Original article
Changes in anti-Helicobacter pylori antibody titers before and after treatment for Helicobacter pylori eradication using latex agglutination test
2021 Volume 59 Issue 4 Pages 394-399
Details
2021 Volume 59 Issue 4 Pages 394-399
Background: The effectiveness of eradication of Helicobacter pylori (H. pylori) can be monitored by the fact that the serum antibody titer falls by 50% or less than the level before eradication. We investigated whether the fall of antibody titers measured using the latex agglutination test is also reliable in assessing eradication of H. pylori.
Subjects and methods: Among those who participated in the health checkup program of both 2010 and 2015, 846 cases that were positive for H. pylori in 2010 and treated for eradication by 2015 were included. The success and timing of eradication were determined by detailed questioning. The ratio of antibody titers before and after eradication measured by H. pylori-LATEX "SEIKEN" (Denka Ltx) was calculated and compared for each eradication period. We tested whether there was an association between serum antibody titers measured by Denka Ltx and regular use of acid secretion inhibitors.
Results: Of the 846 cases, 740 were successful and 106 failed in the eradication therapy. The ratio of antibody titers before and after eradication therapy among the successful subjects was 0.19±0.01 and that among those who failed was 0.44±0.03 (P < 0.0001). The antibody titer ratios were 0.30, 0.23, and 0.16 within six months, one year, and one and a half years after eradication therapy, respectively. The ratios were significantly different between six months and one and a half years (P = 0.0390). On the contrary, there was no significant difference after one year. The positive predictive value for successful eradication of H. pylori was 90.1% (528/559) in cases where antibody titers decreased by more than 50% after a year of eradication. There was no significant association between antibody titers and regular use of acid secretion inhibitors.
Conclusions: Serum H. pylori antibody titers measured by Denka Ltx significantly decreased after eradication therapy, and a decrease in antibody titers by more than 50% at least one year after eradication therapy is useful in determining successful eradication.
