Disease of the Month: Hepatitis - D Disease
Hepatitis D is a liver infection caused by the Hepatitis D virus (HDV) which causes the liver to become inflamed. It is also known by name of Hepatitis Delta virus or Delta Hepatitis1. Hepatitis D is a double infection as HDV requires the Hepatitis B virus (HBV) to replicate itself, therefore in the absence of the HBV, Hepatitis D infection occurs only in those individuals who have been infected by HBV. Globally 5% of people with chronic HBV infection are affected by HDV3. The person can either get infected simultaneously with HBV and HDV (known as “co-infection”) or can get Hepatitis D after being infected with Hepatitis B (known as “superinfection”). The HDV-HBV co-infection is considered the most serious type of chronic viral hepatitis. The liver inflammation caused by HDV can reduce liver functioning and can lead to serious long-term effects like liver scarring, hepatocellular carcinoma, and liver-related death3. This virus is rare in the United States but has common incidence in:
- West Africa
- Pacific Islands
- South America
- Central Asia
The population more likely to infect the viral co-infection include haemodialysis recipients, indigenous populations, and those who inject drugs. The infection can be acute or chronic. Acute infection is a short-term infection that develops suddenly but often causes more severe symptoms. If the body can fight off the infection, the virus may go away. But if the virus persists in the body for six months or longer it develops into a chronic infection1. In chronic infection, the virus may be present inside the body for several months before any visible symptoms occur. It progresses gradually over time and results in serious complications.
The viral infection does not always show symptoms. The signs and symptoms usually start after 3-7 weeks from the initial infection3. The symptoms are no different than the other types of viral hepatitis infection which include:
- Jaundice (yellow eyes and skin)
- Abdomen Pain
- Joint Pain
- Loss of appetite
- Nausea & Vomiting
- Clay-colored stool
- Dark urine
It can be difficult to identify whether HBV or HDV is causing the symptoms. In some scenarios, Hepatitis D can worsen the symptoms of Hepatitis B. Hepatitis D can also cause symptoms in people with non-symptomatic Hepatitis B2.
MODES OF TRANSMISSION
Hepatitis D Virus primarily gets transmitted via activities involving percutaneous (puncture through skin) and at lesser probability through mucosal contact with infected body fluids like urine, vaginal fluids, semen, or blood2. The activities include:
- Sexual contact with an infected person
- Contact with blood from or the open sores of an infected person
- Sharing items with the infected person
- Injection-drug use that includes sharing syringes, needles, or drug-preparation instrument
- Rarely from infected mother to child
It should be noted that Hepatitis D does not get transmitted through water or food, breastfeeding, kissing, sharing utensils, hugging, coughing, holding hands, or sneezing. Also, people with Hepatitis B infection are also at higher risk for developing Hepatitis D infection3.
PEOPLE AT HIGHER RISK OF INFECTION
Though anyone can get infected by HDV, certain people are at an increased risk of getting infected with the virus:
- People using IV or injectable drugs
- Have Hepatitis B
- Person who often receive blood transfusions
- Haemodialysis patients
- People not immune to HBV
- People with HIV
- Commercial sex workers
Until 2020, the treatment for Hepatitis D was unsatisfactory with interferon-α being the only approved drug for over 30 years. Things changed in July 2020 when Hepcludex developed by MYR Pharmaceuticals, now part of Gilead Sciences got its approval from the European Commission. The drug is known as Bulevirtide and is marketed under the brand name Hepcludex6. It was formerly known as Myrcludex B. It is the first-in-class inhibitor used to treat chronic Hepatitis D and prevent HDV and HBV from entering the liver cells. The approval of this new drug brought a ray of hope for approximately 25 million people suffering from Hepatitis D globally.
The mechanism of action of Hepcludex is based on the Lock-and-Key principle. Both Hepatitis B and Hepatitis D viruses can replicate themselves in the liver due to the presence of bile acid transporter NTCP which they use to enter the healthy liver cells6. Hepcludex includes the active substance Bulevirtide which blocks this NTCP receptor present on the surface of hepatocytes and prevents the entry of the virus into the new, regenerated cells within the liver. Hepacludex not only prevents new infection but also works even when the virus has already infected the liver4. The virus requires continuous replication for it to persist but due to the action of Hepcludex, it is not able to infect the new cells, and the currently infected cells are either eliminated by the immune system or die by themselves4.
The efficacy of Hepcludex was indicated in the two main studies. In the first study 55 of 90 patients administered Hepcludex with tenofovir (medicine for Hepatitis B) showed clearance of all their HDV RNA after 6 months, as compared to 1 out of 28 patients treated with only tenofovir. The blood levels of ALT were also found to be reduced on treatment with Hepcludex, indicating an improvement in liver disease5. A second similar study was conducted on 15 patients who were given Hepcludex with peginterferon alfa (medicine for Hepatitis B) for 48 weeks. 8 out of 15 patients showed no detectable levels of HDV RNA after 6 months of treatment. Hepcludex has received the Orphan Drug Designation by EMA and from US FDA for the treatment of HDV infection. It has also been granted the Breakthrough Therapy Designation by FDA and PRIority Medicines (PRIME) scheme eligibility by EMA5. Besides the positives, the most common side effect associated with Hepcludex is increased levels of bile salts in the blood and reaction at the injection site. The serious side effect associated with the drug is worsening of the liver disease once the patient stops Hepcludex5.
- Hepatitis D- NIDDK-NIH
- Hepatitis D- CDC
- Hepatitis D- WHO
- First drug for hepatitis D has been approved by European Commission
- Hepcludex- European Medicines Agency
- New Hepatitis Delta Treatment Approved by European Commission
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Akanksha is a content writer at PharmaShots. She is interested in covering recent innovations from pharma & medtech industry. She covers news related to Product approvals, clinical trial results, and updates. She is passionate, meticulous, diligent, and inquisitive. She can be contacted at [email protected].