Correlation between Autoimmune Hashimoto's Thyroiditis and Helicobacter pylori Infection: A Case-Control Study.

Background: Among environmental factors, infectious agents, including Helicobacter pylori, can act as triggers for autoimmune thyroid diseases. Therefore, this study aimed to investigate the correlation between autoimmune Hashimoto's thyroiditis with H. pylori infection.

Methods: The participants in this case-control study were 74 individuals 17-62 years who were divided into two groups, including 38 diagnosed Hashimoto's thyroiditis patients from an outpatient clinic of endocrinology and 36 apparently healthy individuals that were selected from family members of cases group age-matched and sex-matched. For individuals in two groups, a questionnaire was completed, including demographic information. Then, they were referred to the laboratory for thyroid stimulating hormone (TSH) and free T4 (FT4) in the control group and anti-thyroid peroxidase antibody (TPO-Ab) levels measurement in case and control groups. Stool samples were obtained from all individuals for H. pylori antigen detection using the ELIZA kit.

Results: There was no significant difference in the mean age of case and control groups (P=0.96), and 81.1% of individuals were female. 58.6% of patients with Hashimoto's thyroiditis and 41.4% of the control group had positive H. pylori, but there was no statistically significant difference between the two groups (P=0.34). Furthermore, there was a significant positive correlation between TPO-Ab levels and H. pylori infection (r=0.2, P=0.03).

Conclusion: TPO-Ab levels were associated with H. pylori infection diagnosed by H. pylori antigen.