title: Determination of low level HBsAg in serum by microparticle enzyme immunoassay.
abstract: OBJECTIVE
  To investigate the distribution of the population with low level HBsAg in serum and the characteristics of their HBV serologic markers.
  
  
  METHODS
  We detected HBsAg, HBeAg, anti-HBc, anti-HBe, and anti-HBs in the serum samples from 8089 non-hepatitis inpatients and defined the patients with HBsAg concentration equal to or less than 5 microg/L by using the AxSYM microparticle enzyme immunoassay (MEIA) system.
  
  
  RESULTS
  189 patients with HBsAg equal to or low than 5 microg/L (2.34% of all 8089 patients and 23.16% of 816 HBsAg positive patients) included 84 (44.40%), 33(17.5%) and 72 (38.10%) with HBsAg equal to or less than 1 microg/L, 1-2 microg/L and 2-5 microg/L respectively. Most of these patients were detected with "positive for HBsAg, anti-HBc and anti-HBe but negative for HBeAg and anti-HBs", and anti-HBc antibodies were frequently present in their sera.
  
  
  CONCLUSIONS
  The population with low level HBsAg in serum should not be neglected and it is important to improve the test sensitivity of HBsAg and to detect the other HBV serologic markers.
authors: First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310003, China. chenyuheji1016@sina.com
authors: Yu
authors: Y
authors: Chen
authors: Wei
authors: W
authors: Wu
mesh_terms: D006510:Hepatitis B Antibodies / Q000097:blood; D006514:Hepatitis B Surface Antigens / Q000097:blood*; D006513:Hepatitis B e Antigens / Q000097:blood; D006801:Humans; D007124:Immunoenzyme Techniques / Q000379:methods; D010316:Particle Size
chemical_list: D006510:Hepatitis B Antibodies; D006514:Hepatitis B Surface Antigens; D006513:Hepatitis B e Antigens