再生障碍性贫血患者外周血Th 1/Th2水平测定及其临床意义

目的：探讨辅助性T(T helper,Th)细胞亚群数量和功能的变化在再生障碍性贫血(再障)患者发病机制中的作用，及这两种变化之间的关系；为再障的诊断及疗效预测提供实验依据。方法：流式细胞术检测再障患者及正常人外周血T细胞亚群、Th1和Th2细胞；RT-PCR法测定再障患者及正常人外周血中Th1，Th2型细胞因子基因表达；用ELISA法测定再障患者血浆中IFN-γ和IL-4的水平。结果：再障患者Th1/Th2显著失衡，Th1细胞显著增多，Th1型细胞因子IFN-γmRNA的阳性表达率和血浆IFN-γ浓度均较正常对照显著升高；再障患者Th1细胞百分数分别与IFN-γmRNA相对表达强度(RV)和血浆IFN-γ浓度呈正相关；Th1细胞百分比、IFN-γmRNA的RV及血浆IFN-γ的浓度在比值倒置型与比值超高型患者体内相近且均高于比值正常型患者。结论：Th细胞亚群失衡，Th1细胞数量增多及功能亢进可能是再障发病的重要免疫机制之一；Th1细胞数量及功能异常相互作用是再障患者疾病发生和发展的根本原因；CD4+T或CD8+T细胞相对变化可能是Th细胞在发挥免疫抑制作用后的外在表象。

The changes of Th1/Th2 cells in Immune Pathogenesis of aplastic anemia

Abstract Objective To study the quantitative and functional changes of T helper(Th) cell subsets in peripheral blood(PB) of patients with aplastic anemia(AA), the relationship between these changes and the pathogenesis of AA; To offer evidence for diagnosis and anticipating therapeutic effect in patients with AA. Methods T-cell subsets, Th1 and Th2 cells in PB of AA patients, normal control analyzed by flow cytometry; By RT-PCR, mRNA expression of IFN-γ and IL-4 gene in PBMC from patients with AA, normal controls were measured; By ELISA, the level of TNF-γ, or IL-4 in plasma of AA patients and normal controls were measured. Results The percentage of Th1 cells, and ratio of Th1/Th2 of AA patients were higher than those of normal controls, respectively; IFN-γ mRNA was detected in 12 of 17 AA patients, 2 of 10 normal controls; The level of IFN-γ in plasma of AA patients was significantly higher than that of normal controls; The percentage of Th1 cells in AA patients was positively correlated with their relative value(RV) of IFN-γ mRNA and their levels of IFN-γ in plasma. The percentages of Th1 cells, RV of IFN-γ mRNA and levels of IFN-γ in AA patients with inverted type of ratio were not significantly higher than that of AA patients with hypermormal type of ratio, while, were significantly higher than that of AA patients of normal type of ratio respectively. Conclusion Th1 cells were more predominant in quantity and function, the balance between Th1 and Th2 cells was broken, which played important roles in the pathogenetic mechanism of AA; The interaction between the quantitative changes and dysfunction of Th cells played important roles in the generation and development of AA patients, which results in the relative quantitative changes of the CD4+T or the CD8+T in PB in AA patients.