HIV感染者外周浅表淋巴结中CD4^+T淋巴细胞计数与胶原沉积的关系研究

Correlation between CD4^+T lymphocyte count in peripheral superficial lymph nodes and collagen deposition in HIV-infected individuals

目的通过对不同感染阶段HIV感染者外周浅表淋巴结中CD4+T淋巴细胞、胶原蛋白、白细胞介素(interleukin,IL)-7的检测,以及CD4+T淋巴细胞计数与胶原沉积的相关性分析,探讨HIV感染后胶原沉积对CD4+T淋巴细胞的影响。方法选择HIV感染者43例,分为HIV感染无症状组和AIDS组,留取外周浅表淋巴结活体组织检查(活检)组织;另外选择非HIV感染者12名为健康对照组,同样留取其外周浅表淋巴结活检组织。利用免疫组织化学方法检测研究对象淋巴结中CD4+T淋巴细胞、Ⅰ型胶原蛋白和IL-7定量及分布情况。结果 1随着病程进展,HIV感染者外周浅表淋巴结中胶原沉积逐渐增加,AIDS组高于无症状组,无症状组高于健康对照组,差异均有统计学意义(P均<0.05);2HIV感染无症状组外周浅表淋巴结中CD4+T淋巴细胞计数与健康对照组相比差异无统计学意义(P>0.05),而AIDS组则显著减少(P<0.01);3HIV感染者外周浅表淋巴结中CD4+T淋巴细胞计数与胶原沉积量呈负相关(R2=0.724,P=0.000),与外周血中CD4+T淋巴细胞计数呈正相关(R2=0.702,P=0.000);43组IL-7的表达水平差异无统计学意义(P>0.05),而AIDS组部分患者淋巴结中IL-7呈局部聚集性分泌。结论 HIV感染后外周浅表淋巴结中胶原沉积逐渐增加导致结构破坏,可能是CD4+T淋巴细胞进行性减少的一个重要原因,虽然IL-7有随病程进展而分泌增加的趋势,但仍不足以弥补淋巴结结构破坏对CD4+T淋巴细胞的影响。

Objective To investigate the effects of collagen deposition on CD4^＋ T lymphocyte count in peripheral superficial lymph nodes of HIV-infected individuals by detecting CD4^＋ T lymphocyte count, collagen and interleukin （IL）-7 and analyze the corre- lation between CD4^＋ T lymphocyte count and collagen deposition. Methods Forty-three HIV-infected individuals were divided into asymptomatic HIV carriers （asymptomatic group） and AIDS patients （AIDS group）. Twelve subjects without HIV infection were recruited as a control group. Peripheral superficial lymph nodes of all the groups were obtained. Immunohistochemistry was used to detect expression and distribution of CD4^＋ T lymphocytes, type I collagen and IL-7 in peripheral superficial lymph nodes. Results With disease progression, collagen deposition in peripheral superficial lymph nodes of HIV-infected individuals increased gradually. Collagen deposition in AIDS group was higher than that in asymptomatic group, which was higher than that in the control group, and differences between the three groups were significant （P〈0.05）. CD4^＋ T lymphocyte counts in peripheral superficial lymph nodes were not significantly different between the asymptomatic group and the control group （P〉0.05）, while that of AIDS patients decreased significantly （P〈0.01）. CD4^＋ T lymphocyte count in peripheral superficial lymph nodes of HIV-infected individuals had a strong negative linear correlation with collagen deposition （R^2=0.724, P=0.000）, and a strong positive linear correlation with CD4^＋ T lymphocyte count in peripheral blood （R^2=0.702, P=0.000）. Expressions of IL-7 in peripheral superficial lymph nodes were not significantly different among the three groups （P〉0.05）, but presented with local aggregation in some AIDS patients. Conclusions Gradually increasing collagen deposition destroys the structure of peripheral superficial lymph nodes after HIV infection, which may be one of the important reasons for CD4^＋ T lymphocyte depletion in lymph nodes. Although the expression of IL-7 has a rising tendency in lymph nodes of HIV-infected individuals with disease progression, destruction of lymph nodes structure remains a uncompensatory effect on CD4^＋ T lymphocytes.