Seroconversion and seroreversion of Helicobacter pylori antibodies over a 9-year period and related factors in Japanese adults.
BACKGROUND
There are still insufficient data on the frequency of seroconversion and seroreversion of Helicobacter pylori antibodies. The frequency of serochange and related factors were investigated in this study over 9 years.


METHODS
Using sera from 3104 workers who underwent health checks in 1989 and again in 1998, H. pylori antibodies were measured. Those with intermediate serology were excluded from the study. Information on past history was collected using a questionnaire.


RESULTS
Of the 912 seronegative and 1286 seropositive subjects in 1989, seroconversion was observed in 57 and seroreversion in 91 subjects. Seroconversion and seroreversion rates over the 9-year period were 6.3% and 7.1%, respectively, giving rates per 1000 person-years (with 95% confidence interval) of 7.0 (5.2-8.7) and 7.9 (6.3-9.4), respectively. Subjects that reported abdominal symptoms or gastric fiberscope use showed significantly higher seroconversion rates than controls (8.7 vs. 4.5 and 9.2 vs. 1.6, respectively), which remained significant after adjustment for age and gender. Those with a history of duodenal ulcers, a smoking habit or a drinking habit showed significantly lower seroreversion rates than controls (3.5 vs. 8.9, 5.4 vs. 9.2 and 5.9 vs. 13.3, respectively). After adjustment, the association between seroreversion and smoking habit disappeared, while the associations with history of duodenal ulcers and drinking habit remained.


CONCLUSIONS
Those with a history of nonspecific abdominal symptoms and those with a history of gastric fiberscope use showed higher seroconversion rates. Alcohol consumption and duodenal ulcers may inhibit the autoeradication of H. pylori, possibly through increased acid secretion.
Kikuchi
Shogo
S
Department of Public Health, Aichi Medical University School of Medicine, Nagakute-cho, Aichi-gun, Japan. kikuchis@aichi-med-u.ac.jp
Ohgihara
Atsushi
A
Hasegawa
Ayako
A
Miki
Kazumasa
K
Kaneko
Eizo
E
Mizukoshi
Hiroshi
H
D000328:Adult; D000368:Aged; D000907:Antibodies, Bacterial / Q000097:blood*; D004327:Drinking Behavior; D004381:Duodenal Ulcer; D005260:Female; D016481:Helicobacter Infections / Q000453:epidemiology* / Q000276:immunology*; D016480:Helicobacter pylori / Q000276:immunology*; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D016036:Seroepidemiologic Studies; D012907:Smoking; D013997:Time Factors
D000907:Antibodies, Bacterial