17 - HCV and Cryoglobulinemia

Abstract

Cryoglobulinemia is defined as the presence of circulating immunoglobulins (Ig) that precipitate at temperatures < 37°C and re-dissolve on re-worming. Such an in vitro phenomenon is detectable in a wide number of chronic infectious and immunological disorders, as well as in some hematological malignancies. This chapter discusses Mixed Cryoglobulinemia (MC) that refers to a distinct clinical syndrome in the absence of other well known systemic or neoplastic disorders. Clinically, MC is characterized by a typical triad—purpura, weakness, arthralgias—and by multisystem organ involvement including chronic hepatitis, membranoproliferative glomeruonephritis (MPGN), peripheral neuropathy, skin ulcers, widespread vasculitis, and less frequently lymphatic and hepatic malignancies. The treatment of MC syndrome is particularly challenging because of its complex etiopathogenesis. For a correct therapeutic approach to hepatitis C virus (HCV)-related MC, one must deal with the concomitance of conflicting conditions: HCV infection, autoimmune, and lymphoproliferative alterations. While asymptomatic patients usually do not need any treatment even in the presence of high levels of cryocrit, patients with mildmoderate symptoms—such as palpable purpura—are particularly sensitive to the smallest variations of daily steroid dosage (1-2 mg).