Study On The Association Between Helicobacter Pylori Infection And Autoimmune Thyroid Diseases

Autoimmune thyroid diseases(AITDs)are classic examples of organ-specific autoimmune diseases mediated by T-lymphocytes. Autoimmune thyroid disease which mainly includes Hashimoto's thyroiditis(HT) is the most common autoimmune disorder, and is the most common cause of hypothyroidism. A typical marker of AITDs is the presence of autoantibodies against thyroperoxidase(anti-TPO) and/OR thyroglobulin(anti-Tg) OR Thyrotrophin receptor(TRAb). Both genetic and environmental factors are involved in the pathogenesis of AITDs. Some bacteria and viruses are suspected of being able to mimic the antigenic profile on the thyroid cell membrane, and may play an important role in the onset of autoimmune diseases. Helicobacter pylori(H. Pylori,HP) infection is found worldwide and has an incidence of up to 80% in the population of developed countries. H. pylori correlates with nongastrointestinal conditions such as autoimmune diseases. Several studies have shown a positive correlation between the presence of H. pylori and autoimmune thyroid diseases, although others did not find such an association. The aim of this study was to investigate the association between Helicobacter pylori infection and autoimmune thyroid diseases, and a prospective study to evaluating the effect of H. pylori eradication therapy on the titres of thyroid autoantibodies.The research method include: first, A meta-analysis to investigate the association between H. Pylori infection and autoimmune thyroid diseases. The articles on the association of H. pylori with AITDs were retrieved by searching databases from the inception of each database to October 2015. Meta-analysis was performed using Rev Man 5.3 software, calculating the odds ratio and 95 % confidence interval. Second, A retrospective analysis was used, based on physical examination data of Screening for thyroid antibodies for the first time, from January 201 l to December 2015.The prevalence of Hashimoto's thyroiditis and its risk factors were Analyzed; A case-control study was used, based on the data of screening for H.pylori infection were admitted as cases.Other adults free from autoimmune thyroid diseases who had undergone physical examination in the hospital at the same period, were served as controls. Chi-square test,t-test and multivariate logistic regression analysis were performed.(3)From December 2015 to March 2016, H.pylori infection-outpatients with Hashimoto's thyroiditis or Graves disease from endocrinology clinic departments were enrolled into this study. All the patients were divided into treatment group and control group. All Patients were measured Thyroid antibody after the treatment for 1months, 3months, 6months, 9months, 12 months and compared with those before the treatment.The results in this study included: first the meta-analysis,When Compared with the controls, H.pylori infection significantly increased the risk of autoimmune thyroid diseases development with a pooled of OR=1.86(95%CI:1.18 ~ 2.94). H. Pylori-Cag A infection significantly increased the risk of autoimmune thyroid diseases development with a pooled of OR=2.66(95%CI: 1.61~4.41). H. pylori infection is associated with Graves disease(OR=3.37,95%CI:1.90~5.97)and Hashimoto's thyroiditis(OR=1.83,95%CI:1.22~2.76). Second, The prevalence of Hashimoto's thyroiditis was 18.75%(female 31.35%, male 11.01%). Data from the logistic regression analysis showed that the risk of Hashimoto's thyroiditis was greater in females than male groups, with an odds ratio(95%CI)as(OR =3.785, 95%CI:3.192~4.488). The onset of hashimoto thyroiditis has no correlation with age. Case-control study, the positive rate of H.pylori infection was 41.14% and 36.23% in the case and control group, there was significant difference between the two groups(P<0.05). After adjustment for potential confounding factors,data from the multivariate logistic regression analysis showed that the risk of H.pylori infection was greater in HT than control groups,with an odds ratio(95%CI)as 1.240(95%CI:1.030~1.492).Third,25 patients were included in this study. 18 cases of treatment of H.pylori infection, 10 cases complete 1 month follow-up, 8 cases of successful treatment. Among the eight patients eradication of H. pylori infection,seven showed a remarkable reduction in anti-TPO or anti-TG, No obvious change in 1 case. Among the six patients without H. pylori eradication,thyroid autoantibody titres has remarkably increased.The conclusions in this study includes: The first, H. pylori infection maybe associated with an increased risk of developing the autoimmune thyroid diseases. The second, The prevalence of Hashimoto's thyroiditis was 18.75%.The risk of Hashimoto's thyroiditis was greater in females than male groups. The onset of hashimoto thyroiditis has no correlation with age. The third, H.pylori infection may be one of the risk factors for the Hashimoto's thyroiditis.The fourth, Preliminary findings: Eradication of H.pylori infection maybe decrease some AITDs thyroid autoantibodies.