Cryofibrinogen

Does this test have other names?

Cryofibrinogenemia, CF

What is this test?

This test looks for an abnormal protein called cryofibrinogen in your blood plasma.

People who have this abnormal protein may develop a disorder called cryofibrinogenemia. Although the disorder rarely causes symptoms, if untreated, it can become life-threatening and lead to stroke, heart attack, gangrene, or other medical emergencies. 

Why do I need this test?

You may have this test to find out whether you have cryofibrinogenemia. When this disorder causes signs and symptoms, they may include:

• Sensitivity to cold, including itching, redness, swelling, or hives

• Red or purple marks on the skin, a condition called purpura

• Skin lesions

• Stroke

• Heart attack

• Poor circulation

• Pulmonary embolism, or a blood clot in the lungs

• Phlebitis, or swelling caused by a blood clot, usually in the legs

You may also have this test to monitor your treatment for cryofibrinogenemia or a related disorder.

In primary cryofibrinogenemia, the disease occurs without any other conditions. You may also have a test for secondary cryofibrinogenemia, which is a condition linked to a wide range of disorders. It is unclear whether these diseases cause cryofibrinogenemia. Disorders that are commonly associated with secondary cryofibrinogenemia include:

• Certain cancers, such as non-Hodgkin lymphoma and colorectal cancer

• Infections, such as tuberculosis, streptococcus, herpes, and hepatitis C

• Connective tissue disorders, such as lupus or Crohn's disease

• Vasculitis, a disorder caused by inflammation of blood vessels 

What other tests might I have along with this test?

Your doctor will order other tests if your cryofibrinogen test shows that you have cryofibrinogenemia. To diagnose primary cryofibrinogenemia, your doctor may order an angiogram to look for blocked arteries or a biopsy of affected tissue.

Additional tests depend on your symptoms and history, but may include screenings for cancer, infection, and inflammatory diseases.  

What do my test results mean?

Many things may affect your lab test results. These include the method each lab uses to do the test. Even if your test results are different from the normal value, you may not have a problem. To learn what the results mean for you, talk with your health care provider.

Your test results show whether and how much cryofibrinogen is in your blood plasma. Healthy people can have a small amount of this protein in their blood, so a positive result alone doesn't necessarily mean that you have a problem.  

Results are given in milligrams per liter (mg/L). Generally, a level greater than 50 mg/L means that you have cryofibrinogenemia. You may have levels of under 50 mg/L and no symptoms of disease, yet still have it. This is called asymptomatic cryofibrinogenemia. Some studies estimate that 2 to 9 percent of people tested have asymptomatic cryofibrinogenemia.    

How is this test done?

The test requires a blood sample, which is drawn through a needle from a vein in your arm.

Does this test pose any risks?

Taking a blood sample with a needle carries risks that include bleeding, infection, bruising, or feeling dizzy. When the needle pricks your arm, you may feel a slight stinging sensation or pain. Afterward, the site may be slightly sore.

What might affect my test results?

If you are taking a blood thinner containing heparin, you may get a false-positive test result. 

How do I get ready for this test?

You don't need to prepare for this test. But, be sure your doctor knows about all medicines, herbs, vitamins, and supplements you are taking. This includes medicines that don't need a prescription and any illicit drugs you may use.