Mast cells are claimed to be an important element in the cellular infiltration in the course of gastric mucosal inflammation due to H. pylori infection . There is only little data in literature concerning the number of mast cells in chronic inflammation of the gastric mucosa in pediatric age group and existing data have rather conflicting results.
Mast cell detection is rather easy by a simple and inexpensive staining (Giemsa) which can also be used to detect presence of H. pylori. It is of worth noting that reliable detection is achieved by examining the tissue under oil immersion (x1000) and in lower magnifications they can be missed. Although the gold standard is staining of tissue with anti-tryptase antibody by immunohistochemical methods, it is a time consuming and rather expensive method not recommended for routine pathologic assessment of gastric biopsies.
We decided to study on rather large number of specimens in a referral children hospital with longstanding experience in pediatric gastroenterology and determine mast cell density and its relation to inflammation and presence of H. pylori.
In this study, we did not observe a significant correlation between mast cell density, severity of inflammation, activity of gastritis and presence and density of H. pylori in antrum. Our results are rather in concordance with results of few authors such as Maciorkowska et al., but not others [6–8], although none of these studies were performed on such large series as ours.
H. pylori is the most frequent and significant factor in the etiology of chronic active gastritis, in addition to being implicated in various illnesses such as peptic ulcer, gastric adenocarcinoma, and lymphoma . Our results also showed that there was a significant relationship between infection with H. pylori and severity of gastritis (p = 0.0001).
Mast cells are the most important cells in acute allergic reactions with mediation of IgE. In this study, there was no significant correlation between allergic symptoms stated by parents (food and other allergies) and gastric mast cell density.
Many children undergo endoscopy with common complaint of chronic or recurrent abdominal pain in our center. They are mainly in range of 5 to 7 years of age and no significant changes are observed both endoscopically and by microscopic examination, as in many of our cases (nearly 231 out of 352 cases). Our study shows that mast cell density in this group is slightly higher than other groups (although statistically not significant) and we propose that maybe mast cells play a role in producing such symptoms not by their traditional known pathways in inflammatory processes but by an as yet undefined pathway such as stimulatory effect on gastric nerve plexuses. So we recommend that increase in mast cell density should be included in the final report of gastric biopsies.
Although we did not performed immunohistochemical stains for mast cell detection, we propose that Giemsa stain is a reliable and easy staining method available in all laboratories and also has good interobserver correlation. Although it has also shortcomings such as erroneous detection of artifactual staining as mast cells, effects of edema and shrinkage and also missing them because of degranulation, these have no significant impact on the final count.
Besides the shortcomings of our study it is necessary to mention that it was performed on rather a large series of pediatric patients and the results are not surprisingly concordant with other studies mainly performed in adult age group.