Cryoglobulins are abnormal blood proteins that, by definition, have the unusual properties of precipitating from the blood serum (no longer being able to dissolve in the blood) when it is chilled (hence the "cryo-") and redissolving upon rewarming. Cryoglobulins are gamma globulins with a molecular weight of approximately 200,000.
Cryoglobulins can cause problems by causing:
- The blood to be abnormally "thick" which increases the risk of blood clots forming in the brain (stroke), eyes, and heart.
- Inflammation of blood vessels (vasculitis) which increases the risk of blockage of arteries.
Essential mixed cryoglobulinemia is characterized by joint pains and swelling (arthritis), enlargement of the spleen, inflammation of skin blood vessels (vasculitis) with purplish patches, and nerve, kidney and heart disease.
Treatment is with medications which reduce inflammation and suppress the immune system. Plasmapheresis, in which the blood's serum is replaced with saline (salt water solution) or cryoglobulin depleted plasma (cryofiltration), may be done in severe cases.
Sometimes, small amounts of cryoglobulins are discovered by accident in the lab in a serum sample from someone with no apparent symptoms.