Diagnostic tests are the only method for any doctor to know what virus is causing the hepatitis infection and what course of treatment is best for a patient.
Hepatitis, otherwise called liver inflammation, may be the result of infection with various types of viruses. As different hepatitis viruses cause similar symptoms, it is extremely difficult to tell which virus is causing the problem without running a series of diagnostic tests.
Evaluating Liver Function
If hepatitis is suspected, your doctor might order a series of hepatitis tests that focus on the liver. Liver produces enzymes, proteins and other substances that clear toxins from our body and help in digestion, and convert food into energy. A liver function blood-test can show how well the liver is performing these important tasks.
To perform liver function tests (LFTs), blood sample is collected and analyzed. To obtain most accurate results, an individual may have to fast for 10 – 12 hours before taking the test. Abnormalities in the levels of the following may suggest hepatitis in a person:
- Bilirubin: This pigment is produced when red blood cells break down. If the liver is not working well owing to hepatitis, bilirubin may cause jaundice, yellowing of skin and the whitening of eyes); the bilirubin level will also show as elevated in the blood test.
- Albumin: One of the jobs of the liver is to make albumin, a protein that moves minerals and nutrients through the bloodstream. Low albumin levels can be a sign of liver disease.
- ALP, ALT, AST: High levels of these enzymes may signal hepatitis.
Viral Serology or Hepatitis Panel
A doctor may recommend viral serology panel, a set of blood tests that determines whether a person has hepatitis, which virus strain it is, and the severity of the illness. Blood sample is taken from the hand or arm and the same is used to perform a screening test for all types of the hepatitis virus. The technician at the lab checks the sample for specific markers of the viruses that could have infected the body and, the specific antibodies that our immune system may have produced to fight them off.
Typically blood is tested for:
- Antibody against hepatitis A
- Antibody against hepatitis B
- Antibody against hepatitis C
- Hepatitis A antigen
- Hepatitis B antigen
These diagnostic tests are also used to manage hepatitis for long-term, to keep track of how the treatment is progressing. The presence of an antigen from the virus will go away as soon as the infection clears. The presence of an antigen or antigens in the blood will continue if the infection smolders and becomes chronic.
Hepatitis C RNA Testing
Hepatitis C RNA qualitative (yes or no) is a molecular test that reveals whether the hepatitis C virus is present in an individual’s bloodstream. A qualitative test, used often for screening and to determine if the treatment is working, can detect very low levels of virus.
Hepatitis D Testing
Hepatitis D virus (HDV) is diagnosed by blood tests that detect the Anti HDV antibodies and HDV antigen. Generally, tests are done in Hepatitis B patients because HDV can only co-exist with Hepatitis B virus.
Hepatitis E Testing
The diagnosis of Acute Hepatitis E Virus (HEV) infection is done based on the detection of anti-HEV immunoglobulin M (IgM). Usually, the anti-HEV IgM begins rising after 4 weeks of infection and can be detected for 2 months following the onset of illness.
In few cases, the doctor may examine a liver tissue sample, especially if the disease is suspected to be in an advanced stage. The sample is obtained using a process called a liver biopsy. The patient will either be sedated or administered a local anesthetic, and a small liver tissue sample will be removed with a long needle through a small incision on his or her right side.
If a patient has chronic hepatitis B and C, a biopsy can establish the stage and severity of the disease. A liver biopsy is also used to diagnose a few complications associated with advanced hepatitis, such as cirrhosis, fibrosis and liver cancer.
Liver biopsy can be risky with infection and dangerous bleeding happening often. However, now there is a trend to use less invasive ways to diagnose liver tissue damage from chronic hepatitis.
Other Diagnostic Tools
Other diagnostic tests for advanced disease include checking the liver for signs of fibrosis (scarring or stiffness) that can show a doctor how far along an individual’s hepatitis has progressed. These include:
- Elastography: This is the most accurate, non-invasive test that helps in identifying advanced disease. Elastography checks for fibrosis and uses sound waves to measure the stiffness of the liver.
- Paracentesis: In this test, fluid from the patient’s abdomen is tested to help differentiate among many potential causes of liver disease. During this test, a doctor removes the fluid using a needle.
- Surrogate markers: Surrogate markers are panels of blood tests, which looks for abnormal levels of some substances in the blood that seem to parallel the fibrosis and cirrhosis development. These markers are different than the general blood tests done to diagnose hepatitis.
While diagnosing hepatitis, a set of tests may become necessary to assess the type of hepatitis a person may have, how much it may have progressed and finally, to decide on the best course of treatment for the condition.