title: A simple method to measure antibody affinity against the hepatitis B surface antigen using a routine quantitative system.
abstract: The aim of the study was to establish a simple method to measure antibody affinity to hepatitis B surface antigen (anti-HBs) by using a routine quantitative system to explore the significance of anti-HBs affinity. Serum samples of hepatitis B patients who had been discharged from the hospital were collected at the time of re-examination. The 60 patients with resolved HBV infection were divided into two groups based on the serological markers measured in the samples: an anti-HBs group (anti-HBs-only positive) and an anti-HBs positive with anti-HBc group. The serum samples were diluted prior to the measurement of total anti-HBs by using a commercial assay with the AxSYM device. The total anti-HBs (mIU/mL) of all dilutions were measured, and the positive data (>10 mIU/mL) were transformed into logarithmic values (lgU). The relative affinity of anti-HBs was calculated and derived from the mass action formula. The absolute value of (lgU(1)-lgU(2)) positively correlated with the antibody affinity. The results indicated that affinity of anti-HBs in the samples obtained from the anti-HBs-alone positive group was statistically higher than that of the other group (P<0.05), though no significant difference was noted in regard to the total antibody activity (P>0.05). This simple approach to measurement of anti-HBs antibody affinity may serve as a new tool in clinical laboratories and contribute to the management of patients with hepatitis B.
authors.affiliation: Department of Clinical Immunology, Dalian Medical University, Dalian 116044, China. liuhui60@mail.dlptt.ln.cn
authors.forename: Hui
authors.initials: H
authors.lastname: Liu
authors.forename: Yanan
authors.initials: Y
authors.lastname: Han
authors.forename: Bo
authors.initials: B
authors.lastname: Wang
mesh_terms: D000328:Adult; D000915:Antibody Affinity; D005260:Female; D006510:Hepatitis B Antibodies / Q000276:immunology*; D006514:Hepatitis B Surface Antigens / Q000276:immunology*; D006801:Humans; D007118:Immunoassay / Q000379:methods; D008297:Male; D008875:Middle Aged; D044967:Serum / Q000276:immunology; D014773:Virology / Q000379:methods*
chemical_list: D006510:Hepatitis B Antibodies; D006514:Hepatitis B Surface Antigens