Is There Anything to the Reported Association Between Helicobacter pylori Infection and Autoimmune Thyroiditis?

Abstract

Higher serological prevalence rates of Helicobacter pylori (Hp) infection have been reported in patients with autoimmune thyroiditis (AT), and it has been suggested that monoclonal antibodies against Cag-A positive Hp strains can cross-react with follicular cells of the thyroid gland. We studied the prevalence of AT and thyroid functional status in patients who underwent gastroscopy for dyspeptic symptoms. Patients were tested for TSH, free thyroid hormones, and antithyroglobulin and antithyroperoxidase antibodies (ATPO). Hp positivity was determined using urea breath test (UBT). Serum samples from 302 patients (59.9% women) were evaluated. One hundred ninety-one subjects (63.2%) were Hp-negative, and 111 of 302 (36.8%) were Hp-positive. Forty-three of 191 Hp-negative patients (22.5%; 95% CI, 17.1-29.0%) had an increase of either antibody, compared to 30 of 111 (27.0%; 95% CI, 19.6-36.0%) Hp-positive patients (P = 0.40). Similar results were obtained using positivity for both antibodies (7.3 vs. 7.2%; P = 1) or for ATPO (18.8 vs. 21.6%; P = 0.54). The prevalences of hypothyroidism (4.7 vs. 5.5%) or hyperthyroidism (5.8 vs. 5.5%) were also similar (P = 0.95). Hormonal levels were not different in the two groups (P > 0.22 in all cases). The previously reported association between AT and Hp infection was not observed in our study. Infection by Hp does not appear to increase the risk of AT in individuals with dyspeptic symptoms, and screening for this condition in patients with a positive UBT is not indicated.

Helicobacter Pylori Infection: Association with Hashimoto’s Thyroiditis

“…In contrast to our results Tomasi et al [19] investigated the relationship between H.P infection and ATD 302 patients with signs and symptoms of dyspepsia underwent an upper endoscopy and patients were evaluated for H.P infection and ATD. In this study, 36.81% of the individuals were positive for H.P.…”

Helicobacter pyloriand autoimmune disease: Cause or bystander

“…This was in accordance with a previous study by the same group [116] . Negative findings in regard to Hashimoto's were reported in other studies [103,117] , while some reported a positive association [114,118,119] .…”

Thyroid autoimmunity as a window to autoimmunity: An explanation for sex differences in the prevalence of thyroid autoimmunity

“…Although there is an association with several potential mimics and associated agents, it has not been possible to show a direct establishment of an autoimmune disease in the thyroid with any agent. Indeed, induced animal models (McLachlan and Rapoport, 2014) from agents are common (see for instance: Yoshida, 2010 andTomasi et al, 2005) -but most, except in genetically susceptible individuals (ElRehewy et al, 1981), require an adjuvant as part of the induction process. This can be an important hint if one looks for what could provide an adjuvant-like signal in addition to a mimic.…”