[Cryoglobulinemia].

Cryoglobulins are proteins that precipitate when cooled and dissolve when heated. Cryoglobulinemia may be classified into Type I (monoclonal), Type II (mixed), and Type III (polyclonal). About 5 to 10% of myeloma proteins and 7 to 20% of primary macroglobulinemia proteins are cryoprecipitable (Type I cryoglobulin), and more than half of these have no symptoms attributable to cryoglobulin nature of their M-component. The most common symptoms of Type I cryoglobulinemia include Raynaud's phenomenon, necrosis of the toes or legs, vascular purpura, and urticaria. In Type I cryoglobulinemia due to plasma cell dyscrasias, treatment is directed primarily at the underlying disease. Plasmapheresis and cryofiltration may be helpful particularly when this can be combined with effective chemotherapy.