HIV感染后胃黏膜CD4+、CD8+T细胞数量分布及CD38表达的改变

目的 研究不同感染阶段HIV感染者胃黏膜中CD4+和CD8+T细胞数量和分布情况,及免疫细胞激活状态的改变.方法 有胃黏膜组织活检标本的HIV感染者42例,其中有明确临床分期诊断的36例,另选非HIV感染者胃黏膜组织活检标本10例为对照,利用免疫组织化学方法检测研究对象胃黏膜活检组织中CD4、CD8及CD38的表达,以图像分析系统分析其差异.结果 (1)AIDS患者胃黏膜中CD4+T细胞与对照组和无症状者相比,均显著减少(P(0.01),无症状者多数淋巴滤泡中仍有一定量CD4+T细胞,间质中多呈不均匀聚集分布,统计学与正常对照组差异无统计学意义(P>0.05);(2)HIV感染者胃黏膜内CD8+T细胞普遍噬腺体和黏膜上皮,部分病例胃黏膜内CD8+T细胞局部过度增生,与对照组相比,CD8+T细胞在感染者胃黏膜中显著增多(P<0.01),无症状者与AIDS患者CD8+T细胞差异无统计学意义(P>0.05);(3)在HIV感染者胃黏膜内,CD38阳性细胞主要分布于黏膜表层至浅1/3～2/3层,与对照组相比,HIV感染者胃黏膜中CD38表达增强(P<0.01),无症状者与MDS患者CD38表达差异无统计学意义(P>0.05).结论 HIV感染者胃黏膜中CD4+T细胞的数量和分布与疾病进展有密切联系,HIV对CD4+T细胞的感染和破坏导致黏膜免疫系统功能异常,可能是胃黏膜内CD8+T细胞数量增加,CD38表达增强的重要原因之一.

Frequency, distribution of CD4+, CD8+ T cells and expression of CD38 in gastric mucosa of HIV Infections

Objective To investigate the frequencies and distribution of CD4+ T ceils and CD8+ T cells as well as the changes of immune activation in gastric mucesa of HIV-infected individuals. Methods 42 HIV-infected individuals were recruited into this investigation, and 36 patients had definite diagnosis of clinical stage.Biopsy of gastric mucosal tissues was performed by fiberoptic gastrescope including 10 normal people as a control group. Then, immunohistochemistry was used to detect expression of CD4, CD8 and CD38 in gastric mucosa, and the distinctions among three groups were analyzed with LEICA Qwin image analysis system. Results (1) Compared with asymptomatic HIV carriers and control group, CD4+ T cells remarkably decreased in the gastric mucosa of AIDS patients (P < 0.01). In gastric mucosa of asymptomatic HIV carriers, there were still some CD4+ T cells in lymphoid follicles and stroma where CD4+ T cells were unevenly distributed, the frequency of CD4+ T cells was not significandy different between asymptomatic HIV carriers and control group (P > 0.05) ; (2) Phenomenon of CD8+ T cells infiltrating mucosal epithelium and gland was general in HIV-infected individuals. CD8+ T cells took on local excessive hyperplasia in gastric mucosa of some individuals. As compared with control group, CD8+ T cells markedly increased in gastric mucosa of infected individuals (P < 0.01), but the distinction of asymptomatic HIV carriers and AIDS patients was not significant (P > 0.05); (3) CD38-expressing cells mainly distributed over gastric mucosai surface to superficial layer(1/3-2/3 layer) of HIV-infected individuals, and was more intensive than control group (P≤ 0.01), but there was not noticeable difference between asymptomatic HIV carriers and AIDS patients (P > 0.05). Conclusion The frequencies and distribution of gastric mucosal CD4+ T cells of HIV-infected individuals were closely correlated with progression of disease. Disfunction of mucosal immune system which was resulted from HIV infection and injury of CD4+ T cells could be an important cause of CD8+ T cells increasing and CD38-expressing enhancement.