To determine if symptoms such as sensitivity of extremities to cold are due to the presence of abnormal proteins called cryoglobulins in the blood.
Cryoglobulin
When a person has symptoms such as a rash, bruising, pain, weakness, joint pain, and/or paleness and coolness of the extremities that occur at cold temperatures.
A blood sample taken from a vein in your arm, kept at body temperature until tested in the laboratory..
None required
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How is it used?
A cryoglobulin test is used to help detect the presence and relative quantity of cryoglobulins in the blood. It may be requested along with other tests to help identify or rule out potential causes of cryoglobulinemia. The tests requested depend on what condition or disease is suspected. They may include tests such as rheumatoid factor (RF), antinuclear antibody (ANA), and a variety of other autoantibodies to help identify or rule out an autoimmune disorder, hepatitis C testing, etc.
If the cryoglobulin test is positive, then it will be followed with specialised protein electrophoresis and immunofixation electrophoresis (IFE) testing to determine which type(s) of protein are present as cryoglobulins and which type of cryoglobulinemia the person has.
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When is it requested?
The cryoglobulin test is requested whenever a person has symptoms that may be associated with cryoglobulinemia. Some of these may include:
- Bruising
- Rashes
- Joint pain
- Weakness
- Raynaud's phenomenon, which is characterised by pain, paleness, bluing, numbness, tingling and coldness in the fingers and toes with exposure to cold.
Cryoglobulins may sometimes cause damage to the skin that leads to ulcers and, in severe cases of tissue damage, can cause gangrene.
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What does the test result mean?
The cryoglobulin test is negative in most healthy people and is not routinely requested on those without symptoms.
When the test is positive, it means that cryoglobulins are present and have the potential to precipitate upon exposure to cold. The symptoms experienced when this happens will vary from person to person, may be different with each exposure, and will not necessarily correlate with the quantity of cryoglobulins present.
A positive test for cryoglobulin may be seen in numerous conditions. Some examples include:
- Infections such as Lyme disease, infectious mononucleosis (mono), hepatitis C and HIV/AIDS
- Kidney disease
- Autoimmune diseases such as systemic lupus erythematosus, rheumatoid arthritis, and Sjögren's syndrome
- Cancers of immune cells such as multiple myeloma, lymphoma and lymphoid leukaemia
- Disorders associated with inflammation of blood vessels (vasculitis)
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Is there anything else I should know?
Cryoglobulinemias are sometimes separated into "secondary" cryoglobulinemia, associated with an underlying condition, and "essential or idiopathic" cryoglobulinemia, not associated with another disease. Many of the cases of essential cryoglobulinemia have now been shown to have a disease association, such as Hepatitis C.
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Can someone prevent cryoglobulin-related symptoms?
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Is there something I can do to get rid of my cryoglobulins?
In general, no. If they are due to a temporary condition, such as an infection, then they may go away when the infection resolves. If they are due to a chronic condition, such as an autoimmune disorder, then they may reduce as a consequence of treating the underlying condition, but many persist. In type I cryoglobuinaemia, effective treatment of the underlying immune cell cancer will reduce the amount of cryoglobulin in the blood. In some cases, apheresis may be performed to remove cryoglobulins from the blood and to relieve symptoms, but this may help only temporarily.
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What are some other tests that may be done to determine the underlying cause of cryoglobulinemia?
In addition to protein electrophoresis and, depending on the doctor's suspicions about the underlying condition, other tests that may be performed include hepatitis C tests, ANA, Mono test and RF, complement C4 levels to name a few.
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How is cryoglobulinemia treated?
It is primarily treated by addressing the underlying condition. Drugs such as nonsteroidal anti-inflammatory drugs (NSAIDs), corticosteroids, and other immune suppressants may sometimes be needed to help relieve symptoms and minimise complications. Some patients may be suitable for B-cell depletion therapy (Rituximab).