Hepatitis B Surface Antigen Blood Test

Hepatitis B Surface Antigen Blood Test earliest indicator of the presence of acute infection.

Description

Test blood donors (HBsAg positive individuals are rejected). Hepatitis B surface antigen is the earliest indicator of the presence of acute infection. Also indicative of chronic infection. Test is useful in the differential diagnosis of hepatitis.

Patients who are negative for HBsAg may still have acute type B viral hepatitis. There is sometimes a “core window” stage when HBsAg has become negative and the patient has not yet developed the antibody (anti-HBs). On such occasions, both tests for anti-HBc are usually positive and anti-HBc, IgM is the only specific marker for the diagnosis of acute infection with hepatitis B. In cases with strong clinical suspicion of viral hepatitis, serologic testing should not be limited to detecting HBsAg, but should include a battery of tests to evaluate different stages of acute and convalescent hepatitis.