Cryoglobulins (CRGs) are antibodies made up of abnormal circulating proteins (antibodies) in the blood. At temperatures below 37 ° they can aggregate and precipitate, however this is a reversible process.
CRGs can be present, in small concentrations, even in the blood of healthy people. The presence of CRGs is most frequently associated with a large variety of diseases:
- infections, such as mononucleosis, hepatitis C and HIV / AIDS
- kidney disease
- autoimmune diseases, such as rheumatoid arthritis and systemic lupus erythematosus
- tumors, characterized by an increase in the number of white blood cells, such as multiple myeloma, lymphomas and lymphatic leukemia
- diseases associated with inflammation of the blood vessels (vasculitis)
Aggregates made up of these proteins can impede blood circulation, damaging the skin, joints, nerves and organs, particularly the kidneys and liver.
Often these antibodies do not cause any problems and therefore no drug treatment may be required. On the contrary, in some people they can cause vasculitis, which is the inflammation of the small and medium blood vessels called precisely cryoglobulinemic vasculitis. This condition may require drug treatment to ensure speedy recovery.
The presence of a large amount of cryoglobulins in the blood is called cryoglobulinemia.
It can occur with bruising (bruising), skin rashes, joint pain and weakness.
It can also cause Raynaud's phenomenon, a condition characterized by pain, bluish discoloration, numbness, paleness, tingling and cold in the fingers and toes (these disorders can occur in some individuals even in the absence of cryoglobulinemia but in the presence of other diseases, for example autoimmune).
Cryoglobulins can damage the skin to the point of causing injury (ulceration) and, in severe cases, gangrene.
They can also cause an uncontrolled activation of the immune system, with the consequent deposition of protein aggregates in the tissues, causing inflammation, bleeding and clot formation that can compromise the blood supply to organs such as the kidneys and liver.
The assessment (diagnosis) of cryoglobulinemia is carried out on the basis of the disorders and clinical manifestations present and through a specific laboratory test for cryoglobulins. A biopsy of the affected tissue or organ may be necessary to confirm this.
The most important treatment involves treating the disease underlying the abnormal production of antibodies. It is essential to have a correct diagnosis.
People with severe forms of vasculitis may need additional therapy with: steroids, non-steroidal anti-inflammatory drugs (NSAIDs), immunosuppressive drugs, plasma exchange with donor plasma (plasmapheresis).
Mayo Clinic. Cryoglobulinemia (English)
Vasculitis UK (English)