Abstract
[Objective] Differences in the results of serum HP antibody tests according to test method (CLEIA method or LA method) were investigated. In addition, the relation between the ABC classification (the risk of developing gastric cancer) and the results of serum HP antibody tests was investigated.
[Subjects] The subjects were 199 volunteers who underwent an HP antibody/pepsinogen (PG) test as part of a comprehensive medical examination and a health checkup at our institution since August 2016.
[Methods] The CLEIA method was performed with “SphereLight Wako” and its dedicated reagents “SphereLight H. pylori antibody J” and “SphereLight pepsinogen I/II”. Test by the LA method was outsourced and was performed by using the “LZ Test Eiken H. pylori antibody.” The HP antibody-positive rate was compared between the CLEIA method and the LA method. Also, the ABC classification was compared between subjects who were HP antibody-positive with the CLEIA method and subjects who were positive with the LA method. The HP antibody cut-off value was 4 U/mL for the CLEIA method and 10 U/mL for the LA method.
[Results] Serum HP antibody tests were positive in 27 (13.6%) of the 199 subjects by the CLEIA method and in 15 subjects (7.5%) by the LA method. Tests were positive in 13 subjects (6.5%) by both the CLEIA method and the LA method. The HP antibody test results differed in 16 subjects, only being positive by the CLEIA method in 14 of the 16 subjects and only being positive by the LA method in two subjects. The concordance rate of antibody tests with the ABC classification was 92.0%.
[Discussion] The percentage of subjects who were HP antibody-positive was higher when the CLEIA method was used compared to the LA method. This is considered to be attributable to differences of the cut-off value, detectability, or HP strains. For more accurate determination of the ABC classification, it is important to reduce the number of persons with a false-negative test for HP antibodies. Because HP antibody detectability was greater when the CLEIA method was used, this suggests that the CLEIA method is superior to the LA method.
