Could Helicobacter pylori cause an abnormal immune response?

To the Editor

Rostami-Nejad et al and Samasca et al. found that the screening of H. pylori infection is necessary in patients with CD and iron deficiency (1,2). In a recent our study, the prevalence of H. pylori infection in our pediatric lot was 12%. 38 patients were positive for IgA H. Pylori antibodies. We performed IgA tissue transglutaminase antibodies to all 38 patients with positive results for IgA H. pylori antibodies, however, the results were negative. But, clinical diagnosis of children with H. pylori infection was diversified, moreover, nutritional diseases were the most frequent. H. pylori was involved in the following autoimmune diseases: type 1 diabetes mellitus (T1DM), thyroiditis and arthritis (Table 1). CD may be associated with H. pylori gastritis infection (3) however, few studies revealed this aspect. The association between H. pylori infection and thyroiditis in patients with T1DM was observed (4). H. pylori and patterns of gut microbiome have associated with low risk of T1DM (5). We also observed an association between H. pylori and T1DM in our study. Therefore, could autoimmunity be triggered by a decreased exposure to bacterial antigens? In our study, H. Pylori was associated with autoimmune diseases such as: type 1 diabetes mellitus, thyroiditis or arthritis but further studies are necessary for this etiology.

Table 1

Clinical diagnosis in patients with positive H. pylori infection

Diagnostic	Absolute frequency
Mild or moderate protein-energy malnutrition	5
Diabetes mellitus type 1	4
Gastritis/duodenitis	4
Nutritional anemia	3
Urticaria and erythema	2
Diarrhoea and gastroenteritis of presumed infectious origin	1
Bacterial infection	1
Benign tumor of the breast	1
Hereditary deficiency through missing factor VIII	1
Other coagulation abnormalities	1
Other bleeding disorders	1
Thyroiditis	1
Obesity	1
Pulmonary valve disorders	1
Other chronic obstructive pulmonary disease	1
Asthma	1
Acute appendicitis	1
Erythema nodosum	1
Other abnormalities in of pigmentation	1
Infectious arthropathy	1
Other arthritis	1
Back pain	1
Abnormal heart rhythm	1
Bleeding from respiratory system	1
Nausea and vomiting	1
TOTAL	38

Conflict of interests

The authors declare that they have no conflict of interest.