The most widely described associated condition is cryoglobulinemia. This condition is due to the presence of abnormal antibodies (called cryoglobulins) that come from hepatitis C virus stimulation of lymphocytes (white blood cells). These antibodies can deposit in small blood vessels, thereby causing inflammation of the vessels (vasculitis) in tissues throughout the body including the skin, joints, and kidneys (glomerulonephritis).
Most people with cryoglobulinemia have no symptoms. When symptoms occur, they may include:
In addition, people with cryoglobulinemia may develop Raynaud's phenomenon, in which the fingers and toes turn color (white, then purple, then red) and become painful in cold temperatures.
The diagnosis of cryoglobulinemia is made by doing a special test in the laboratory to detect the cryoglobulins in the blood. In this test, the cryoglobulins are identified when the blood sample is exposed to the cold (cryo means cold). In addition, a finding of typical inflammation of small blood vessels in certain tissue biopsies (for example, the skin or kidney) supports the diagnosis of cryoglobulinemia. Symptoms of cryoglobulinemia often resolve with successful treatment of the hepatitis C virus infection.
B-cell non-Hodgkin's lymphoma, a cancer of the lymph tissue, has also been associated with chronic hepatitis C virus. The cause is thought to be the excessive stimulation by the hepatitis C virus of B-lymphocytes, which results in the abnormal reproduction of the lymphocytes. Interestingly, treatment with interferon therapy has caused come cases of hepatitis C virus-associated low-grade (not very active) non-Hodgkin's lymphoma to go into remission. However, most individuals with hepatitis C virus-associated high-grade non-Hodgkin's lymphoma will require the usual anti-cancer therapies.
Skin Conditions and Hepatitis C
Two skin conditions, lichen planus and porphyria cutanea tarda, have been associated with chronic hepatitis C virus. Porphyria cutanea tarda may resolve with successful interferon therapy for the hepatitis C virus. There have been cases, however, where lichen planus actually worsened during interferon treatment. In addition, up to 65% of hepatitis C virus patients have autoimmune antibodies, such as anti-nuclear antibody, anti-smooth muscle antibodies, and rheumatoid factor. But true rheumatoid arthritis is uncommon in people with hepatitis C virus.