Abstract: Objective To investigate the significance of achaete-scute homologue 2 (Ascl2) expression in T follicular helper (Tfh) cells during chronic hepatitis B virus infection. Methods Frequencies of CD4⁺CXCR5⁺ Tfh cells and CD4⁺CXCR5⁺PD-1⁺ Tfh cells in peripheral blood mononuclear cells (PBMC) were analyzed by flow cytometry, respectively. The expression of Ascl2 in Tfh cells was determined by quantitative real-time polymerase chain reaction. The levels of serum interleukin-21 (IL-21) and interleukin-17 (IL-17) were measured using enzyme-linked immunosorbent assay. Results The frequencies of CD4⁺CXCR5⁺ and CD4⁺CXCR5⁺PD-1⁺ Tfh cells were significantly higher in PBMC from chronic hepatitis B (CHB) patients than that from healthy controls (t=4.786, P<0.05). The expression of Ascl2 was significantly higher in Tfh cells of CHB patients (t=4.655, P<0.05). Furthermore, the levels of serum IL-21 and IL-17 were significantly higher in CHB patients (t=4.896 and t=3.764, P<0.05). Conclusion It was implied that transcription factor Ascl2 plays an important role in the differentiation and development of Tfh cells in CHB patients.

Key words: Chronic hepatitis B; T follicular helper; Achaete-scute homologue 2