Abstract
ABC classification is now performed to assess gastric cancer risk, and the stratification is based on pepsinogen levels and the Helicobacter pylori antibodies titer. In this study, we enrolled 750 individuals who underwent upper gastrointestinal endoscopy as part of a medical checkup. Serum pepsinogen levels were measured by SphereLight Wako system. Antibodies to H. pylori were also measured by both the new SphereLight Wako kit and E-plate kit. Positive rates of H. pylori antibody obtained from SphereLight Wako and E-plate kit were 28.5% and 25.2%, respectively. ABC classification by SphereLight Wako showed larger Groups B and C, and smaller Groups A and D in comparison with that by E-plate.
Disagreement of positive decision measured by SphereLight Wako and E-plate kit was accepted in 27 individuals. Positive decisions used by SphereLight Wako were observed in most cases (26/27) while those were negative by E-plate kit. Furthermore, 22 of 27 E-plate kit negative individuals were under cut-off value (3-9 U/mL).
Pepsinogen levels were also used to screen for atrophic gastritis of grade C-2 or worse (Kimura and Takemoto endoscopic classification) among individuals in Group A with the SphereLight Wako stratification. This reassessment could effectively decrease the rate of atrophic gastritis in Group A (from 5.8% to 3.0%).
In conclusion, SphereLight Wako system might contribute to the accuracy of ABC classification. The management of Group A (both negative cases for antibody and pepsinogen test method) still needs attention because atrophic gastritis cannot be completely excluded by only pepsinogen levels.
