Test Id : 13ACT
Coagulation Factor XIII (13) Activity Assay, Plasma
Useful For
Suggests clinical disorders or settings where the test may be helpful
Measuring factor XIII activity
Method Name
A short description of the method used to perform the test
Fluorescence-Based Enzyme Activity
NY State Available
Indicates the status of NY State approval and if the test is orderable for NY State clients.
Reporting Name
Lists a shorter or abbreviated version of the Published Name for a test
Aliases
Lists additional common names for a test, as an aid in searching
Factor XIII
13ACT
Factor XIII (13)
FXIII
Factor 13
Specimen Type
Describes the specimen type validated for testing
Plasma Na Cit
Ordering Guidance
Coagulation testing is highly complex, often requiring the performance and correlation of factor XIII activity with multiple assays and correlation with clinical information. For that reason, if indicated, consider ordering ALBLD / Bleeding Diathesis Profile, Limited, Plasma.
Specimen Required
Defines the optimal specimen required to perform the test and the preferred volume to complete testing
Patient Preparation:
1. Fasting: 8 hours, preferred but not required
2. It is best to perform this study pre-plasma transfusion if possible. If patient has been recently transfused, wait at least 48 hours after transfusion before collecting the specimen.
3. Specimen should be collected prior to factor replacement therapy.
Collection Container/Tube: Light-blue top (3.2% sodium citrate)
Submission Container/Tube: Plastic vial
Specimen Volume: 1 mL Platelet-poor plasma
Collection Instructions:
1. For complete instructions, see Coagulation Guidelines for Specimen Handling and Processing.
2. Centrifuge, transfer all plasma into a plastic vial, and centrifuge plasma again.
3. Aliquot plasma into a plastic vial, leaving 0.25 mL in the bottom of centrifuged vial.
4. Freeze plasma immediately (no longer than 4 hours after collection) at -20 degrees C or, ideally, -40 degrees C or below.
Additional Information:
1. Double-centrifuged specimen is critical for accurate results.
2. Each coagulation assay requested should have its own vial.
Special Instructions
Library of PDFs including pertinent information and forms related to the test
Forms
If not ordering electronically, complete, print, and send an Coagulation Test Request (T753) with the specimen.
Specimen Minimum Volume
Defines the amount of sample necessary to provide a clinically relevant result as determined by the testing laboratory. The minimum volume is sufficient for one attempt at testing.
Platelet-poor plasma: 0.5 mL
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 | 180 days |
Useful For
Suggests clinical disorders or settings where the test may be helpful
Measuring factor XIII activity
Clinical Information
Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test
Factor XIII (FXIII) is found in plasma and platelets. Plasma FXIII consists of 2 A subunits and 2 B subunits; platelet FXIII consists of only 2 A subunits. After FXIII is activated by thrombin, it catalyzes the formation of peptide bonds between adjacent molecules of fibrin monomers, thus conferring mechanical and chemical stability to the fibrin clot. Fibrin that is not covalently crosslinked exhibits an increased susceptibility to fibrinolysis.
Congenital FXIII deficiency is an autosomal recessive bleeding disorder. Individuals with severe FXIII deficiency (FXIII:C <1%) may experience intracranial hemorrhage, soft tissue hemorrhage, hemarthrosis, and hematomas. Typically, affected patients suffer from delayed bleeding occurring 24 to 48 hours after the initial hemostatic response to an injury. In newborns, bleeding from the umbilical stump may occur after separation of the umbilical cord, as well as intracranial bleeding. Poor wound healing and abnormal scar formation are also observed. Asymptomatic individuals with milder deficiencies may experience post-surgical or trauma-related bleeding; additionally female patients may experience recurrent spontaneous abortions and heavy menstrual bleeding.
Although felt to be rare, acquired FXIII deficiency is likely more commonly encountered than congenital deficiency state. In one series of patients, the large majority of patients had an acquired deficiency state as opposed to a congenital deficiency. The various etiologies included consumptive coagulopathy, infection related, or due to development of autoantibodies. These patients develop adult-onset bleeding.
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.
> or =55%
Interpretation
Provides information to assist in interpretation of the test results
Decreased factor XIII (FXIII) activity could reflect acquired conditions (eg, autoimmune conditions [systemic lupus erythematosus, rheumatoid arthritis, malignancy, monoclonal gammopathy of undetermined significance, medication-isoniazid], increased consumption [surgery, disseminated intravascular coagulation/intravascular coagulation and fibrinolysis, inflammatory bowel disease, Henoch-Schonlein purpura, sepsis, thrombosis], decreased synthesis [liver disease, leukemia, medication-valproic acid and tocilizumab]), autoantibodies to FXIII, or a congenital deficiency state.
Normal FXIII activity makes a congenital or acquired FXIII deficiency less likely. Individuals with heterozygous FXIII-A deficiency have FXIII activity between 30% and 70% and are generally considered to be asymptomatic. However, several studies have reported severe bleeding in affected individuals.
Recent transfusion of plasma, cryoprecipitate, or FXIII concentrate will raise FXIII levels and may mask a diagnosis of FXIII deficiency.
Cautions
Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances
Factor XIII (FXIII) activity results may be underestimated by:
-Bilirubin greater than 7 mg/dL
-Hemoglobin greater than 125 mg/dL
-Lipemia greater than 3500 mg/dL
Residual platelets in frozen-thawed plasma can increase FXIII activity such that the FXIII activity may be falsely normal. Specimens that are to be frozen before testing must be centrifuged twice to remove as many of the platelets as possible before freezing.
Factor XIII results on Ceveron s100 are not affected by rheumatoid factor up to 600 mg/dL, fibrinogen up to 6 g/L, ammonia up to 2 mM and heparin up to 10 U/mL.
Clinical Reference
Recommendations for in-depth reading of a clinical nature
1. Anwar R, Miloszewski KJ. Factor XIII deficiency. Br J Haematol. 1999;107(3):468-484
2. Kottke-Marchant K. Performance and interpretation of routine coagulation assays. In: Laboratory Hematology Practice. Wiley Blackwell Publishing; 2012:420-434
3. Hoffman R, Benz EJ Jr, Siberstein LE, et al. Hematology: Basic Principles and Practice. 7th ed. Elsevier; 2018
4. Kohler HP, Ichinose A, Seitz R, Ariens RA, Muszbek L; Factor XIII and Fibrinogen SSC Subcommittee of the ISTH. Diagnosis and classification of factor XIII deficiencies. J Thromb Haemost. 2011;9(7):1404-1406
5. Al Sharif MA, Mathews N, Tasneem S, et al. Measurement of factor XIII for the diagnosis and management of deficiencies: insights from a retrospective review of 10 years of data on consecutive samples and patients. Res Pract Thromb Haemost. 2025;9(1):102689
6. Dorgalaleh A, Jozdani S, Zadeh MK. Factor XIII deficiency: Laboratory, molecular, and clinical aspects. Semin Thromb Hemost. 2025;51(2):155-169. doi:10.1055/s-0044-1796673
Method Description
Describes how the test is performed and provides a method-specific reference
Factor XIII (FXIII) is activated by thrombin in the presence of calcium. Activated FXIII then cleaves the sidechain carboxamide bond of the assay’s substrate and thereby releases the dark quencher (2,4-dinitrophenyl) linked to the cadaverine spacer. Subsequently, the increase of fluorescence results from the N-terminally attached fluorophore N-methyl-2-aminobenzoic acid. The fluorescent signal is proportional to the FXIII activity in the plasma sample.(Package insert: Technofluor FXIII Activity. Technoclone; 07/15/2020)
PDF Report
Indicates whether the report includes an additional document with charts, images or other enriched information
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.
Specimen Retention Time
Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded
Performing Laboratory Location
Indicates the location of the laboratory that performs the test
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.
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- Prospective clients should contact their account representative. 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 was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. It 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.
CPT codes are provided by the performing laboratory.
85290
LOINC® Information
Provides guidance in determining the Logical Observation Identifiers Names and Codes (LOINC) values for the order and results codes of this test. LOINC values are provided by the performing laboratory.
| Test Id | Test Order Name | Order LOINC Value |
|---|---|---|
| 13ACT | Factor XIII(13) Activity, P | In Process |
| Result Id | Test Result Name |
Result LOINC Value
Applies only to results expressed in units of measure originally reported by the performing laboratory. These values do not apply to results that are converted to other units of measure.
|
|---|---|---|
| 623415 | Factor XIII (13) Activity, P | In Process |