关键词: 儿童, 幽门螺杆菌, T淋巴细胞亚群

Abstract: AbstractObjectiveTo study the changes of T lymphocyte subsets in Helicobacter pylori(H.pylori) infected children with gastritis and duodenal ulcer.MethodsTwelve patients with H.pylori positive chronic superficial gastritis(H.pylori+CSG),five patients with H.pylori positive duodenal ulcer(H.pylori+DU) and twentyone patients with H.pylori negative chronic superficial gastritis(H.pylori-CSG) were assessed by endoscopy,histology and bacterial examination.Gastric biopsy specimens and peripheral blood samples were obtained from each patient.H.pylori infection was identified by rapid urease test and histology,both of those positive was considered to be H.pylori infected.Four gastric antrum mucosa specimens were placed in Hanks’s balanced salt solution containing 1 mM dithiothreitol (DTT) and 1 mM ethylenediamine tetraacetic acid(EDTA).The specimens were agitated for one hour at 37℃ and washed three times with RPMI 1640 after removing the epithelial layer,and then treated with collagenase,type Ⅰ (120u/mL) for three hours at 37℃ with agitation.The monoclear cells were collected by means of removing undigested material and washed three times with RPMI 1640.Isolated gastic mononuclear cells were stained for CD3FITC(fluorescein isothiocyanate),CD4PE(Rphycoerthrin),CD8PerCP(Peridininchlorophyllα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.ResultsThe percentage of isolated mononuclear cells within the CD3 gate were 3.14±2.03 in H.pylori-CSG,4.58±2.30 in H.pylori+CSG,6.49±4.49 in H.pylori+DU.Relative CD+4 (%),CD+8 (%) and CD+4/CD+8 within the CD3+ cells respectively were 19.81±9.25,47.30±12.83,0.43±0.19 in H.pylori-CSG group,40.66±12.52,29.25±8.58,1.42±0.31 in H.pylori+CSG group,31.98±14.02,49.52±19.00，0.72±0.43 in H.pylori+DU group.CD+4,CD+4/CD+8 in H.pylori+CSG group were significantly higher than those of H.pylori-CSG group and CD+8 was lower than those of H.pylori-CSG group (P<0.01).CD+4,CD+4/CD+8 in H.pylori+DU were also higher than those of H.pylori-CSG group (P<0.05),but CD+8 was not significantly different.CD+8 in H.pylori+DU group was significantly higher than those of H.pylori+CSG group and CD+4 was no significantly different and CD+4/CD+8 was declined (P<0.01).There was no significant difference of peripheral blood T lymphocyte subsets among three groups.ConclusionThe changes of gastric mucosal T lymphocyte subsets in the H.pylori infected children indicat that the T lymphocyte response between H.pylori+CSG and H.pylori+DU is different and the local cellular immune reaction may play a critical role in the pathogenesis of H.pylori infection.

Key words: T lymphocyte , Helicobacter pylori