Hepatitis D – Diagnostics – Overview of Information and Clinical Research

Hepatitis D is a unique liver infection that can only occur in people who already have hepatitis B. Understanding when and how to diagnose this condition is crucial, as it represents the most severe form of viral hepatitis and can lead to rapid liver damage. Proper testing helps identify those at risk and enables timely management of this challenging infection.

Introduction: Who Should Be Tested and When

Hepatitis D does not occur on its own. If you have hepatitis B, or if you are at risk of getting hepatitis B, you should consider testing for hepatitis D. This condition is sometimes called hepatitis delta or HDV, and it requires the hepatitis B virus to survive and spread in your body.^[1]

Testing becomes especially important if you already know you have hepatitis B and you notice new or worsening symptoms. Perhaps you feel more tired than usual, your skin or eyes turn yellow, or your belly hurts more than before. These could be signs that hepatitis D has entered your system. Because this virus makes hepatitis B much more serious, early detection can make a real difference in how your condition is managed.^[2]

Certain groups of people face higher risk and should talk to their doctor about testing. If you inject drugs, share needles, or have sexual partners who have hepatitis B or D, you are at increased risk. Men who have sex with men, people living with HIV, those receiving hemodialysis, and healthcare workers who might be exposed to blood are also considered high-risk groups. Additionally, if you come from or have traveled to regions where hepatitis D is common—such as Eastern Europe, parts of Africa, the Middle East, or the Amazon Basin—testing may be advisable.^[1]^[3]

Even if you tested negative for hepatitis D in the past, you might need to be tested again if your situation has changed. For instance, if you moved back to an area where the virus is common, or if your liver enzyme levels suddenly rise without explanation, repeat testing makes sense. Some people with hepatitis B infection may acquire hepatitis D later in life through what doctors call superinfection—this happens when someone who already has hepatitis B gets infected with hepatitis D at a later time. These superinfections tend to lead to more severe and long-lasting illness compared to getting both viruses at once.^[1]^[15]

⚠️ Important

Not everyone infected with hepatitis D will have symptoms right away. Some people feel perfectly fine even though the virus is damaging their liver. That’s why testing based on risk factors, rather than waiting for symptoms to appear, is so important. Don’t wait until you feel sick to ask your doctor about hepatitis D screening if you have hepatitis B or any of the risk factors mentioned above.

Classic Diagnostic Methods

The only reliable way to find out if you have hepatitis D is through blood tests. Your doctor cannot diagnose this infection just by examining you or asking about your symptoms. Blood testing is essential because it looks for specific markers that show whether the virus is present in your body.^[1]^[5]

The first step in diagnosing hepatitis D is usually a test that looks for anti-HDV antibodies in your blood. Antibodies are proteins your immune system creates to fight infections. If you have been exposed to the hepatitis D virus, your body will have made these specific antibodies. Finding anti-HDV antibodies tells your doctor that you have come into contact with the virus at some point. This initial screening test is straightforward and helps identify who needs further evaluation.^[15]^[22]

If the antibody test comes back positive, your doctor will want to know whether the virus is still active in your body. This is done through a test that measures HDV viral load, also called HDV RNA testing. This test detects the genetic material of the virus itself and tells your doctor whether you have an ongoing, active infection. It also helps determine how much virus is in your bloodstream. The amount of virus present can guide decisions about treatment and monitoring.^[15]

Your doctor will also check your liver function through additional blood tests. These tests measure substances called liver enzymes—such as alanine aminotransferase (ALT) and aspartate aminotransferase (AST)—that leak into your blood when liver cells are damaged. High levels of these enzymes suggest that your liver is inflamed or injured. While these tests don’t diagnose hepatitis D specifically, they give important clues about how your liver is doing and whether treatment is needed urgently.^[4]^[5]

In some cases, your doctor may order imaging tests to see your liver more clearly. An abdominal ultrasound uses sound waves to create pictures of your liver and can show whether there is scarring, called cirrhosis, or other structural problems. Another test called elastography measures how stiff your liver is, which helps doctors estimate the amount of scarring without needing a surgical procedure. These imaging studies are not used to diagnose hepatitis D directly, but they help assess the extent of liver damage caused by the infection.^[2]^[9]

Understanding the difference between coinfection and superinfection is also part of the diagnostic process. If you get hepatitis B and hepatitis D at the same time, this is called coinfection. When this happens, you may have two waves of symptoms at different times because each virus may cause illness separately. If you already had hepatitis B and then caught hepatitis D later, this is a superinfection. Superinfections usually cause symptoms that come on quickly and are more severe. Your doctor will look at your medical history and test results to figure out which type of infection you have, as this can affect your prognosis and treatment plan.^[1]^[4]

Sometimes, doctors may recommend a liver biopsy to get a small sample of liver tissue. This is a more invasive procedure, usually done with a needle, and it allows doctors to look at your liver cells under a microscope. A biopsy can show the severity of inflammation and scarring and help rule out other causes of liver disease. However, biopsies are not always necessary for diagnosing hepatitis D. Your doctor will decide if this step is needed based on your specific situation.^[4]

⚠️ Important

Hepatitis D is often underdiagnosed because many doctors do not routinely test for it, even in people with hepatitis B. If you have hepatitis B and your liver function suddenly worsens, or if you have risk factors for hepatitis D, make sure to ask your doctor specifically about hepatitis D testing. Early diagnosis can help prevent serious complications.

Diagnostics for Clinical Trial Qualification

Clinical trials are research studies that test new treatments for hepatitis D. If you are interested in joining a clinical trial, you will need to undergo specific tests to see if you qualify. These tests help researchers make sure the study is safe for you and that the results will be meaningful. The tests used for clinical trial screening are similar to those used in regular diagnosis, but they may be more detailed or require additional steps.^[11]^[14]

First, you will need to have confirmed hepatitis D infection through blood tests. This means having both a positive anti-HDV antibody test and a detectable HDV viral load. Researchers want to know that you have active infection before enrolling you in a study. They may also measure the exact amount of virus in your blood at the start of the trial, as this helps them track whether the treatment is working.^[11]

Liver function tests are also standard for clinical trial qualification. Researchers will check your ALT, AST, and other markers to understand how much your liver is affected. Some trials only accept people with a certain level of liver damage, while others may include people at earlier stages of disease. Your doctor will explain what the specific trial requires.^[14]

Imaging tests such as ultrasound or elastography are often required to assess liver scarring. Some clinical trials focus on people who already have cirrhosis, while others are designed for those without advanced scarring. Knowing the condition of your liver helps researchers match you to the right study.^[11]

In addition to hepatitis D testing, you will also need tests to confirm your hepatitis B status. This includes checking for hepatitis B surface antigen (HBsAg) and hepatitis B viral load. Because hepatitis D cannot exist without hepatitis B, understanding both infections is critical for trial enrollment.^[4]

Some trials may also require tests to rule out other health problems. For example, you might be tested for HIV, hepatitis C, or other conditions that could affect your liver or interfere with the study treatment. Blood tests to check your kidney function, blood cell counts, and overall health are also common. These tests ensure that it is safe for you to participate and that the researchers can accurately measure the effects of the treatment being studied.^[11]^[14]

Clinical trials often involve follow-up testing throughout the study. You may need to have your blood drawn regularly to monitor your viral load, liver enzymes, and any side effects from the treatment. Imaging tests might be repeated to see if the treatment is preventing further liver damage. While this may seem like a lot of testing, it helps ensure your safety and contributes valuable information to the development of new treatments for hepatitis D.^[14]

If you are considering a clinical trial, talk to your doctor about what tests are required and what the process will involve. Participating in a trial can give you access to new therapies that are not yet available to the general public, and it also helps advance medical knowledge that can benefit others living with hepatitis D in the future.^[11]

Prognosis and Survival Rate

Prognosis

The outlook for people with hepatitis D depends on several factors, including how the infection was acquired and how much liver damage has already occurred. Hepatitis D is considered the most severe form of viral hepatitis because it speeds up liver damage and increases the risk of serious complications more than hepatitis B alone.^[3]^[10]

People who get both hepatitis B and hepatitis D at the same time (coinfection) usually have a better long-term outlook. In most of these cases, the body clears both viruses within a few months, and fewer than 5% of adults develop chronic, long-lasting infection. However, during the acute phase, coinfection can cause severe illness and even liver failure in some cases.^[1]^[23]

In contrast, people who already have hepatitis B and then get hepatitis D (superinfection) face a much more serious situation. Superinfection is much more likely to become chronic and can lead to rapid progression of liver scarring (cirrhosis), liver failure, and liver cancer. Studies show that people with chronic hepatitis D develop complications faster than those with hepatitis B alone.^[1]^[3]

Other factors that affect prognosis include your overall health, whether you have other infections like HIV or hepatitis C, your age, and how quickly you receive appropriate care. Access to medical monitoring and emerging treatments can also influence outcomes. People who stop using alcohol and drugs, maintain a healthy lifestyle, and follow their doctor’s recommendations tend to do better over time.^[4]

Survival Rate

Hepatitis D is known to have the highest death rate among all forms of viral hepatitis. Studies suggest that about 20% of people with both hepatitis B and hepatitis D may die from complications related to the infection, making it the most dangerous hepatitis virus combination.^[7]^[19]

The risk of developing liver-related complications is much higher in people with hepatitis D than in those with hepatitis B alone. Research shows that hepatitis D co-infection may explain about one in five cases of severe liver disease and liver cancer among people living with hepatitis B.^[3]^[10]

People with chronic hepatitis D and hepatitis B together face faster progression to cirrhosis and liver failure. Without treatment, many will develop serious liver disease within years rather than decades. The speed of progression varies from person to person, but chronic superinfection tends to lead to liver failure and death more quickly than hepatitis B infection alone.^[3]^[4]

While these statistics may sound frightening, it’s important to remember that early diagnosis, careful monitoring, and emerging treatments offer hope. New therapies are being developed and tested in clinical trials, and some have already been approved in certain countries. Staying informed, working closely with your healthcare team, and seeking access to the best available care can improve your chances of living longer and healthier with hepatitis D.^[11]^[14]