Autoimmune Hypothyroidism Associated with Helicobacter Pylori Infection

Objective: The study aimed to investigate the correlation between Helicobacter pylori (H. pylori) and thyroid autoimmunity. Material and Methods: To demonstrate the possible correlation between H. pylori infection and autoimmune hypothyroidism, 200 individuals were enrolled in this research (100 patients with active H. pylori infection and 100 healthy controls). All of them were tested for serum levels of thyroid hormones, thyroid stimulating hormone (TSH), and autoantibodies, as well as Helicobacter pylori-Immunoglobulin G (H. pylori-IgG) and cytotoxin-associated gene A-Immunoglobulin G (cagA-IgG) antibodies. Results: The study found that H. pylori infection was associated with higher levels of TSH, thyroperoxidase and thyroglobulin (TPO and TG) (p-value<0.000, 0.001 and 0.006, respectively) and a significant decrease in the levels of free-thyroid hormone (FT3 and FT4) (p-values=0.008 and 0.007 respectively) in patients compared with the control group. Moreover, using Pearson’s correlation tests, significant proportional correlations were found between H. pylori IgG and TSH (r=0.302, p-value=0.001), and a significant negative correlation was found between anti-H. pylori-IgG and with FT3 and FT4 (r=-0.261, p-value=0.003 and r=-0.260, p-value=0.003, respectively). Moreover, Spearman’s correlation results showed that H. pylori IgG was positively linked to TPO (r=0.531, p-value<0.001) and TG (r=0.320, p-value=0.001). Conclusion: The current investigation found that H. pylori infection was linked to higher concentrations of thyroid autoantibody and TSH and lower levels of thyroid hormones, suggesting that the bacterium may play a role in the development of subclinical autoimmune hypothyroidism.