Although the sensitivity and specificity to evaluate the status ofinfection by antibody responses are relatively lower than13C-UBT, it is more feasible, practical, and cost-effective in a large scale population-based anti-treatment (12). and HpaA were reversely associated with eradication failure [for FliD, odds ratio (OR)=0.44, 95% confidence interval (95% CI): 0.27C0.73; for HpaA, OR=0.32, 95% CI: 0.17C0.60]. The subjects with multiple positive specific antibodies at baseline were more likely to be successfully eradicated in a linear fashion (Ptrend=0.006). Conclusions Our study suggested that total anti-IgG level may serve as a potential monitor of long-term impact on anti-treatment, and priority fortreatment may GDC0853 be endowed to the subjects with multiple seropositive antibodies at baseline, especially for FliD and HapA. (treatment could reduce the risks of precancerous gastric lesions and gastric cancer (3-6). Therefore, gastric cancer prevention by eradication ofin a high risk population is usually highly motivated (7). Although new regimens have been developed to eradicateinfection, two challenges GDC0853 existed, failure of eradication and recurrence of the contamination (8,9). Currently, even under conventionaleradication therapy, there were still 10%C30% failure (8,10). Moreover, the annual recurrence rates after eradication were about 3.4% in developed countries and 8.7% in developing countries, respectively (9). The short- and long-term impacts on anti-treatment may require a relevant monitor to evaluate biological effectiveness of the eradication and recurrence, particularly in a large community-based gastric cancer intervention. 13C-urea breath test (13C-UBT) is currently a golden standard to identifyinfection but it requires specific devices and the cost is relatively high (11). And alternative to13C-UBT, serum biomarker is an area of investigation, particularly forspecific antibodies. Although the sensitivity and specificity to evaluate the status ofinfection by antibody responses are relatively lower than13C-UBT, it GDC0853 is more feasible, practical, and cost-effective in a large scale population-based anti-treatment (12). In addition, it is also interesting to know whether certain serumantibodies are more specifically associated with the outcomes oftreatment, which could be potential markers for targeting population at a high risk of gastric cancer. Our previous Shandong Intervention Trial in Linqu County (SIT, clinicaltrials.gov identifier: “type”:”clinical-trial”,”attrs”:”text”:”NCT00339768″,”term_id”:”NCT00339768″NCT00339768), one of the highest risk areas of gastric cancer in the world, provided us a unique opportunity to conduct such investigation (3,13,14). This 7.3-year follow-up trial allowed us to dynamically assess the total anti-immunoglobulin G (IgG) and specific antibody levels before and after anti-microbial treatment, which may serve as a surrogate monitor of13C-UBT to evaluate long-term risk of recurrence, and short-term impact on the effectiveness of eradication. Materials and methods Study subjects Details of this trial were described in elsewhere (3,15). Briefly, 3,365 eligible trial participants aged 35C64 years were recruited from 13 villages selected at random to conduct a randomized, double-blind, placebo-controlled intervention trial in 1995. Theinfection status of each individual was determined by serumantibody test at baseline. Amoxicillin and omeprazole treatment ofinfection or the corresponding placebos were randomly assigned to 2,258seropositive GDC0853 subjects in 1995. Among them, a total of 1 1,803 trial participants received a13C-UBT at 45-d after the completion of antibiotic treatment and at the end of this trial in 2003. In the meantime, total serum anti-antibody levels were parallelly determined among the same trial participants at 1-year (in 1996), 2-year (in 1997) and 7.3-year (in 2003) after anti-treatment, respectively. For the current study, we further randomly selected 473 participants from active treatment group (908 eligible subjects) and 56 participants from placebo group (895 eligible subjects), to evaluate serum total anti-IgG and 10 specific antibody levels before and after treatment at 1-, 2- and 7.3-year. This study was approved by the Institutional Review Board of Peking Rabbit Polyclonal to GABBR2 University Cancer Hospital, and written informed consent was provided by all participants in the study. Questionnaires At study enrollment, all participants were interviewed in person by trained interviewers using a structured questionnaire, consisting of the following sections: 1) demographic background; 2) personal habits; 3) medical history; and 4) dietary habits (3,15). 13C-UBT Details of13C-UBT were described previously (15). In brief, participants fasted overnight before baseline exhaled CO2 samples were collected. Expired gas was collected 30 min later after drinking 20 mL water with a pill of 80 mg13C-urea ( 99%) (Baylor Medical College, Houston, Texas, USA).13CO2 values were determined by a gas isotopic ratio mass spectrometry (Finnigan MAT, Bremen, Germany), and any concentration of13CO2 at.