Diagnosing deficiency of coagulation factor X, congenital or acquired
Evaluating hemostatic function in liver disease
Investigation of prolonged prothrombin time or activated partial thromboplastin time
Optical Clot-Based
Factor X Activity Assay
Factor X
Plasma Na Cit
Coagulation testing is highly complex, often requiring the performance of multiple assays and correlation with clinical information. For that reason we suggest ordering Coagulation Consultations.
If priority specimen, mark request form, give reason, and request a call-back.
See Coagulation Guidelines for Specimen Handling and Processing in Special Instructions.
Specimen Type: Platelet-poor plasma
Collection Container/Tube: Light-blue top (citrate)
Submission Container/Tube: Plastic vial
Specimen Volume: 1 mL
Collection Instructions:
1. Within 4 hours of collection, centrifuge, transfer all plasma into a plastic vial, and centrifuge plasma again. Aliquot plasma into separate plastic vial leaving 0.25 mL in the bottom of centrifuged vial.
2. Freeze plasma immediately (no longer than 4 hours after collection) at -20 degrees C, or, ideally at < or =-40 degrees C.
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.
If not ordering electronically, complete, print, and send a Coagulation Test Request (T753) with the specimen.
0.5 mL
Gross hemolysis | Reject |
Gross lipemia | Reject |
Gross icterus | Reject |
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
Plasma Na Cit | Frozen | 14 days |
Diagnosing deficiency of coagulation factor X, congenital or acquired
Evaluating hemostatic function in liver disease
Investigation of prolonged prothrombin time or activated partial thromboplastin time
Factor X is a vitamin K-dependent serine protease that is synthesized in the liver. Its biological half-life is 24 to 48 hours. Factor X participates
Congenital factor X deficiency is rare. Acquired deficiency associated with liver disease, warfarin therapy, vitamin K deficiency, systemic
Adults: 70-150%
Normal, full-term newborn infants or healthy premature infants may have decreased levels (> or =15-20%) which may not reach adult levels for > or =180 days postnatal.*
*See Pediatric Hemostasis References section in Coagulation Guidelines for Specimen Handling and Processing in Special Instructions.
Acquired deficiency is more common than congenital deficiency.
Homozygotes: <25%
Heterozygotes: 25% to 50%
Liver disease, warfarin therapy, or vitamin K deficiency may
1. Girolami A, Scandellari R, Scapin M, Vettore S: Congenital bleeding disorders of the vitamin K-dependent clotting factors. Vitam Horm 2008;78:281-374
2. Brenner B, Kuperman AA, Watzka M, Oldenburg J: Vitamin K-dependent coagulation factors deficiency. Semin Thromb Hemost 2009 Jun;35(4):439-446
3. Menegatti M, Peyvandi F: Factor X deficiency. Semin Thromb Hemost 2009 Jun;35(4):407-415
4. Girolami A, Ruzzon E, Tezza F, et al: Congenital FX deficiency combined with other clotting defects or with other abnormalities: a critical evaluation of the literature. Haemophilia 2008;14(2):323-328
5. Girolami A, Scarparo P, Scandellari R, Allemand E: Congenital factor X deficiencies with a defect only or predominantly in the extrinsic or in the intrinsic system: a critical evaluation. Am J Hematol 2008;83(8):668-671
The factor X assay is performed on the Instrumentation Laboratory ACL TOP using the prothrombin time (PT) method and a factor-deficient substrate. Patient plasma is combined and incubated with a factor X-deficient substrate (normal plasma depleted of factor X by immunoadsorption). After a specified incubation time, a PT reagent is added to trigger the coagulation process in the mixture. Then the time to clot formation is measured optically at a wavelength of 671 nm.(Owen CA Jr, Bowie EJW, Thompson JH Jr: Diagnosis of Bleeding Disorders. Second edition. Little, Brown and Company, Boston, MA. 1975; Meijer P, Verbruggen and Spannagi M: Chapter 33: Clotting factors and inhibitors: Assays and Interpretation. In Laboratory Hematology Practice. Edited by K Kottke-Marchant. Wiley Blackwell Publishing, 2012, pp 435-446)
Monday through Friday
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.
85260
Test Id | Test Order Name | Order LOINC Value |
---|---|---|
F_10 | Coag Factor X Assay, P | 3218-5 |
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.
|
---|---|---|
F_10 | Coag Factor X Assay, P | 3218-5 |