CD4+ and CD8+ T cells in gastric mucosa in children infected with Helicobacter pylori / 中华儿科杂志

ABSTRACT

<p><b>OBJECTIVE</b>To study the changes of gastric mucosal CD4(+) and CD8(+) T cells in Helicobacter pylori (Hp) infected children.</p><p><b>METHODS</b>Seventy nine patients with digestive tract symptoms were assessed by endoscopy, rapid urease test and histology. Forty four patients had Hp positive chronic superficial gastritis (Hp(+)CSG) and 35 patients had Hp negative chronic superficial gastritis (Hp(-)CSG). Gastric biopsy specimens were obtained from each patient. Peripheral blood samples were obtained from 33 patients (12 with Hp(+)CSG, 21 with Hp(-)CSG). Hp infection was identified by rapid urease test and histology. Hp infection was confirmed when a patient was positive for both of these tests. Four pieces of gastric antrum mucosal specimens were placed in Hank's balanced salt solution containing 1 mmol/L dithiothreitol (DTT) and 1 mmol/L ethylenediamine tetraacetic acid (EDTA). The specimens were treated with collagenase type I (120 U/ml) for three hours at 37 degrees C with agitation. The mononuclear cells were collected by removing undigested material and washed three times with RPMI 1640. Isolated gastic mononuclear cells were stained with CD3-FITC (fluorescein isothiocyanate), CD4-PE (R-phycoerthrin), CD8-PerCP (Peridinin-chlorophyll-alpha-protein) and measured by flow cytometry. Mucosal T lymphocytes were gated for the expression of CD3. Peripheral blood lymphocyte subsets were analysed by direct immunofluorescence.</p><p><b>RESULTS</b>The percentage of isolated gastric mononuclear cells within the CD3 gate were 3.26 +/- 1.98 in Hp(-)CSG, 4.37 +/- 1.97 in Hp(+)CSG. Relative CD4(+)(%), CD8(+)(%) and CD4(+)/CD8(+) of the CD3(+) cells respectively were 23.74 +/- 10.37, 47.04 +/- 12.00, 0.52 +/- 0.23 in Hp(-)CSG group, 40.28 +/- 11.35, 27.91 +/- 8.84, 1.55 +/- 0.52 in Hp(+)CSG group. CD4(+)(%), CD4(+)/CD8(+) in Hp(+)CSG group were significantly higher than those of Hp(-)CSG group and CD8(+)(%) was lower than those of Hp(-)CSG group (P < 0.01). There were no significant differences in peripheral blood T lymphocyte subsets between the two groups.</p><p><b>CONCLUSION</b>The difference of gastric T lymphocyte response between Hp(+)CSG and Hp(-)CSG in children indicated that the local cellular immune reaction may play a critical role in the pathogenesis of Hp infection.</p>