Development of an ELISA for Quantitative Detection of Immunoglobulin G

Background/Aims: We aimed to develop a quantitative en-zyme-linked immunosorbent assay (ELISA) using whole-cell lysates of Helicobacter pylori 51 and to investigate its validity. Methods: Data from 300 plates were obtained by two differ-ent operators. Standard sera were used to make a standard curve to analyze the quantity of anti-H. pylori immunoglobulin G (IgG) and IgA antibody. We obtained reproducible data with fewer dilutions of samples by the addition of serially diluted standard serum to each ELISA plate. To evaluate the validity of this ELISA, the 114 H. pylori-positive and-negative sub-jects were stratified into four age groups, i.e., 0 to 4, 5 to 9, 10 to 15, and 20 to 29 years, before testing. Results: The mean IgG-antibody titers in H. pylori-positive and-negative subjects were 1,766.4 IU/mL and 654.3 IU/mL (p<0.001). The mean IgA-antibody titers in H. pylori-positive and-nega-tive subjects were 350.1 IU/mL and 193.5 IU/mL (p<0.001). Anti-H. pylori IgG and IgA titers in the four age groups were higher in H. pylori-positive subjects than in H. pylori-negative subjects (p<0.05). Conclusions: Using the current ELISA based on whole-cell lysates of H. pylori 51, reliable anti-H. py-lori antibody titers were obtained regardless of the subject’s age. (Gut Liver 2013;7:437-442) Key Words: Helicobacter pylori; Enzyme-linked immunosor-bent assay; Antibodie