/SiteAssets/Images/FMOLHSBlankBanner.png

Health Information

Factor IX assay
Bookmarks

Factor IX assay

Print-Friendly  

Christmas factor assay; Serum factor IX

The factor IX assay is a blood test that measures the activity of factor IX. This is one of the substances involved in blood clotting (coagulation).

I Would Like to Learn About:

  • How the Test is Performed

    A sample of blood will be taken from your vein.

  • How to Prepare for the Test

    You may need to stop taking some medicines before this test. Your health care provider will tell you which ones.

  • How the Test will Feel

    You may feel slight pain or a sting when the needle is inserted to draw blood. You may feel some throbbing afterward.

  • Why the Test is Performed

    This test is used to find the cause of too much bleeding (decreased blood clotting). It is also done if a family member is known to have hemophilia B. The test may used to see how well treatment for hemophilia B is working, as well.

  • Normal Results

    A normal value is 50 - 200% of the laboratory control or reference value.

    Normal value ranges may vary slightly among different laboratories. Talk to your doctor about the meaning of your specific test results.

    The examples above show the common measurements for results for these tests. Some laboratories use different measurements or may test different specimens.

  • What Abnormal Results Mean

    Decreased factor IX activity may be related to:

    • Congenital deficiency of factor IX (hemophilia B)
    • Disseminated intravascular coagulation (DIC)
    • Fat malabsorption
    • Liver disease (such as cirrhosis)
    • Vitamin K deficiency
    • Warfarin (Coumadin) use
  • Risks

    Veins and arteries vary in size so it may be harder to take a blood sample from one person than another.

    Other slight risks from having blood drawn but may include:

    • Excessive bleeding
    • Fainting or feeling light-headed
    • Hematoma (blood accumulating under the skin)
    • Infection (a slight risk any time the skin is broken)

    This test is most often done on people who have bleeding problems. The risk of excessive bleeding is slightly more than for people without bleeding problems.

  • Considerations

    When you bleed, the body starts a series of activities that help the blood clot. This is called the coagulation cascade. The process involves special proteins called coagulation factors (factor IX is a coagulation factor).

    Each factor's reaction triggers the next reaction. The final product of the coagulation cascade is the blood clot. Blood clots may not form normally if any one of the clotting factors is abnormally low.

Related Information

  Hemophilia BMalabsorptionLiver diseaseCirrhosisVitamin K     CirrhosisVitamins

References

Carcao M, Moorehead P, Lillicrap D. Hemophelia A and B. In: Hoffman R, Benz EJ Jr, Silberstein LE, Heslop HE, Weitz JI, eds. Hematology: Basic Principles and Practice. 6th ed. Philadelphia, PA: Saunders Elsevier; 2012:chap 137.

Ragni M. Hemorrhagic disorders: Coagulation factor deficiencies. In: Goldman L, Schafer AI, eds. Goldman's Cecil Medicine. 24th ed. Philadelphia, PA: Saunders Elsevier; 2011:chap 177.

BACK TO TOP 

Review Date: 3/3/2013  

Reviewed By: Yi-Bin Chen, MD, Leukemia/Bone Marrow Transplant Program, Massachusetts General Hospital. Also reviewed by A.D.A.M. Health Solutions, Ebix, Inc., Editorial Team: David Zieve, MD, MHA, Bethanne Black, Stephanie Slon, and Nissi Wang.

The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. © 1997- A.D.A.M., Inc. Any duplication or distribution of the information contained herein is strictly prohibited.

adam.com

 
A.D.A.M. content is best viewed in IE9 or above, Fire Fox and Google Chrome browser.