[Study of the correlation between elevated level of T-bet expression and liver damage in peripheral plasma cells of patients with autoimmune hepatitis].

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-CD27hiCD38hi), 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. Key words: Hepatitis, autoimmune; Plasma cells; T-box expressed in T cell; Liver damage