Interferons | Therapy of Hepatitis B

Interferons

Another therapeutic option for chronic hepatitis B disease is the group of antivirals. Here, a distinction is made between so-called nucleoside analogues and nucleotide analogues. The principle of action of the two groups of substances is very similar: the drugs resemble the building blocks that a virus needs to pass on its DNA, i.e. its genetic information.

If the virus divides, it uses the drug as a building block of its DNA – but this is chemically modified in such a way that the genetic information breaks down at this point and the virus cannot divide further and thus multiply. This is also described by the name “antiviral”, which means nothing else but that the reproduction of the virus is stopped. Typical substances in the nucleoside analogues are lamivudine, entecavir and telbivudine.

Tenofovir is still mainly used as a nucleotide analogue, the predecessor adefovir is no longer recommended. Antivirals are generally used when interferons are not effective or contraindicated, i.e. cannot be used because, for example, pregnancy is present or the liver damage has already progressed too far. Antivirals are often better tolerated than interferon-alpha and can be taken as tablets, which many patients find more comfortable.

Since resistance occasionally occurs and the multiplication of the viruses cannot be sufficiently prevented, it is often necessary to switch to a different antiviral drug in the course of therapy. The duration of therapy depends on the response to the therapy and can only be terminated when there are no more hepatitis B antigens in the blood. Various newer drugs are currently still being tested in studies. So far, a complete cure (curative therapy) is not possible with these drugs. However, they alleviate the course of chronic hepatitis B and reduce the risk of late complications.

Liver Transplantation

If a patient develops hepatitis B, this can lead to liver failure. This is a very dangerous complication, as the liver is too badly damaged to maintain its function. Since the liver is a vital organ, patients with absolute liver failure must receive a liver transplant.

Liver transplantation may also be necessary in cases of liver cirrhosis or liver cell carcinoma caused by hepatitis B. This means that their liver is removed in an operation and they are given the liver of an organ donor. However, since this liver is not recognized by our immune system as the body’s own, it attacks the foreign organ – this is what the term organ rejection describes.

In order to counteract this, the patient must subsequently take medication for the rest of his or her life that downregulates the immune system. These drugs are called immunosuppressive drugs. To prevent the new liver from also being infected with the hepatitis B viruses, an antiviral therapy with hepatitis B immunoglobulins and an antiviral agent is also carried out. Only if the blood values are negative for hepatitis B in the long term, the immunoglobulins can be discontinued and a sole preventive therapy with antiviral tablets can be carried out.