Hepatitis B: A strategy for evaluation and management
ABSTRACTIn hepatitis B virus (HBV) infection, a single approach to treatment cannot be applied to all patients. Acute, adult-acquired HBV infection rarely requires treatment, whereas treatment for chronic infection should be based on the patient’s clinical situation and test results. The ideal agent for treating hepatitis B does not exist, and trade-offs are the essence of agent selection. In last month’s Journal (Cleve Clin J Med 2008; 75:881–889), we outlined the natural history and diagnosis of chronic HBV infection; in this article we outline its management.
KEY POINTS
- Patients with HBV infection should be screened for hepatocellular carcinoma, especially if they have cirrhosis.
- Nucleoside and nucleotide analogue reverse transcriptase inhibitors are easy to use and therefore are usually the first-line therapy. Problems with these agents are that the optimal treatment duration is not known, and that drug resistance can emerge.
- Patients with advanced liver disease or hepatocellular carcinoma should be referred promptly for possible liver transplantation.
- Candidates for immunosuppressant therapy or cytotoxic chemotherapy should be screened for HBV, as this therapy can cause a potentially fatal flare of HBV.
- People at risk should be vaccinated; many have not been.
VACCINATION HAS REDUCED THE INCIDENCE OF ACUTE HEPATITIS B
HBV vaccination, a major achievement in HBV management, has played a big role in reducing the incidence of acute HBV infection, especially in children and adolescents.20
The currently available vaccines in the United States contain HBV surface antigen derived through recombinant DNA technology from yeast.21 Two single-antigen vaccines are available in the United States, under the brand names Recombivax HB and Engerix B. Of the three licensed combination vaccines, one (Twinrix) is used in adults, and two (Comvax and Pediarix) are used in infants and young children. Twinrix contains recombinant HBV surface antigens and inactivated hepatitis A virus and it is recommended for people age 18 years and older and at risk of both HBV and hepatitis A infections.20
Vaccinate all infants
All infants should be vaccinated against HBV as part of the recommended childhood immunization schedule. The vaccine is given on a three-dose schedule at birth and again at 1 month and 6 months of age.16 All children and adolescents under age 19 who have not previously received HBV vaccine should be vaccinated at any age with an appropriate dose and schedule.16
Vaccinate adults at risk—or who ask for it
Vaccination is less effective in older people
The three-dose vaccine series given intramuscularly initially, then again at 1 month and 6 months, produces a protective antibody response in approximately 30% to 55% of healthy adults under age 40 after the first dose, 75% after the second dose, and more than 90% after the third dose.21,22 After age 40, however, the proportion of persons who have a protective antibody response after three doses declines to less than 90%, and by age 60, protective levels of antibody develop in only 75%.23
Other factors that lower the response to vaccination are smoking, obesity, genetic factors, and immune suppression.20
Postvaccination serologic testing for immunity is not necessary after routine vaccination of adults, but it is recommended for patients whose subsequent clinical management depends on knowledge of their immune status, such as health care workers who have contact with patients or blood and are at ongoing risk of injuries with sharp instruments or needlesticks; chronic hemodialysis patients and people infected with HIV or otherwise immunocompromised; and sex partners or needle-sharing partners of people positive for HBV surface antigen.20 A protective concentration of HBV surface antibody measured 1 to 2 months after completion of the vaccine series is defined as 10 mIU/mL. Further periodic testing to document persistence of protective levels of surface antibody is not indicated.
If the first series does not ‘take’
Patients who do not respond to the primary vaccine series should complete a second three-dose series, with doses at 0, 1, and 6 months. Serologic testing is done 1 to 2 months after finishing the second series.
Patients who do not have protective levels of HBV surface antibody after revaccination by the appropriate schedule in the deltoid muscle (< 5% of those receiving six doses of hepatitis B vaccine) either are primary nonresponders or are infected with HBV.20 Therefore, they should be tested for HBV surface antigen. If this test is negative, then they should be considered susceptible to HBV infection and should be counseled accordingly.
Contraindications and precautions
HBV vaccination is contraindicated in people with a history of hypersensitivity to baker’s yeast or to a previous dose of HBV vaccine.20 Patients with moderate or severe acute illness at the time the shot is scheduled should wait until they recover before getting HBV vaccine. Pregnancy is not a contraindication.20
