A 69-year-old woman was referred to us because of abnormally high serum pepsinogen (PG) levels in the ABC method (blood test for gastric cancer screening) done in April 2016, which resulted in group A. EGD performed in May 2016 revealed diffuse redness and mucosal swelling, indicating HP-associated gastritis, although the endoscopic findings in 2014 had indicated a HP-negative gastric mucosa. A rapid urease test was positive. From April to June 2016, serum PGI levels decreased, and serum HP antibody levels increased and changed from negative to positive. Thus, the initial HP infection was found by abnormally high PG levels and then converted to chronic persistent infection. The ABC method should be evaluated not only by the groups but also by serum PG and HP antibody levels, as well as endoscopic findings.
