1. Introduction

Previous studies showed a so-called Th1 immune response with an increased production of IFN-γ, TNF-α and other pro-inflammatory cytokines that occur in the stomach, when the subject is infected with Helicobacter pylori, as well as in the small intestine, when the subject with celiac disease (CD) eats normal bread ^[1]. Today, this possible immunological association between H. pylori infection and CD is linked to the hygiene hypothesis. Hygiene hypothesis revealed that low exposure to bacterial antigens can trigger autoimmunity. H. pylori and CD are inversely related ^[2]. A low prevalence of Crohn's disease and CD was seen in H. pylori-positive patients ^[3].

Although the stomach was a hostile environment, Helicobacter pylori infection has been extensively studied since 1984 ^[4]. It is also well known that bacterial species prevail in the intestinal microbiota of patients with celiac disease (CD) ^[5] but little evidences were related linked to existing of H. pylori in the gut of patients with CD. Recent studies highlighted H. pylori infection and CD as main aspects of pediatric gastroenterology in recent years ^[6].

The aim of this study was to find current state of immunopathological knowledge about association of H. pylori infection and CD. A potential link between H. pylori and CD was analysed. We searched in PubMed database with the following keywords: H. pylori, CD, immunopathology. Only relevant papers were included in our present study.

2. Gastric Lymphocytosis

Early studies showed that lymphocytic gastritis was associated with CD, but H. pylori infection was not showed in children with lymphocytic gastritis ^[7] and the relationship between lymphocytic gastritis and CD required further elucidation ^[8]. Lymphocytic gastritis occurred most often in CD, but rarely with other entities ^[9]. More recent studies have shown that CD might be associated with H. pylori gastritis, but clinical presentation of CD was not affected ^[10]. A pathogenic relationship between CD and lymphocytic gastritis was highlighted. H. pylori might be another cause of lymphocytic gastritis in children ^[11]. So the main causes of lymphocytic gastritis were H. pylori infection and CD ^[12]. When the histopathological result showed lymphocytosis alone, lymphocytic gastritis was associated with CD and not with H. Pylori infection. But when the histopathological result showed significant infiltration of neutrophils, the diagnosis would be "chronic active gastritis", often associated with H. pylori infection ^[13].

3. Duodenal Lymphocytosis

The first studies showed that in some patients, increased duodenal intraepithelial lymphocytes could be due to an autoimmune response to H. pylori ^[14]. The presence / absence of H. pylori were independent of normalization of duodenal mucosa to CD patients ^[15]. The most common duodenitis etiology were: CD (32%), Crohn's disease (13%), ulcerative colitis (3%) and H. pylori infection (6%) ^[16]. There were no statistically significant differences of duodenal intraepithelial lymphocytes according to H. pylori status among children with CD: 73.1 (± 26.1) positive vs. 72.6 (± 26.5) negative ^[17]. H. pylori prevalence was similar in patients with CD and controls, and higher in patients with minor duodenal injuries ^[18]. H. pylori infection seems to be less frequent in patients with CD and villous atrophy suggesting that histological damage appears to be similar in patients with H. pylori infection ^[19]. Therefore, H. pylori infection is one of the main causes of duodenal lymphocytosis and together with HLA are strong predictors for CD development ^[20].

4. Conclusions

There are many “for” and “against” conclusions on immunopathological association between CD and H. pylori infection. But if celiac disease is associated with H. pylori infection, clinical evidence can occur: gastric lymphocytosis, duodenal lymphocytosis.

References

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