Objective: To study the correlation between the level of T-bet expression and liver damage in peripheral plasma cells of patients with autoimmune hepatitis (AIH) in order to provide reference for the study of pathogenesis and development of diseases. Methods: The peripheral venous blood and clinical examination data of 29 cases with AIH and 6 healthy volunteers were collected. The percentage of subpopulations of peripheral blood B cells and the proportion of T-bet(+) cells in each subgroup were detected by flow cytometry. Plasma cells (CD19(+)CD10(-)CD27(hi)CD38(hi)), primary B cells (CD19(+)CD10(-)CD27(-)IgD(+)), transitional B cells (CD19(+)CD10(+)), and memory B cells (CD19(+)CD10(-)CD27(+)IgD(-)) were the included subsets of B cells. Serum immunoglobulin G (IgG) and alanine aminotransferase (ALT) levels, the proportion of B cells in peripheral blood subsets and IgG level, the proportion of T-bet(+) cells in each subset and the proportion of T-bet(+) plasma cells in each subset in B cells, the proportion of T-bet(+) plasma cells and the level of serum ALT were analyzed for correlation analysis. Statistical analysis was performed using two independent sample t-tests and linear regression. Results: The serum IgG level of AIH patients with abnormal ALT (19.47 ± 1.039)g/L was significantly higher than that of normal ALT patients (15.5 ± 1.069)g/L, and the difference was statistically significant (t = 2.65, P < 0.05). The percentage of peripheral plasma cells in B cells of AIH patients (2.80 ± 0.14) % was higher than that of healthy volunteers (0.73 ± 0.09) %, and the difference was statistically significant (P < 0.01). The percentage of T-bet(+) cells in peripheral plasma cells of AIH patients (23.54 ± 1.61) % was higher than that of healthy volunteers (6.59±0.59) % , and the difference was statistically significant (P < 0.01). The correlation analysis showed that the proportion of T-bet(+) cells in peripheral plasma cells of AIH patients was positively correlated with the proportion of plasma cells to B cells (r = 0.224 7, P < 0.01), and the percentage of peripheral plasma cells to B cells was positively correlated with the level of serum IgG (r = 0.299 1, P < 0.01). Serum IgG level was correlated with the level of ALT, reflecting an indicator of liver damage (t = 2.65, P < 0.05). Conclusion: The increase of T-bet expression in the peripheral plasma cells of AIH patients is associated with liver damage, which is a new mechanism of AIH pathogenesis and disease progression.
目的： 研究自身免疫性肝炎（AIH）患者外周血浆细胞T-bet表达水平与肝损害的相关性，为疾病发生和发展的机制研究提供参考。 方法： 收集29例AIH患者和6例健康志愿者的静脉血及临床检验资料，流式细胞技术检测外周血B细胞各亚群的比例和各亚群T-bet(+)细胞的比例，其中B细胞亚群包括浆细胞（CD19(+)CD10(-)CD27(hi)CD38(hi)）、初始B细胞（CD19(+)CD10(-)CD27(-)IgD(+)）、transitional B细胞（CD19(+)CD10(+)）和记忆B细胞（CD19(+)CD10(-)CD27(+)IgD(-)）。将血清免疫球蛋白G（IgG）与丙氨酸氨基转移酶（ALT）水平，外周血各亚群B细胞比例与IgG水平，T-bet(+)细胞在各亚群中的比例与各亚群在B细胞中的比例，T-bet(+)浆细胞比例和血清ALT水平做相关分析，采用两独立样本t检验和线性回归进行统计学分析。 结果： ALT异常组的AIH患者血清IgG水平（19.47±1.039）g/L显著高于ALT正常组患者的IgG水平（15.5±1.069）g/L，差异有统计学意义（t = 2.65，P < 0.05）。AIH患者外周血浆细胞占B细胞的比例2.80%±0.14%高于健康对照的外周血浆细胞占B细胞比例0.73%±0.09%，差异有统计学意义（P < 0.01）；AIH患者外周血浆细胞中T-bet(+)细胞比例23.54%±1.61%高于健康对照外周血浆细胞中T-bet(+)细胞比例6.59%±0.59%，差异有统计学意义（P < 0.01）。相关分析显示，AIH患者外周血浆细胞中T-bet(+)细胞比例与浆细胞比例占B细胞比例呈正相关（r = 0.2247,P < 0.01），外周血浆细胞占B细胞比例与血清IgG水平呈正相关（r = 0.2991，P < 0.01），血清IgG水平与反映肝损害的指标ALT水平相关（t = 2.65，P < 0.05）。 结论： AIH患者外周血浆细胞中T-bet的表达水平升高与肝损害相关，是AIH发病及病情发展的新机制。.
Keywords: Hepatitis, autoimmune; Liver damage; Plasma cells; T-box expressed in T cell.