hematology and oncology
Dysproteinemias Causing Vascular Purpura
Cryoglobulinemia
Cryoglobulinemia produces immunoglobulins that precipitate when plasma is cooled (ie, cryoglobulins) while flowing through the skin and subcutaneous tissues of the extremities. Cryoglobulins may be IgG, IgM, or IgA. Mixed cryoglobulins are usually composed of IgM complexed with a monoclonal or polyclonal IgG. The immune complexes can interfere with normal platelet function and fibrin polymerization. Monoclonal immunoglobulins formed in Macroglobulinemia (lymphoplasmacytic lymphoma) or in Cryoglobulins can also be idiopathic. Cryoglobulinemia can also lead to small-vessel vasculitis, which can cause purpura; hyperviscosity and direct vascular trauma can contribute. Cryoglobulinemia can manifest with acral hemorrhagic necrosis, palpable purpura, livedo reticularis, and leg ulcers. Cryoglobulins can be detected by laboratory testing. 