"...Causes
Cryoglobulins are antibodies. It is not yet known why they become solid at low temperatures. When they do thicken or become somewhat gel-like, they can block blood vessels throughout the body. This may lead to complications ranging from skin rashes to kidney failure.
Cryoglobulinemia is part of a group of diseases that cause vasculitis -- damage and inflammation of the blood vessels throughout the body. The disorder is grouped into three main types, depending on the type of antibody that is produced:
* Cryoglobulinemia type I
* Cryoglobulinemia typeII
* Cryoglobulinemia type III
Types II and III are also referred to as mixed cryoglobulinemia.
Type I cryoglobulinemia is most often related to cancer of the blood or immune systems.
Types II and III are most often found in people who have a chronic (long-lasting) inflammatory condition, such as an autoimmune disease or hepatitis C. Most patients with mixed cryoglobulinemia have a chronic hepatitis C infection...."
http://www.nlm.nih.gov/medlineplus/ency/article/000540.htm