Robert Gish, MD, on Advances in Managing Hepatitis B and D

Let's start out with some basic facts about hep D.

Why is it dependent on hepatitis B? What's the interaction there?

So this is an incomplete RNA virus.

The RNA message is important because that implies that it's curable.

But because it's incomplete, it requires the hepatitis B surface antigen.

to coat the virus, protect the virus, and allow the virus to enter the next liver cell because the surface antigen is part of the uptake of the hepatitis B virus and now delta virus into the liver cell through what's called the NTCP receptor.

So it's a clever virus, but it also needs host proteins.

That means the human liver cell proteins to replicate.

incomplete, doesn't have its own shelled, and it also doesn't have all the enzyme systems that are needed for replication.

Can you explain the difference between the concepts of superinfection and co-infection? Does one type present greater treatment challenges or carry a greater risk of poor outcomes than the other?

Co-infection is when you acquire, the patient acquires B and Delta at the same time.

This has a high rate of developing fulminant or acute liver failure.

And importantly, most of the people clear Delta and many of them can clear hepatitis B with this co-infection.

Super infection is when somebody has Crohn's.

chronic B and then gets the second infection with Delta at a different time.

Most of those patients, more than half, go on to develop chronic Delta infection and then are at high risk of progression to cirrhosis, transplant, cancer or death, less than 20 years, often less than 10 years.

It's the most deadly of any chronic viral infection other than something like Ebola or Hantavirus.

You've heard about those in the news recently.

But from a chronic perspective, because those are acute infections, this is a chronic infection in general.

I didn't mention the acute disease, but the acute Delta with co-infections quite rare these days.