[Change of hepatitis B surface antigen in serum from patients with chronic hepatitis B]

To study the clinical significance of hepatitis B surface antigen (HBsAg) levels in chronic hepatitis B, sera from five patients with chronic hepatitis B HBsAg levels were measured quantitatively by counting immunoassay (CIA). CIA is an immunoassay that combines the latex agglutination method and particle counting technique. The results were as follow: 1) In four patients with chronic active hepatitis, the increases of HBsAg levels were earlier than that of alanine aminotransferase levels, and HBsAg levels had approximately the same changes as hepatitis B virus associated DNA polymerase (HBV DNA-p) activities. 2) In four patients treated with interferon-alpha or beta, HBsAg levels after treatment decreased in the same manner as HBV DNA-p activities. 3) In a patient with chronic inactivate hepatitis. HBsAg levels were the same changes as HBV DNA-p activities. These results suggested that quantitative analysis of HBsAg levels is useful to evaluate the prognosis and exacerbation for chronic hepatitis B.