弓形虫感染患儿淋巴细胞亚群及干扰素-γ的变化及临床意义

目的探讨淋巴细胞各亚群及细胞免疫应答产物干扰素-γ(IFN-γ)水平在弓形虫感染患儿细胞免疫应答中的变化趋势及临床意义。方法选取2011年1月至2014年4月检测出Tox-Ig M阳性的34例患儿为Tox-Ig M阳性组,同时选取既往感染的TOX-Ig G阳性患儿12例为TOX-Ig G阳性组,另选取行健康体检的健康儿童54例为对照组。应用流式细胞仪检测各组外周血淋巴细胞CD4+、CD8+、CD19+和NK细胞水平,并计算CD4+/CD8+比值;采用酶联免疫吸附试验(ELISA)检测各组患儿血清中IFN-γ的水平。结果 Tox-Ig M阳性组患儿CD4+、CD4+/CD8+比值明显低于TOX-Ig G阳性组和对照组,CD8+、NK细胞和血清IFN-γ水平高于TOXIg G阳性组和对照组(P0.05)。TOX-Ig G阳性组患儿血清IFN-γ水平高于对照组(P0.05)。Tox-Ig M阳性组患儿CD8+水平与血清IFN-γ水平呈正相关(r=0.756,P0.05)。结论 CD4+、CD8+以及NK细胞等免疫细胞及其免疫应答产物IFN-γ水平变化在弓形虫感染过程中发挥着重要的作用。

Changes in lymphocyte subsets and serum IFN-γ levels in children with toxoplasma infection

Objective To study the changes and significance of lymphocyte sunsets and serum interferon-γ (IFN-γ) levels in children with toxoplasma infection. Methods Thirty-four children who were newly diagnosed with toxoplasma infection (TOX-IgM⁺ group) between January 2011 and April 2014, 12 children who had ever been diagnosed with toxoplasma infection (TOX-IgG⁺ group), and 54 healthy children (control group) were enrolled. The percentages of CD4⁺, CD8⁺, CD19⁺ and NK cells in peripheral blood lymphocytes were detected by flow cytometry. Serum levels of IFN-γ were measured using ELISA. Results The percentages of CD4⁺ cells and the CD4⁺/CD8⁺ ratio in the TOX-IgM⁺ group were significantly lower than in the TOX-IgG⁺ and control groups, while the percentages of CD8⁺ and NK cells and serum IFN-γ levels were significantly higher than in the other two groups (P<0.05). The TOXIgG⁺ group had higher serum IFN-γ levels than the control group (P<0.05). There was a positive correlation between the percentage of CD8⁺ cells and serum IFN-γ levels in the TOX-IgM⁺ group (r=0.756; P<0.05). Conclusions CD4⁺, CD8⁺ and NK cells may play important roles in the resistance against toxoplasma infection by promoting the secretion of cytokines.