The Connection Between Hepatitis C and Autoimmune Disorders
Infection with the hepatitis C virus (HCV) can trigger autoimmune hepatitis (AIH) in a minority of patients. This means that the liver cells are damaged not only by the virus but also by the body's own immune system.
Chronic hepatitis C is a long-lasting liver infection caused by the hepatitis C virus. During the first 6 months of the infection, it's called acute hepatitis. For most people with acute hepatitis C -- up to 80% -- their illness moves on to a chronic, lasting hepatitis C infection.
AIH triggers the body to attack its liver cells as if the liver cells were harmful foreign substances. Patients with a combination of HCV and autoimmune hepatitis may suffer from more debilitating symptoms than patients with HCV alone. Autoimmune hepatitis is associated with other autoimmune illnesses, including thyroiditis (inflammation of the thyroid), diabetes, rheumatoid arthritis (inflammation of the joints), and ulcerative colitis (inflammation of the large intestine).
Below are some frequently asked questions about the complex relationship between HCV and autoimmune hepatitis.
Q. What are the Symptoms of Autoimmune Hepatitis?
A. In its most clandestine form, AIH may be detected during the evaluation of HCV in a person who is asymptomatic (without symptoms). An asymptomatic presentation occurs approximately 15% to 20% of the time. People whose condition is asymptomatic often have a milder course of disease. At the opposite extreme, AIH may be discovered during an attack of the disease, usually characterized by grossly elevated liver-related blood tests, jaundice, severe itching, right upper quadrant pain, and fatigue. This occurs in up to 25% of the cases. Other people fall somewhere in between, having vague symptoms such as a general sense of lethargy, muscle and joint aches, or mild abdominal discomfort.
Fatigue is the most common and often the sole symptom, occurring in approximately 85% of symptomatic people. The severity of fatigue does not always correlate with the degree of liver inflammation and damage.
Extrahepatic (involving organ and tissue other than the liver) features result from the immune system harming other organs of the body. These symptoms can include absence of a menstrual period, bloody diarrhea (due to ulcerative colitis), abdominal pain, arthritis, rashes, anemia, kidney disease, dry eyes, and dry mouth.
People with AIH typically have a chronic fluctuating course. AIH is characterized by exacerbations (worsening) and remissions of disease, which occur at varying intervals.
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.