Development of an ELISA for Quantitative Detection of Immunoglobulin G (IgG) and IgA Antibodies to Helicobacter pylori for Use in Korean Patients with H. pylori-Associated Diseases

BACKGROUND/AIMS We aimed to develop a quantitative enzyme-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 different 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 subjects 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 -negative 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. pylori antibody titers were obtained regardless of the subject's age.