Cryoglobulinaemia

Key Information	Appropriate Tests
	Cryoglobulins.
Type I cryoglobulinaemia. Associated with:	Monoclonal cryoglobulins They are monoclonal immunoglobulins which self aggregate via their Fc receptors.
Macroglobulinaemia
Multiple myeloma
Type II cryoglobulinaemia (mixed monoclonal).	Mixed cryoglobulins These are usually composed of a monoclonal component (usually IgG, IgM or IgA) and a polyclonal component (mainly IgG). Identification and quantitation of the cryoglobulin(s), Rheumatoid factor, complement components C3 and C4. Rheumatoid factor is commonly positive, with reduced complement components C3 and C4.
Type III cryoglobulinaemia	Type III mixed cryoglobulinaemia – composed of polyclonal immunoglobulins of all isotypes.
Both type II and type III mixed cryoglobulinaemia may be associated with:
Autoimmune diseases. Infection Hepatitis C virus infection is a very common cause. Hepatitis B virus infection less common. Other viral, parasitic and bacterial infectious causes are described but much less common. Lymphoproliferative disorders are a rare cause.

Glossary Terms