Relationship Between Virulence Factors Of Helicobacter Pylori And Gastroduodenal Disease And Influence On Eradication Therapy

Objective: Helicobacter pylori infection is one of the most common chronic bacterial infections worldwide. It is associated with chronic gastristis , peptic ulcer disease, gastric cancer and gastric mucosa-associated lymphoid tissue lymphoma. However, it remains unclear why only a small number of infected patients develop such severe diseases. This phenomenon may be due to the virulence of bacterial strains. It has been reported in several studies that CagA, VacA are associated with gastrodudenal disease. But other repoets suggest that neither VacA nor CagA are associated with more serious gastrodudenal disease. So, it is necessary to study the relationship between CagA, VacA and gastrodudenal disease.Some, but not all studies have provided evidence that the CagA,VacA status of Helicobacter pylori strains is a predictive factor for the outcome of eradication therapy.So that the link between CagA, VacA status and eradication outcome remains controversial.The aim of our study is to investigate the frequency of seropositivity CagA,VacA in patients with Helicobacter pylori(H.pylori) positive chronic active gastristis, peptic ulcer, functional dyspepsia and gastric carcinoma. To evaluate the relationship between CagA,VacA and eradication for H.pylori by sequential therapy and determine the influence of virulence factors on eradication therapy.Methods:1 Patient selection: A total of one hundred and sixty-one patiens were included.They were referred to the digestive department of Hebei Medical University Third Hosipital between March 2009 and Dec 2010. 1.1 Inclusion Criteria: Age from18 to 70. Rapid urease test or 14C-urea breath test had positive test results. They had not received bismuth,proton pump inhibitor,antiacids and antibiotics in the 1 month before the examination. All patients were diagnosed by endoscopy and biopsy. They included chronic active gastristis, peptic ulcer and gastric carcinoma. Functional dyspepsia were diagnosed according to RomeⅢDiagnostic Criteria for Functional Gastrointestinal Disorders.1.2 Exclusion criteria: Patients with severe diseases , such as cardiac insufficiency and respiratory failure etc,could not receive endoscopy. Patients who were allergic to drugs in this study. Pregnancy or lactation women. Patients who could not obey doctor's advice, such as mental disorders etc.1.3 Termination test indications: Symptom aggravated during the treatment period; Patients could not demonstrate compliance because of severe side effects; Severe diseases were found during the treatment period; Pregnancy during the treatment period.1.4 Ordinary circumstances: A total of one hundred and sixty-one patiens(72 males and 89 females; median age, 49.29years; range, 18～70 years) were included. There were 45 functional dyspepsia patients, 50 chronic active gastristis patients, 50 peptic ulcer patients and 16 gastric carcinoma patients in the examination.2 Methods:2.1 Grouping: All of the patients in our study were divided intofour groups: Group A: chronic active gastristis group, 50 patients; Group B: functional dyspepsia group, 45 patients; Group C: peptic ulcer group, 50 patients; Group D: gastric carcinoma group, 16 patients.2.2 Methods: Fasting serum samples were obtained from all patients to test CagA ang VacA. Patients from group A, B and C received sequential therapy to eradicate H.pylori. Sequential therapy: esomeprazole 20 mg bid plus amoxicillin 1000mg bid for 5 days, followed by esomeprazole 20mg bid plus clarithromycin 500mg bid plus Furazolidonefor 100mg bid another 5 days. 2.3 H.pylori Eradication Standard: Eradication was assessed by 14C-urea breath test 4 weeks after therapy.2.4 Observation Indexes: CagA and VacA positive rates in four groups; Eradication rates of CagA positive and negative patients; Eradication rates of VacA positive and negative patients.2.5 Statistical Analysis:All data were calculated usingχ2test. P<0.05 was considered statistically significant. All the statistical analyses were performed using SAS V8 for Windows.Results:1 Test completion: A total of 161 patiens were receiving serum CagA and VacA test.142 patients were receiving an eradication treatment of H.pylori. 3 patients(2 chronic active gastristis patients and 1 peptic ulcer patients) were lost. None of them terminated test.2 CagA positive rate:29 patients were CagA positive, positive rate was 18.01%.The percentage of positive to different groups were as follows: CagA positive with chronic active gastristis 8 of 50(16%), with functional dyspepsia 7 of 45(15.56%), with peptic ulcer 9 of 50(18%),with gastric carcinoma 5 of 16(31.25%).χ2=2.2196, p=0.5281, there was no significant difference. VacA positive rate: 93 patients were VacA positive, positive rate was 57.76%. The percentage of positive to different groups were as follows: VacA positive with chronic active gastristis 28 of 50(56%), with functional dyspepsia 27 of 45(60%), with peptic ulcer 30 of 50(60%),with gastric carcinoma 8 of 16(50%).χ2=0.6538, p=0.8840, there was no significant difference.21patients were CagA and VacA positive, positive rate was 13.04%. The percentage of positive to different groups were as follows: CagA and VacA positive with chronic active gastristis 7 of 50(14%), with functional dyspepsia 5 of 45(11.11%), with peptic ulcer 7 of 50(14%), with gastric carcinoma 2 of 16(12.5%).χ2=0.2330, p=0.9721, there was no significant difference. 3 Eradication rates of H.pylori: Successful eradication was achieved in 23 of 24 (95.83%)patients with CagA positive and in 95 of 118(80.51%) patients with CagA negative.χ2=2.3330, p=0.1267, there was no significant difference. Successful eradication was achieved in 72 of 85 (84.71%) patients with VacA positive and in 46 of 57(80.7%) patients with VacA negative.χ2=0.3895, p=0.5326, there was no significant difference. Successful eradication was achieved in 18 of 19 (94.74%) patients with CagA and VacA positive and in 41 of 51(80.39%) patients with CagA and VacA negative.χ2=1.2039, p=0.2725, there was no significant difference.Conclusion:1 The percentage of CagA and VacA positive are no significant difference in chronic active gastristis, peptic ulcer, functional dyspepsia and gastric carcinoma.2 The percentage of CagA and VacA positive are no significantly associated with successful eradication.