Helicobacter pylori Related Health Problems in Children.

Dear Editor-in-Chief

Helicobacter pylori infection is the most frequently seen infection worldwide. It is the most widely seen agent of gastrointestinal disease, primarily gastric disease. It causes also a wide spectrum of extra-gastrointestinal disorders. Cancer, lymphoma, cardiovascular disease, dermatological disease, liver and gallbladder diseases, anemia, diabetes mellitus, autoimmune disease, atopy, asthma, neurological disease, growth, failure to thrive, bone disease, and micronutrient deficiency could be associated with H. pylori infection, as has been suggested in literature, especially in the adults (1). As a result of the interaction of H. pylori in the place it directly settles in the stomach with the organism, it leads to diseases apart from in the gastro-intestinal system by a series of hormonal, immunological, cytokine and chemokine mediators. Although H. pylori infection is mainly acquired in childhood, complications generally arise much later. Therefore, pediatricians may not be aware of such situations.

The aim of this study was to update our knowledge with a review of literature on H. pylori infection and related events. This review was prepared by examining the relationship between H. pylori infection and related conditions in publications from the last decade pertaining to childhood. H. pylori is the most common cause of gastritis which develops in all people infected with the bacteria (2). It is responsible for 95% of duodenal ulcer etiology and for 70–85% of stomach ulcer etiology (3). MALT (Mucosa associated lymphoid tissue) is a lymphoid tissue tumor associated with the mucosa and H. pylori plays a significant role in the pathogenesis. After eradication of the micro-organism, a remission rate of 60–70% is seen in MALT lymphoma (4).

H. pylori has a possible association with several gastro-intestinal system diseases such as non-ulcer dyspepsia, lymphocytic gastritis, Menetrier disease, protein-losing enteropathy and gastro-oesophageal reflux (5).

Several studies have proven a strong relationship between iron deficiency anaemia and iron deficiency with H. pylori infection in children (1). How the bacteria lead to iron deficiency is not fully understood but various mechanisms have been suggested. One is the loss of iron in gastro-intestinal bleeding related to H. pylori. Chronic gastrointestinal bleeding is not responsible (6). Another explanation of the mechanism is that H. pylori leads to hypochlorhydria with a negative effect on iron absorption.

Ascorbic acid has a significant effect on the increase of iron absorption (7). Another mechanism which has been suggested is that reduced ascorbic acid secretion of H. pylori reduces iron absorption. The prevalence of iron deficiency in H. pylori sero-positive children has been determined as significantly high compared to seronegative children and in cases with unexplained iron deficiency anemia, the anemia recovered and iron absorption test results returned to normal following eradication of H. pylori.

A further hypothesis is the relationship of H. pylori with hypochlorhydria. According to this, by raising the levels of gastric interleukine (IL)-1β and tumor necrosis factor (TNF)-α, H. pylori inhibits acid secretion, thereby causing hypochlorhydria and reduced iron absorption (1). A further association which has not been fully clarified is that the response to the combination of H. Pylori eradication with the application of anemia treatment is better than the response to anemia treatment alone.

An increase in autoimmune diseases with H. pylori eradication has shown that asthma, inflammatory intestinal diseases and multiple sclerosis are observed more in H. pylori negative children (8).

There are several studies on the relationship between H. pylori and idiopathic thrombocytopenic purpura (ITP), which have proposed that ITP develops as a result of the reaction of auto-antibodies which develop against the micro-organism with thrombocyte glycoproteins (9).

In recent years, H. pylori infection has been a factor affecting the rate of growth in children. H. pylori infection has a negative effect on height alone while others have stated it to be both height and weight gain. In addition, the prevalence of H. pylori infection seen in children with constitutional growth delay has been determined to increase with age (10).

In Europe, more than half the children presenting with delayed growth were infected with H. pylori and in a study in Scotland, infection was found at a higher rate in girls who were determined with delayed growth in puberty. H. pylori as an infection acquired in early childhood seems to be one of the major factors affecting growth in children (1).

In conclusion, it is of great importance that new research is conducted in developed and developing countries to better clarify the relationship between growth, asthma and atopy and H. pylori supported by relatively strong evidence of the connection with ITP, iron deficiency anemia and vitamin B12 deficiency.