Hepatitis - Autoimmune Hepatitis

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Hepatitis C RNA assays also determine virus levels (called viral load). Such levels do not reflect the severity of the condition or speed of progression, as they do for other viruses, such as HIV. However, high viral loads may suggest a poorer response to treatment with interferon drugs.

Patients with detectable viral loads should have HCV genotyping performed. Knowing the specific genotype of the virus is helpful in determining a treatment approach. There are six main genetic types of hepatitis C and more than 50 subtypes. They do not appear to affect the rate of progression of the disease itself, but they can differ significantly in their effects on response to treatment. Specific genotypes vary in prevalence around the world. Genotype 1 is the most difficult to treat and is the cause of up to 75% of the cases in the U.S. The other common genetic types in the U.S. are types 2 (15%) and 3 (7%), which are more responsive to treatment than genotype 1. People with hepatitis C need to have their genotype tested so that doctors can make appropriate treatment recommendations. Researchers are working on developing a genetic test to identify which patients with chronic hepatitis C are most at risk of developing cirrhosis.

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Liver Biopsy. Liver biopsy may be helpful both for diagnosis and for determining treatment decisions. Only a biopsy can determine the extent of injury in the liver. Some doctors recommend biopsies only for patients who do not have genotypes 2 or 3 (as these genotypes tend to respond well to treatment). A liver biopsy in patients with other genotypes may help clarify risk for disease progression and allow doctors to reserve treatment for patients with moderate-to-severe liver scarring (fibrosis). Even in patients with normal alanine aminotrasferase (ALT) liver enzyme levels, a liver biopsy can reveal significant damage.

Tests for Liver Function

In people suspected of having or carrying viral hepatitis, doctors will measure certain substances in the blood.

• Bilirubin. Bilirubin is one of the most important factors indicative of hepatitis. It is a red-yellow pigment that is normally metabolized in the liver and then excreted in the urine. In patients with hepatitis, the liver cannot process bilirubin, and blood levels of this substance rise. (High levels of bilirubin cause the yellowish skin tone known as jaundice.)
• Liver Enzymes (Aminotransferases). Enzymes known as aminotransferases, including aspartate (AST) and alanine (ALT), are released when the liver is damaged. Measurements of these enzymes, particularly ALT, are the most important tests for detecting hepatitis and monitoring treatment effectiveness. Enzyme levels vary, however, and are not always an accurate indicator of disease activity. (For example, they are not useful in detecting progression to cirrhosis.)
• Alkaline Phosphatase (ALP). High ALP levels can indicate bile duct blockage.
• Serum Albumin Concentration. Serum albumin measures protein in the blood (low levels indicate poor liver function).
• Prothrombin Time (PT). The PT test measures in seconds the time it takes for blood clots to form (the longer it takes the greater the risk for bleeding).

Liver Biopsy

A liver biopsy may be performed for acute viral hepatitis caught in a late stage or for severe cases of chronic hepatitis. A biopsy helps determine treatment possibilities, the extent of damage, and the long-term outlook.

A biopsy involves a doctor inserting a biopsy fine needle, guided by ultrasound, to remove a small sample of liver tissue. Local anesthetic is used to numb the area. Patients may feel pressure and some dull pain. The procedure takes about 20 minutes to perform.

Review Date: 09/29/2010
Reviewed By: Harvey Simon, MD, Editor-in-Chief, In-Depth Reports; Associate Professor of Medicine, Harvard Medical School; Physician, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.

A.D.A.M., Inc. is accredited by URAC, also known as the American Accreditation HealthCare Commission (www.urac.org).