Treatment: Interferon Alpha
This is still one of the most commonly used treatments for chronic HBV carriers.

Background
Interferon is a protein naturally produced by many cells in the body. Interferons help the body fight disease through a cellular pathway known aptly as the interferon pathway. During the course of an infection, the interferon pathway is often upregulated. This upregulation usually coincides with a downregulation of viral replication. Interferons also appear to signal other, uninfected cells, making them more resistent to viral intection. Interferons are also thought to modulate immune system activity. However, some people have deficient interferon levels or have low interferon response. Thus, the need for interferon treatment.

The most commonly used interferon for chronic HBV treatment is Interferon Alpha-2B (Intron-A).

Success Rates:
For HBV infection, about 20-25% appear to be cured of their infection while 25% - 45% convert from active to persistent/subclinical HBV infection. Success rates are lower in cases of long term infection or if co-infected with HIV or HCV. Relapse rates are also higher if HIV positive, so an HIV test may be appropriate.

Typical Interferon Dosing Information:
The typical duration of treatment is four to six months. Recommended dosing of Intron-A is 2.5 to 5 Million Units (MU) per meter square (/MSq) of body surface area three times a week. Higher doses (up to 10MU/MSq) of interferon may used and some studies indicate that higher doses have an improved response rate. However, higher doses also come with higher chances of unwanted side-effects. If you decide to take interferon, discuss dosage with your doctor .(Interferon is expensive and cost may be relevant, depending on your medical insurance or heath care system.) An alternate schedule is 5 million units daily which may ensure a more consistent level of interferon in the body.

Common Side-Effects:
Many individuals experience a flu like illness characterized by fever, chills, headache, muscle aches, and nausea within four to eight hours following the first administration of interferon. These symptoms can be reduced by giving acetaminophen thirty minutes to one hour before the time of injection.

Long-term therapy is accompanied by other side effects such as fatigue, muscle aches, poor appetite, weight loss, alopecia, bone marrow suppression, autoimmune phenomena, bacterial infections (which can be severe or life-threatening, particularly in patients with established cirrhosis), and psychological side effects (for example, anxiety, depression, irritability, and moodiness). The side effects are dose-related and generally reversible. Less than 10% to 20% of patients require interruption of therapy. Treatment with interferon is contraindicated in patients with psychosis, autoimmune disease, renal, or heart failure.

It is extremely important that patients be carefully evaluated, including a psychological evaluation, before initiating treatment with interferon. Appropriately selected patients often can tolerate very high doses while others are intolerant of even the smallest doses.

Contraindications:
Narcotics, hypnotics, or sedatives should be taken with caution when under interferon treatment. Xanthine derivatives should also be administered with caution and if so serum theophyline levels should be measured. (Note: Xanthine derivatives are frequently found in cough mixtures). It is highly recommended that one discusses any other medicines (prescription or over the counter) with both your doctor and the pharmacist before mixing them with your interferon treatment.

Typical Response Profile:
The severity of side-effects will be felt usually within the first week upon commencing interferon treatment. Blood tests to measure the success of treatment are typically taken at 1,2, 4, 8, 12 and 16 weeks after first injection.

Patients who respond to interferon may have fluctuating ALT levels. Detectable DNA will disappear within four to six months, followed by HBeAg. Finally, HBeAb will be found in the serum indicating a successful seroconversion.

Relapse After Treatment:
A small number of individuals (~5%) who initially respond to interferon treatment may relapse some months or years later. (Elevation of ALT immediately after therapy is not considered a relapse, but rather treatment failure.) The definition of relapse requires that after completion of therapy the patient has a prolonged period of HBV DNA negativity with normal ALT and seroconversion to an anti-HBe-positive state. Patients who relapse after therapy usually respond to a second course of treatment. HBeAg-positive HBV carriers who relapse after treatment can be retreated.

When It Fails:
Patients who have undergone a full course of interferon therapy but have failed to normalize ALT or lose HBeAg are considered non-responders. Retreatment of such patients is usually futile except in certain circumstances such as if the HBV DNA levels fall spontaneously. Retreatment of initial treatment failures with interferon is not recommended. Patients should be referred to an expert for consideration of other options.