The Connection Between Hepatitis C and Autoimmune Disorders
Q. What Causes These Symptoms?
A. When the immune system becomes activated, as in the case of an autoimmune disease, there is increased production of inflammatory cells (T-cells), antibodies, and other inflammatory chemicals. The overactivated immune system can lead to systemic symptoms of fatigue and low-grade fever. Some other symptoms, such as glomerulonephritis and arthritis, are due to deposits of antibodies that accumulate in the kidney or joints, leading to damage in those tissues.
Q. What Is the Process by Which HCV Triggers Autoimmune Conditions?
A. Although the mechanism is still poorly understood, it is theorized that proteins appear on the surface of infected liver cells. This leads to an autoimmune response, in which cells of the immune system (including T and B cells) recognize these new proteins as foreign bodies. These cells then attack the liver, causing inflammation of the liver cells and eventual destruction of liver tissue.
Q. How Is Autoimmune Hepatitis Diagnosed?
A. Autoimmune hepatitis requires laboratory tests to distinguish it from uncomplicated hepatitis C infections. When AIH is triggered, the immune system produces protective antibodies that actually attack the enemy organ. These antibodies are known as autoantibodies. Hypergammaglobulinemia, an excess of antibodies in the blood, is a common finding in autoimmune hepatitis. Blood tests for certain autoantibodies may also provide diagnostic clues. The diagnosis may, however, require a liver biopsy.
Q. How Is Treatment for Patients With Autoimmunity Determined?
A. Interferon is the only approved treatment for HCV, but its use in people with autoimmune hepatitis has been shown to exacerbate the disease. In general, steroids are used for people with autoimmune hepatitis due to non-viral causes. But in patients with hepatitis C, steroids can increase viral replication.
A liver biopsy is usually recommended to determine which disease process is causing the greatest damage to the liver: the HCV infection or the autoimmune hepatitis. In general, if the HCV infection were predominant and the autoimmune hepatitis mild, treatment of HCV with a regimen containing interferon would be considered. However, if the autoimmune hepatitis were severe, leading to such complications as kidney damage, rashes, or rapid liver failure, steroids or other immunosuppressant drugs would more likely be recommended.
The choice between these treatment options boils down to the immune system. Alfa interferon, which activates the immune system to reduce viral replication, could be problematic for those whose immune system was already over-activated due to severe autoimmune hepatitis. Steroids, which suppress the immune system, could be problematic for those with severe HCV-infection, leading to a compromise of the body's ability to fight the infection.