儿童幽门螺杆菌感染时T淋巴细胞亚群的变化

目的研究儿童幽门螺杆菌(H.pylori)感染时的T淋巴细胞亚群变化。方法流式细胞仪直接免疫荧光法测定38例［H.pylori+慢性浅表性胃炎(CSG)12例；H.pylori+十二指肠溃疡(DU)5例；H.pylori-CSG 21例］儿童胃窦黏膜及外周血T淋巴细胞亚群。各组患儿均在内镜检查下取胃窦黏膜作快速尿素酶试验、组织学检查及淋巴细胞提取，同时抽取外周肝素抗凝静脉血2mL。提取的淋巴细胞经CD3 FITC、CD4 PE、CD8 PerCP染色后行流式测定。其中，胃黏膜T淋巴细胞亚群的检测以CD3设门。结果(1)胃黏膜CD+3(%)细胞的检出率分别为：H.pylori-CSG组3.14±2.03,H.pylori+CSG组4.58±2.30,H.pylori+DU组为6.49±4.49；(2)胃黏膜CD+3细胞中CD+4(%),CD+8(%)的相对比例及CD+4/CD+8值分别为：H.pylori-CSG组为19.81±9.25,47.30±12.83,0.43±0.19，H.pylori+CSG组为40.66±12.52,29.25±8.58,1.42±0.31,H.pylori+DU组为31.98±14.02,49.52±19.00，0.72±0.43。H.pylori+CSG组局部胃窦黏膜CD+4细胞、CD+4/CD+8比值明显高于H.pylori-CSG组，CD+8细胞则低于H.pylori-CSG组(P<0.01)。H.pylori+DU组CD+4、CD+4/CD+8比值也高于H.pylori-CSG组(P<0.05)，但CD+8细胞无统计学差异。H.pylori+DU组CD+8细胞高于H.pylori+CSG组而CD+4细胞无统计学差异，CD+4/CD+8比值则低于H.pylori+CSG组(P<0.01)。(3)外周血T淋巴细胞亚群的变化在三组之间并无明显的差异。结论H.pylori+DU与H.pylori+CSG的宿主的T淋巴细胞反应并不相同，而局部胃窦黏膜的T淋巴细胞亚群的异常可能在儿童H.pylori感染的免疫致病机制中起一定的作用。

The changes of T lymphocyte subsets in the Helicobacter pylori infected children.

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.