Hepatitis C: extrahepatic manifestations.

Chronic hepatitis C virus (HCV) infection is associated with multiple extrahepatic manifestations (EHM) affecting various organs in the body. Approximately 40% to 75% of patients with chronic HCV infection experience at least one clinical EHM during the course of the HCV infection. Mixed cryoglobulinemia (type 2) is the most documented EHM associated with chronic HCV infection. This has been documented in up to 50% of patients. Clinically, it presents as arthralgia, weakness, and cutaneous symptoms. Morphologically, immune complex depositions are identified in small vessels and glomerular capillary walls, leading to leukocytoclastic vasculitis in the skin and membranoproliferative glomerulonephritis in the kidney. In other EHMs of chronic HCV infection not related to cryoglobulinemia, such as Sjögren syndrome, lichen planus, and autoimmune thyroiditis, autoimmune processes resulting in chronic inflammatory infiltrates are thought to be the underlying mechanism.