Hepatitis B The Problem Biology

Essay add: 28-10-2015, 15:50   /   Views: 148

Hepatitis B is an increasingly alarming infectious disease that is spread primarily by the infected person's bodily fluid such as the blood and semen. Interestingly enough, it is of epidemiological significance because it can also spread via the contact route, such as the practice of body tattooing and body piercing and through improper sterilization of surgical instruments or acupuncture.

The disease is primarily acute, in about 90% of the cases. Only 9% of HBV infections run a chronic course and only 1% undergoes fulminant (hypersensitive) hepatitis. The disease in its acute form is usually self limiting after it runs its natural course. The first stage of an apparent symptomatic infection is characterized by the pre-icteric period, characterized by flu-like symptoms such as weakness, loss of appetite, nausea, vomiting and body aches. This is followed by an icteric period, manifesting as jaundice, discolouring the sclera, skin and mucosae a yellow colour, dark urine and light coloured stools. [15]After the jaundice, the convalescence and recovery period follows, where the patient regains his health.


Acute hepatitis B infection usually subsides and is fought off spontaneously by our immune system. The treatment is conservative.

Practicing healthy diet, which includes detoxification programs and treatment besides reducing alcohol intake is crucial. Spasmolytic drugs can alleviate symptoms while cholestasis-targetted drugs reduce stagnation of bile. Osmotic diuretics such as dupholac and lactulose can function to flush out harmful microbes from the intestine before they migrate to the gall bladder. The bile contained here is very good nutrient source for them, so they multiply and replicate, causing apparent bacterial infection Enzymes are given to treat indigestion, which slows down nutrient absorbing and healing process.

However, chronically infected individuals characterized by persistently elevated serum alanine aminotransferase, and high HBV DNA levels after six months should be put on therapy. The enzyme alanine transferase, found in the cytoplasm of hepatocytes is released when cytolisis occurs. It is a direct marker of hepatocellular damage and hepatitis.


Interferons (IFNs) belong to the large class of glycoproteins known as cytokines. They are divided into type I (alpha and beta) and type II (gamma interferon), both types differing in specific mechanism and functions. Synthesized by lymphocytes in response to the presence of viruses, they allow communication between cells to trigger the protective defenses of the immune system that eliminate these foreign materials.

Interferons interrupt viral replication within host cells. As an infected cell dies from a cytolytic virus, viral particles are released that can infect nearby cells. However, the infected cell can warn neighboring cells of a viral presence by releasing interferon. 

Interferon alpha

Alpha interferons are generally produced by fibroblasts, monocytes and infected cells as a reaction to viral infection.They bind to the same cellular receptor and protect uninfected cells by inducing the intracellular production of molecules that inhibit viral RNA and DNA production. They also increase the expression of Major Histocompability Complex (MHC) class I molecules, leading to enhanced lysis of virally infected cells by specific cytotoxic T lymphocytes. Type I interferons also have antiproliferative function. Clinical trials have shown that IFN-alpha causes suppression of virus replication, manifested by a reduction in HBeAg, viral DNA polymerase activity, and serum HBV DNA. Seroconversion from HBeAg to anti-HBeAg occurs in 50% of IFN-treated patients, but disappearance of HBsAg occurs in a much lower percentage. In the intact host, immunoregulatory mechanisms influenced by IFNs (e.g. stimulation of natural killer cell activity) may help in eliminating infected cells or actively replicating virus. [8]

Pegylated interferon alpha

As the name suggests, these interferons are actually attached with a polyethylene glycol l(PEG) molecule to enhance the half-life. Thus, one dose taken can last longer in the patients' body. As of now, pegylated interferon alpha-2a and pegylated interferon alpha-2b have been approven by the FDA for treatment of hepatitis.

Nucleoside analogues are claimed to be predominant antivirals than PEGinterferons. However,among most available drugs for Hepatitis B, PEGinterferons have shown the highest rate of off-treatment sustained response after a one-year course of therapy

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