甲苯二异氰酸酯职业暴露者外周血淋巴细胞亚群分析

Analysis of lymphocyte subsets in peripheral blood of toluene diisocyanate exposed workers

[目的]研究甲苯二异氰酸酯(TDI)对暴露工人外周血淋巴细胞亚群的影响,为探讨TDI的免疫毒性提供依据。[方法]采用横断面研究方式,以整群抽样法选取甘肃省TDI作业工人53名为暴露组,选取同地区非职业性TDI暴露工人55名为对照组。气相色谱法检测作业环境中TDI水平和尿中代谢产物甲苯二胺(TDA)浓度。应用流式细胞术检测外周血淋巴细胞亚群水平,并结合血常规中淋巴细胞总数的结果,计算CD3+T细胞、CD4^+T细胞、CD8^+T细胞、B细胞和NK细胞绝对数。[结果]暴露组尿中总TDA浓度M(P_(25)~P_(75))为15.86(7.91~29.99)μg/L。淋巴细胞亚群分析,对照组的淋巴细胞、CD3+T细胞、CD4^+T细胞、CD8^+T细胞、B细胞和NK细胞分别为1.80(1.40~2.30)×10~9/L、(1.24±0.35)×10~9/L、0.65(0.53~0.75)×10~9/L、0.47(0.35~0.57)×10~9/L、0.18(0.13~0.23)×10~9/L和0.23(0.19~0.31)×10~9/L。暴露组淋巴细胞、CD8^+T细胞和NK细胞分别为1.92(1.59~2.46)×10~9/L、0.54(0.40~0.67)×10~9/L和0.45(0.35~0.61)×10~9/L,暴露组高于对照组,差异有统计学意义(P<0.05)。依据尿中总TDA浓度中位数进行分组,低暴露组淋巴细胞、CD3+T细胞、CD4^+T细胞、CD8^+T细胞和NK细胞分别为2.13(1.84~2.45)×10~9/L、(1.42±0.34)×10~9/L、0.70(0.58~0.83)×10~9/L、0.60(0.53~0.69)×10~9/L和0.48(0.33~0.64)×10~9/L,高于对照组(P<0.05);高暴露组NK细胞为0.43(0.32~0.55)×10~9/L,高于对照组(P<0.05)。所有指标在低、高暴露组间差异无统计学意义(P>0.05)。暴露组TDI暴露工龄与淋巴细胞亚群的变化无相关(P>0.05)。[结论]TDI暴露可导致作业工人外周血淋巴细胞亚群发生变化,提示TDI职业暴露者免疫功能受到影响。

[ Objective ] To investigate the effects of toluene diisocyanate （TDI） exposure on lymphocyte subsets in peripheral blood of workers and explore the immunotoxicity of TDI.[ Methods ] In this cross-sectional study, we recruited 53 TDI exposed workers and 55 non-TDI exposed workers by cluster sampling in Gansu Province. The concentration of TDI in working environment and the concentration of urinary toluenediamine （TDA）in workers were measured by gas chromatography. The lymphocyte subsets in peripheral blood were analyzed by flow cytometry. Combined with lymphocyte count measured by automatic blood analyzer, major lymphocyte subsets were calculated including CD3＋T cells, CD4＋T cells, CD8＋T cells, B cells, and NK cells.[ Results ] The median （P25-P75） of total urinary TDA was 15.86 （7.91-29.99） μg/L in the TDI exposed workers. The lymphocyte, CD3＋T cell, CD4＋T cell, CD8＋T cell, B cell, and NK cell counts in the control group were 1.80 （1.40-2.30）×10^9,/L, （1.24 ＋ 0.35） ×10^9/L, 0.65 （0.53-0.75） × 10^9/L, 0.47 （0.35-0.57） × 10^9/L, 0.18 （0.13-0.23） × 10^9/L, and 0.23 （0.19-0.31） × 10^9/L, respectively. The lymphocyte, CD8＋T cell, and NK cell counts in the TDI exposed workers were 1.92 （1.59-2.46）× 10^9/L, 0.54 （0.40-0.67）×10^9/L, and 0.45 （0.35-0.61） × 10^9/L, respectively, which were higher than those in the control group （P 〈 0.05）. We classified the exposed workers into two groups by the median of total urinary TDA levels： The counts of lymphocytes, CD3＋T cells, CD4＋T cells, CD8＋T cells, and NK cells in the low exposure group were 2.13 （1.84-2.45） ×10^9/L, （1.42 ± 0.34） × 10^9/L, 0.70 （0.58-0.83）× 10^9/L, 0.60 （0.53-0.69） × 10^9/L, and 0.48 （0.33-0.64） × 10^9/L, respectively, and were significantly higher than those in the control group （P〈 0.05）; The count of NK cells was 0.43 （0.32-0.55）× 10^9/L in the high exposure group, higher than that in the control group （P〈0.05）. However, no difference was found between the low and high exposure groups （P〉0.05）. Working years and the change of lymphocyte subsets were not associated （P〉0.05）.[ Conclusion ] TDI exposure could cause the change of lymphocyte subsets in peripheral blood of occupationally exposed workers, implying potential impacts of TDI on immunological functions.