The enigma of complement activation in mixed cryoglobulinemia

Abstract

Mixed Cryoglobulins are immune complexes which form when subsets of IgM Rheumatoid Factor complex with IgG in the cold. The IgM component of these complexes demonstrates a spectrum of clonality ranging from being polyclonal (Type III) to monoclonal (Type II), the latter almost always IgMκ defined in part by cross-reactive idiotypy. They are prevalent in patients infected with Hepatitis C Virus (HCV), as well as some patients with Primary Sjogren's syndrome (SS) or Systemic Lupus Erythematosus (SLE) with the clinical manifestations of vasculitis and/or glomerulonephritis [1].