胆红素对早产儿T淋巴细胞功能的影响及相关机制的研究

目的:探讨不同血清胆红素水平对早产儿T淋巴细胞功能的影响。方法:应用流式细胞仪法测定不同胎龄、不同胆红素水平下CD4+、CD8+、白细胞介素-4(Interleukin-4、IL-4)、肿瘤坏死因子-γ(Tumor necrosis factor-γ、IFN-γ)、Fas基因表达。结果:①胎龄≥32周早产儿的CD4+和CD8+表达量>胎龄<32周早产儿,差异有统计学意义(P<0.05)。②不同胆红素浓度对早产儿T淋巴细胞功能的影响:胆红素153.9～220.6μmol/L组和胆红素>220.6μmol/L组早产儿CD4+的表达水平均明显低于无黄疸组和胆红素<153.9μmol/L组(P<0.05);胆红素>220.6μmol/L组早产儿CD8+的表达水平低于无黄疸组、胆红素<153.9μmol/L组和胆红素153.9～220.6μmol/L组(P<0.05)。IL-4的表达量与4组比较无差异(P>0.05)。IFN-γ的表达量于胆红素153.9～220.6μmol/L组和胆红素>220.6μmol/L组均<无黄疸组和胆红素<153.9μmol/L组(P<0.05)。Fas基因的表达量于胆红素153.9～220.6μmol/L组和胆红素>220.6μmol/L组均高于无黄疸组和胆红素<153.9μmol/L组(P<0.05)。结论:①胎龄是影响早产儿T淋巴细胞功能的重要因素之一,胎龄越小免疫功能越低。②黄疸对早产儿T淋巴细胞功能有显著抑制作用,随胆红素浓度的增加抑制作用越显著,同时Fas基因的表达量逐渐增高,提示此种抑制作用与淋巴细胞凋亡增多有关。

Effect of bilirubin on the function of T lymphocytes of premature infants and the mechanism

Objective:To explore the effects of different levels of serum bilirubin on the function of T lymphocytes of premature infants. Methods:Flow cytometry was used to detect the expression levels of CD4+,CD8+,interleukin-4,tumor necrosis factor-γ,and Fas gene among the premature infants of different fetal ages and bilirubin levels. Results:The expression levels of CD4+ and CD8+ in premature infants of fetal age≥32 weeks were significantly higher than those in premature infants of fetal age<32 weeks(P<0.05).The effects of different concentrations of bilirubin on the function of T lymphocytes of premature infants: among the premature infants,the expression levels of CD4+ in bilirubin 153.9-220.6 μmol/L group and bilirubin>220.6 μmol/L group were significantly lower than those in non-jaundice group and bilirubin<153.9 μmol/L group(P<0.05).The expression level of CD8+ in bilirubin>220.6 μmol/L group was significantly lower than those in non-jaundice group,bilirubin<153.9 μmol/L group,and bilirubin 153.9-220.6 μmol/L group(P<0.05).There was no significant difference in the expression level of interleukin-4 among the three groups(P>0.05).The expression levels of tumor necrosis factor-γ in bilirubin 153.9-220.6 μmol/L group and bilirubin>220.6 μmol/L group were significantly lower than those in non-jaundice group and bilirubin<153.9 μmol/L group(P<0.05).The expression levels of Fas gene in bilirubin 153.9-220.6 μmol/L group and bilirubin>220.6 μmol/L group were significantly higher than those in non-jaundice group and bilirubin<153.9 μmol/L group(P<0.05). Conclusion:Fetal age is one of the important influencing factors of function of T lymphocytes of premature infants,the lower the fetal age is,the lower the immune function is.Jaundice can inhibit the function of T lymphocytes of premature infants significantly,and the inhibiting effect aggravates with the increase of bilirubin content,at the same time,the expression level of Fas gene increases,which indicates that the inhibiting effect is correlated with the increase of apoptosis of lymphocytes.