Hepatatis B Virus Surface Antigen

Introduction

HBV carries antigens on its surface that cause your immune system to produce antibodies. Surface antigens for Hepatitis B can be discovered in your blood within a few weeks of infection. They are one of the first symptoms of hepatitis B. One of the five hepatitis viruses is HBV. Hepatitis A, C, D, and E are the others. These five viruses cause the majority of hepatitis illnesses. HBV is transmitted by blood, seminal fluid, and vaginal secretions. After becoming infected, it can take several months to acquire signs of hepatitis B.Hepatitis B surface antigen (HBsAg) testing is a blood test used to evaluate whether or not a person is infected with the hepatitis B virus. If it is identified, combined with specific antibodies, it indicates that the person has hepatitis B. If your blood tests positive for HBsAg, it signifies you are infected with the virus and can spread it to others via your blood or bodily fluids.

Hepatitis B

Hepatitis B surface antigen (HBsAg) testing is a blood test used to evaluate whether or not a person is infected with the hepatitis B virus. If it is identified, combined with specific antibodies, it indicates that the person has hepatitis B. If your blood tests positive for HBsAg, it signifies you are infected with the virus and can spread it to others via your blood or bodily fluids. Even though their signs and symptoms are severe, most adults infected with hepatitis B recover completely. Children and infants are more likely to have chronic hepatitis B infections. Hepatitis B can be prevented with a vaccine, but there is no cure if you already have it.The Hepatitis B virus (HBV) is found all over the world. Percutaneous contact with infected blood products is the most common way for the illness to spread (eg, blood transfusion, sharing of needles by intravenous drug addicts). The virus has also been detected in numerous human body fluids, and it is known to transmit via oral and vaginal contact.

If you are affected, you can assist prevent the spread of HBV to others by following certain precautions(Seto, Wai-Kay; Lo, Ying-Ru; Pawlotsky, Jean-Michel; Yuen, Man-Fung (2018).)

Causes

The Hepatitis B virus spreads from person to person by blood, sperm, or other bodily fluids.

HBV is commonly spread in the following ways2:

1.Sexual contact: If you have unprotected sex with an infected partner whose blood, saliva, sperm, or vaginal fluids enter your body, you may get infected

2..Sharing needles: HBV can be easily transferred through contaminated needles and syringes. You are at significant risk of contracting hepatitis B if you share intravenous (IV) drug paraphernalia.

3.Hepatitis B is a risk for healthcare professionals and anyone else who comes into contact with human blood.

4.Mother to child: Pregnant women who are infected with HBV can transmit the virus to their babies during childbirth. In virtually all cases, however, the newborn can be immunised to avoid infection.  If you are pregnant or intend to become pregnant, talk to your doctor about getting tested for hepatitis B.

Need for the test

If your doctor suspects you have an HBV infection in your liver, you may need this test. If you have hepatitis B symptoms, you may require this test. Symptoms frequently appear gradually. Many people have no symptoms or have only a mild case of the flu. You may not have symptoms unless the infection is severe or chronic.

The most common symptom is extreme tiredness. Other symptoms may include:

  • Nausea
  • Loss of appetite
  • Muscle aches
  • Fever
  • Yellowed skin and eyes (jaundice)
  • Dark-coloured urine
  • Belly (abdominal) pain
  • Swelling and confusion. This is in extreme cases.

HBs

A protein found on the surface of the hepatitis B virus that can be found in high concentrations in serum after acute or chronic hepatitis B virus infection. The presence of HBsAg implies that the individual is contagious. In self-limited infections, HBsAg is eliminated in four to six months (infections that resolve by themselves). It can be identified in the blood during both acute and chronic infections (infections that last for longer than six months).In addition to a patient’s signs and symptoms, other antibodies can be examined to differentiate between acute and chronic infections. As part of the natural immunological response to infection, the body develops antibodies to HBsAg. The antigen HBsAg is utilised in the production of hepatitis B vaccination.

Hepatitis B surface antibody (anti-HBs): The presence of anti-HBs is commonly regarded as showing hepatitis B virus recovery and immunity. Anti-HBs antibodies can also develop in people who have been successfully immunised against hepatitis B.Hepatitis B serologic testing entails measuring several antigens and antibodies specific to the hepatitis B virus (HBV). Various serologic “markers” or combinations of markers are used to detect distinct stages of HBV infection and to assess if a patient has acute or chronic HBV infection, is immune to HBV due to prior infection or vaccination, or is vulnerable to infection.Hepatitis B surface antigen (HBsAg) is the first serologic marker to show in serum 6 to 16 weeks after HBV exposure. HBsAg normally disappears 1 to 2 months after the onset of symptoms in an acute infection. The presence of HBsAg for more than 6 months indicates the emergence of either a chronic carrier state or chronic HBV infection.

DNA, which includes the genes used by the hepatitis B virus to replicate itself, is at the heart of the virus. A protein called hepatitis B core antigen (HBcAG) surrounds the DNA and cannot be detected with blood testing. Surrounding this is HBsAg, which is a component of the virus’s “envelope” that protects it from attack by the body’s immune system. However, the immune system is adept at breaking through this envelope and killing the virus. When this happens, surface antigen protein remnants are left in the blood as debris, which lab testing can detect3.

Hepatitis-B blood test

A single blood sample is required for a hepatitis B blood test, however, the “Hepatitis B Panel” consists of three parts. All three test results are required to determine whether or not a person is infected. HBsAg (Hepatitis B surface antigen) – A “positive” or “reactive” HBsAg test result indicates hepatitis B infection. This test can detect the presence of the hepatitis B virus (known as the “surface antigen”) in your blood. If a person tests “positive,” more testing is required to determine whether this is a new “acute” or “chronic” hepatitis B infection. A positive HBsAg test result indicates that you are infected with the hepatitis B virus and can spread it to others through your blood (Jackson K, Locarnini S, Gish R: Diagnostics of hepatitis B virus.)

anti-HBs or HBsAb (Hepatitis B surface antibody) – A “positive” or “reactive” anti-HBs (or HBsAb) test result indicates that the individual is immune to the hepatitis B virus. This protection can be obtained through the hepatitis B vaccine or by successfully recovering from a previous hepatitis B infection.

Useful for

The status of chronic hepatitis B infection is determined. For blood donor specimens, this test is not available as a screening or confirmatory test. For blood donor specimens, this test is not available as a screening or confirmatory test. This test is ineffective in the “window period” of acute hepatitis B virus (HBV) infection (ie, after the disappearance of hepatitis B surface antigen and before the appearance of hepatitis B surface antibody ). Acute HBV infection testing should additionally include hepatitis B core IgM antibodies(5) .

Cautions

Positive screen results (ie, signal-to-cutoff ratio >100.0) without the requirement for confirmation testing should be interpreted in conjunction with other hepatitis B virus (HBV) serologic marker test results (eg, hepatitis B surface antibody [anti-HBs], hepatitis B core antibody [anti-HBc] total, and anti-HBc IgM).Positive hepatitis B surface antigen (HBsAg) test findings should be reported to the State Department of Health by the health care provider, as required by law in some states.

Individuals who have recently received hepatitis B immunisation, particularly neonates and toddlers, may have temporary positive HBsAg test results due to the massive dose of HBsAg utilised in the vaccine.

Conclusion

Hepatitis B virus (HBV) is a DNA virus that causes both acute and chronic liver infections Hepatitis B screening is suggested for pregnant women at their initial prenatal appointment, as well as adolescents and adults at high risk of chronic infection. Hepatitis B vaccine is indicated for medically stable infants weighing 2,000 g or more within 24 hours of delivery, unvaccinated infants and children, and unvaccinated people who wish to be protected against hepatitis B or are at increased risk of infection. The presence of jaundice or high serum alanine transaminase levels, as well as test findings indicating hepatitis B surface antigen and hepatitis B core antigen, all indicate acute hepatitis B. There is no evidence that antiviral therapy is useful in the treatment of acute hepatitis B. The presence of hepatitis B surface antigen for more than six months is considered chronic hepatitis B. Individuals with chronic hepatitis B are at risk of developing hepatocellular carcinoma and cirrhosis, but with proper treatment, morbidity and death are minimised. Determining the stage of liver illness (e.g., evidence of inflammation, fibrosis) is critical for guiding therapy decisions and determining the need for hepatocellular carcinoma surveillance. Treatment should be tailored to the patient’s clinical and laboratory features, as well as the risk of developing cirrhosis and hepatocellular cancer. Immunologic cure, defined as the removal of hepatitis B surface antigen with long-term HBV DNA suppression, is possible with current pharmacological therapy that inhibits HBV DNA replication while improving liver inflammation and fibrosis. As first-line treatments for chronic hepatitis B, pegylated interferon alfa-2a, entecavir, and tenofovir are indicated.