Evaluation of selected immunocompetent cells expression in gastric mucosa in children with Helicobacter pylori infection before and after eradication treatment--a preliminary study]

Helicobacter pylori infection activates local immunological response and causes mononuclear cells infiltration in the gastric mucosa. On this account the studies on lymphocyte subpopulations in the gastric mucosa in children during Helicobacter pylori infections are inconsistent. It has been shown that the morphological status of gastric mucosa in children with Helicobacter pylori infection is different than in adult patients. THE AIM OF THE STUDY was the evaluation of chosen immunocompetent cells expression in gastric mucosa in children before and after eradication treatment.Forty-nine children with chronic abdominal pain was enrolled in the study. They were divided into the following groups: 22 children without infection (negative urease test and absence of Helicobacter pylori antigen assessed by immunoenzymatic and immunofluorescent methods) and 27 with Helicobacter pylori infection. Part of the children (11) from the second group had a follow-up endoscopy after eradication therapy. The tissue samples from the gastric antrum and fundus were obtained for morphological and immunohistochemistry assays by direct immunofluorescent and immunoenzymatic methods.There were negative Helicobacter pylori tests in group I. In the group of infected children superficial colonisation of pathogen dominated In analysed groups percentage of patients with superficial antigens and cytokines (CD3, CD4, CD8, CD20, IL-4, IL-6, INF-gamma) characteristic for each lymphocytes subpopulations were established. In infammatory infiltrations T lymphocytes CD4 and B lymphocytes CD20 dominated localised mainly in the lamina propria of the gastric mucosa. Expression of above lymphocytes subpopulations diminished after eradication treatment. After treatment the total eradication of Helicobacter pylori was observed in 5 children and in 6 patients the pathogen persisted.The dominant role in local response during Helicobacter pylori infection in children is played by T CD4 and B CD20 lymphocytes localised mainly in lamina propria of gastric mucosa. Degree of T cells CD4 and CD20 expression decreases after eradication treatment.