The relationship between cytotoxin-associated gene A positive Helicobacter pylori infection and autoimmune thyroid disease.

OBJECTIVE: The aim of this study was to determine whether there is an association between cagA [cytotoxin-associated gene A] positivity and thyroid autoimmunity and thyroid volume. METHODS: This prospective study included 78 Helicobacter pylori-positive (H. pylori) dyspeptic patients in the study group, and 50 age-, gender-, and body mass index-matched H. pylori-negative dyspeptic patients in the control group. All the controls were evaluated via upper gastrointestinal endoscopic biopsy or breath test, and were found as H. pylori negative. Gastric biopsy specimens were obtained via endoscopy and histological examination was performed for documentation of H. pylori. RESULTS: In all, 55.1% (n = 43) of the H. pylori-positive patients were cagA positive. There was no significant difference in metabolic syndrome parameters or thyroid function test results between the study and control groups. The frequency of anti-TPO and Hashimoto's thyroiditis positivity was significantly higher in the study group than in the control group. Thyroid volume was higher and severe parenchymal heterogeneity was more common in the H. pylori-positive patients. CONCLUSIONS: H. pylori infection might be a risk factor for autoimmune thyroid disease and high thyroid volume in patients diagnosed with histological evaluation. However, cagA positivity has no additional effect on these parameters.