Examination of H. pylori Antibody Latex Agglutination Method Reagent in Comprehensive Health Checkup~A Consideration on the Cutoff Value~

Abstract

 [Purpose] To examine the usefulness of LA method of serum Helicobacter pylori antibody (Hp antibody) measurement in gastric cancer risk assessment, we compared three methods (ELISA, CLEIA and LA method) with their performance in ABC classification screening.

 [Methods] Fresh serum was collected from 929 persons of the comprehensive medical examination with written consent. The pepsinogen I/II were measured by CLEIA method and LA method, and the Hp-antibody was measured by ELISA method, CLEIA method, LA method, respectively. The results were stratified into A, B, C, D group according to the proposal of Inoue et al. The degree of atrophy by endoscopy examination was based on Kimura -Takemoto classification.

 [Results] There were 929 samples being investigated, including 832 in C0 classification, 32 in C1, 26 in C2, 13 in C3, 16 in O1, 6 in O2, and 4 in O3, respectively. By ELISA method with a cut-off value (CO) of 3U/mL, 849 were stratified in group A, 59 in group B, 17 in group C, and 4 in group D. By CLEIA method (CO:4.0 U/mL), it was 849 (group A), 59 (group B), 16 (group C), and 5 (group D), respectively, consistent with the results of ELISA method. The LA method (Fujifilm Wako Pure Chemical Corporation) (CO:4.0 U/mL) resulted in 823 (group A), 83 (group B), 18 (group C), and 5 (group D), respectively. However, when CO of the LA method was set at 6.0 U/mL, the results were similar to those measured by the other two methods. It was observed that depends on the object population it may obtain a fluctuating CO.

 [Conclusion] For screening test in medical examination, it is necessary to reduce the false negatives and to keep the false positives within acceptable range. It is also necessary to be applicable to automated analyzers for accurately measuring a large number of samples. The results of LA method (CO:6.0 U/mL) were similar to those of the other two methods. Since the LA method can be used in the automated analyzer, it's suitable for the ABC classification screening with a large number of subject persons.