慢性乙型肝炎患者抗病毒治疗早期T细胞表面PD-1的表达

背景：慢性乙型肝炎病毒（HBV）感染者T细胞表面程序性死亡受体1（PD-1）呈持续性高表达。然而关于抗病毒治疗前后慢性乙型肝炎（CHB）患者T细胞表面PD-1表达变化及其与病毒载量关系的报道较少。目的：动态观察CHB患者抗病毒治疗早期外周血CD4＋和CD8＋T细胞表面PD-1表达水平，探讨其表达与血清HBV DNA载量和丙氨酸氨基转移酶（ALT）水平之间的关系。方法：以流式细胞术分别检测31例CHB患者抗病毒治疗前或基线期（T1）、治疗后4～8周（他）和12．16周（T3）的外周血CD4^＋和CD8^＋T细胞表面PD-1表达水平，以实时荧光定量聚合酶链反应（PCR）检测血清HBV DNA载量，同时检测血清ALT水平。结果：抗病毒治疗早期，CHB患者外周血CD4^＋和CD8^＋T细胞表面PD．1表达水平逐渐下调（P〈0．05），血清HBV DNA载量和ALT水平亦逐步降低（P〈0．01）；CD4^＋和CD8^＋T细胞表面PD-1表达与HBV DNA载量（P〈0．01）和ALT水平（P〈0．05）均呈正相关。结论：有效的抗病毒治疗可通过降低CHB患者的病毒载量使T细胞表面PD-1表达下调，T细胞表面PD-1表达水平与患者疾病状态密切相关。

Expression of PD-1 on T Cells in Patients with Chronic Hepatitis B at Early Phase of Antiviral Treatment

Background： Programmed death 1 （PD-1） on T cells is expressed persistently at a high level in chronic hepatitis B virus （HBV） infection, however, there are few studies focus on the change of PD-1 expression on T cells in patients with chronic hepatitis B （CHB） during antiviral therapy and its relationship with viral load. Aims： To observe longitudinally the PD-1 expression on CD4^＋ and CD8^＋ T cells in peripheral blood of CHB patients at early phase of antiviral therapy, and to explore the relationship between PD-1 expression and serum levels of HBV DNA and alanine aminotransferase （ALT）. Methods： Levels of PD-1 expression on peripheral blood CD4^＋ and CD8^＋ T cells in 31 CHB patients undergoing antiviral therapy were assessed by flow cytometry prior to the treatment or at baseline （T1）, and 4-8 weeks （T2） and 12-16 weeks （T3） during treatment course, respectively. Serum HBV DNA load was determined by real-time fluorescent quantitative polymerase chain reaction （PCR）. Serum ALT level was also measured at the same time points. Results： A significant reduction in PD-1 expression level on both peripheral CD4^＋ and CD8^＋ T cells in CHB patients was observed at early phase of antiviral therapy （P〈0.05）. Serum HBV DNA and ALT levels were also markedly reduced from T1 to T3 （P〈0.01）. Furthermore, significant positive correlations between PD-1 expression on CD4^＋ and CD8^＋ T cells and HBV DNA load （P〈 0.01）, and ALT level （P〈0.05） were observed. Conclusions： Effective antiviral treatment induced reduction of viral load results in down-regulation of PD-1 expression on T ceils in CHB patients. Furthermore, PD-1 expression on T cells is closely correlated with disease status.