Chromogenic Factor X

Label Mnemonic:	CH10
Epic code:	LAB1020
Downtime form:	A-1a Doctor/Provider Orders - Pathology Core and Specialty Care Nursery

Hemostasis/Thrombosis
6240 RCP
356-3573

Specimen(s):

Plasma More information

Collection Medium:

Light Blue top tube 2.7 mL (Na Citrate)

Minimum:

Full draw; 2.7 mL light blue top

Rejection Criteria:

Short drawn tube, clot, traumatic tap (excessive hemolysis).

Delivery Instructions:

Deliver to laboratory immediately after collection.

Testing Schedule:

0800-1630 Monday, Wednesday and Friday. If you need results STAT, call Hematology resident (0800-1630, M-F) at 356-8628. All other times page the Pathology resident on-call at 3404.

Turn Around Time:

24-36 hours

Reference Range:

59 – 130%

Therapeutic reference range is 20 – 40%

Interpretive Data:

An approximate Chromogenic Factor X range of 20-40% corresponds to a therapeutic INR range of 2.0-3.0. This assay can be used for monitoring warfarin therapy in patients with lupus anticoagulants. Anti-phospholipid antibodies may influence the prothrombin time and resulting INR calculation, causing it to not accurately reflect the true level of anticoagulation.

Rosborough, T.K. and Shepherd, M.F. Unreliability of International Normalized Ratio for Monitoring Warfarin Therapy in Patients with Lupus Anticoagulant. Pharmacotherapy 2004;24(7):838-842.

McGlasson, D.L., Romick, B.G., and Rubal, B.J. Comparison of a Chromogenic Factor X Assay with International Normalized Ratio for Monitoring Oral Anticoagulation Therapy. Blood Coagulation and Fibrinolysis 2008;19:513-517.

Test Limitations:

This test is to be used for coumadin monitoring of patients with positive Lupus anticoagulants.

Methodology:

Activity detection by chromogenic substrate

CPT Code:

85260

See Additional Information:
Specimens Requiring Immediate Delivery
Phlebotomy Tubes and Order of Draw
Hemolysis Chart