Helicobacter Pylori CagA antibodies and thyroid function in latent autoimmune diabetes in adults

Abstract. – OBJECTIVE: H. pylori infection is
reportedly associated with autoimmune diseases
such as chronic thyroiditis and autoimmune
diabetes. The aim of this study is to determine
the association between H. pylori infection
and its virulent strain CagA with antibodies
against thyroperoxidase (TPO Ab) and thyrotropin
(TSH) in a cohort of latent autoimmune
diabetes in adult (LADA) patients.
PATIENTS AND METHODS: We included 234
LADA patients (53.8% women). Antibodies
against H. pylori whole antigens and CagA, TPO
Ab and TSH were assessed in all patients.
RESULTS: Prevalence of IgG against H. pylori
and GagA was 52.1% and 20.9% respectively.
Antibodies against H. pylori were not associated
with TPO Ab and TSH (rho = 0.067, p = 0.620 and
rho = 0.156, p = 0.099, respectively). Antibodies
against CagA showed a positive association
with TSH and TPO Ab (respectively rho = 0.309, p
= 0.036 and rho = 0.419, p = 0.037). Subjects with
hypothyroidism (TSH ≥ 3.5 μU/ml) had an increased
frequency of Ab anti CagA (p = 0.059).
CONCLUSIONS: The infection by H. pylori
strains expressing CagA is associated with increased
TPO Ab and TSH levels in LADA patients,
suggesting a possible mechanism involved
in thyroid autoimmunity and dysfunction
of the gland. Further research is needed to test
this hypothesis.