Cryoglobulinemia is the presence of abnormal proteins in the blood. These abnormal proteins become thick or gel-like in cold temperatures.

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.

Other conditions that may be related to cryoglobulinemia include:

• Leukemia
• Multiple myeloma
• Mycoplasma pneumonia
• Primary macroglobulinemia
• Rheumatoid arthritis
• Systemic lupus erythematosus

• Difficulty breathing
• Enlargement of the liver and spleen
• Fatigue
• Glomerulonephritis
• Joint pain
• Muscle pain
• Purpura
• Raynaud's phenomenon
• Skin death
• Skin ulceration

Tests for cryoglobulinemia include:

• CBC
• Complement assay -- numbers will be low
• Cryoglobulin test -- may show presence of cryoglobulins
• Liver function tests -- may be high
• Rheumatoid factor -- positive in types II and III
• Skin biopsy -- may show vasculitis
• Urinalysis -- may show blood in the urine if kidneys are affected

Other tests may include:

• Angiogram
• Chest x-ray
• ESR
• Hepatitis C test
• Nerve conduction tests, if weakness in arms or legs is present
• Protein electrophoresis - serum