The nearly 4 million Americans chronically infected with the hepatitis C virus (HCV) can transmit the infection to others through blood and other bodily fluids. The route of transmission can usually be determined in over 90% of new cases.
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).
People with cryoglobulinemia can have a variety of symptoms. These symptoms may include:
joint pain or swelling (arthralgia or arthritis)
a raised, purple skin rash (palpable purpura) usually in the lower portion of the legs
swelling of the legs and feet due to loss of protein in the urine from the kidney involvement
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. All of the symptoms of cryoglobulinemia often resolve with successful treatment of the hepatitis C virus infection.
B-cell non-Hodgkin's lymphoma and Hepatitis C
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 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. Both of these skin conditions can resolve with successful interferon therapy for the hepatitis C virus. In addition, up to 25% 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.
Diabetes and Hepatitis C
Chronic hepatitis C is also associated with type 2 diabetes and insulin resistance.