using a LA-sensitive partial thromboplastin reagent. If LA is present in the test plasma, the LA would typically be neutralized by the hexagonal phase phospholipid in tube 2 but not by the buffer in tube 1, resulting in a significant shortening of the clotting time of tube 2 compared with that of tube 1. By comparing the difference between the 2 clotting times, the presence of LA antibodies (anti-protein/phospholipid) in the test plasma can be identified.(Triplett DA, Barna LK, Unger GA: A hexagonal II phase phospholipid neutralization assay for lupus anticoagulant identification. Thromb Haemost;1993:70[5];787-793)

 

The incorporation of a heparin inhibitor (polybrene) in the Staclot LA assay system allows testing when heparin is in the sample. Accurate results can be expected in samples containing up to 1 U/mL of heparin. The Staclot LA method also includes the addition of normal plasma to correct for coagulation factor deficiencies that may result in a prolonged APTT. This enables testing of specimens from patients receiving oral anticoagulant therapy, as well as those with other congenital or acquired coagulation factor deficiencies, as a cause of the prolonged APTT.

PDF Report
Indicates whether the report includes an additional document with charts, images or other enriched information

No

Day(s) Performed
Outlines the days the test is performed. This field reflects the day that the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time before the test is performed. Some tests are listed as continuously performed, which means that assays are performed multiple times during the day.

Monday through Friday

Report Available
The interval of time (receipt of sample at Mayo Clinic Laboratories to results available) taking into account standard setup days and weekends. The first day is the time that it typically takes for a result to be available. The last day is the time it might take, accounting for any necessary repeated testing.

Same day/1 to 3 days

Specimen Retention Time
Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded

7 days

Performing Laboratory Location
Indicates the location of the laboratory that performs the test

Rochester

Fees
Several factors determine the fee charged to perform a test. Contact your U.S. or International Regional Manager for information about establishing a fee schedule or to learn more about resources to optimize test selection.

  • Authorized users can sign in to Test Prices for detailed fee information.
  • Clients without access to Test Prices can contact Customer Service 24 hours a day, seven days a week.
  • Prospective clients should contact their Regional Manager. For assistance, contact Customer Service.

Test Classification
Provides information regarding the medical device classification for laboratory test kits and reagents. Tests may be classified as cleared or approved by the US Food and Drug Administration (FDA) and used per manufacturer instructions, or as products that do not undergo full FDA review and approval, and are then labeled as an Analyte Specific Reagent (ASR) product.

This test has been modified from the manufacturer's instructions. Its performance characteristics were determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the US Food and Drug Administration.

CPT Code Information
Provides guidance in determining the appropriate Current Procedural Terminology (CPT) code(s) information for each test or profile. The listed CPT codes reflect Mayo Clinic Laboratories interpretation of CPT coding requirements. It is the responsibility of each laboratory to determine correct CPT codes to use for billing.

CPT codes are provided by the performing laboratory.

85598

Test Setup Resources

Setup Files
Test setup information contains test file definition details to support order and result interfacing between Mayo Clinic Laboratories and your Laboratory Information System.

Excel | Pdf

Sample Reports
Normal and Abnormal sample reports are provided as references for report appearance.

Normal Reports | Abnormal Reports

SI Sample Reports
International System (SI) of Unit reports are provided for a limited number of tests. These reports are intended for international account use and are only available through MayoLINK accounts that have been defined to receive them.

SI Normal Reports | SI Abnormal Reports