Finding out about hep C will help you plan for the future. Our Hep C Action Newsletter Program can help guide you through testing and treatment.
How Is Hep C Diagnosed?
Blood Tests
Diagnosis starts with a simple blood test. A virus detection test looks for the presence of the hep C virus, or viral load, in the blood or body tissue. If the virus is detected, it means you have hep C.
The most commonly used way to check for liver problems is through liver function tests. These blood tests look for chemicals in the body that are produced when the liver does its various jobs.
- ALT (alanine aminotransferase)—ALT is an enzyme that is normally found in the liver cells and in the blood. When liver cells become damaged, they leak into the bloodstream, causing levels of liver enzymes to be raised. An increase in ALT levels can indicate acute liver damage. However, a single ALT test will not reveal the severity of liver damage. Many people with chronic hep C have normal ALT levels, so this test is not considered a completely accurate marker of disease progression. Also, use of certain substances before the test—such as aspirin or alcohol—may alter the result.
Other liver enzymes that may be measured by blood tests include AST (aspartate aminotransferase), GGT (gamma-glutamyl transferase), and alkaline phosphatase.
- Bilirubin—Red blood cells have a limited life span. When they break down naturally, they produce bilirubin, a yellow pigment that’s passed on to the liver and excreted in the bile. Most of the time, the body produces as many red blood cells as it breaks down. However, if the red blood cells break down more rapidly or if the liver is not working well, bilirubin levels in the blood rise. In patients with hepatitis, bilirubin levels tend to go up and down. Consistently high bilirubin usually indicates severe liver dysfunction for a patient with chronic hep C.
- Albumin—Albumin is a protein manufactured by the liver. A decrease in albumin may reflect a reduction in the liver’s ability to synthesize this protein, and a significant sustained decrease in this protein may mean poor liver function. However, decreases in albumin levels may also occur for reasons not related to the liver. Your doctor will take this into account when interpreting test results.
- Prothrombin time—When the liver is damaged, it may fail to produce blood-clotting factors. This test measures blood-clotting ability to see if this may be a problem. Prothrombin time is simply the amount of time it takes for the liquid portion of blood (the serum) to clot.
- Complete blood count—A complete blood count analysis can be used to help detect liver scarring. If the liver becomes scarred, blood may back up into the spleen. This causes the spleen to enlarge and to trap blood elements, removing them from circulation and lowering blood counts.
Liver Biopsy
In order to track the progression of the disease, your doctor may perform a liver biopsy every few years. This is a procedure in which a tiny sample of tissue from the liver is removed and examined in a laboratory. A liver biopsy is an essential tool in monitoring hep C—in fact, it is the best way to measure the extent of liver damage. Liver biopsies are also important in ruling out any other forms of liver disease.
Today, liver biopsies are performed as outpatient procedures. General anesthesia is not necessary. Patients receive local anesthesia at the area where the needle will be inserted (usually the right side of the rib cage). Although the test itself only takes a few minutes—with the actual biopsy being done in seconds—you may be monitored at the testing facility for several hours.
Patients often describe the sensation they experience during the test as a feeling of strong pressure on the spot where the tissue is removed. You may feel tired after the test, so it is a good idea to schedule some rest time after having a biopsy. You should speak to your doctor about the specific details and risks of liver biopsy.
The degree of liver damage measured from a liver biopsy is scored in stages:
- Stage I—In the earliest stage of liver damage, the liver is inflamed (immune cells called lymphocytes are present), but scarring has not yet occurred. There is little damage to the liver at this point.
- Stage II—In this early stage of liver damage, the liver is inflamed, and mild scarring (fibrosis) has begun to form.
- Stage III—In this stage, scar tissue from one area of the liver bridges (connects) to scar tissue from other areas, leading to advanced fibrosis.
- Stage IV—In this advanced stage of liver damage, cirrhosis (advanced scarring) has occurred. At this point, the degree of damage to the liver is more serious.
With respect to the liver, the goals of therapy for hep C are to delay or stop disease progression by:
- Delaying the progression of scarring
- Preventing cirrhosis
- Preventing liver cancer
